Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    Pesticide use and off-site risk assessment : a case study of glyphosate fate in Chinese Loess soil
    Yang, X. - \ 2016
    Wageningen University. Promotor(en): Coen Ritsema; Violette Geissen, co-promotor(en): Hans Mol; Fei Wang. - Wageningen : Wageningen University - ISBN 9789462576759 - 152
    pesticides - risk assessment - pesticide residues - glyphosate - loess soils - soil pollution - erosion - china - pesticiden - risicoschatting - pesticidenresiduen - glyfosaat - lössgronden - bodemverontreiniging - erosie - china

    Pesticide use and off-site risk assessment: a case study of glyphosate fate in Chinese Loess soil

    Xiaomei Yang

    Abstract: Repeated applications of pesticide may contaminate the soil and water, threatening their quality within the environmental system and beyond it through water erosion related processes and leaching. Taking into account the situation of intense farming, pesticide use and erosion in China, and in the loess area in particular, this study aims to further the science of pesticide risk assessment by increasing the understanding of the fate of glyphosate and its main metabolite AMPA while also assessing their risks related to soil erosion in Chinese loess soil. Four main objectives are conducted:

    1) Assessment of farmers’ knowledge and awareness of pesticide use in the Wei River catchment

    In this study, we presented the information for the knowledge and awareness of pesticide risks via face-to-face interview among farmers (209) and retailers (20) in two rural regions (Qianyang County (S1) and Chencang County (S2)) of the Wei River catchment in China where the modes of farming and the state of erosion are very different. The results showed that farmers learned about the use and risk related to of pesticide use mainly by oral communication (p<0.01), rather than by introduction labelled on pesticide package bag/bottle and media tools (TV/newspaper/Internet/books). Protective measures were inadequate and washing hands (>70%) was the most common mode of personal hygiene after spraying, comparing to wearing masks, showering, and changing clothes. Regarding to dealing with the packages or containers of pesticide, farmers dumped them directly onto the land or into water, and over 85% of farmers claimed to use illegal pesticides. Compared to farmers, pesticide retailers were well-informed and highly conscious of their responsibility for the safe use of pesticides. Educational programmes targeted to age groups, proper disposal of pesticide waste, and sufficient supervision from authorities should consequently be considered for improving the levels of knowledge and awareness of the dangers of pesticides to human health and environmental pollution in the Wei River catchment, China.

    2) Investigation of off-site transport of glyphosate and AMPA by runoff and erosion in Chinese loess soil

    In this study, we assessed the short-term transport (1h duration, 1 mm min-1 rainfall) of glyphosate and its metabolite aminomethylphosphonic acid (AMPA) related to erosion and runoff on bare loess soil with different slopes (10° and 20°)and application rates (3.6 kg ha-1 and 7.2 kg ha-1) in hydraulic flumes. Significant power and exponent function described a significantly negative relation between rainfall duration and the content of glyphosate and AMPA (p<0.01) in runoff and suspended load, respectively. The transport rate of glyphosate (including AMPA) by runoff and suspended load was approximately 4% and 10% of the applied amount, respectively indicating that it mainly underlies particulate transport. The glyphosate and AMPA content in the flume soil at the end of the experiment (after 1h) decreased significantly with depth (p<0.05), and 72, 2, and 3% of the applied glyphosate (including AMPA) remained in the 0-2, 2-5, and 5-10 cm soil layers, respectively. Thus, the risk of leaching was low. In view of loss of 14 % of the initially applied glyphosate after 1 h, “buffer zone”, referred as the protection area for ecosystem discharge between farming land and public rivers, is strongly recommended, especially in regions where rain-induced soil erosion is common.

    3) Investigation of the on-site fate of glyphosate and AMPA formation in Chinese loess soil

    In this study, we observed glyphosate decay, erosion and runoff related transport of glyphosate and AMPA at different slopes (10° and 20°) and application rates (3.6 kg ha-1 and 7.2 kg ha-1) under field condition during 35 d, September-October in 2012 (16.8±2.1°C with 35 mm rainfall in total) and July-August in 2013 (27 ± 2.3°C with 74 mm rainfall in total). The initial glyphosate decayed rapidly (half-life of 3.5 d) in the upper 2 cm of soil following a first-order rate of decay. AMPA content in the 0-2 cm soil layer correspondingly peaked 3 d after glyphosate application and then gradually decreased. The residues of glyphosate and AMPA decreased significantly with soil depth (p<0.05) independently of the slope inclination and application rate. About 0.36% of the glyphosate initially applied was transported off-site plots after one erosive rain 2 days after the application. Glyphosate and AMPA concentration in runoff were low while the contents in the sediment was much higher than in the upper 2 cm of the soil. This suggested that even though the transported glyphosate is limited, the off-site risk of glyphosate and AMPA is high. Consequently, a realistic erosion-pesticide model should be developed that can simulate the particulate-facilitated transport of glyphosate and its off-site risks involving decay processes.

    4) Off-site risk assessment of particle-facilitated pesticide transport related to erosion

    In this study, we have developed a parsimonious integrative model of pesticide displacement by runoff and erosion that explicitly accounts for water infiltration, erosion, runoff, and pesticide transport and degradation in soil. The conceptual framework was based on broadly accepted assumptions such as the convection-dispersion equation and lognormal distributions of soil properties associated with transport, sorption, degradation, and erosion. To illustrate the concept, a few assumptions are made with regard to runoff in relatively flat agricultural fields: dispersion is ignored and erosion is modelled by a functional relationship. A sensitivity analysis indicated that the total mass of pesticide associated with soil eroded by water scouring increased with slope, rain intensity, and water field capacity of the soil. The mass of transported pesticide decreased as the micro-topography of the soil surface became more distinct. The timing of pesticide spraying and rate of degradation before erosion negatively affected the total amount of transported pesticide. The mechanisms involved in pesticide displacement, such as runoff, infiltration, soil erosion, and pesticide transport and decay in the topsoil, were all explicitly accounted for, so the mathematical complexity of their description can be high, depending on the situation.

    Overall, the outcome of this study indicates that it is urgent to improve farmers knowledge and awareness on pesticide use in order to reduce pesticide risks before they are applied in environmental system. The rapid decay of glyphosate to AMPA in loess soil suggests that on-site risks of glyphosate is mainly related to AMPA, especially under warmer climatic conditions. The off-site transport of glyphosate in our study was about 14% of the applied dose after 1 h of rainfall indicating that the off-site risks of glyphosate should be taken into account in regions highly prone to soil erosion. The concept of particulate transport elaborated in objective 4 should be incorporated in existing erosion models, such as LISEM, to predict off-site effects of glyphosate applications.

    Verbetering waterkwaliteit door minder emissie uit open teelten
    Werd, H.A.E. de; Wenneker, M. ; Nieuwenhuizen, A.T. - \ 2013
    Gewasbescherming 44 (2013)1. - ISSN 0166-6495 - p. 6 - 9.
    oppervlaktewaterkwaliteit - waterkwaliteit - pesticiden - emissie - gewasbescherming - akkerbouw - vollegrondsteelt - uitspoelen - pesticidenresiduen - surface water quality - water quality - pesticides - emission - plant protection - arable farming - outdoor cropping - leaching - pesticide residues
    In dit artikel wordt een overzicht gegeven van recente ontwikkelingen om de emissie van gewasbeschermingsmiddelen uit de open teelten naar het oppervlaktewater terug te dringen. Dit begint met de oorzakenanalyse en verschillende emissieroutes. Daarna volgen oplossingsrichtingen, die onderwerp van onderzoek zijn of zijn geweest. Het artikel sluit af met een blik in de toekomst.
    Analyse van residugegevens en spuitschema's in kleinfruit (rode bes)
    Wenneker, M. - \ 2013
    Randwijk : Praktijkonderzoek Plant en Omgeving, Bloembollen, Boomkwekerij & Fruit (PPO 2013-04) - 23
    fruitteelt - bessen - kleinfruit - pesticidenresiduen - residuen - kwaliteitscontroles - spuiten - analyse - landbouwkundig onderzoek - fruit growing - berries - small fruits - pesticide residues - residues - quality controls - spraying - analysis - agricultural research
    Residuen van gewasbeschermingsmiddelen op vruchten zijn in toenemende mate een probleem voor de afzet. Door retailers worden steeds hogere eisen gesteld aan het aantal verschillende residuen dat mag worden aangetroffen en aan het residuniveau dat geaccepteerd wordt (bovenwettelijke eisen). In kleinfruit (m.n. rode bessen) zijn hierdoor in de afgelopen jaren problemen ontstaan, omdat veel verschillende actieve stoffen in de residu-analyses worden teruggevonden, en de hoeveelheid residu soms de MRL-waarde nadert. Om aan de eisen van de retail te kunnen voldoen is het noodzakelijk dat het aantal stoffen dat bij residu-analyses wordt aangetoond vermindert én het residuniveau wordt verlaagd. Tevens werden bijbehorende spuitschema’s geanalyseerd.
    Residuvrij telen van vruchtgroenten: bedreiging of kans?
    Messelink, Gerben - \ 2013
    greenhouse horticulture - fruit vegetables - residues - pesticide residues - uses - plant pests - biological control agents - biological control - detection
    Zuivering sorteerwater heeft heldere toekomst - Interview met Marcel Wenneker
    Ossenbruggen, M. van; Wenneker, M. - \ 2012
    De Fruitteelt 102 (2012)12. - ISSN 0016-2302 - p. 8 - 9.
    fruitteelt - sorteermachines - waterzuivering - waterfilters - pesticidenresiduen - gewasbescherming - fruit growing - sorters - water treatment - water filters - pesticide residues - plant protection
    In opdracht van het Waterschap Scheldestromen en onder coördinatie van de NFO werd in 2009 het project waterbehandeling bij fruitsorteerinstallaties opgezet. Nu, drie jaar later, is er veel meer bekend over de werking, wat wel en niet mogelijk is en heeft de sorteerder keus uit diverse zuiveringsinstallaties. NFO-kring Midden- Nederland en het Waterschap Rivierenland gaven 6 maart een informatie avond voor fruitsorteerders.
    Extrapolation of effects of pesticides on aquatic communities and ecosystems across different exposure patterns
    Zafar, M.I. - \ 2012
    Wageningen University. Promotor(en): Paul van den Brink, co-promotor(en): Rene van Wijngaarden. - S.l. : s.n. - ISBN 9789461733719 - 202
    pesticidenresiduen - toxiciteit - aquatische toxicologie - aquatische gemeenschappen - aquatische ecosystemen - risicoschatting - pesticide residues - toxicity - aquatic toxicology - aquatic communities - aquatic ecosystems - risk assessment
    Het gebruik van bestrijdingsmiddelen voor de productie van agrarische gewassen brengt het risico met zich mee dat deze in aangrenzende waterlichamen, zoals sloten, vijvers, meren en/of beken, terecht kunnen komen. Er zijn verschillende manieren waarop bestrijdingsmiddelen in deze waterlichamen terecht kunnen komen, bijvoorbeeld door bovengrondse afstroming op hellende agrarische velden, door overwaaiing wanneer de toepassing van bestrijdingsmiddelen dichtbij wateroppervlakten plaatsvindt of door uitspoeling van bestrijdingsmiddelen naar het oppervlakte- of grondwater. Omdat bestrijdingsmiddelen zijn ontwikkeld voor het aantasten van voor gewassen schadelijke biota, kunnen deze chemische gewasbeschermingsproducten ook schadelijk zijn voor verwante (aquatische) organismen.
    Recent developments and market opportunities for IPM in greenhouse tomatoes in southern Europe; Consequences for advanced IPM toolboxes and greenhouse engineering
    Velden, N.J.A. van der; Suay, R. ; Urbaneja, A. ; Giorgini, M. ; Ruocco, M. ; Poncet, C. ; Lefèvre, A. - \ 2012
    The Hague : LEI, part of Wageningen UR (LEI memorandum / LEI Wageningen UR 12-077) - 41
    marktonderzoek - geïntegreerde bestrijding - tomaten - pesticidenresiduen - glastuinbouw - zuid-europa - duitsland - market research - integrated control - tomatoes - pesticide residues - greenhouse horticulture - southern europe - germany
    The market for greenhouse tomatoes requires a production system with lower use and risks of pesticides. These requirements culminate in the tight restrictions on residues for German retailers, both in number and in levels of residues. Germany is an important import country for tomatoes because of the size of the German market. Furthermore, exports to Germany entail a price premium. For that reason the revenues of IPM in greenhouse tomatoes are more important than the costs. Consequently, the experiments in task 3 and the ex post assessment in task 4 of work package 7 of the Pure programme should focus on IPM strat egies by which the German residue restrictions can be respected.
    Emissie door oppervlakkige afspoeling : relevantie en preventie : tussenrapportage 2011
    Evenhuis, A. ; Beltman, W.H.J. ; Weide, R.Y. van der; Zeeland, M.G. van; Schepers, H.T.A.M. ; Deneer, J.W. - \ 2012
    Wageningen : Praktijkonderzoek Plant & Omgeving B.V. - 68
    oppervlakkige afvoer - landbouwgronden - oppervlaktewater - emissie - pesticiden - pesticidenresiduen - gewasbescherming - neerslag - infiltratie - meteorologische waarnemingen - runoff - agricultural soils - surface water - emission - pesticides - pesticide residues - plant protection - precipitation - infiltration - meteorological observations
    De doelstelling van het rapportage-project was: - Op basis van bestaande kennis uit binnen- en buitenland (metingen, modelstudies) inzichtelijk maken in hoeverre oppervlakkige afspoeling van (vrijwel) vlakke percelen verantwoordelijk kan zijn voor (piek) belasting van oppervlaktewater; - Inzichtelijk maken in hoeverre een vergelijking met andere emissieroutes mogelijk is en, zo mogelijk, deze vergelijking inzichtelijk maken; - Verkenning van de mate van overeenstemming tussen de uitgangspunten van de modelmatige berekening van afspoeling en de situatie op representatieve praktijksituaties in Nederland. Wanneer relevante afwijkingen verwacht worden, deze benoemen; - Vaststellen of er zicht is op effectieve maatregelen om oppervlakkige afspoeling tegen te gaan. Dit kunnen bestaande of nieuwe maatregelen zijn. Hiervoor is een korte internationale literatuurscan uitgevoerd naast een verkenning om te bepalen hoe vaak afspoeling van water kan optreden op landbouwgronden in het vlakke deel van Nederland. Voor dit laatste onderdeel zijn neerslaggegevens van 30 jaar geanalyseerd op de frequentie van optreden van buien voor 3 meteostations en zijn zand- en kleigronden gekarakteriseerd met hun infiltratiesnelheid.
    Economic analysis of pesticide use and environmental spillovers under a dynamic production environment
    Skevas, T. - \ 2012
    Wageningen University. Promotor(en): Alfons Oude Lansink, co-promotor(en): Spiro Stefanou. - S.L. : s.n. - ISBN 9789461732194 - 175
    akkerbouw - bedrijfseconomie - pesticiden - dynamica - milieu - pesticidenresiduen - aanwendingen - gewasbescherming - stimulansen - productie - onzekerheid - nederland - milieubeleid - arable farming - business economics - pesticides - dynamics - environment - pesticide residues - uses - plant protection - incentives - production - uncertainty - netherlands - environmental policy
    Pesticides are used in agriculture to protect crops from pests and diseases, with indiscriminate pesticide use having several adverse effects on the environment. In an era of an increasing public awareness on pesticides’ environmental spillovers, the EU is trying to update its pesticide policy by using economic incentives, aiming at reducing pesticide use and environmental spillovers. This dissertation focuses on assessing how pesticide use and its related environmental spillovers are affecting farmers’ production environment under a dynamic production setting, thus assisting policy makers in designing optimal pesticide policy tools.
    Waterbehandeling bij fruitsorteerinstallaties : ontwikkeling van een prototype
    Vliet, H.P.M. van; Wenneker, M. ; Meulenkamp, R.J.A. - \ 2012
    De Bilt : Grontmij - 67
    fruitteelt - sorteermachines - waterverontreiniging - waterzuivering - pesticidenresiduen - proefprojecten - haalbaarheidsstudies - fruit growing - sorters - water pollution - water treatment - pesticide residues - pilot projects - feasibility studies
    Doel van het project is het ontwikkelen van een praktijkrijpe oplossing voor de problematiek met betrekking tot het lozen van ernstig met gewasbeschermingsmiddelen verontreinigd fruittransportwater, zodat emissies naar water kunnen worden beëindigd. Binnen het project is een proefinstallatie ontworpen en gerealiseerd die op locatie gedurende langere tijd (drie duurproeven) getest is. Ter ondersteuning zijn ook losstaand proeven uitgevoerd.
    Ontwikkeling prototype residuverwijdering met VAM-Residuce : eindrapportage 1 Januari 2010- 15 Mei 2011
    Jong, P.F. de; Antwerpen, E. van; Berg-Somhorst, B.P.M. van de; Bastiaan-Net, S. - \ 2012
    Wageningen : Wageningen UR - Food & Biobased Research (Rapport / Wageningen UR Food & Biobased Research nr. 1310) - ISBN 9789461732583 - 13
    behandeling na de oogst - pesticidenresiduen - pesticiden - fruit - fruitteelt - reductiemiddelen - schuimen - meting - postharvest treatment - pesticide residues - pesticides - fruit - fruit growing - reducing agents - foaming - measurement
    Voor het succesvol implementeren van een residuverwijderingsprototype in de huidige sorteerlijnen is het belangrijk dat tijdens het sorteerproces niet te veel schuim ontstaat in het sorteerwater en dat de concentratie van het gebruikte reducerend middel (VAM-Residuce) in het sorteerproces op peil gehouden kan worden. Een tweetal titratiemethodes en een schuim-onderdrukkende techniek zijn ontwikkeld om respectievelijk de concentratie VAM-Residuce te controleren en overmatige schuimvorming tijdens het sorteerproces tegen te gaan.
    Geïnduceerde afbraak residuen op fruit : nieuwe technieken 2011 : eindrapportage
    Bastiaan-Net, S. ; Berg-Somhorst, B.P.M. van de - \ 2012
    Wageningen : Wageningen UR - Food & Biobased Research (Rapport / Wageningen UR Food & Biobased Research nr. 1308) - ISBN 9789461732576 - 12
    behandeling na de oogst - pesticidenresiduen - pesticiden - fruit - fruitteelt - reductiemiddelen - postharvest treatment - pesticide residues - pesticides - fruit - fruit growing - reducing agents
    Een behandelingstap met het reducerend middel VAM-Residuce geeft reeds veelbelovende resultaten op het gebied van residuvermindering op appel en peer maar deze techniek vergt verdere optimalisatie om de supermarkten tegemoet te kunnen komen. De activiteiten binnen dit onderzoek hebben zich gericht op het verbeteren van deze behandelingstap met additionele technieken. In 2011 zijn voornamelijk de technieken “Koude Plasma” en “Geëlektrolyseerd water” getest op hun residu reducerend vermogen. De koude plasma techniek blijkt niet geschikt te zijn om het niveau van gewasbeschermingsmiddelen effectief op hardfruit te verlagen. De test met geëlektrolyseerd water gaf geen éénduidige residuvermindering aan op Elstar appelen. Literatuur geeft aan dat deze techniek residu reducerend vermogen bezit.
    Evaluatie van de nota Duurzame gewasbescherming : deelrapport Voedselveiligheid
    Boon, P.E. ; Donkersgoed, G. ; Noordam, M.Y. ; Biesebeek, J.D. te; Ven-van den Hoogen, B.M. van de; Klaveren, J.D. van - \ 2012
    Bilthoven : RIVM
    gewasbescherming - pesticiden - pesticidenresiduen - voedselveiligheid - groenten - fruit - voedingsmiddelenwetgeving - Nederland - plant protection - pesticides - pesticide residues - food safety - vegetables - fruit - food legislation - Netherlands
    Het percentage groente- en fruitmonsters waarop in Nederland te veel resten van gewasbeschermingsmiddelen zijn aangetroffen, is tussen 2003 en 2010 met 70% gedaald. Daarnaast is de absolute hoeveelheid resten van gewasbeschermingsmiddelen op dit type voedsel verminderd. De meeste producten waarop resten zijn aangetroffen, zijn afkomstig uit het buitenland. Verder is de voedselveiligheid sinds 2003 verbeterd. Dit blijkt uit een evaluatie van het beleidsdoel voor voedselveiligheid, zoals geformuleerd in de nota Duurzame gewasbescherming van het ministerie van Landbouw, Natuur en Voedselkwaliteit (nu Economische Zaken, Landbouw en Innovatie). Het doel hiervan is het aantal overschrijdingen met 50% te verminderen.
    Gebiedsanalyse waterkwaliteit Peel & Maasvallei
    Wal, E. van der; Moonen, V. ; Bolt, F.J.E. van der - \ 2011
    H2O : tijdschrift voor watervoorziening en afvalwaterbehandeling 44 (2011)5. - ISSN 0166-8439 - p. 58 - 61.
    oppervlaktewater - oppervlaktewaterkwaliteit - landbouw en milieu - gewasbescherming - pesticidenresiduen - waterschappen - noord-limburg - midden-limburg - surface water - surface water quality - agriculture and environment - plant protection - pesticide residues - polder boards - noord-limburg - midden-limburg
    Waterschap Peel en Maasvallei heeft een gebiedsanalyse laten uitvoeren voor stoffen, die een slechte waterkwaliteit veroorzaken en waarvan de landbouw een relevante bron kan zijn. CLM Onderzoek & Advies en Alterra hebben de meetgegevens van het waterschap voor deze stoffen (nutriënten, zware metalen en gewasbeschermingsmiddelen) in samenhang met gebiedskenmerken en de landbouwpraktijk geanalyseerd. Deze analyse dient als basis voor gesprekken met agrariërs en vor het opstellen van een plan van aanpak voor een betere waterkwaliteit.
    Residu doorkruist middelenkeus: Ziektebestrijding, bemesting en rassendemo's waren de balangrijkste items tijdens de Internationale Peendag in Lelystad
    PPO Akkerbouw, Groene Ruimte en Vollegrondsgroente, - \ 2011
    carrots - plant protection - fungus control - pesticide residues - plant disease control - foliar application - fungicides
    Residuen op groenten en fruit ter discussie
    Woltering, E.J. - \ 2011
    Voeding Nu 2011 (2011)1/2. - ISSN 1389-7608 - p. 18 - 19.
    pesticidenresiduen - groenten - fruit - zuigelingenvoedsel - voedselveiligheid - voeding en gezondheid - toxische stoffen - pesticide residues - vegetables - infant foods - food safety - nutrition and health - toxic substances
    De nVWA en het RIVM doen al jaren onderzoek naar residuen van giftige stoffen op groenten en fruit. Uit onderzoek blijkt dat met name peuters en baby’s meer groenten en fruit binnenkrijgen dan eerder werd gedacht. Met meer groenten en fruit zouden ze ook meer residuen binnenkrijgen. Ernst Woltering van Wageningen Universiteit plaatst het één en ander in perspectief.
    Kwaliteit lozingwater verrassend hoog : eerste resultaten project Zuivering Fruittransportwater veelbelovend
    Vliet, H. van; Wenneker, M. ; Bruchem, J. van - \ 2010
    De Fruitteelt 100 (2010)42. - ISSN 0016-2302 - p. 10 - 11.
    fruitteelt - fruitgewassen - pesticidenresiduen - gewasbescherming - waterkwaliteit - economische haalbaarheid - milieubeheer - zuiveringsinstallaties - fruit growing - fruit crops - pesticide residues - plant protection - water quality - economic viability - environmental management - purification plants
    Midden 2009 ging het tweejarig project Zuivering Fruittransportwater van start. Na inleidende experimenten en het bouwen van de proefinstallatie werden twee duurproeven uitgevoerd. De eerste proef duurde enkele dagen, het tweede onderzoek ruim twee maanden. Voor de komende periode staat de derde, afsluitende duurproef gepland.Tot op heden zijn de resultaten van het project veelbelovend.
    Versneld afbreken van residuen van gewasbeschermingsmiddelen op appel en peer
    Jong, P.F. de; Bastiaan-Net, S. - \ 2010
    Randwijk : Praktijkonderzoek Plant & Omgeving, Bloembollen, Boomkwekerij & Fruit - 50
    appels - peren - pyrus communis - malus pumila - pesticidenresiduen - degradatie - opslag - ozon - zepen - apples - pears - pyrus communis - malus pumila - pesticide residues - degradation - storage - ozone - soaps
    Er is een grotere bewustwording bij de consumenten over de aanwezigheid van residuen op fruit. Dit als gevolg van aandacht voor dit thema in de media. Als reactie daarop hebben een aantal supermarkten hun normen aangescherpt. Het gebruik van gewasbescherming is echter noodzakelijk om aan de kwaliteitseisen te voldoen die de consument stelt. Het eenvoudig weglaten van bestrijdingsmiddelen zou leiden tot een grote toename van aantastingen van ziekten en plagen met grote verliezen tot gevolg. Daarom zal gekeken moeten worden naar mogelijkheden om met minder residu op het geconsumeerde fruit toch te komen tot hetzelfde kwaliteitsniveau. Een oplossing die mogelijk op korte termijn haalbaar is, is het versneld afbreken van residuen op de vrucht na bewaring.
    Beleidsondersteunend onderzoek plantgezondheid BO-06 : M.i.v. 2010: beleidsondersteunend onderzoek agroketens en visserij, onderbouwing wet- en regelgeving (BO-12.07) : resultaten 2009 : Kaderrichtlijn water, emissiereductie & beoordelingsmethodieken toelating gewasbeschermingsmiddelen (BO-06-006, BO-06-009 & BO-06-010)
    Boonekamp, P.M. - \ 2010
    Wageningen : Plant Sciences Group Wageningen UR - 29
    gewasbescherming - plagenbestrijding - plantenziektebestrijding - drift - fruitteelt - boomteelt - akkerbouw - oppervlaktewater - grondwater - waterkwaliteit - waterzuivering - landbouwbeleid - pesticidenresiduen - vollegrondsteelt - oppervlaktewaterkwaliteit - kaderrichtlijn water - plant protection - pest control - plant disease control - drift - fruit growing - arboriculture - arable farming - surface water - groundwater - water quality - water treatment - agricultural policy - pesticide residues - outdoor cropping - surface water quality - water framework directive
    Ruim zes jaar loopt het beleidsondersteunende onderzoeksprogramma Plantgezondheid. De resultaten zijn vervat in 20 verslagen: Effects of different exposure regimes of an insecticide on freshwater outdoor microcosms; Development of Dutch exposure scenarios for aquatic organisms; A Geographic Information System (GIS)-based study on regional pesticide deposition; Development of a methodology to assess atmospheric deposition on surface waters; Surface water monitoring results in the authorisation of plant protection products; Ontwikkeling van een doppenclassificatiesysteem in de fruitteelt; Onderbouwing van drift en driftreducerende maatregelen in de fruitteelt; Driftreductie bij bespuitingen in laanbomen; Drift en depositie bij (precisie) toedieningstechnieken in de akkerbouw, bollen- en fruitteelt; Ondersteuning ‘Schone Bronnen’ door oplossen waterkwaliteitsproblemen; Vermindering puntbelastingen van middelen uit de open teelten; Zuiveren recirculatiewater in de rozenteelt; The Species Sensitivity Distribution approach in the risk assessment for pesticides; Development of CASCADE-TOXSWA model to assess exposure at catchment scale; Development and validation of methods for the estimation of spray drift deposition on surface water; Revision of the FOCUS groundwater scenarios; Exposure assessment for soil organisms at EU level; Knowledge development on spray drift deposition and the effect on non-target plants; Modelling emissions of plant protection products from protected cultivation to surface water; Development of the new Dutch environmental indicator for plant protection products.
    Telers Woudse Droogmakerij streven naar emissievrij (interview met Ruud Maaswinkel en Ellen Beerling)
    Thoenes, E. ; Maaswinkel, R.H.M. ; Beerling, E.A.M. - \ 2009
    Groenten en Fruit. Algemeen 2009 (2009)33. - ISSN 0925-9694 - p. 24 - 25.
    tuinbouwbedrijven - emissie - pesticidenresiduen - voedingsstoffengehalte - oppervlaktewater - normen - waterfilters - oppervlaktewaterkwaliteit - market gardens - emission - pesticide residues - nutrient content - surface water - standards - water filters - surface water quality
    In de polder Woudse Droogmakerij in regio Delfland begon in 2008 een samenwerkingsverband om de uitstoot van middelen en voedingsstoffen te verminderen. Doel van dit project is de kwaliteit van oppervlaktewater meetbaar verbeteren zonder dat dit ten koste gaat van het teeltrendement
    Achtergrond document Netwerken aan water - Samen aan de slag om de waterkwaliteit in de Greenport Boskoop te verbeteren- versie november
    Dalfsen, P. van; Reuler, H. van; Dolmans, N.G.M. ; Dorrestein, W. - \ 2009
    Lisse : PPO Bloembollen, Boomkwekerij en Fruit - 51
    boomkwekerijen - oppervlaktewater - waterkwaliteit - gewasbescherming - pesticidenresiduen - stikstof - fosfaat - oppervlaktewaterkwaliteit - waterschappen - zuid-holland - forest nurseries - surface water - water quality - plant protection - pesticide residues - nitrogen - phosphate - surface water quality - polder boards - zuid-holland
    Greenport Boskoop is een boomkwekerij teeltcentrum van ca. 1100 ha, waarin ongeveer 720 bedrijven actief zijn. Uit metingen van het Hoogheemraadschap van Rijnland blijkt dat er geregeld te hoge concentraties gewasbeschermingsmiddelen en stikstof en fosfaat worden aangetroffen in het oppervlaktewater van Greenport Boskoop. De boomkwekerijsector wil samen met het Hoogheemraadschap van Rijnland werken aan een verbetering van de waterkwaliteit. Het project Netwerken aan Water, dat is uitgevoerd door DLV Plant en WUR-PPO, moet hiervoor handvaten bieden. In dit achtergrondrapport worden de beschikbare gegevens m.b.t de waterkwaliteit gepresenteerd om de betrokken partijen op de hoogte te stellen van de beschikbare informatie. Op deze wijze start iedereen vanaf hetzelfde vertrekpunt. In het rapport worden verschillende mogelijkheden beschreven om de milieubelasting van voedingstoffen en gewasbeschermingsmiddelen te verminderen. Veel van deze maatregelen zijn al onderzocht en bruikbaar voor de praktijk. In andere gevallen is aanvullend onderzoek nodig
    Project zuivering fruittransportwater van start
    Vliet, H. van; Wenneker, M. ; Koning, S. - \ 2009
    De Fruitteelt 99 (2009)20. - ISSN 0016-2302 - p. 17 - 17.
    fruitteelt - fruitgewassen - sorteermachines - zuiveringsinstallatie - pesticidenresiduen - arbeidsomstandigheden - fruit growing - fruit crops - sorters - clarifiers - pesticide residues - working conditions
    De behandeling of zuivering van het transportwater uit fruitsorteerinstallaties staat centraal in het project 'Zuivering van Fruittransportwater' dat in april van start is gegaan. Dit project met een looptijd van twee jaar heeft als randvoorwaarde dat de toegepaste zuiveringstechieken de arbeidsomstandigheden niet mogen aantasten. Bovendien moet de oplossing bedrijfseconomisch verantwoord zijn
    Resultaten van een inventarisatie van de waterkwaliteit : nog teveel gewasbeschermingsmiddelen in oppervlaktewater
    Staaij, M. van der - \ 2009
    Onder Glas 6 (2009)3. - p. 76 - 77.
    kassen - afvloeiingswater - pesticiden - waterkwaliteit - normen - pesticidenresiduen - oppervlaktewater - lozing - glastuinbouw - oppervlaktewaterkwaliteit - waterschappen - nutriëntenuitspoeling - greenhouses - runoff water - pesticides - water quality - standards - pesticide residues - surface water - disposal - greenhouse horticulture - surface water quality - polder boards - nutrient leaching
    In alle waterstromen in een kas zijn gewasbeschermingsmiddelen aangetroffen. Als norm voor de waterstromen binnen de kas is de MTR (Maximaal Toelaatbaar Risico) voor oppervlaktewater genomen. Wanneer water met een concentratie aan middel boven de MTR wordt geloosd kan dit een probleem zijn voor de kwaliteit van het oppervlaktewater. Recirculeren is de beste oplossing, maar telers zijn dan afhankelijk van de kwaliteit van het water waarmee ze starten
    "Gewasbescherming en bewaring Controlled Atmosphere"-warmtebehandeling : een duurzame methode voor de bestrijding van aardbeimijt (Phytonemus pallidus) in basisplantgoed
    Kruistum, G. van; Vlaswinkel, M.E.T. ; Verschoor, J.A. ; Schaik, A.C.R. van; Spoorenberg, P.M. - \ 2008
    Gewasbescherming 39 (2008)suppl.. - ISSN 0166-6495 - p. 59S - 59S.
    gewasbescherming - phytonemus pallidus - pesticidenresiduen - ziektebestrijdende teeltmaatregelen - geïntegreerde plagenbestrijding - plant protection - phytonemus pallidus - pesticide residues - cultural control - integrated pest management
    Evaluation of the 2006 proposal for risk assessment of persistence of plant protection products in soil
    Linden, A.M.A. van der; Boesten, J.J.T.I. ; Brock, T.C.M. ; Eekelen, G.M.A. van; Horst, M.M.S. ter; Jong, F.M.W. de; Montforts, M.H.M.M. ; Pol, J.W. - \ 2008
    De Bilt : RIVM (RIVM report 601712002/2008) - ISBN 9789069601977 - 165
    pesticiden - pesticidenresiduen - onbedoelde effecten - toxische stoffen - bodemverontreiniging - risicoschatting - pesticides - pesticide residues - nontarget effects - toxic substances - soil pollution - risk assessment
    This report describes the evaluation of the 2006 proposal for the risk assessment of persistence of plant protection products in soil. The proposal considered three protection goals and proposed tiered assessment and decision schemes for each protection goal. The three schemes appeared to be consistent, both internally and with each other. It was found that both pore water concentrations and total content have to be considered in the soil risk assessment. The evaluation has been performed for five substances with all available information from both registration dossiers and open literature. Nevertheless, insufficient information was available to evaluate all aspects of the proposal. In practice this means that pesticide industry has to provide additional information for many dossiers. Furthermore, it was found that existing information often needs to be re-interpreted and a need for standardisation of evaluation of terrestrial (semi-)field experiments was observed. The proposal would require specific expertise and investments of evaluating authorities as well as stakeholders. To better understand fate and effects of persistent substances, it is recommended to investigate the behaviour of substances in the field over longer periods, to perform exposure concentration measurements while performing ecotoxicological tests, to develop protocols for testing effects on fungi, and to gain the necessary experience on the conduct and interpretation of (semi-)field studies with respect to the relation between exposure and effects of plant protection products.
    Protection goals, criteria and scenarios : 9 - 11 October 2007
    Bosch, H. van den; Chuanjiang, T. - \ 2007
    Wageningen : Alterra / ICAMA - 10
    milieubescherming - pesticidenresiduen - risicoschatting - geïntegreerde bestrijding - environmental protection - pesticide residues - risk assessment - integrated control
    Protection goals, criteria and scenarios of Sino, Dutch Pesticide Environmental Risk Assessment Project
    Trends in normoverschrijdingen, overschrijdingen van de acute refentiewaarde en gesommeerde blootstelling
    Klaveren, J.D. van; Noordam, M.Y. ; Boon, P.E. ; Donkersgoed, G. van; Ossendorp, B.C. ; Raaij, M.T.M. van; Roest, J.G. van der - \ 2007
    Wageningen : RIKILT (Rapport / RIKILT 2006.011) - 196
    voedselveiligheid - gewasbescherming - pesticidenresiduen - pesticiden - residuen - toxiciteit - duurzaamheid (sustainability) - normen - kennis - food safety - plant protection - pesticide residues - pesticides - residues - toxicity - sustainability - standards - knowledge
    Dit rapport beschrijft de resultaten van een tussentijdse evaluatie van de mate van realisatie van de doelstellingen ten aanzien van voedselveiligheid zoals geformuleerd in de nota Duurzame gewasbescherming. Beschreven wordt hoe de conclusies tot stand gekomen zijn en dit document geeft een gedetailleerd overzicht van nationale en internationale wetgeving ten aanzien van het vaststellen van residunormen, ook wel aangeduid als Maximum Residu Limiet (MRL). Tevens wordt beschreven hoe de relatie tussen normstelling, die altijd betrekking heeft op één voedingsmiddel en één bestrijdingsmiddel, en voedselveiligheid het beste geïnterpreteerd kan worden
    Contaminanten en micro-organismen in biologische producten : vergelijking met gangbare producten
    Hoogenboom, L.A.P. ; Bokhorst, J.G. ; Northolt, M.D. ; Broex, N.J.G. ; Mevius, D.J. ; Meijs, J.A.C. ; Roest, J.G. van der - \ 2006
    Wageningen : RIKILT (Rapport / RIKILT 2006.002) - 52
    biologische productie - voedselbesmetting - microbiële besmetting - voedselveiligheid - kennis - biologische voedingsmiddelen - besmetters - pesticidenresiduen - micro-organismen - landbouwkundig onderzoek - gezondheid - biological production - food contamination - microbial contamination - food safety - knowledge - organic foods - contaminants - pesticide residues - microorganisms - agricultural research - health
    Voor dit rapport is een beperkt aantal contaminanten en micro-organismen in biologisch geproduceerde producten of productiewijzen bekeken. Resultaten zijn vervolgens vergeleken met die uit de gangbare landbouw. Aan de orde komen Mycotoxinen in tarwe; zware metalen en arseen in tarwe, sla, peen en aardappel, in varkensvlees en in eieren; nitraat in sla, peen en aardappel; residuen van pesticiden in tarwe, sla, peen en aardappel; microbiële besmetting van sla, varkens, melkvee, vleeskuikens en leghennen; residuen van antibiotica en coccidiostatica in varken, runderen en eieren en antibiotica-resistentie. Alhoewel een aantal resultaten wijst op verschillen tussen biologisch en gangbaar, betreft het hier een momentopname. In een aantal gevallen bevestigen de resultaten die van ander onderzoek, zoals de lagere nitraatgehaltes in biologische kropsla, geen verschillen in mycotoxine-gehaltes bij tarwe, minder Salmonella maar meer Campylobacter bij vleeskuikens en minder antibiotica-resistentie bij vleeskuikens. Voor nitraat in biologische peen zijn er aanwijzingen voor een trend naar verhoogde gehaltes. In andere gevallen moet vervolgonderzoek uitwijzen of er daadwerkelijk sprake is van een duidelijke trend, zoals bij de lagere incidentie van antibiotica-resistente bacteriën in biologische varkens en de lagere Salmonella- incidentie bij varkens van meer ervaren biologische bedrijven.
    Probabilistic intake calculations performed for the Codex Committee on Pesticides Residues
    Boon, P.E. ; Tjoe Nij, E.I.M. ; Donkersgoed, G. van; Klaveren, J.D. van - \ 2004
    Wageningen : RIKILT (Report / RIKILT 2004.005) - 42
    pesticidenresiduen - waarschijnlijkheidsmodellen - opname (intake) - codex alimentarius - pesticide residues - probabilistic models - intake - codex alimentarius
    Some explorations into Bayesian modelling of risks due to pesticide intake from food
    Voet, H. van der; Paulo, M.J. - \ 2004
    In: Bayesian statistics and quality modelling in the agro-food production chain / van Boekel, M.A.J.S., Stein, A., van Bruggen, A.H.C., Dordrecht : Kluwer - ISBN 9781402019166 - p. 145 - 162.
    bayesiaanse theorie - monte carlo-methode - wiskundige modellen - voedselveiligheid - pesticidenresiduen - risicoschatting - bayesian theory - monte carlo method - mathematical models - food safety - pesticide residues - risk assessment
    This paper presents some common types of data and models in pesticide exposure assessment. The problems of traditional methods are discussed in connection with possibilities to address them in a Bayesian framework. We present simple Bayesian models for consumption of food and for residue monitoring data
    Estimation of the acute dietary exposure to pesticides using the probabilistic approach and the point estimate methodology
    Boon, P.E. ; Lignell, S. ; Klaveren, J.D. van; Tjoe Nij, E.I.M. - \ 2004
    onbekend : RIKILT - Veiligheid & Gezondheid (Report / RIKILT 2004.008)
    pesticidenresiduen - opname (intake) - risicoschatting - waarschijnlijkheidsmodellen - pesticide residues - intake - risk assessment - probabilistic models
    Dietary habits and exposure to pesticides in Dutch infants
    Boon, P.E. ; Tjoe Nij, E.I.M. ; Koopman, N. ; Klaveren, J.D. van - \ 2004
    onbekend : RIKILT - Veiligheid & Gezondheid (Report / RIKILT 2004.017)
    voedingsgewoonten - pesticidenresiduen - zuigelingenvoeding - consumptiepatronen - risicoschatting - nederland - feeding habits - pesticide residues - infant nutrition - consumption patterns - risk assessment - netherlands
    Off-target dust deposition for two granule application techniques : calculations based on the IDEFICS spray drift model
    Holterman, H.J. - \ 2004
    Wageningen : Agrotechnology & Food Innovations (Report / Agrotechnology & Food Innovations 224) - ISBN 9789067548045 - 35
    pesticiden - toedieningswijzen - waterverontreiniging - pesticidenresiduen - spuitapparatuur - simulatiemodellen - pesticides - application methods - water pollution - pesticide residues - spraying equipment - simulation models
    Resultaten monitoring afspoeling glyfosaat en AMPA en waarnemingen van onkruidbeelden in zeven proefgemeenten (voorjaar en najaar 2003) : rapportage in het kader van het project Duurzaam onkruidbeheer op verhardingen (DOB-project
    Withagen, J.C.M. ; Horst, C.L.M. van der; Beltman, W.H.J. ; Kempenaar, C. - \ 2004
    Wageningen : Plant Research International (Nota / Plant Research International 297) - 76
    onkruidbestrijding - chemische bestrijding - glyfosaat - herbiciden - pesticidenresiduen - milieubeheer - oppervlakkige afvoer - monitoring - wegen - nederland - weed control - chemical control - glyphosate - herbicides - pesticide residues - environmental management - runoff - monitoring - roads - netherlands
    The effects of a pesticide mixture on aquatic ecosystems differing in trophic status: responses of the macrophyte Myriophyllum spicatum and the periphytic algal community
    Wendt-Rasch, L. ; Brink, P.J. van den; Crum, S.J.H. ; Woin, P. - \ 2004
    Ecotoxicology and Environmental Safety 57 (2004)3. - ISSN 0147-6513 - p. 383 - 398.
    aquatisch milieu - waterplanten - schadelijke waterplanten - asulam - herbicidenmengsels - lambda-cyhalothrin - metamitron - onbedoelde effecten - niet-doelorganismen - pesticidenresiduen - trofische graden - onkruiden - aquatic environment - aquatic plants - aquatic weeds - asulam - herbicide mixtures - lambda-cyhalothrin - metamitron - nontarget effects - nontarget organisms - pesticide residues - trophic levels - weeds - fresh-water microcosms - insecticide dursban(r) 4e - phytoplankton succession - pyrethroid insecticides - fungicide carbendazim - phosphorus release - final conclusions - primary producers - model-ecosystems - zooplankton
    The effects of a pesticide mixture (asulam, fluazinam, lambda-cyhalothrin, and metamitron) on aquatic ecosystems were investigated in 20 outdoor aquatic microcosms. Ten of the microcosms simulated mesotrophic aquatic ecosystems dominated by submerged macrophytes (Elodea). The others simulated eutrophic ecosystems with a high Lemna surface coverage (Lemna). This paper describes the fate of the chemicals as well as their effects on the growth of Myriophyllum spicatum and the periphytic algal community. In the Elodea-dominated microcosms significant increase in the biomass and alterations of species composition of the periphytic algae were observed, but no effect on M. spicatum growth could be recorded in response to the treatment. The opposite was found in the Lemna-dominated microcosms, in which decreased growth of M. spicatum was observed but no alterations could be found in the periphytic community. In the Elodea-dominated microcosms the species composition of the periphytic algae diverged from that of the control following treatment with 0.5% spray drift emission of the label-recommended rate (5% for lambda-cyhalothrin), while reduced growth of M. spicatum in the Lemna-dominated microcosms was recorded at 2% drift (20% for lambda-cyhalothrin). This study shows that the structure of the ecosystem influences the final effect of pesticide exposure.
    Gif in sloot door drift kun je voorkomen
    Schans, D.A. van der - \ 2003
    Kennisakker.nl 2003 (2003)15 okt.
    spuitapparaten - toedieningswijzen - pesticidenresiduen - pesticiden - cultuurmethoden - verontreinigingsbeheersing - waterverontreiniging - akkerbouw - sprayers - application methods - pesticide residues - pesticides - cultural methods - pollution control - water pollution - arable farming
    Regels worden strikter, meetnetten voor waterkwaliteit fijnmaziger en analyses van stoffen nauwkeuriger. De teler moet steeds vaker inzien dat oppervlaktewater wordt vervuild door teeltmaatregelen. Er kunnen allerlei maatregelen worden genomen om dit te voorkomen en bestrijdingsmiddelen op de plaats te houden waar ze worden gespoten. Spuittechniek, keuze van spuitdop en toepassing van luchtondersteuning, teelt- en spuitvrije stroken langs de sloot en natuurlijke of kunstmatige schermen langs oppervlakte water zijn mogelijkheden. Vooral teeltvrije stroken kunnen hoge kosten voor de teler met zich mee brengen.
    Methodeontwikkeling voor de bepaling van polaire bestrijdingsmiddelen met behulp van vloeistofchromatografie-massaspectrometrie (LC-MS) : fase 2 initiërend onderzoek
    Rijk, T.C. de; Zomer, P. ; Traag, W.A. - \ 2002
    Wageningen : Rijks-Kwaliteitsinstituut voor land- en tuinbouwproducten (RIKILT) (Rapport RIKILT 2002.001) - 16
    pesticidenresiduen - vloeistofchromatografie - massaspectrometrie - analytische methoden - pesticide residues - liquid chromatography - mass spectrometry - analytical methods
    Inventarisatie problematiek residuen van bestrijdingsmiddelen in dierlijke producten
    Kloet, D.G. ; Kleter, G.A. ; Traag, W.A. ; Noordam, M.Y. - \ 2002
    Wageningen : RIKILT (Rapport / RIKILT 2002.010) - 65
    pesticidenresiduen - dierlijke producten - monitoring - pesticide residues - animal products - monitoring
    Methodeontwikkeling voor de bepaling van polaire bestrijdingsmiddelen met behulp van vloeistofchromatografie-masssaspectrometrie (LC-MS) Fase 2 Initiërend onderzoek
    Rijk, T.C. de; Zomer, P. ; Traag, W.A. - \ 2002
    Wageningen : Rijks-Kwaliteitsinstituut voor land- en tuinbouwproducten (RIKILT) (Rapport RIKILT 2002.001) - 16 p.
    pesticide residues - liquid chromatography - mass spectrometry - analytical methods
    Literatuurstudie ten behoeve van de methodeontwikkeling voor de analyse van residuen van polaire en/of thermisch instabiele bestrijdingsmiddelen in vegetatie, voedingsmiddelen en daaraan gerelateerde matrices op laag niveau
    Blok-Tip, L. - \ 2001
    Wageningen : RIKILT (Rapport / RIKILT 2001.013) - 30
    pesticidenresiduen - hplc - vloeistofchromatografie - massaspectrometrie - literatuuroverzichten - analytische scheikunde - pesticide residues - hplc - liquid chromatography - mass spectrometry - literature reviews - analytical chemistry
    Onderzoek naar residuen van bestrijdingsmiddelen in nederwiet
    Traag, W.A. ; Gercek, H. ; Kloet, D. ; Wychgel, H.D. ; Faasen, I.S. ; Kerssemaker, R.P. - \ 2001
    Wageningen : RIKILT - 19
    pesticidenresiduen - furalaxyl - propamocarb - abamectine - parathion - drugsmisbruik - nederland - risicoschatting - pesticide residues - furalaxyl - propamocarb - abamectin - parathion - drug abuse - netherlands - risk assessment - propamocarp
    Rationeel onkruidbeheer op verhardingen
    Kempenaar, C. ; Boer, L. den; Beltman, W.J. ; Lotz, L.A.P. - \ 2001
    Gewasbescherming 32 (2001)4/5. - ISSN 0166-6495 - p. 106 - 107.
    onkruiden - bestrating - onkruidbestrijding op niet-akkerland - herbiciden - cost effective analysis - pesticidenresiduen - duurzaamheid (sustainability) - gewasbescherming - milieu - onkruidbestrijding - oppervlaktewater - waterkwaliteit - wegdek - weeds - pavements - non-crop weed control - herbicides - cost effectiveness analysis - pesticide residues - sustainability
    Verslag van een workshop over duurzaam onkruidbeheer op verhardingen. Belangrijkste thema's waren afspoeling van herbiciden en kosten-effectief onkruidbeheer
    Acute giftigheid en risico's voor kinderen actueel
    Kloet, D. - \ 2000
    Voedingsmiddelentechnologie 33 (2000)20. - ISSN 0042-7934 - p. 57 - 58.
    residuen - pesticidenresiduen - resteffecten - toxiciteit - nadelige gevolgen - toxische stoffen - kinderen - codex alimentarius - normen - voedingsmiddelen - gevaren - gezondheidsgevaren - residues - pesticide residues - residual effects - toxicity - adverse effects - toxic substances - children - codex alimentarius - standards - foods - hazards - health hazards
    Tijdens de vergaderingen van 1 tot en met 8 mei in Den Haag vormde de acue giftigheid en risico's voor kinderen een belangrijk onderwerp. Vooralsnog komen er geen strengere normen maar de berekeningsmethode voor acute giftigheid wordt verfijnd
    Average TMDI and the distribution of calculated theoretical pesticide intake in the Netherlands
    Dooren - Flipsen, M.M.H. van; Klaveren, J.D. van - \ 1999
    Wageningen : RIKILT-DLO (Report / DLO-state Institute for Quality Control of Agricultural Products (RIKILT-DLO) 99.003) - 25
    voedselbesmetting - pesticidenresiduen - nederland - food contamination - pesticide residues - netherlands
    Variations in the lethal body burdens of organophosphorus compounds in the guppy
    Deneer, J.W. ; Budde, B.J. ; Weijers, A. - \ 1999
    Chemosphere 38 (1999)7. - ISSN 0045-6535 - p. 1671 - 1683.
    cyprinidae - pesticidenresiduen - bioaccumulatie - ecotoxicologie - cyprinidae - pesticide residues - bioaccumulation - ecotoxicology
    Statistical instruments for dietary risk assessment concerning acute exposure to residues and contaminants
    Voet, H. van der; Boer, W.J. de; Keizer, L.C.P. - \ 1999
    Unknown Publisher
    voedselbesmetting - pesticidenresiduen - statistiek - risicoschatting - residuen - geneesmiddelenresiduen - food contamination - pesticide residues - statistics - risk assessment - residues - drug residues
    Effect of lindane on the clearance rate of Daphnia magna
    Hartgers, E.M. ; Heugens, E.W. ; Deneer, J.W. - \ 1999
    Archives of Environmental Contamination and Toxicology 36 (1999). - ISSN 0090-4341 - p. 399 - 404.
    pesticidenresiduen - insecticiden - oppervlaktewater - waterverontreiniging - ecotoxicologie - pesticide residues - insecticides - surface water - water pollution - ecotoxicology
    The impact of the insecticide lindane (%-hexachlorocyclohexane) on the clearance rate (CR) of Daphnia magna was investigated using artificial beads. CR (24-h EC50: 65 7g Lm1) was found to be a more sensitive endpoint than acute lethality for D. magna (48-h LC50: 516 7g Lm1). The onset of the effect was rapid; after 2 h of exposure to approximately 241 7g Lm1 of lindane a significant decrease in CR was observed. Daphnids recovered rapidly after transfer to clean water; after 24 h of exposure to approximately 250 7g Lm1 lindane, transfer into clean water resulted in recovery to 80% of control levels within 2 h and complete recovery within 24 h.
    Ecological and statistical evaluation of effects of pesticides in freshwater model ecosystems
    Brink, P.J. van den - \ 1999
    Agricultural University. Promotor(en): M. Scheffer; T.C.M. Brock; C.J.F. ter Braak. - S.l. : Van den Brink - ISBN 9789054859987 - 164
    ecosystemen - zoet water - verontreiniging - pesticiden - pesticidenresiduen - zoetwaterecologie - milieueffect - risicoschatting - habitats - modellen - herbiciden - fungiciden - insecticiden - waterinvertebraten - stress omstandigheden - aquatische ecosystemen - ecotoxicologie - ecosystems - fresh water - pollution - pesticides - pesticide residues - freshwater ecology - environmental impact - risk assessment - habitats - models - herbicides - fungicides - insecticides - aquatic invertebrates - stress conditions - aquatic ecosystems - ecotoxicology

    Aquatic risk assessment of pesticides

    The first tier in the aquatic risk assessment procedure consists of a comparison between a Predicted Environmental Concentration (PEC) with a No Effect Concentration (NEC). A requirement for registration is that the PEC should not exceed the NEC. The NEC is calculated from the toxicity of the pesticide for defined standard test species (viz. algae Daphnia , fish) and an assessment factor, which accounts for potential differences between standard test species and indigenous species. The assessment factors used are 100 (to be multiplied with the acute EC50 of Daphnia and fish) or 10 (to be multiplied with the chronic NOEC of fish or EC50 of algae). Because this approach lacks ecological realism, the first aim of the present thesis was to validate the assessment factors used in the first tier by evaluating three chemicals with different modes of action (insecticide, herbicide, fungicide) as benchmark compounds.

    We compared the No Observed Effect Concentrations (NOECs), resulting from microcosm and mesocosm experiments using these compounds, with the NECs as used for the risk assessment procedure. Table 1 summarises the standards calculated from the first tier criteria set by the Uniform Principles (UP-standard), as well as the NOEC ecosystem for acute and chronic exposure regimes for the three substances. In addition, Table 1 lists the Dutch water quality standards. The assessment factors seem to protect the tested aquatic ecosystem against acute and chronic exposure to the insecticide chlorpyrifos and against chronic exposure to the herbicide linuron and the fungicide carbendazim (Table 1; chapters 2, 3 and 4). Dutch water quality standards for these three compounds were lower than the UP-standards and thus also seem to protect the aquatic ecosystems tested when exposed to individual compounds.

    A comparison between the UP-standards and the Lowest Observed Effect Concentration at the ecosystem level (LOEC ecosystem ) indicates that when the NEC is exceeded by a factor of 10, effects cannot be excluded in the case of chronic exposure. In the case of a single application of the insecticide chlorpyrifos, however, the assessment factor can be considered overprotective; an assessment factor of 10 instead of 100 would also seem to suffice. Two extensive literature reviews on the impact of insecticides and herbicides on aquatic microcosms and mesocosms also demonstrate that the first tier criteria of the Uniform Principles are generally adequate to protect different aquatic ecosystems from pesticide stress (Lahr et al., 1998; Van Wijngaarden et al., 1998). For compounds such as fungicides, however, hardly any information could be found in the open literature, so that validation of the assessment factors for these types of pesticide needs further attention.

    Table 1:Derived UP-standards, Dutch water quality standards and NOEC ecosystem observed in semi-field studies for the insecticide chlorpyrifos, the herbicide linuron and the fungicide carbendazim (all concentrations in µg/L). UP-standards were calculated from criteria set by the first tier of aquatic risk assessment. For references to toxicity values see Table 3 in chapter 1 of this thesis.
    UP-standardDutch water quality standardNOEC ecosystem / LOEC ecosystem
    Short-termLong-termAcute exposureChronic exposure
    Chlorpyrifos0.01 a0.01 c0.0030.1 / 0.9 (Chapter 2)0.01 d/ 0.1 e
    Linuron0.6 b*0.6 b*0.25- / -0.5 / 5 (Chapter 3)
    Carbendazim3.2 a1 c0.11- / -3.3 / 33 (Chapter 4)
    * Dutch standard would be 0.1 µg/L (0.1 x NOEC of the standard test algae; Anonymous, 1995); - No data available; a: 0.01 × LC50 Daphnia ; b: 0.1 × EC50 Algae; c: 0.1 × NOEC Daphnia; d: data from unpublished experiment, Van den Brink et al., in prep.; e: data from Van den Brink et al., 1995.

    Ecological effects and recovery

    One of the aims of the present thesis was to gain insight into long-term community responses and into the factors determining the recovery of affected populations after a single application of an insecticide in experimental ditches. As was expected from its mode of action, application of chlorpyrifos resulted in large adverse effects on arthropod taxa (chapter 2). Because this experiment was performed in relatively large, outdoor systems, the recovery of the affected populations could be investigated. The recovery of populations of individual species was highly dependent on their life-cycle characteristics, such as the number of generations per year, the presence of resistant life stages and the ability to migrate from one system to another. In chapter 2 this is illustrated by the responses of two mayflies, cladocerans and an amphipod. The mayflies Cloeon dipterum and Caenis horaria do not have life stages resistant to chlorpyrifos, but are able to migrate from one ditch to another. They are also almost equally susceptible to chlorpyrifos in the laboratory but showed a very different recovery pattern.

    The former species recovered within 12 weeks at the highest treatment level, whereas the latter species took 24 weeks to recover fully. This can be explained from the difference in the number of generations per year. C. dipterum has many generations per year and thus recolonises the ditch repeatedly, thus recovering as soon as the concentration of chlorpyrifos allows this. C. horaria , however, produces only one generation per year, so that recovery can only take place when the next generation recolonises the ditch. Unlike mayflies, Cladocerans are not able to migrate actively from one ditch to the other. They did, however, show a very fast recovery at the higher concentration (Chapter 2). This is possible because they have a short generation time and resistant life stages in the form of ephyppia. If a taxon is not able to recolonise an impacted system and does not have resistant life stages, the species can become extinct in isolated systems like the experimental ditches. This applies for the amphipod Gammarus pulex , which became extinct at the two highest concentrations and did not recover within the 55 week experimental period. No significant effects on the invertebrate community, with the exception of Gammarus, were found from week 24 after insecticide application onwards, suggesting recovery.

    As part of the third aim of the thesis, the long-term responses in ecosystem structure and functioning after chronic exposure to a herbicide and fungicide were studied in aquatic microcosms. The higher concentration of the photosynthesis-inhibiting herbicide linuron resulted in a decreased biomass of the macrophyte Elodea nuttallii and decreased abundance of most algal taxa (chapter 3). The dissolved oxygen and pH levels also decreased at lower pesticide concentrations as a consequence of inhibited photosynthesis. Although a decrease in the abundance of most algal taxa was observed after to the herbicide application, a net increase in chlorophyll-a was found for the phytoplankton, periphyton and neuston. This increase was completely caused by the green alga Chlamydomonas sp., which appeared to be relatively tolerant to linuron and also had the ability to develop a tolerance to relatively high concentrations within a week. As a result of this tolerance and the reduced competition for nutrients with macrophytes, the community in the microcosms shifted from macrophyte-dominated to an algae-dominated state, especially at the highest treatment level (150 µg/L). The Copepoda and Cladocera benefited from this increased food supply and showed elevated abundance values at the higher treatment levels. Some macrophyte-associated invertebrates decreased in abundance as a result of the decline of their habitat.

    The fungicide carbendazim, which belongs to the bendimidazoles, is known to adversely affect microorganisms and worms. This property explains its effects on the "worm-like" taxa of the Turbellaria and Oligochaeta, but could not explain its effects on invertebrate groups like Amphipoda, Gastropoda and Cladocera (chapter 4). Unlike the direct effects of chlorpyrifos and linuron, therefore those of carbendazim on freshwater populations could not be completely deduced from the latter's taxonomic relation with the pest organisms, carbendazim it is supposed to control. The fungicide appeared to have the mode of action of a biocide rather than a chemical with a specific mode of action. Due to the decline of many invertebrates and the concomitant reduction in grazing pressure, the chlorophyll-a level and the abundance values of some phytoplankton taxa increased at the two highest concentrations (330 and 1000 µg/L).

    The "eutrophication-like" consequences of insecticide contamination have also often been reported and discussed in the literature (e.g. DeNoyelles et al., 1994, Cuppen et al., 1995). The increased abundance of algae due to a decrease in susceptible herbivores is a commonly reported consequence of insecticide contamination (Van Wijngaarden et al., 1998).

    In the present thesis, the occurrence of herbicides in the aquatic ecosystem is regarded as an undesirable side effect of its use on land. However, herbicides are also deliberately released into aquatic ecosystems for the control of nuisance aquatic vegetation (Pieterse and Murphy, 1990). Aquatic weeds are most commonly removed using compounds with a mode of action specific to macrophytes. Since algae are relatively tolerant to these chemicals (Lahr et al., 1998), they may increase their biomass due to reduced competition for nutrients (Kobriae and Whyte, 1996). Terrestrial weeds are, in the Netherlands, usually controlled by means of photosynthesis-inhibiting herbicides (NEFYTO, 1996). Although their mechanism is different, chapter 3 shows that prolonged exposure to the photosynthesis-inhibiting herbicide linuron may also result in a shift from macrophyte dominance to plankton dominance. The review published by Lahr et al. (1998) shows that this may be true for photosynthesis-inhibiting herbicides in general.

    The effects of fungicides are largely unstudied, but chapter 4 indicates that fungicide contamination can also cause elevated algal densities. This means that all three pesticides can contribute to "eutrophication-like" effects, though the mechanisms differ. The significance of realistic concentrations of pesticides in causing symptoms of eutrophication in surface waters, however, largely remains to be investigated.

    Tools to evaluate microcosm and mesocosm experiments

    Semi-field experiments are usually evaluated at the taxon level. Since many species normally have low abundance values and/or show high variability (Van Wijngaarden et al., 1996), this approach has the great disadvantage that only a limited number of species can be properly analysed. This means that a substantial part of the information gathered is not used for the evaluation. This thesis presents a new multivariate tool for the analysis of treatment effects at the community level. Multivariate techniques have already been used for a long time in ecology to analyse the relation between communities and their environment. The most commonly used ordination technique is correspondence analysis, which is based on the bell-shaped unimodal model. This model fits in with the theory of the rise and fall in a preference of a species along an environmental gradient, described by their optimum and tolerance.

    Chapter 7 indicates why clustering and ordination based on correspondence analysis are not suitable for the analysis of the ecotoxicological data sets presented in this thesis. It argues that species normally have no optimum along the environmental axis of a stressor such as pesticides. Their response is more accurately described by a linear method; expected direct effects will increase with the concentration. On the basis of laboratory tests, this relation between the endpoint and the concentration of stressor is assumed to be sigmoid, and it is argued that a linear response model is a good approximation of this.

    Chapters 2 and 3 use Redundancy Analysis (RDA) to elucidate the effects of pesticides at the community level. RDA is the constrained version of the well-known ordination technique Principal Component Analysis (PCA) and is based on a linear response model (Jongman et al., 1995). In chapters 2 and 3 the analysis is constrained to the variance explained by treatment, time and their interaction. It was concluded that RDA successfully summarised the effects of a pesticide on a community in a single diagram, and is very useful especially when combined with Monte Carlo permutation tests for the determination of the significance of treatment effects. Kersting and Van den Brink (1997), however, found that output from RDA can sometimes result in very cluttered diagrams.

    Chapter 5 presents a new method, termed the Principal Response Curves, which overcomes this problem. PRC is based on RDA and extracts the first principal component from the treatment variance, by excluding from the analysis the variance explained by time as well as differences between replicates. It results in an easy-to-read diagram, showing the deviations of all treatments from the control in time. In contrast to most other techniques, it also allows a quantitative interpretation down to the species level. Chapter 6 introduces the rank 2 model of PRC, this means that after the extraction of the first basic response pattern, a second pattern is extracted, which expresses the most important deviation from the first response present in the data set. The second pattern is of particular importance if no single dominant response pattern is present in a data set but several sub-dominant ones occur. In chapter 6 this is illustrated by an analysis of the invertebrate and phytoplankton data sets of a microcosm experiment with two stressors, the insecticide chlorpyrifos and nutrient additions. This example shows that PRC is also able to summarise several different response patterns in two diagrams.

    Microcosm and mesocosm experiments are often said to be of limited value due to ecological variability and noise. From the experiments and statistical tools as described in this thesis we can conclude that despite the noise clear response patterns are revealed, if experiments are properly designed and analysed. Chapters 2, 3 and 4 illustrate that, even with a limited number of replicates, an ecological threshold level (e.g. NOEC ecosystem ) and an effect-chain covering different trophic levels can be obtained.

    Suggestions for future research

    In normal agricultural practice, protection of crops from pest organisms is not achieved by the application of a single compound; usually, several different compounds with different target organisms are used. Some pesticides are also administered repeatedly. The effects of combinations of pesticides on freshwater ecosystems are, however, largely unstudied (Hartgers et al., 1998). Therefore, it is important to develop criteria for the ecological risk assessment of mixtures of compounds, using realistic pesticide treatment regimes for particular crops.

    The problem of combination toxicity becomes even more complex when other substances used in agricultural areas, such as fertilisers, are taken into account. The combined effects of eutrophication and contaminant stress are largely unknown. It can be expected, however, that the trophic status of an ecosystem will alter the effects of pesticides (Chapter 6; Kramer et al., 1997).

    The ecological effect chain resulting from the experiments with the herbicide linuron and fungicide carbendazim demonstrated that microcosm and mesocosm experiments with pesticides as stressors can be very useful tools to investigate trophic interactions in aquatic ecosystems. The results of these experiments are currently being used to build a food-web model (Traas et al., 1998). Such models are considered to hold great promise for an improved understanding of ecosystem functioning and may eventually provide the ability to predict effects of contaminants at ecosystem level (Health Council of the Netherlands, 1997). The greatest obstacles that have to be overcome are the lack of solid data on parameter values (data on for instance maximum growth rate) and the lack of validation. This means that the further development of food web models require not only laboratory research on parameters values but also semi-field research for the collection of validation data sets (Health Council of the Netherlands, 1997).

    The modeling of direct effects and recovery patterns at the population level can be of great use for an assessment of the risks and a ranking of the effects of pesticides. For the future, modeling treatment effects and recovery patterns may be of great value as a research tool but also as a predictive tool. Models have the advantage that they allow integration of ecological and ecotoxicological knowledge, something that was largely absent from ecotoxicology until a few years ago. Development of these models will allow to a better evaluation of microcosm and mesocosm experiments performed for scientific or registration purposes.

    Resultaten onderzoek organochloorbestrijdingsmiddelen, chloorbifenylen en zware metalen in organen en vetten : jaaroverzicht 1997 (Nationaal plan hormonen en overige stoffen en concept nationaal plan pluimvee)
    Roos, A.H. ; Kamp, H.J. van der; Oostrom, J.J. van - \ 1998
    Wageningen : RIKILT-DLO (Rapport / DLO-Rijks-Kwaliteitsinstituut voor Land- en Tuinbouwprodukten 98.009) - 9
    dierlijk vet - gechloreerde koolwaterstofpesticiden - zware metalen - polychloorbifenylen - pesticidenresiduen - animal fat - organochlorine pesticides - heavy metals - polychlorinated biphenyls - pesticide residues
    PEsticide Leaching and Accumulation model (PESTLA) version 3.4 : description and user's guide
    Berg, F. van den; Boesten, J.J.T.I. - \ 1998
    Wageningen : DLO-Staring Centrum (Technisch document / DLO-Staring Centrum 43) - 150
    uitspoelen - pesticidenresiduen - bodem - modellen - leaching - pesticide residues - soil - models
    A food web model for fate and direct and indirect effects of Dursban#R 4E (active ingredient chlorpyrifos) in freshwater microcosms
    Traas, T.P. ; Janse, J.H. ; Aldenberg, T. ; Brock, T.C.M. - \ 1998
    Aquatic Ecology 32 (1998)2. - ISSN 1386-2588 - p. 179 - 190.
    ecologie - voedselketens - pesticiden - pesticidenresiduen - modellen - plankton - ecotoxicologie - aquatische ecosystemen - ecology - food chains - pesticides - pesticide residues - models - plankton - ecotoxicology - aquatic ecosystems
    Drift naar sloten bij spuittechnieken in de sierteelten in de regio Boskoop
    Smidt, R.A. ; Smelt, J.H. ; Looman, B.H.M. ; Boom, A.P.C. van den; Langedijk, R.P.J. - \ 1998
    Wageningen : DLO-Staring Centrum - 58
    houtachtige planten als sierplanten - gewasbescherming - pesticiden - pesticidenresiduen - persistentie - lucht - hygiëne - luchtverontreiniging - rivieren - waterlopen - kanalen - water - oppervlaktewater - waterverontreiniging - waterkwaliteit - nederland - zuid-holland - ornamental woody plants - plant protection - pesticides - pesticide residues - persistence - air - hygiene - air pollution - rivers - streams - canals - water - surface water - water pollution - water quality - netherlands - zuid-holland
    Multivariate technieken voor de analyse van toxische stress op levensgemeenschappen in experimentele ecosystemen
    Brink, P.J. van den; Braak, C.J.F. ter - \ 1998
    In: Methoden voor de analyse van effecten van toxische stoffen in veldsituaties : verslag van de SAVE-workshop, Bilthoven, 10 maart 1998 / Lahr, J., Wageningen : IBN-DLO (SAVE - document 1998-1) - p. 6 - 11.
    ecosystemen - herbiciden - pesticidenresiduen - multivariate analyse - ecotoxicologie - aquatische ecosystemen - ecosystems - herbicides - pesticide residues - multivariate analysis - ecotoxicology - aquatic ecosystems
    Praktijkproef emissiebeperking bestrijdingsmiddelen in Zeeland; eindrapport van het proefgebied Aagtekerke op Walcheren en de Herdijkte Zwarte Polder in West-Zeeuws Vlaanderen in de provincie Zeeland
    Deneer, J.W. ; Merkelbach, R.C.M. - \ 1998
    Wageningen : DLO-Staring Centrum - 63
    gewasbescherming - pesticiden - pesticidenresiduen - persistentie - rivieren - waterlopen - kanalen - water - oppervlaktewater - waterverontreiniging - waterkwaliteit - statistiek - nederland - zeeland - zeeuws-vlaanderen - plant protection - pesticides - pesticide residues - persistence - rivers - streams - canals - water - surface water - water pollution - water quality - statistics - netherlands - zeeland - zeeuws-vlaanderen
    Ecologische risico's van bestrijdingsmiddelen in zoetwater ecosystemen. Deel 1: Herbiciden
    Lahr, J. ; Brink, P.J. van den; Brock, T.C.M. - \ 1998
    Utrecht : Stowa (STOWA 98-30) - ISBN 9789057730429 - 121
    waterverontreiniging - pesticidenresiduen - herbiciden - normen - aquatische ecosystemen - water pollution - pesticide residues - herbicides - standards - aquatic ecosystems
    Sensitivity analysis of the TOXSWA model simulating fate of pesticides in surface waters
    Westein, E. ; Jansen, M.J.W. ; Adriaanse, P.I. ; Beltman, W.H.J. - \ 1998
    Wageningen : DLO Winand Staring Centre - 119
    oppervlaktewater - waterwegen - pesticiden - sloten - monte carlo-methode - kalibratie - blootstelling - schade - pesticidenresiduen - variantie-analyse - surface water - waterways - pesticides - ditches - monte carlo method - calibration - exposure - damage - pesticide residues - analysis of variance
    The TOXSWA model calculates the acute exposure concentration and the average exposure concentrations (AECs) of pesticides in ditches after 4, 21 and 28 days. In a (global) sensitivity analysis based on the Monte Carlo method the most sensitive processparameters (pesticide properties) and the most sensitive system parameters (e.g. ditch dimensions) with respect to AECs were determined. The process parametes "transformation rate in the water layer", "coefficient for sorption to macrophytes" and "Henry coefficient" were identified as contributing most to the varation in the AECs. The full range of pesticides was characterized by these three parameters and subsequently the flow velocity, water depth and dry weight of macrophyutes were identified sas sensitive system parameters with respect to the AECs. Analytically, the water depth, bottom width of the ditch and the sorption coefficients for sorption to macrophytes and suspended solids were identified as sensitive parameters with respect to the acute exposure concentration.
    Application of the pesticide transport assessment model to a field study in a humic sandy soil in Vredepeel, the Netherlands
    Tiktak, A. ; Linden, A.M.A. van der; Pas, L.J.T. van der - \ 1998
    Pesticide science : a journal of international research and technology on crop protection and pest control 52 (1998)4. - ISSN 0031-613X - p. 321 - 336.
    bodem - uitspoelen - gewasbescherming - pesticiden - pesticidenresiduen - persistentie - zandgronden - modellen - onderzoek - noord-brabant - de peel - soil - leaching - plant protection - pesticides - pesticide residues - persistence - sandy soils - models - research - noord-brabant - de peel
    Risk analysis in relation to exposure of children to pesticide residues
    Kloet, D.G. ; Dooren, M.M.H. van; Klaveren, J.D. van - \ 1998
    Wageningen : RIKILT-DLO - 50
    gewasbescherming - pesticiden - pesticidenresiduen - persistentie - voedingswaarde - voedsel - voedingsmiddelen - voedselsamenstelling - kwaliteit - eigenschappen - kinderen - zuigelingen - risicoschatting - plant protection - pesticides - pesticide residues - persistence - nutritive value - food - foods - food composition - quality - properties - children - infants - risk assessment
    Voorlopig advies voor inrichting en beheer van de spuit- en teeltvrije zone in de bloembollenteelt
    Tamis, W.L.M. ; Aartrijk, J. van - \ 1997
    Lisse etc. : Laboratorium voor Bloembollenonderzoek [etc.] (Rapport bloembollenonderzoek nr. 112) - ISBN 9789051911091 - 51
    bloembollen - milieubescherming - milieubeheer - milieu - kwaliteit - gewasbescherming - plagenbestrijding - ziektebestrijding - pesticiden - pesticidenresiduen - persistentie - overheidsbeleid - milieubeleid - milieuwetgeving - luchtverontreiniging - bodemverontreiniging - waterverontreiniging - rapporten - nederland - ornamental bulbs - environmental protection - environmental management - environment - quality - plant protection - pest control - disease control - pesticides - pesticide residues - persistence - government policy - environmental policy - environmental legislation - air pollution - soil pollution - water pollution - reports - netherlands
    Overwaaien, atmosferische depositie en afspoelen van bestrijdingsmiddelen in de akkerbouw en groenteteelt op kleigrond
    Pas, L.J.T. van der; Geus - van der Eijk, J.G. de; Leistra, M. - \ 1997
    Wageningen : DLO-Staring Centrum (Rapport / DLO-Staring Centrum 506) - 63
    lucht - luchtverontreiniging - akkerbouw - kanalen - zware kleigronden - veldgewassen - hygiëne - uitspoelen - nederland - persistentie - pesticidenresiduen - pesticiden - gewasbescherming - rivieren - bodem - waterlopen - oppervlaktewater - water - waterverontreiniging - waterkwaliteit - vollegrondsteelt - air - air pollution - arable farming - canals - clay soils - field crops - hygiene - leaching - netherlands - persistence - pesticide residues - pesticides - plant protection - rivers - soil - streams - surface water - water - water pollution - water quality - outdoor cropping
    De omvang van enkele bovengrondse emissieroutes voor bestrijdingsmiddelen naar waterlopen bij lage vollegrondsteelten is onderzocht. Het overwaaien van spuitvloeistof bij de toediening leidt veelal tot grote overschrijding van de ecotoxicologische norm en van de norm voor oppervlaktewater bestemd voor de drinkwaterbereiding. De 90e-percentielwaarden voor bestrijdingsmiddelen in de neerslag liggen veelal wat boven de drinkwaternorm van 0,1 Šg/l. Het onderzoek naar de afspoeling over het bodemoppervlakdient te worden voortgezet voor gevoelige situaties (bodem, neerslag), omdat de betrokken bestrijdingsmiddelconcentraties hoog kunnen zijn.
    Oorzaken van de verschillen in berekende en gemeten concentraties van bestrijdingsmiddelen in drainagewater van kasgronden
    Leistra, M. ; Berg, F. van den; Boesten, J.J.T.I. - \ 1997
    Wageningen : DLO-Staring Centrum (Rapport / DLO-Staring Centrum 566) - 47
    gewasbescherming - pesticiden - pesticidenresiduen - persistentie - bodem - uitspoelen - rivieren - waterlopen - kanalen - water - oppervlaktewater - waterverontreiniging - waterkwaliteit - glastuinbouw - plant protection - pesticides - pesticide residues - persistence - soil - leaching - rivers - streams - canals - water - surface water - water pollution - water quality - greenhouse horticulture
    Estimation method for the volatilization of pesticides from fallow soil
    Smit, A.A.M.F.R. ; Berg, F. van den; Leistra, M. - \ 1997
    Wageningen : DLO Winand Staring Centre (Environmental Planning Bureau series 2) - 107
    bodemchemie - luchtverontreiniging - pesticiden - pesticidenresiduen - persistentie - vervluchtiging - soil chemistry - air pollution - pesticides - pesticide residues - persistence - volatilization
    Uitspoeling van nutrienten en bestrijdingsmiddelen vanuit de akkerbouw en groenteteelt op kleigrond naar grondwater en waterlopen
    Geus - van der Eijk, J.G. de; Pas, L.J.T. van der; Leistra, M. ; Matser, A.M. ; Roelsma, J. - \ 1997
    Wageningen : DLO-Staring Centrum (Rapport / DLO-Staring Centrum 556) - 69
    bodem - uitspoelen - nitraten - gewasbescherming - pesticiden - pesticidenresiduen - persistentie - rivieren - waterlopen - kanalen - water - oppervlaktewater - waterverontreiniging - waterkwaliteit - nederland - zuid-holland - zuidhollandse eilanden - soil - leaching - nitrates - plant protection - pesticides - pesticide residues - persistence - rivers - streams - canals - water - surface water - water pollution - water quality - netherlands - zuid-holland - zuidhollandse eilanden
    Extractie- en opwerkingsmethoden voor bestrijdingsmiddelen in water, grond en waterbodem : voorstudie voor normalisatie van meetmethoden
    Harmsen, J. ; Berg, H. van den - \ 1997
    Wageningen : DLO-Staring Centrum (Rapport / DLO-Staring Centrum 530) - 51
    chemische analyse - analytische methoden - water - bepaling - verontreinigende stoffen - pesticiden - pesticidenresiduen - persistentie - grondanalyse - kwantitatieve technieken - kwaliteitsnormen - waterbodems - chemical analysis - analytical methods - water - determination - pollutants - pesticides - pesticide residues - persistence - soil analysis - quantitative techniques - quality standards - water bottoms
    Persistence and toxicological effects of pesticides in topsoil: use of the equilibrium partitioning theory
    Ronday, R. ; Kammen-Polman, A.M.M. van; Dekker, A. ; Houx, N.W.H. ; Leistra, M. - \ 1997
    Environmental Toxicology and Chemistry 16 (1997)4. - ISSN 0730-7268 - p. 601 - 607.
    persistentie - pesticidenresiduen - pesticiden - fysicochemische eigenschappen - gewasbescherming - bodemchemie - bodemeigenschappen - bioaccumulatie - ecotoxicologie - persistence - pesticide residues - pesticides - physicochemical properties - plant protection - soil chemistry - soil properties - bioaccumulation - ecotoxicology
    The springtail Folsomia candida was exposed to the insecticide parathion in loamy, sandy and peaty soils. The dose-response relationships were measured and used to calculate the 50%-effect (EC50) values. The toxicity of parathion in the three soils could be explained from its bio-availability, as a result of adsorption and transformation. In soil, bio-availability decreased faster than pesticide content, due to continued shift to stronger adsorption. A first estimate of pesticide effect on soil organisms can be obtained by combining water-only toxicity values with measurements/calculations of the concentration in soil solution.
    Ontwikkeling van het prototype instrumentarium PEGASUS; pesticide emmission to groundwater and surface waters
    Kruijne, R. ; Merkelbach, R.C.M. - \ 1997
    Wageningen : DLO-Staring Centrum (Reeks Milieuplanbureau 1) - 45
    gewasbescherming - pesticiden - pesticidenresiduen - persistentie - bodem - uitspoelen - rivieren - waterlopen - kanalen - water - oppervlaktewater - waterverontreiniging - waterkwaliteit - hydrologie - modellen - analogen - Nederland - plant protection - pesticides - pesticide residues - persistence - soil - leaching - rivers - streams - canals - water - surface water - water pollution - water quality - hydrology - models - analogues - Netherlands
    A proposed policy for differentiated hazard evaluation of pesticides in surface waters; exposure concentrations simulated by TOXSWA and ecotoxicological hazards of pesticides in field ditches and main watercourses
    Adriaanse, P.I. ; Beltman, W.H.J. ; Westein, E. ; Brouwer, W.W.M. ; Nierop, S. van - \ 1997
    Wageningen : DLO Winand Staring Centre - 302
    toxicologie - chemicaliën - rivieren - waterlopen - kanalen - water - oppervlaktewater - waterverontreiniging - waterkwaliteit - gewasbescherming - pesticiden - pesticidenresiduen - persistentie - overheidsbeleid - milieubeleid - milieuwetgeving - luchtverontreiniging - bodemverontreiniging - nederland - toxicology - chemicals - rivers - streams - canals - water - surface water - water pollution - water quality - plant protection - pesticides - pesticide residues - persistence - government policy - environmental policy - environmental legislation - air pollution - soil pollution - netherlands
    Exposure assessment of pesticides in field ditches: the TOXSWA model
    Adriaanse, P.I. - \ 1997
    Pesticide science : a journal of international research and technology on crop protection and pest control 49 (1997)2. - ISSN 0031-613X - p. 210 - 212.
    chemicaliën - sloten - drainage - modellen - persistentie - pesticidenresiduen - pesticiden - gewasbescherming - onderzoek - toxicologie - chemicals - ditches - drainage - models - persistence - pesticide residues - pesticides - plant protection - research - toxicology
    Volatilization of fenpropimorph and clopyralid after spraying onto a sugar beet crop
    Smelt, J.H. ; Smidt, R.A. ; Berg, F. van den; Matser, A.M. ; Stork, A. ; Ophoff, H. - \ 1997
    Wageningen : DLO Winand Staring Centre - 45
    pesticidenresiduen - spuiten - beta vulgaris - suikerbieten - clopyralid - fenpropimorf - vervluchtiging - pesticide residues - spraying - beta vulgaris - sugarbeet - clopyralid - fenpropimorph - volatilization
    Volatilization rates of pesticides were measured with two micrometeorological methods. For fenpropimorph, the highest rates (1.3-3.0% per hour) were measured in the first hours after application. The rate gradually declined to less than 0.01% per houron the sixth day. Clopyralid had much lower volatilization rates. They were highest (0.1% per hour) on the day after the day of application and declined below the detection limit (less than 0.01% per hour) on the sixth day after application. Rates calculated with the aerodynamic method were slightly higher than those calculated with the Bowen ratio.
    Landelijk meetnet bodemkwaliteit; resultaten 1994
    (RIVM) Groot, M.S.M. ; (RIVM) Bronswijk, J.J.B. ; (RIVM) Willems, W.J. ; Haan, T. de; (AB-DLO) del Castilho, P. - \ 1997
    Bilthoven : RIVM - 151
    bodem - zware metalen - bodemverontreiniging - gezondheid - polycyclische koolwaterstoffen - aromatische koolwaterstoffen - gewasbescherming - pesticiden - pesticidenresiduen - persistentie - grondanalyse - nederland - soil - heavy metals - soil pollution - health - polycyclic hydrocarbons - aromatic hydrocarbons - plant protection - pesticides - pesticide residues - persistence - soil analysis - netherlands
    Het Landelijk Meetnet Bodemkwaliteit (LMB) heeft als primaire doelstelling de trendmatige veranderingen na te gaan in de kwaliteit van de bodem ten gevolge van diffuse belasting van de bodem. Het object van onderzoek is de toplaag van de bodem (0-10 cm); daarnaast wordt ook een diepere bodemlaag en het bovenste grondwater onderzocht. Het LMB wordt in samenwerking met LEI-DLO en AB-DLO uitgevoerd. Jaarlijks worden een 2-tal combinaties van bodemgebruik en grondsoort bemonsterd, bestaande uit ca. 20 locaties per combinatie. In 1993 is gestart met de bemonstering van landbouwgrond op zandgrond. Voor het bodemgebruik landbouw is het bedrijf de schaal van de locatie. De categorieen die in 1994 zijn onderzocht, zijn melkveehouderijbedrijven met een groot aandeel intensieve veehouderij op zandgrond en bos op zandgrond. Naast algemene kwaliteitsparameters zijn parameters onderzocht die gerelateerd zijn aan de milieuthema's vermesting en verspreiding. Vermestingsparameters zijn fosfaat (bodem en grondwater) , nitraat, kalium en ammonium (grondwater). Voor verspreiding zijn zware metalen onderzocht (bodem en grondwater). Voorts zijn bodemgehalten aan PAK en een aantal organochloorbestrijdingsmiddelen (OCB) bepaald.
    Simulation and model comparison of unsaturated movement of pesticides from a large clay lysimeter.
    Vink, J.P.M. ; Gottesbüren, B. ; Diekkrüger, B. ; Zee, S.E.A.T.M. van der - \ 1997
    Ecological Modelling 105 (1997). - ISSN 0304-3800 - p. 113 - 127.
    gewasbescherming - pesticiden - pesticidenresiduen - persistentie - infiltratie - hydraulisch geleidingsvermogen - kwel - zware kleigronden - modellen - onderzoek - plant protection - pesticides - pesticide residues - persistence - infiltration - hydraulic conductivity - seepage - clay soils - models - research
    A long-term (>10 months) leaching experiment was conducted with a large clay soil column and a rain simulator to study unsaturated transport of the nematicide aldicarb and the herbicide simazine in a cracked clay soil. Water retention and soil conductivity were derived from experimental outflow data and deterministic parameter estimation techniques. Under conventional application rates and realistic rain events, aldicarb's aerobic metabolites were found in very high concentrations, and did not meet the normal EC levels for water during the entire measuring period. A mass balance for aldicarb showed that 0.35% of the initial dose was leached. However, when the two isosteric metabolites aldicarb-sulfoxide and aldicarb-sulfone were included in the mass balance, this percentage increased dramatically to 19.7%. Simazine was found in relatively low concentrations of 0.05-0.6 g/l, and only 0.11% of the initial dose was leached over 280 days. The absence of a `breakthrough behaviour' (peak exposure) implies long term delivery (chronic exposure) of the compound from the soil. The predictive performances of the widely used pesticide leaching models VARLEACH, LEACHP, MACRO, PESTLA and SIMULAT, which differ in their basic concepts for calculating water and solute transport and pesticide behaviour, were compared. This ring test revealed that none of the models were able to describe both water percolation and pesticide leaching to a completely satisfying degree. Moreover, there is little agreement on maximum pesticide concentrations and the time period in which these occur. This conclusion seriously limits the possibilities of model application and conducting reliable risk assessments for pesticides which are applied on the studied, or similar type of clay soils.
    Microbial transformation of highly persistent chlorinated pesticides and industrial chemicals
    Middeldorp, P.J.M. - \ 1997
    Agricultural University. Promotor(en): A.J.B. Zehnder; G. Schraa. - S.l. : Middeldorp - ISBN 9789054856429 - 114
    microbiële afbraak - gewasbescherming - pesticidenresiduen - chemische industrie - persistente organische verontreinigende stoffen - microbial degradation - plant protection - pesticide residues - chemical industry - persistent organic pollutants

    Organic pollutants can be transformed, both in unsaturated and saturated areas of the soil, by means of biologically mediated reactions. The potential of soil microorganisms to clean up polluted soils is enormous. However, soil systems are highly heterogeneous with respect to the spatial distribution of substrates, nutrients and microorganisms, and also with respect to various phases and interfaces (e.g. water, air, minerals, organic matter). To come to the development of appropriate soil bioremediation techniques, comprehensive knowledge is required about the biological and physico- chemical processes and parameters that determine the rate, the nature and the degree of degradation of organic compounds within a certain time scale in soil. The most important processes and parameters that influence the behavior of pollutants in soil are shown in Figure 7.1.

    Several aspects, which may arise when assessing the application of microorganisms in soil remediation. techniques, have been studied in this thesis.

    A major part of this thesis concerns the environmental conditions, that are essential for biodegradation. The biodegradability of a pollutant depends not only on the molecular structure of this pollutant, but also on the occurrence of the appropriate enviromnental conditions. The biodegradation of many enviromnental pollutants has been studied primarily under aerobic conditions, since these conditions are prevailing in polluted locations and easy to maintain. However, the anaerobic degradation of pollutants forms a relatively new potential of interesting reactions, which may be used for bioremediation purposes.

    For instance, β-hexachlorocyclohexane (β-HCH), a waste product from the production of the pesticide lindane, is considered extremely recalcitrant under aerobic conditions.

    This may be due to the spatial arrangement of the chlorine atoms in this HCH isomer. Disappearance of β-HCH under anaerobic conditions has been reported, but product identifications and mass balances were lacking in these studies. In Chapter 2, the biodegradation of β-HCH under anaerobic conditions is described. It is shown that β-HCH can be dechlorinated under methanogenic conditions. The observed dechlorination products of β-HCH, benzene and chlorobenzene, have individually been found for the anaerobic biodegradation of γ-HCH, but they were never reported to be formed simultaneously from any HCH isomer by microorganisms.

    The dechlorination products of β-HCH, benzene and chlorobenzene, accumulate under the conditions studied. The formation of these products, which are potentially toxic, introduces a new problem since chlorobenzene is recalcitrant under methanogenic conditions and anaerobic benzene degradation has been observed in only a few cases. However, many studies have shown that these compounds are degradable in the presence of molecular oxygen. Therefore a bioremediation process in which subsequently anaerobic and aerobic conditions are created would lead to a total mineralization of β-HCH.

    Such a sequential change from anaerobic to aerobic conditions also applies to the decontamination of soils polluted with polychlorinated benzenes (CBs) and biphenyls (PCBs). These compounds, when substituted with five or more chlorine atoms, generally persist under aerobic conditions. However, anaerobic reductive dechlorination of these compounds has abundantly been shown. The products of this dechlorination process are important for several reasons. From a toxicological point of view, because ortho -chlorinated PCBs are considered 10-100 times less toxic than non ortho -chlorinated ones (coplanar PCBs), but also from a biotechnological point of view, since the dechlorination products are the substrates in an eventually following aerobic treatment. Microbial reductive dechlorination of PCBs is mainly limited to meta - and para -dechlorination, and therefore reduces the toxicity of the PCBs. Dechlorination of CBs and PCBs also increases the water solubility and therefore the mobility of these compounds in the soil. This may be advantageous in the case of an ex situ bioremediation. However, since this process has been shown to occur in undisturbed polluted sediment and will also occur in biological soil treatments in situ , one should prevent the pollutant to move away from the polluted site.

    The dechlorination of CBs and PCBs is carried out by different groups of microorganisms, originating from different locations. Chapter 3 describes the dechlorination of these compounds in a methanogenic consortium, enriched from a mixture of Polluted sediments on 1,2,4-trichlorobenzene (TCB). CBs appear to be extensively dechlorinated by this consortium, with 1,2- and 1,3-dichlorobenzene (DCB) as well as chlorobenzene as the final products. This is in contrast with the performance of previously reported enrichments, which have been obtained mainly using hexa- and pentachlorobenzene as substrates for dechlorination. Such cultures show a lesser extent of dechlorination and produce 1,3,5-TCB or 1,3-TCB as final products, which are problematic compounds for an eventually following aerobic mineralization. Chapter 3 also shows that, whereas mono- through pentachlorobenzenes are dechlorinated within 2 days, hexachlorobenzene (HCB) and several PCBs are dechlorinated after a lag phase of about two weeks. Dechlorination of the latter compounds occurs via a different pathway, in which only chlorines with two adjacent chlorines are removed. Chapter 3 also shows that dechlorination of highly chlorinated benzenes can be directed to the formation of chlorobenzene as the only product by the addition of 2-bromoethanesulfonic acid (BrES), a methanogenic inhibitor. These observations show that different dechlorinating activities are present in the consortium. They are probably carried out by different physiological groups of microorganisms. In contrast, Chapter 4 describes a different methanogenic consortium which has the capacity to dechlorinate both CBs and PCBs with the same specificity toward chlorine substution pattern of these compounds. This and the fact that similar lag phases for the dechlorination of CBs and PCBs were observed, shows that the dechlorination of these compounds may be carried out by the same type of microorganisms.

    Chapter 5 applies to the environmental conditions which are necessary for a fast dechlorination of PCBs. Anaerobic reductive dechlorination of PCBs is a slow process, in which lag periods of weeks to months are commonly observed before dechlorination starts. Also the maintenance and subcultivation of PCB dechlorinating microbial consortia are extremely difficult. The optimal enviromnental conditions for the dechlorination process are not known. This is partly due to our lack of knowledge about the physiology of microbial reductive dehalogenation in general and about dechlorination of PCBs in particular. In Chapter 5, the lag phase of the reductive dechlorination of 2,3,4,5-tetrachlorobiphenyl (TeCBP), performed by the consortium described in Chapter 4, was reduced by means of different types of additions to the medium. Sterile Rhine sand appears to shorten the lag phase and to be essential for the maintenance of the consortium. A similar positive effect of sand was also observed in other dechlorinating consortia (Chapter 2 and 3) and for the degradation of toluene in a manganese reducing consortium.

    The mechanism of the reduction of the lag phase by Rhine sand is not known. The Rhine sand that we added to our medium, may contain additional trace metals, necessary for dechlorination. Although the organic carbon content in the Rhine sand we used is very low (<0.05% w/w), another explanation may be that the organic matter served as a supply of growth factors, like vitamins, for the dechlorinating bacteria. Sorption of 2,3,4,5-TeCBP to the sand might also improve the contact between the PCBs and the dechlorinating cells, if these cells tend to settle out or grow on the sand surface (adhesion).

    The addition of anaerobic granular sludge (AGS), either autoclaved or not, also reduced the lag phase before dechlorination of 2,3,4,5-TeCBP drastically. The decrease of the lag phase, achieved by the addition of AGS, may be caused by factors, originating from microorganisms in the AGS. However, the addition of the redox mediator vitamin B 12 , Which is abundantly present in AGS, had little effect on the lag phase. Reduction of the lag phase for PCB dechlorination was also observed by Abramowicz et al. who added fluid thioglycolate medium with beef extract (FTMBE) to polluted Hudson River sediments. In fact, the use of undefined additions such as AGS and FTMBE illustrates how little is known about the mechanism of reductive dechlorination of PCBs. It is of practical importance that a relatively cheap and easily available material such as AGS also reduces the lag phase for dechlorination in a methanogenic enrichment, which is capable of dechlorinating the complex PCB mixture Aroclor 1260 (Chapter 5). It may be worth trying to introduce AGS into methanogenic river sediments polluted with PCBs, to stimulate in situ dechlorination.

    Another aspect one should consider when taking biodegradation into practice is the availability of the pollutant for biodegradation. This is illustrated in Chapter 6, which deals with the biodegradation of pentachlorophenol (PCP) in different soil types by inoculated Rhodococcus chlorophenolicus. After an initially high mineralization rate of the PCP in the inoculated soils, this rate decreased during time and levelled off, leaving behind a residual amount of PCP. Such a non- degraded residue has been observed in many soil biodegradation studies and is referred to as a fraction that is not available for biotransformation, i.e. not bioavailable. Limited bioavailability is considered as one of the most important problems impeding the development of successful bioremediation techniques.

    The rate at which microorganisms can degrade pollutants during bioremediation depends on the intrinsic metabolic activity of the cell, and on the transfer of the pollutant to the cell. Thus, bioavailability of a pollutant is determined by the rate of mass transfer, relative to the activity of the microbial cells. As bacteria generally degrade pollutants to concentrations which are much lower than the residual concentrations observed in soils, it appears that mass transfer is the limiting factor for further degradation. This was confirmed by Bosma et al. who quantified bioavailability by modelling the effect of both mass transfer and the intrinsic activity of the microbial cells. Bioavailability of a pollutant is controlled by a number of physico-chemical processes, such as sorption, diffusion and dissolution. Especially in old polluted sites, part of the pollutants appears to be inaccessible to degrading bacteria. This was shown for a soil contaminated with chlorophenols for over 40 years, in which bioremediation through composting resulted in a residual concentration of about 40 mg/kg. No further degradation was observed when the soil was inoculated with PCP mineralizing bacteria. However, 14C-labelled PCP which was freshly added to this soil led immediately to a complete mineralization of the added PCP. Similar results were reported for two soils contaminated with polycyclic aromatic hydrocarbons and for the reductive dechlorination of hexachlorobenzene in sediment. Rijnaarts et al. showed that biodegradation rates of α-hexachlorocyclohexane in soil could be increased by breaking up the soil particles.

    Such observations indicate a reduced bioavailability due to a so-called "ageing" of the pollutant in the soil. This may be caused by different processes. The first process is a slow diffusion of the pollutant into the deeper and smaller pores of the soil particles and absorption into organic matter as visualized in Figure 7.2. The pollutant can only reach the degrading microorganisms - which are not small enough to penetrate into the deeper pores - by means of diffusion.

    A second process is the occurrence of the pollution as solid particles or as non-aqueous phase liquids (NAPLs) with surrounding semi-rigid films, from which mass transfer into the water phase is limited. Here, bioavailability is controlled by the actual dissolution rate. The third process is bound residue formation and involves the incorporation of pollutants into humic compounds via oxidative coupling reactions. This process especially applies to naphtolic compounds, chlorinated phenols, benzoic acids and anilines, due to their similarity to natural organic compounds. Oxidative coupling can be catalyzed by inorganic materials, such as sesquioxides, clay minerals, oxides and oxohydroxides of iron, silica, and allophane, but also by peroxidases and phenol monooxygenases. Bound residue formation alters the original chemical and biological activity of the pollutants, which therefore become less available, less toxic and less mobile in the soil system. Chapter 6 shows that PCP, freshly added to a sandy and a peaty soil, can be partly recovered as extractable organic halogen (EOX) after 4 months of incubation. However, a chloride mass balance reveals that in the peaty soil, not all measured EOX can be ascribed to PCP, its transformation product pentachloroanisole, or any other possible low molecular weight organic chlorinated compound (MW < 512). This indicates that bound residue formation may have taken place in a time period of 4 months.

    The use of the oxidative enzymes has been proposed as a method to immobilize organic pollutants into the humic material of the soil by stimulating bound residue formation. However, uncontrollable release and distribution of the pollutant cannot be guaranteed. Macromolecular components of dissolved organic matter may form colloids which serve as carriers facilitating the transport of contaminants that bind to the organic matter. Furthermore, fungal oxidative enzymes have also been shown to catalyze unwanted reactions, like the formation of highly toxic chlorinated dibenzodioxins from coupling reactions with chlorinated phenols as substrate.

    It can be concluded that bioavailability is more a physico-chemical problem rather than a microbiological problem. Solutions have therefore to be sought in physico-chemical techniques to increase the transport of the pollutants to the degrading bacteria. These techniques may comprise pulverizing soil particles, increasing the water content of the soil (slurry systems), heating the soil, and using detergents to increase solubility and/or desorption.

    In this thesis, the ever increasing capability of microorganisms to degrade chlorinated pesticides and industrial chemicals is demonstrated, provided that the appropriate enviromnental conditions are created. Despite this enormous potential, the limited bioavailability of pollutants in old contaminated sites and strict soil quality standards, largely hamper the application of microorganisms in soil remediation techniques. The mentioned techniques to increase the availability of pollutants have economical or enviromnental drawbacks. Alternative remediation techniques like incineration or solvent-extraction yields soils without any biological activity, which' destiny is mainly to be used as raw material for building purposes.

    On the other hand, one should ask what the consequences can be of the slow release of the residual amount of a pollutant from a soil that has been biologically treated. (Eco)toxicological assessment of such soil may serve the development of guidelines for the urgency to remove residual pollutants from such soils. Such an approach would stimulate the use of in situ bioremediation techniques, which eventually prevents polluted soil from being excavated. Of course, a continuous monitoring of the soil quality and an appropriate groundwater management of run-off water are essential.

    Effect of oxygen status on pesticide transformation and sorption in undisturbed soil and lake sediment.
    Vink, J.P.M. ; Zee, S.E.A.T.M. van der - \ 1997
    Environmental Toxicology and Chemistry 16 (1997). - ISSN 0730-7268 - p. 608 - 616.
    adsorptie - sorptie - gewasbescherming - pesticiden - pesticidenresiduen - persistentie - microbiële afbraak - waterbodems - adsorption - sorption - plant protection - pesticides - pesticide residues - persistence - microbial degradation - water bottoms
    Pesticide biotransformation and fate in heterogeneous environments
    Vink, J.P.M. - \ 1997
    Agricultural University. Promotor(en): F.A.M. de Haan; S.E.A.T.M. van der Zee. - Lelystad : Directoraat-Generaal Rijkswaterstaat, Directie IJsselmeerpolders - ISBN 9789054857105 - 137
    pesticiden - pesticidenresiduen - milieuafbraak - microbiële afbraak - biotransformatie - fysicochemische eigenschappen - bodemeigenschappen - bodemchemie - rivieren - waterlopen - kanalen - oppervlaktewater - nederland - pesticides - pesticide residues - environmental degradation - microbial degradation - biotransformation - physicochemical properties - soil properties - soil chemistry - rivers - streams - canals - surface water - netherlands

    The effects and relative impacts of environmental variables on the behaviour of pesticides, through the effect on pesticide-degrading microorganisms, was studied in a broad spectrum and covered the most relevant emission routes. It is shown that the effect of landscape geochemistry, which is a pre-set condition in an agricultural management, may be significant (chapter 2). Adjoining soil types, which occur within short distance in an agricultural unit, were characterized and tested on their pesticide leachability and potential risk to groundwater. The use of a 14C radio-labelled pesticide enabled accurate study of its movement in soil layers. Distinctly different pesticide behaviour in topsoil and subsoil layers were observed within this soil series sequence. An alternative of conventional (i.e. uniform) pesticide application rates, which generally results in over-treating some sites and under-treating others, is site specific treatment. In such managements, doses are tailored to individual soil types or soil properties. This may be beneficial from both an economical as an environmental point of view. A prerequisite in such pest managements is the accuracy and reliability in which the leaching potentials of pesticides in various soils are predicted. Of much concern is the fact that there appears to be little agreement between the existing pesticide leaching models in predicting the residence time in soil and subsequent leaching to groundwater (chapter 3). This may be especially valid in soils that display preferent flow patterns, in which solutes by-pass the soil matrix without being subjected to significant sorption and degradation. It was concluded that the introduction of a variety of conceptual descriptions, thus covering ranges in specific soil properties, may improve the applicability of such models. From an environmental point of view, it is necessary to approximate concentrations not only in terms of magnitude but also at the time and the duration at which these occur. With conventional application rates, distinctly different leaching behaviour was observed in a clay lysimeter for aldicarb, a carbamate nematicide, and simazine, an s- triazine herbicide. Aldicarb leached almost instantaneously, but its aerobe metabolites were found in very high concentrations which did not meet the EC-norm level for water over a period of 300 days. A mass balance for aldicarb showed that 0.35% of the initial dose had leached from the soil. However, when the two isosteric metabolites aldicarb-sulfoxide and aldicarb-sulfone were included in the mass balance, this percentage increased dramatically to almost 20%. The concentrations of both metabolites far exceeded those of the parent compound over a long period. Aldicarb is isosteric to acetylcholine, which plays an important role in the nerve system of organisms, and is therefore capable of inhibiting the performance of acetylcholine-esterase. Since aldicarb's metabolites are oxidation products, in which the critical molecular length is not altered, it may be assumed that aldicarb-sulfoxide and aldicarb-sulfone are capable of doing the same. Therefore, the toxicity of these metabolites may be at least additive. In contrast, simazine leaches in relatively low concentrations - only 0.11% of the initial dose was recovered - but these concentrations were measured over a very long period. The absence of a 'breakthrough behaviour' (peak exposure to aqueous environments), as was observed for aldicarb, implies long term delivery (chronic exposure) of simazine from the soil. To better quantify the effects on intrinsic pesticide behaviour, the relative impact of individual soil characteristics and environmental properties was discussed (chapter 6). For the herbicide metamitron, it is shown that transformation rates were dictated, in order of significance, by temperature, oxygen availability and sorption to organic carbon. Since these variables show large variation in depth of the soil column, the resulting biodegradation rates may change dramatically. Half lives increased from several days in the topsoil to over one year in subsoil layers. The underlying dynamics of microbial growth and development that are proposed (chapter 4 and 5) show that a multi-layered approach and the assignment of realistic concentrations and conditions to soil layers may improve approximations of microbial inhibition and growth in depth. These nonlinear dynamics can be linked, simultaneously, to pesticide metabolism and disappearance rates, using parameter estimation techniques.

    Transformation rates and pathways that occur over the soil-aqueous transition zone (i.e. aerobic topsoil-subsoil- anearobic sediment) were tested extensively for four distictly different pesticides that represent their chemical group (chapter 7). It is shown that the prevailing redox conditions have a large impact on pesticide transformation rates. Some phenoxy-acetic compounds, which are considered improbable leachers based on their short aerobic half lives, appear to be persistent in low-oxygeneous conditions. The opposite effect was observed for aldicarb, in which chemical catalysis increased transformation rates when redox potentials decreased. It is shown that a temporal but severe period of oxygen inhibition can be survived by the microbial population. The involved microorganisms can temporarily decrease their activity and can recover within some days from a 109 day stress period. A dynamic chain reaction model is presented, which describes the formation of metabolites from the parent compound, and subsequent transformation, as an interactive, concentration-dependent process.

    An attempt to identify the major discriminating variables that determine the fate of pesticides in surface waters was undertaken (chapter 8). A large set of environmental parameters, composed of physico-chemical, bio-chemical and chemical characteristics, was reduced to three major component groups, explaining the majority of variance of transformation rates of four pesticides that were observed in a variety of surface waters. The first component contains variables that promote biorespiratory processes. The second component is a macro/micro- nutrient group. The third component is the phosphorous group. It is shown that small, lotic systems such as field ditches have a larger potential to degrade specific compounds than large, lentic systems, such as channels and lakes. This effect is largely attributed to microbial activity and the possibility of a relevant community to develop. The specific role of Mg/Mn and phosphorus concentrations in nitrifying surface waters on biotransformation rates is identified (chapter 9). Large phosphorus concentrations favour bacterial growth, but a large fraction of less available phosphates may inhibit transformation rates of aldicarb. Addition of orthophosphate increased the residence time of dissolved Mn, which may under certain conditions promote biotransformation rates. Furthermore, PO 4 enrichment may decrease concentrations of aldicarb's metabolites. In a mechanically aerated batch experiment, it was shown that simazine is virtually persistent except for a short period that coincides with the nitrification process in which NH 4 dissipates and NO 2 and NO 3 are formed. Respectively, relationships of Mg/Mn concentrations with MCPA transformation rates, and P/PO 4 concentrations with aldicarb transformation rates, are presented. These relationships may be used to assess these elements as environmental indicators for potential biotransformation of these compounds, or members of the chemical group, but only in combination with conditions that warrant the development and growth of a degrading population over a longer period of time. An illustration of the effects of the individual properties, that were identified in chapter 8 and 9, is given in figure 1. The relationships between these properties were previously discussed in detail. It is generally believed that the dissolved fraction of a compound, as opposed to the sorbed fraction, is much better available to microorganisms and is therefore degraded rapidly. For surface waters however, it is likely that sorption may in fact enhance biodegradation by concentrating the target compound, by concentrating nutrients, and by providing a large surface area for the attachment of bacteria.

    It should be emphasised that the observed behaviour of the studied pesticides is not restricted to the individual compound, but may represent analogies for compounds within their chemical group. It is evident that laboratory breakdown tests, which are mostly conducted in a batch- type set up, should include system characterisation, and should recognise the influence of alterations in these characteristics. Co-precipitation, which is a common phenomenon in heterogeneous solutions, may lead to deficiencies of essential elements that are utilised by pesticide degrading microorganisms, and therefore affect the interpretation of such experiments.

    A key issues in pesticide risk assessments is the fact that many compounds are readily transformed to compounds which are toxic to target and non-target organisms throughout the environment. Organophosphate and organosulfur insecticides commonly have initial transformation products with well-established insecticidal activity, often of greater potency than the parent compound. A common reaction observed in many sulfide- containing pesticides is oxidation to sulfoxides and sulfones which are usually active on a spectrum of pests similar to the parent compound. The formation of aldicarb sulfoxide and sulfone, which is described in chapter 7, is an example of this. The simultaneous occurrence of parent compound and oxides may even lead to an increased toxicity. Of much concern is the fact that these toxicologically active transformation products tend to be more mobile than the respective parent compound (Chapter 3). Thus, there is an underestimation of the environmental risks when the parent compound rather than the residue concentrations are used. It may well be stated that metabolite formation must be considered a key issue in pesticide risk evaluations that consider the terrestrialaquatic emission route. However, there is much hesitation to study pesticide transformation products. This is due to mainly four arguments:
    1. High costs are associated with the analyses of the numerous possible compounds.
    2. The increase in polarity makes the isolation and analysis of metabolites often more difficult than the analysis of the parent compound.
    3. If a metabolite standard is not available, synthesis may be required.
    4. The problem of which metabolites to identify, to prioritise, and to assign as important, environmental risk indicators.

    The last argument is of particular importance, and future scientific efforts should focus on this issue. The recent advances in solid phase extraction (SPE) techniques, which have increased the ability to isolate metabolites from water, have attributed significantly to the feasibility of this goal.

    A second key issue in risk assessments originates from the fact that the environment is subjected to a

    range of pesticides that occur simultaneously. This is true for soil, but may be of particular importance for surface waters and aquatic sediments. According to the published literature, the toxicity of many pesticide combinations is at least additive. In some cases, pesticide mixtures - particularly those involving insecticides - have been shown to be synergistic. The bilateral effects in pesticide mixtures on sorption has also been discussed in chapter 7. The most appropriate approach to minimising risks for pesticide mixtures appears to be to assume additive toxicity in all cases, which may include the possible formation of specific metabolites. Still, the problem remains of identifying the environmental compartment that dictates the bottle-necks in risk assessments of a specific pesticide or chemical group.

    Risico's van bestrijdingsmiddelen voor grondwater-ecosystemen.
    Dijk, H.F.G. van; Haan, F.A.M. de - \ 1997
    H2O : tijdschrift voor watervoorziening en afvalwaterbehandeling 30 (1997). - ISSN 0166-8439 - p. 155 - 156, 159.
    chemicaliën - grondwaterverontreiniging - nederland - persistentie - pesticidenresiduen - pesticiden - gewasbescherming - verontreinigingsbeheersing - bescherming - toxicologie - waterkwaliteit - chemicals - groundwater pollution - netherlands - persistence - pesticide residues - pesticides - plant protection - pollution control - protection - toxicology - water quality
    Emissies van bestrijdingsmiddelen bij het spoelen van bloembollen
    Beltman, W.H.J. ; Boesten, J.J.T.I. - \ 1996
    Wageningen : DLO-Staring Centrum (Rapport / DLO-Staring Centrum 429) - 73
    gewasbescherming - pesticiden - pesticidenresiduen - persistentie - rioolwater - afvalwater - landbouw - rivieren - waterlopen - kanalen - water - oppervlaktewater - waterverontreiniging - waterkwaliteit - milieu - verontreinigende stoffen - verontreiniging - nadelige gevolgen - schoonmaken - indeling - afpellen - wassen (activiteit) - bloembollen - opslagloodsen - slib - afvalverwijdering - afvoer - bodem - uitspoelen - nederland - plant protection - pesticides - pesticide residues - persistence - sewage - waste water - agriculture - rivers - streams - canals - water - surface water - water pollution - water quality - environment - pollutants - pollution - adverse effects - cleaning - grading - peeling - washing - ornamental bulbs - stores - sludges - waste disposal - discharge - soil - leaching - netherlands
    De emissies van bestrijdingsmiddelen naar grondwater en via af te voeren spoelslib uit de bloembollenteelt is geschat met eenvoudige modellen. In spoelslib zullen vooral middelen worden aangetroffen die sterk adsorberen aan organische stof of in hoge dosering worden toegepast, zoals tolclofosmethyl en prochloraz. De gemeten verzadigde doorlatendheid van bassinbodems bedroeg 0,2 tot 0,5 cm/d, wat resulteerde in berekende waterfluxen door de bassinbodem van 4 tot 5 cm/d. Bij zulke hoge fluxen zal de concentratie van carbendazim maar weinig dalen tijdens het transport vanuit bassins naar het grondwater
    Wvo-heffingen voor de landbouw : verkenning van de praktische mogelijkheden
    Anonymous, - \ 1996
    Den Haag : Projectteam NW4 - 83
    waterkwaliteit - waterbeheer - gewasbescherming - pesticiden - pesticidenresiduen - persistentie - nitraten - betalingen - belastingen - rekeningen van landbouwbedrijf - boekhouding van landbouwbedrijf - nederland - water quality - water management - plant protection - pesticides - pesticide residues - persistence - nitrates - fees - taxes - farm accounts - farm accounting - netherlands
    Theoretical maximum daily intake of pesticide residues in the Netherlands - a model for risk assessment
    Dooren-Flipsen, M.M.H. van; Klaveren, J.D. van; Donkersgoed, G. van - \ 1996
    Wageningen : RIKILT-DLO (Report / Rikilt 96.28) - 20
    pesticidenresiduen - risicoschatting - nederland - pesticide residues - risk assessment - netherlands - chemical industry - pesticides - toxic substances - physiology - chemicals - xenobiotics
    Uitspoeling van chemische gewasbeschermingsmiddelen in grondgebonden teelten
    Runia, W.T. ; Leistra, M. ; Steekelenburg, N.A.M. van - \ 1996
    Naaldwijk : Proefstation voor Bloemisterij en Glasgroente, Vestiging Naaldwijk (Rapport / Proefstation voor Bloemisterij en Glasgroente, Vestiging Naaldwijk 57) - 147
    uitspoelen - persistentie - pesticidenresiduen - pesticiden - gewasbescherming - onderzoek - bodem - statistiek - nederland - zuid-holland - glastuinbouw - leaching - persistence - pesticide residues - pesticides - plant protection - research - soil - statistics - netherlands - zuid-holland - greenhouse horticulture
    De uitspoeling van organofosfaatbestrijdingsmiddelen na toepassing in grondgebonden teelten in de glastuinbouw is onderzocht. De middelen werden frequent in het drainagewater aangetoond, zo nu en dan in relatief hoge concentraties. De ecotoxicologische normen en de drinkwaternorm werden regelmatig overschreden. De cholinesteraseremming door de residuen in het drainagewater lag veelal boven de AMK-norm van 0,5 Šg paraoxonequivalent per liter. Het percentage sterfte van het toetsorganisme Daphnia magnain het verontreinigde drainagewater liep uiteen van 7 tot 77. Bij deze residuniveaus moet de afvoer van het drainagewater naar de waterlopen worden vervangen door hergebruik op de bedrijven.
    TOXSWA 1.0; user's manual
    Beltman, W.H.J. ; Adriaanse, P.I. ; Elswijk, M.J.B. van - \ 1996
    Wageningen : SC-DLO (Technical document / DLO-Staring Centrum 33) - 101
    chemicaliën - computersimulatie - persistentie - pesticidenresiduen - pesticiden - gewasbescherming - simulatie - simulatiemodellen - toxicologie - chemicals - computer simulation - persistence - pesticide residues - pesticides - plant protection - simulation - simulation models - toxicology
    TOXSWA is a computer model that simulates pesticide concentrations in the water and sediment layers of a field ditch. The theoretical concepts are briefly discussed. A sample simulation is presented to guide the user in running TOXSWA. The input and output files are described. Writing the input files with the aid of a user-friendly input editor, running the program and creating the graphical output are discussed. Guidelines are given for estimating the input parameters.
    Transformation of 3-chloroallyl alcohol in water-saturated subsoil studied with a column method
    Beltman, W.H.J. ; Leistra, M. ; Matser, A.M. - \ 1996
    Pesticide science : a journal of international research and technology on crop protection and pest control 47 (1996)4. - ISSN 0031-613X - p. 299 - 307.
    bloembollen - persistentie - pesticidenresiduen - pesticiden - fysicochemische eigenschappen - gewasbescherming - bodemchemie - bodemeigenschappen - ornamental bulbs - persistence - pesticide residues - pesticides - physicochemical properties - plant protection - soil chemistry - soil properties
    The performance of a newly developed column method for pesticide transformation rate measurements in the subsoil was tested using (Z)- and (E)-3-chloroallyl alcohol as model compounds. The subsoil columns were filled in situ. In the column experiment the half-life ranged from 0.5-5.2 d for (Z)-3-chloroallyl alcohol and from 1.0-5.5 d for (E)-3-chloroallyl alcohol. The transformation rates were compared with rates in laboratory incubation systems, in which the 3-chloroallyl alcohols were transformed gradually in the first three days, with a half-life of 1.9 d for both isomers. The two methods yielded similar results for these rapidly transforming compounds.
    Belasting van grond- en oppervlaktewater met bestrijdingsmiddelen in de stroomgebieden van de Beerze, Reusel en Rosep
    Aarnink, W.H.B. ; Bolt, F.J.E. van der; Merkelbach, R.C.M. ; Westein, E. - \ 1996
    Wageningen : DLO-Staring Centrum - 105
    bodem - uitspoelen - gewasbescherming - pesticiden - pesticidenresiduen - persistentie - waterkwaliteit - verontreinigingsbeheersing - grondwaterverontreiniging - bescherming - rivieren - waterlopen - kanalen - water - oppervlaktewater - waterverontreiniging - nederland - noord-brabant - soil - leaching - plant protection - pesticides - pesticide residues - persistence - water quality - pollution control - groundwater pollution - protection - rivers - streams - canals - water - surface water - water pollution - netherlands - noord-brabant
    De belasting van grond- en oppervlaktewater via verschillende emissieroutes is gekwantificeerd. De belasting wordt veroorzaakt door een klein aantal bestrijdingsmiddelen. Of deze stoffen in het grond- en oppervlaktewater belanden, wordt sterk door de hydrologie bepaald. Zowel de bodemfysische en bodemchemische omstandigheden als fysisch-chemische eigenschappen van een bestrijdingsmiddel hebben eveneens grote invloed op het gedrag van de stof.
    Effects of the insecticide Dursban 4E (active ingredient chlorpyrifos) in outdoor experimental ditches: I. comparison of short-term toxicity between the laboratory and the field
    Wijngaarden, R.P.A. van; Brink, P.J. van den; Crum, S.J.H. ; Oude Voshaar, J.H. ; Brock, T.C.M. ; Leeuwangh, P. - \ 1996
    Environmental Toxicology and Chemistry 15 (1996)7. - ISSN 0730-7268 - p. 1133 - 1142.
    chemicaliën - experimenteel veldonderzoek - persistentie - pesticidenresiduen - pesticiden - gewasbescherming - toxicologie - chemicals - field experimentation - persistence - pesticide residues - pesticides - plant protection - toxicology
    By means of the insecticide chlorpyrifos, results of acute single-species toxicity tests were compared with direct effects in outdoor mesocosms. In the mesocosms, chlorpyrifos concentrations between 0.1 and 44 Šg/l were sprayed once. Acute effects were observed on arthropods. Effects could be quantified for seven species. For these species, EC50s were similar to their laboratory EC50s. The most sensitive standard test species was about representative of susceptible indigenous species. Effects were negligible at 0.1 Šg/l. A factor of 0.1 * 48-h LC50 of Daphnia magna may have protected most species in the community from direct effects. A safety factor of 0.01 may have protected the most susceptible taxa we found.
    Suitability of seven species of soil-inhabiting invertebrates for testing toxicity of pesticides in soil pore water
    Ronday, R. ; Houx, N.W.H. - \ 1996
    Pedobiologia 40 (1996)2. - ISSN 0031-4056 - p. 106 - 112.
    persistentie - pesticidenresiduen - pesticiden - gewasbescherming - bodemoplossing - bodemwater - bioaccumulatie - ecotoxicologie - persistence - pesticide residues - pesticides - plant protection - soil solution - soil water - bioaccumulation - ecotoxicology
    This study assessed the suitability of seven species of soil invertebrates for toxicologically testing pesticides in water. Requirements were that the organisms must survive in water, be easy to handle, be easy to breed, be sensitive to pesticides, and show unambiguous toxicological effects. The organisms tested were the nematodes Plectus parietinus and Globodera rostochiensis, the white pot-worms Enchytraeus buchholzi and Enchytraeus albidus, the manure worm Eisenia fetida, the mite Caloglyphus mycophagus, and the springtail Folsomia candida. The springtail met all the requirements and proved to be the most suitable of the organisms tested for soil quality assessment with soil pore water.
    Hoeveel last hebben bodemdieren van verontreinigde grond?
    Ronday, R. - \ 1996
    Bodem 6 (1996)3. - ISSN 0925-1650 - p. 120 - 122.
    persistentie - pesticidenresiduen - pesticiden - gewasbescherming - bodembiologie - bioaccumulatie - ecotoxicologie - persistence - pesticide residues - pesticides - plant protection - soil biology - bioaccumulation - ecotoxicology
    Het niveau waarin verontreinigingen voorkomen in de bodem, wordt meeestal weergegeven als het gehalte van die stoffen. Vaak kan slechts een deel daarvan worden opgenomen door bodemorganismen. Deze biologische beschikbaarheid verschilt per bodemtype endaardoor veroorzaakt eenzelfde gehalte van een stof uiteenlopende giftigheid. Ook voor bestrijdingsmiddelen zijn gehalten niet maatgevend voor ongewenste neveneffecten. Om de biologische risico's van bestrijdingsmiddelen in de bodem beter te beoordelenmoet men de concentraties in het bodemporiewater kennen en vergelijken met blootstelling-effectrelaties bepaald in laboratoriumtoxiciteitstoetsen. Voor diverse bodemorganismen kunnen deze toetsen in water worden uitgevoerd.
    Effects of the insecticide Dursban 4E (active ingredient chlorpyrifos) in outdoor experimental ditches: II. invertebrate community responses and recovery
    Brink, P.J. van den; Wijngaarden, R.P.A. van; Lucassen, W.G.H. ; Brock, T.C.M. ; Leeuwangh, P. - \ 1996
    Environmental Toxicology and Chemistry 15 (1996)7. - ISSN 0730-7268 - p. 1143 - 1153.
    chemicaliën - experimenteel veldonderzoek - persistentie - pesticidenresiduen - pesticiden - gewasbescherming - toxicologie - chemicals - field experimentation - persistence - pesticide residues - pesticides - plant protection - toxicology
    This paper describes long-term effects of chlorpyrifos on macro-invertebrates and zooplankton after a single application. Crustaceans and insects showed a rapid, concentration-dependent decrease in numbers after application (direct effects). A significant increase in gastropods and oligochaetes was found, suggesting indirect effects. The start of recovery of the invertebrate populations affected depended not only on the susceptibility of the taxa, but also on ecological characteristics, such as length of the life cycle. Safe concentrations, based on no observed short-term effect levels for some characteristic indigenous taxa susceptible to chlorpyrifos, also appeared to protect the total invertebrate community in the long term.
    Fate of pesticides in field ditches: the TOXSWA simulation model
    Adriaanse, P.I. - \ 1996
    Wageningen : SC-DLO - 203
    lucht - luchtverontreiniging - kanalen - hygiëne - uitspoelen - modellen - persistentie - pesticidenresiduen - pesticiden - gewasbescherming - onderzoek - rivieren - bodem - waterlopen - oppervlaktewater - water - waterverontreiniging - waterkwaliteit - air - air pollution - canals - hygiene - leaching - models - persistence - pesticide residues - pesticides - plant protection - research - rivers - soil - streams - surface water - water - water pollution - water quality
    The TOXSWA model describes the fate of pesticides entering field ditches by spray drift, atmospheric deposition, surface run-off, drainage or leaching. It considers four processes: transport, transformation, sorption and volatilization. Analytical andnumerical solutions corresponded well. A sample simulation showed that sorption to macrophytes can considerably reduce the concentration in the water phase. However, sorption to macrophytes leads to a slower transport and thus to longer residence times for the pesticide in the water layer. Sedimentation and resuspension of suspended solids were not considered, so that the model can only be applied for periods shorter than one month.
    Data- en programmabeschrijving ISBEST versie 2.0
    Lentjes, P.G. ; Denneboom, J. - \ 1996
    Wageningen : SC-DLO (Technisch document / DLO-Staring Centrum 31) - 81
    milieu - verontreinigende stoffen - verontreiniging - nadelige gevolgen - gewasbescherming - pesticiden - pesticidenresiduen - persistentie - databanken - computer software - toepassingen - environment - pollutants - pollution - adverse effects - plant protection - pesticides - pesticide residues - persistence - databases - computer software - applications
    Het programmapakket ISBEST is een informatiesysteem waarmee het verbruik van bestrijdingsmiddelen in kaart kan worden gebracht. Dit technisch document beschrijft de database en de procedures om de gegevens in de database te krijgen en de procedures enprogramma's om de gegevens in de database te verwerken tot informatie.
    Acute toxicity test for terrestrial hazard assessment with exposure of Folsomia candida to pesticides in an aqueous medium
    Houx, N.W.H. ; Dekker, A. ; Kammen-Polman, A.M.M. van; Ronday, R. - \ 1996
    Archives of Environmental Contamination and Toxicology 30 (1996)1. - ISSN 0090-4341 - p. 9 - 14.
    chemicaliën - persistentie - pesticidenresiduen - pesticiden - gewasbescherming - toxicologie - chemicals - persistence - pesticide residues - pesticides - plant protection - toxicology
    An acute-toxicty test is described in which the springtail Folsomia candida was exposed to pesticides in water for four days. The test method has been designed for the direct and economical chemical analyses of all the concentrations during the execution of the test. The 96-hour EC50 values determined for parathion, carbofuran, dimethoate and oxamyl were 0.0087, 0.222, 16.2 and 23.6 mg/l, respectively. The toxicity of the pesticides was correlated with their lipophilicity. For terrestrial hazard assessment procedures the use of the intrinsic toxicity of chemicals to soil organisms, as determined in this simple test, is proposed.
    Modelling regional transport of pesticide residues in groundwater
    Leistra, M. ; Beltman, W.H.J. ; Boesten, J.J.T.I. ; Matser, A.M. ; Zee, S.E.A.T.M. van der - \ 1996
    In: Soil structure and transport processes : implications for water, gases, nutrients, pesticides, and contaminants in soils / Raats, P.A.C., Rogaar, H., van den Heuvel-Pieper, A.H., Wageningen : Netherlands Integrated Soil Research Programme (Netherlands Integrated Soil Research Programme reports 6) - ISBN 9789073270206 - p. 75 - 81.
    bodem - uitspoelen - waterkwaliteit - verontreinigingsbeheersing - grondwaterverontreiniging - bescherming - gewasbescherming - pesticiden - pesticidenresiduen - persistentie - modellen - onderzoek - soil - leaching - water quality - pollution control - groundwater pollution - protection - plant protection - pesticides - pesticide residues - persistence - models - research
    The movement of pesticides through soil and groundwater to pumping wells for drinking-water supply was modelled. Most of the retardation and transformation occurs when a pesticide moves through the unsaturated zone. Computed leaching to groundwater increased when soil heterogeneity was taken into account. A column method was developed to measure the rate of pesticide transformation in the aquifer as input for models. The fluctuation of the concentration in the pumping well due to the application pattern was computed to be largest for aquifers with short characteristic travel times of the solute.
    A field test of Root Zone Water Quality Model - pesticide and bromide behavior
    Ahuja, L.R. ; Ma, Q.L. ; Rojas, K.W. ; Boesten, J.J.T.I. ; Farahani, H.J. - \ 1996
    Pesticide science : a journal of international research and technology on crop protection and pest control 48 (1996)2. - ISSN 0031-613X - p. 101 - 108.
    colloïdale eigenschappen - persistentie - pesticidenresiduen - pesticiden - gewasbescherming - bodem - bodemkunde - bodemoplossing - colloidal properties - persistence - pesticide residues - pesticides - plant protection - soil - soil science - soil solution
    The Root Zone Water Quality Model is a process-based model that integrates physical, chemical and biological processes to simulate the fate and movement of water and agrochemicals over and through the root zone at a representative point in a field with various management practices. The model was evaluated with field data for the movement of water and bromide, and the transformation and transport of cyanazine and metribuzin in the soil profile. The model reasonably simulated soil water and bromide movement. Pesticide persistence was predicted reasonably well with a two-site sorption model that assumes a rate-limited adsorption-desorption process with the additional assumption of negligible degradation of interaggregate-adsorbed pesticides.
    Development and duration of accelerated degradation of nematicides in different soils
    Smelt, J.H. ; Peppel-Groen, A.E. van de; Pas, L.J.T. van der; Dijksterhuis, A. - \ 1996
    Soil Biology and Biochemistry 28 (1996)12. - ISSN 0038-0717 - p. 1757 - 1765.
    microbiële afbraak - nematiciden - persistentie - pesticidenresiduen - pesticiden - fysicochemische eigenschappen - gewasbescherming - bodemchemie - bodemeigenschappen - microbial degradation - nematicides - persistence - pesticide residues - pesticides - physicochemical properties - plant protection - soil chemistry - soil properties
    The development and duration of accelerated degradation of nematicides were studied in incubation experiments with soils from three experimental fields that had been treated annually for three to ten years with aldicarb, oxamyl, ethoprophos, fenamiphos or 1,3-dichloropropene. Highly accelerated degradation rates were measured for aldicarb, oxamyl and ethoprophos in a sandy soil (pH 7.3) treated three times. After five years without further treatments, these high rates were still found for aldicarb and oxamyl, but not for ethoprophos. In another field (sandy soil, pH 5.6) little or no increase in the degradation rates was measured in plots that had been treated ten times.
    Uitspoeling van bestrijdingsmiddelen uit kasgronden naar waterlopen; gegevens over de kasteeltsystemen
    Matser, A.M. ; Leistra, M. ; Pellikaan-van Harten, H.A.J. ; Berg, F. van den; Runia, W.T. - \ 1996
    Wageningen : DLO-Staring Centrum
    gewasbescherming - pesticiden - pesticidenresiduen - persistentie - bodem - uitspoelen - rivieren - waterlopen - kanalen - water - oppervlaktewater - waterverontreiniging - waterkwaliteit - modellen - onderzoek - nederland - glastuinbouw - plant protection - pesticides - pesticide residues - persistence - soil - leaching - rivers - streams - canals - water - surface water - water pollution - water quality - models - research - netherlands - greenhouse horticulture
    Onderzocht is of de uitspoeling van bestrijdingsmiddelen uit kasgronden via drainagestelsels naar waterlopen kan worden teruggedrongen. De belasting van de bodem kan worden verminderd door de gewasbehandelingsmiddelen meer gewasgericht toe te dienen. De watergiften in kassen zijn hoger dan nodig is; dit vergroot het uitspoelingsrisico aanzienlijk. De omzettingssnelheid van de voorbeeldmiddelen diazinon, heptenofos en tolclofosmethyl in kasgronden werd gemeten. Vervluchtiging en fotochemische omzetting leveren nauwelijks een bijdrage aan de afname van de middelen op het bodemoppervlak in kassen. Dit onderzoek levert de invoergegevens die nodig zijn voor uitspoelingsberekeningen met een standaardmodel.
    Berekening inname residuen en contaminan ten. Conversietabel primaire agrarische produc ten
    Dooren-Flipsen, M.M.H. van; Klaveren, J.D. van; Boeijen, I. ; Donkersgoed, G. van - \ 1996
    Voeding 57 (1996)5. - ISSN 0042-7926 - p. 6 - 9.
    voedingsmiddelen - voedselproducten - landbouwproducten - gewasbescherming - pesticiden - pesticidenresiduen - persistentie - consumenteninformatie - kwaliteit - databanken - voedselhygiëne - voedingstoestand - consumptiepatronen - foods - food products - agricultural products - plant protection - pesticides - pesticide residues - persistence - consumer information - quality - databases - food hygiene - nutritional state - consumption patterns
    De conversietabel geeft een eenduidige koppeling tussen primaire agrarische produkten en consumeerbare voedingsmiddelen, zodat m.b.v. informatiesytemen over voedselconsumptie en gehaltes aan residuen en contaminanten de inname van negatieve bestanddelen via de voeding kan worden berekend
    Reduction of agricultural water use and decreased pollution of nutrients and pesticides by protected cultivations
    Os, E.A. van; Stanghellini, C. - \ 1996
    In: Utilizacion y manejo sostenible de los recursos hidricos : [proceedings of the seminar, San Jose, Costa Rica, 28 November and 1 December 1994] / Reynolds Vargas, J., - p. 167 - 178.
    persistentie - pesticidenresiduen - pesticiden - gewasbescherming - waterbeheer - waterkwaliteit - nederland - glastuinbouw - persistence - pesticide residues - pesticides - plant protection - water management - water quality - netherlands - greenhouse horticulture
    Pesticide leaching on loamy sands
    Groen, K.P. ; Feddes, R.A. ; Boesten, J.J.T.I. ; Schultz, E. ; Koopmans, R. ; Dam, J.C. van - \ 1996
    In: Crop - water - environmental models : selected papers 16th ICID congress, Cairo, 1996 / Ragab, R., Cairo : ICID - p. 1 - 16.
    uitspoelen - persistentie - pesticidenresiduen - pesticiden - gewasbescherming - lichte zavel - bodem - leaching - persistence - pesticide residues - pesticides - plant protection - sandy loam soils - soil
    Emission of solutes in cracked clay soils.
    Groen, K.P. ; Feddes, R.A. ; Boesten, J.J.T.I. ; Schultz, E. ; Koopmans, R. ; Dam, J.C. van - \ 1996
    In: Crop - water - environment models : selected papers to the workshop at the occasion of the 16th congress of the International Commission on Irrigation and Drainage at Cairo, Egypt, 17 September 1996 : [47th International executive council meeting]. - - p. 29 - 41.
    zware kleigronden - scheurvorming - uitspoelen - modellen - persistentie - pesticidenresiduen - pesticiden - gewasbescherming - onderzoek - krimp - bodem - opzwellen - clay soils - cracking - leaching - models - persistence - pesticide residues - pesticides - plant protection - research - shrinkage - soil - swelling
    Some physicochemical and environmental factors affecting transformation rates and sorption of the herbicide Metamitron in soil.
    Vink, J.P.M. ; Zee, S.E.A.T.M. van der - \ 1996
    Pesticide science : a journal of international research and technology on crop protection and pest control 46 (1996). - ISSN 0031-613X - p. 113 - 119.
    absorptie - adsorptie - gewasbescherming - pesticiden - pesticidenresiduen - persistentie - microbiële afbraak - bodemchemie - absorption - adsorption - plant protection - pesticides - pesticide residues - persistence - microbial degradation - soil chemistry
    Gewasbeschermingsmiddelen en nutrienten in compost en percolaatwater
    Wondergem, M.J. - \ 1995
    Lisse : Laboratorium voor Bloembollenonderzoek (Rapport bloembollenonderzoek nr. 95) - 27
    kanalen - bestrijdingsmethoden - geïntegreerde bestrijding - geïntegreerde plagenbestrijding - uitspoelen - nederland - persistentie - pesticidenresiduen - pesticiden - plantenziekten - plantenplagen - gewasbescherming - rivieren - bodem - waterlopen - oppervlaktewater - water - waterverontreiniging - waterkwaliteit - canals - control methods - integrated control - integrated pest management - leaching - netherlands - persistence - pesticide residues - pesticides - plant diseases - plant pests - plant protection - rivers - soil - streams - surface water - water - water pollution - water quality
    Overwaaien van bestrijdingsmiddelen naar waterlopen bij bespuiting in de bloembollenteelt
    Peppel - Groen, A.E. van de; Smidt, R.A. ; Leistra, M. - \ 1995
    Wageningen : DLO-Staring Centrum (Rapport / DLO-Staring Centrum 367) - 37
    lucht - luchtverontreiniging - kanalen - hygiëne - bloembollen - persistentie - pesticidenresiduen - pesticiden - gewasbescherming - rivieren - spuiten - waterlopen - oppervlaktewater - water - waterverontreiniging - waterkwaliteit - air - air pollution - canals - hygiene - ornamental bulbs - persistence - pesticide residues - pesticides - plant protection - rivers - spraying - streams - surface water - water - water pollution - water quality
    Het overwaaien van bestrijdingsmiddelen bij bespuitingen in de bloembollenteelt, als mogelijke bron van verontreiniging van waterlopen, is onderzocht. De methoden voor het meten van de depositie van de voorbeeldstoffen esfenvaleraat, chloridazon en Brilliant Sulfoflavine op verschillende collectoren zijn getoetst. In de drie veldproeven nam de aërieke depositie buiten het gewas af tot respectievelijk 0,6%, 0,9% en 2,1% van de dosering op de benedenwindse slootrand (op 3 u 4 m afstand). De aërieke depositie op het wateroppervlak (op ongeveer 5 m afstand) lag rond 0,5% van de dosering. Een spuitvrije zone van 4 u 5 m breedte levert een grote bijdrage aan het verminderen van overwaaien van spuitvloeistof naar de waterlopen.
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