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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    Trace elements in pacific Dunlin (Calidris alpina pacifica): patterns of accumulation and concentrations in kidneys and feathers
    St. Clair, C.T. ; Baird, P. ; Ydenberg, R.C. ; Elner, R.W. ; Bendell, L.I. - \ 2015
    Ecotoxicology 24 (2015)1. - ISSN 0963-9292 - p. 29 - 44.
    san-francisco bay - western sandpiper - heavy-metals - larus-argentatus - herring-gulls - aquatic birds - wadden sea - cadmium - selenium - mercury
    Trace element concentrations were measured in Pacific Dunlin (Calidris alpina pacifica) to identify factors that influence accumulation and to assess toxicity risks. We report concentrations of cadmium, copper, and zinc in kidneys as well as copper, lead, mercury, selenium and zinc in feathers. Relationships between element concentrations and Dunlin age, sex, bill length, habitat preference, trophic level, and sample group were investigated with regression analyses. Stable isotope ratios of carbon and nitrogen in Dunlin muscle tissue were used to determine habitat preference and trophic level, respectively. Cadmium concentrations in kidneys were significantly related to habitat preference: [Cd] in estuarine foragers >[Cd] in terrestrial foragers. Cadmium accumulation was age-dependent as concentrations increased significantly within 10 months of hatch dates but not afterward. Concentrations of cadmium and zinc in kidneys as well as lead and mercury in feathers were below those known to cause deleterious effects in birds. In contrast, selenium concentrations in feathers (range: 2.1–14.0 µg/g) were often at levels associated with toxicity risks (>5 µg/g). Toxicity thresholds are not available for copper in kidneys or copper and zinc in feathers; however, measured concentrations of these elements were within documented ranges for sandpipers. Future studies should assess potential impacts of selenium on embryonic development in Dunlin and other sandpipers. Risk assessments would yield more conclusive results for all elements if impacts under ecologically relevant stresses (e.g. development in the wild, migration, predation) were better understood.
    Sources of variation in innate immunity in great tit nestlings living along a metal pollution gradient: An individual-based approach
    Vermeulen, A. ; Müller, W. ; Matson, K.D. ; Tieleman, B.I. ; Bervoets, L. ; Eens, M. - \ 2015
    Science of the Total Environment 508 (2015). - ISSN 0048-9697 - p. 297 - 306.
    storks ciconia-ciconia - acute-phase responses - parus-major - heavy-metals - tree swallows - insectivorous passerines - reproductive success - tachycineta-bicolor - population-growth - oxidative stress
    Excessive deposition of metals in the environment is a well-known example of pollution worldwide. Chronic exposure of organisms to metals can have a detrimental effect on reproduction, behavior, health and survival, due to the negative effects on components of the immune system. However, little is known about the effects of chronic sublethal metal exposure on immunity, especially for wildlife. In our study, we examined the constitutive innate immunity of great tit (Parus major) nestlings (N = 234) living in four populations along a metal pollution gradient. For each nestling, we determined the individual metal concentrations (lead, cadmium, arsenic) present in the red blood cells and measured four different innate immune parameters (agglutination, lysis, haptoglobin concentrations and nitric oxide concentrations) to investigate the relationship between metal exposure and immunological condition. While we found significant differences in endogenous metal concentrations among populations with the highest concentrations closest to the pollution source, we did not observe corresponding patterns in our immune measures. However, when evaluating relationships between metal concentrations and immune parameters at the individual level, we found negative effects of lead and, to a lesser extent, arsenic and cadmium on lysis. In addition, high arsenic concentrations appear to elicit inflammation, as reflected by elevated haptoglobin concentrations. Thus despite the lack of a geographic association between pollution and immunity, this type of association was present at the individual level at a very early life stage. The high variation in metal concentrations and immune measures observed within populations indicates a high level of heterogeneity along an existing pollution gradient. Interestingly, we also found substantial within nest variation, for which the sources remain unclear, and which highlights the need of an individual-based approach.
    In-situ measurement of free trace metal concentrations in a flooded paddy soil using the Donnan Membrane Technique
    Pan, Y. ; Koopmans, G.F. ; Bonten, L.T.C. ; Song, J. ; Luo, Y. ; Temminghoff, E.J.M. ; Comans, R.N.J. - \ 2015
    Geoderma 241-242 (2015). - ISSN 0016-7061 - p. 59 - 67.
    dissolved organic-matter - ray-absorption spectroscopy - copper redox transformation - reduced sulfur groups - ion activity model - sandy soil - humic substances - natural-waters - higher-plants - heavy-metals
    The field Donnan Membrane Technique (DMT) has been used successfully to measure in-situ free trace metal concentrations in surface waters. However, it has not been applied previously in submerged soil systems including flooded paddy rice fields.Wetested this technique in a columnexperimentwith a flooded paddy soil contaminated with trace metals and compared the DMT measurements with predictions from a geochemical speciation model. Flooding led to a strong gradient in the redox potential (Eh) along the soil column, and the pH and concentrations ofMn, Fe, and dissolved organic carbon increased with decreasing Eh. Total dissolved tracemetal concentrations decreased from the overlying water layer to the soil layers, which might be ascribed to the elevated pH outweighing the effect of the increased DOC concentrations under anaerobic conditions. Also, free trace metal concentrations were lower in the soil solution of the upper and bottom soil layers than in the overlying water layer, largely due to the increased pH under anaerobic conditions. The DMT measurements and model predictions were similar in the aerobic water layer, except for Pb. In both anaerobic soil layers, however, Cu and Pb were poorly predicted. The applied geochemical modeling approach, which is frequently being used and performswell under aerobic conditions, does not fully capture all the chemical processes occurring under anaerobic conditions. Overall, the field DMT proved to be a useful tool for the in-situ measurement of free trace metal concentrations in flooded paddy soils.
    Partitioning of humic acids between aqueous solution and hydrogel. 2. Impact of physicochemical conditions
    Zielinska, K. ; Town, R.M. ; Yasadi, K. ; Leeuwen, H.P. van - \ 2015
    Langmuir 31 (2015)1. - ISSN 0743-7463 - p. 283 - 291.
    ionic-strength - alginate gel - heavy-metals - fluorescence - substances - ph - aggregation - media - soil - spectroscopy
    The effects of the physicochemical features of aqueous medium on the mode of partitioning of humic acids (HAs) into a model biomimetic gel (alginate) and a synthetic polyacrylamide gel (PAAm) were explored. Experiments were performed under conditions of different pH and ionic strength as well as in the presence or absence of complexing divalent metal ions. The amount of HA penetrating the gel phase was determined by measuring its natural fluorescence by confocal laser scanning microscopy. In both gel types, the accumulation of HA was spatially heterogeneous, with a much higher concentration located within a thin film at the gel surface. The thickness of the surface film (ca. 15 µm) was similar for both types of gel and practically independent of pH, ionic strength, and the presence of complexing divalent metal ions. The extent of HA accumulation was found to be dependent on the composition of the medium and on the type of gel. Significantly more HA was accumulated in PAAm gel as compared to that in alginate gel. In general, more HA was accumulated at lower background salt concentration levels. The distribution of different types of HA species in the gel body was linked to their behavior in the medium and the differences in physicochemical conditions inside the two phases.
    Long term plant biomonitoring in the vicinity of waste incinerators in The Netherlands
    Dijk, C.J. van; Doorn, W. van; Alfen, A.J. van - \ 2015
    Chemosphere 122 (2015). - ISSN 0045-6535 - p. 45 - 51.
    refuse incinerator - heavy-metals - dioxins - health - bioindicators - cadmium - lead
    Since the mid-nineties new waste incineration plants have come into operation in the Netherlands. Burning of waste can result in the emission of potentially toxic compounds. Although the incineration plants must comply with strict conditions concerning emission control, public concern on the possible impact on human health and the environment still exists. Multiple year (2004–2013) biomonitoring programs were set up around three waste incinerators for early detection of possible effects of stack emissions on the quality of crops and agricultural products. The results showed that the emissions did not affect the quality of crops and cow milk. Concentrations of heavy metals, PAHs and dioxins/PCBs were generally similar to background levels and did not exceed standards for maximum allowable concentrations in foodstuffs (e.g. vegetables and cow milk). Some exceedances of the fluoride standard for cattle feed were found almost every year in the maximum deposition areas of two incinerators. Biomonitoring with leafy vegetables can be used to monitor the real impact of these emissions on agricultural crops and to communicate with all stakeholders.
    Biotechnologies for critical raw material recovery from primary and secondary sources: R&D priorities and future perspectives
    Hennebel, T. ; Boon, N. ; Maes, S. ; Lenz, M. - \ 2015
    New Biotechnology 32 (2015)1. - ISSN 1871-6784 - p. 121 - 127.
    acid-mine drainage - heavy-metals - waste-water - selective precipitation - bacterial surfaces - nanoparticles - selenium - removal - copper - biosorption
    Europe is confronted with an increasing supply risk of critical raw materials. These can be defined as materials of which the risks of supply shortage and their impacts on the economy are higher compared to most of other raw materials. Within the framework of the EU Innovation Partnership on raw materials Initiative, a list of 14 critical materials was defined, including some bulk metals, industrial minerals, the platinum group metals and rare earth elements. To tackle the supply risk challenge, innovation is required with respect to sustainable primary mining, substitution of critical metals, and urban mining. In these three categories, biometallurgy can play a crucial role. Indeed, microbe–metal interactions have been successfully applied on full scale to win materials from primary sources, but are not sufficiently explored for metal recovery or recycling. On the one hand, this article gives an overview of the microbial strategies that are currently applied on full scale for biomining; on the other hand it identifies technologies, currently developed in the laboratory, which have a perspective for large scale metal recovery and the needs and challenges on which bio-metallurgical research should focus to achieve this ambitious goal.
    Impacts of NF concentrate recirculation on membrane performance in an integrated MBR and NF membrane process for wastewater treatment
    Kappel, C. ; Kemperman, A.J.B. ; Temmink, B.G. ; Zwijnenburg, A. ; Rijnaarts, H. ; Nijmeijer, K. - \ 2014
    Journal of Membrane Science 453 (2014). - ISSN 0376-7388 - p. 359 - 368.
    natural organic-matter - nanofiltration membranes - activated-sludge - treatment plants - heavy-metals - bioreactor - retention - acids
    As water shortages are increasing, the need for sustainable water treatment and the reuse of water is essential. Water reuse from wastewater can be accomplished in a membrane bioreactor (MBR) in the secondary activated sludge stage of a wastewater treatment plant. To remove viruses, dissolved organics and inorganics still present in the MBR permeate, nanofiltration (NF) can be applied. Nevertheless, the major drawback of nanofiltration membranes is the production of a concentrate stream that cannot be discharged to the environment. In this research we investigate the concept of a combined MBR and NF system with NF concentrate recirculation back to the MBR to produce reusable water in a sustainable way. Long-term continuous operation (1 year) shows that the NF permeate quality is riot impacted by the recirculation. Fouling on the NF membrane is mostly the result of inorganics, while organics (e.g. humic acids) do not have a major impact on NF fouling. In fact, the flux of the NF was enhanced by the presence of humic acids due to recirculation. However, the MBR showed increased fouling and consequently more frequent membrane cleaning. The results presented show that the continuous production of reusable water from wastewater in a combined MBR and NO process with NO concentrate recirculation can be successful. (C) 2013 Elsevier B.V. All rights reserved
    Urban agriculture in Portugal: Availability of potentially toxic elements for plant uptake
    Cruz, N. ; Rodriguez, S.M. ; Coelho, C. ; Carvalho, L. ; Duarte, A.C. ; Pereira, E. ; Romkens, P.F.A.M. - \ 2014
    Applied Geochemistry 44 (2014). - ISSN 0883-2927 - p. 27 - 37.
    halimione-portulacoides - contaminated soils - european cities - trace-elements - lolium-perenne - heavy-metals - part i - vegetables - cadmium - mercury
    Soils from urban areas often contain enhanced pseudo-total levels of potentially toxic elements (PTEs). Considering the expanding tendency of urban agricultural practices it is necessary to understand if these contaminants are available for plant uptake and if they pose risks to animal and human health. This study showed that estimates of Daily Intakes (DIs) of Cu, Pb and Zn for grazing animals were above animal Acceptable Daily Intakes (ADIs) at specific sites under the influence of an airport, an oil refinery and near highways with high traffic rates in the "Grande Porto" urban area (Portugal). These results suggest that there is a potential for dietary transfer of contaminants associated with the ingestion of both contaminated soil and feed by cows and sheep at unacceptably high concentrations.Furthermore, results showed that 40% of variability of ryegrass shoot contents of Cu, Pb and Ni; 60% for Ba; 70% for Zn; and 80% for Cd can be significantly (p
    Lanthanum from a modified clay used in eutrophication control is bioavailable to the marbled crayfish (Procambarus fallax f. virginalis)
    Oosterhout, F. van; Goitom, E. ; Roessink, I. ; Lurling, M. - \ 2014
    PLoS ONE 9 (2014)7. - ISSN 1932-6203 - 9 p.
    phosphorus binding clay - copper nickel smelters - rare-earth-elements - heavy-metals - fresh-water - lakes - toxicity - accumulation - phoslock(r) - sediment
    To mitigate eutrophication in fresh standing waters the focus is on phosphorus (P) control, i.e. on P inflows to a lake as well as a lake's sediment as internal P source. The in-lake application of the lanthanum (La) modified clays – i.e. La modified bentonite (Phoslock) or La modified kaolinite, aim at dephosphatising the water column and at reducing the release of P from a lake's sediment. Application of these clays raises the question whether La from these clays can become bioavailable to biota. We investigated the bioavailability of La from Phoslock in a controlled parallel groups experiment in which we measured the La in carapace, gills, ovaries, hepatopancreas and abdominal muscle after 0, 14 and 28 days of exposure to Phoslock. Expressing the treatment effect as the difference of the median concentration between the two treatment groups (Phoslock minus control group) yield the following effects, the plus sign (+) indicating an increase, concentrations in µg g-1 dry weight: Day 14: carapace +10.5 µg g-1, gills +112 µg g-1, ovaries +2.6 µg g-1, hepatopancreas +32.9 µg g-1 and abodminal muscle +3.2 µg g-1. Day 28: carapace +17.9 µg g-1; gills +182 µg g-1; ovaries +2.2 µg g-1; hepatopancreas +41.9 µg g-1 and abodminal muscle +7.6 µg g-1, all effects were statistically significant. As La from Phoslock is bio-available to and taken up by the marbled crayfishes (Procambarus fallax f. virginalis), we advocate that the application of in-lake chemical water treatments to mitigate eutrophication should be accompanied by a thorough study on potential side effects
    Multi-face modeling to predict free zinc ion concentrations in low-zinc soils
    Duffner, A. ; Weng, L. ; Hoffland, E. ; Zee, S.E.A.T.M. van der - \ 2014
    Environmental Science and Technology 48 (2014)10. - ISSN 0013-936X - p. 5700 - 5708.
    donnan membrane technique - organic-matter - heavy-metals - contaminated soils - isotopic exchange - humic substances - trace-metals - sandy soil - adsorption - speciation
    Multi-surface models are widely used to assess the potential ecotoxicological risk in metal-contaminated soils. Their accuracy in predicting metal speciation in soils with low metal levels was not yet tested. Now highly sensitive analytical techniques are available to experimentally validate such models at low concentration levels. The objective of this study was to test the accuracy of a multi-surface model to predict the Zn2+ concentration and to improve our understanding of Zn bioavailability in low-Zn soils. High-Zn soils were included as controls. Model parameters were determined independently on the basis of earlier peer-reviewed publications. Model output was validated against free Zn2+ concentrations determined with the soil column Donnan membrane technique in a range of soils varying in potentially available Zn, organic matter, clay silicate, and iron (hydr)oxide contents and pH. Deviations between predicted Zn2+ concentrations and experimentally determined values over the whole Zn concentration range were less or equal to the experimental standard error, except for one low-Zn soil. The Zn2+ concentration was mainly controlled by adsorption, where organic matter was predicted to be the dominant soil sorbent. The predicted Zn2+ concentration depends more sensitively upon changes of the reactive Zn pool (application of 0.6, 1.2, 2.4, and 3.6 mg of Zn kg–1 of soil) and organic matter content (±0.2 and 0.4%) than pH changes (±0.5 and 1 pH unit).
    Retention and distribution of Cu, Pb, Cr, and Zn in a full-scale hybrid constructed wetland receiving municipal sewage
    Xiao, H.W. ; Zhang, S.L. ; Zhai, J. ; He, Q. ; Mels, A.R. ; Ning, K.J. ; Liu, J. - \ 2013
    Water Science and Technology 67 (2013)10. - ISSN 0273-1223 - p. 2257 - 2264.
    afvalwaterbehandeling - helofytenfilters - zware metalen - verontreinigde sedimenten - plantenweefsels - waste water treatment - artificial wetlands - heavy metals - contaminated sediments - plant tissues - waste-water treatment - acid-mine drainage - heavy-metals - removal - performance - experience - decades - china
    This study was conducted to investigate the retention and distribution of Cu, Pb, Cr, and Zn in a hybrid constructed wetland (CW) that consists of both vertical baffled flow wetlands (VBFWs) and horizontal subsurface flow wetlands (HSSFs) with unique flow regimes and oxygen distribution. The heavy metal concentrations in water, sediments, and plant tissues in the hybrid CW were analysed. The removal of heavy metals from the water stream in the monitoring period was not statistically significant. Metal concentrations in the sediments generally decreased along the wastewater treatment process. The reductive anaerobic condition in the VBFW may promote the sulphate reduction and form highly insoluble Cu, Pb, and Zn sulphides, resulting in the higher concentration of the bivalent cations in the VBFW sediments than the corresponding values in the HSSF; however, the aerobic and anoxic environments in the HSSF enhanced the removal of Cr with the co-precipitation of iron and manganese oxides, and their hydroxides. Metal concentrations in plant tissues were not significantly influenced by the concentrations in sediments, while roots contained statistically higher metal concentrations than stems and leaves. The sediments stored 94.01, 86.31, 95.85, and 89.51% of the total Cu, Pb, Cr, and Zn retained in the hybrid CW system, respectively, while only small fractions (
    Estimation of atmospheric nutrient inputs to the Atlantic Ocean from 50 degrees N to 50 degrees S based on large-scale field sampling: Iron and other dust-associated elements
    Baker, A.R. ; Adams, C. ; Bell, T.G. ; Jickells, T.D. ; Ganzeveld, L.N. - \ 2013
    Global Biogeochemical Cycles 27 (2013)3. - ISSN 0886-6236 - p. 755 - 767.
    north-atlantic - wet deposition - saharan dust - mediterranean-sea - aerosol-particles - tropical north - trace-elements - heavy-metals - major ions - transport
    Atmospheric inputs of mineral dust supply iron and other trace metals to the remote ocean and can influence the marine carbon cycle due to iron's role as a potentially limiting micronutrient. Dust generation, transport, and deposition are highly heterogeneous, and there are very few remote marine locations where dust concentrations and chemistry (e.g., iron solubility) are routinely monitored. Here we use aerosol and rainwater samples collected during 10 large-scale research cruises to estimate the atmospheric input of iron, aluminum, and manganese to four broad regions of the Atlantic Ocean over two 3month periods for the years 2001-2005. We estimate total inputs of these metals to our study regions to be 4.2, 17, and 0.27Gmol in April-June and 4.9, 14, and 0.19Gmol in September-November, respectively. Inputs were highest in regions of high rainfall (the intertropical convergence zone and South Atlantic storm track), and rainfall contributed higher proportions of total input to wetter regions. By combining input estimates for total and soluble metals for these time periods, we calculated overall percentage solubilities for each metal that account for the contributions from both wet and dry depositions and the relative contributions from different aerosol types. Calculated solubilities were in the range 2.4%-9.1% for iron, 6.1%-15% for aluminum, and 54%-73% for manganese. We discuss sources of uncertainty in our estimates and compare our results to some recent estimates of atmospheric iron input to the Atlantic.
    Arsenate and phosphate adsorption in relation to oxides composition in soils: LCD modelling
    Cui, Y. ; Weng, L. - \ 2013
    Environmental Science and Technology 47 (2013)13. - ISSN 0013-936X - p. 7269 - 7276.
    charge-distribution - humic substances - competitive adsorption - ion adsorption - heavy-metals - speciation - parameters - minerals - sorption - binding
    The pH dependent solid-solution distribution of arsenate and phosphate in five Dutch agricultural soil samples was measured in the pH range 4–8, and the results were interpreted using the LCD (ligand and charge distribution) adsorption modeling. The pH dependency is similar for both oxyanions, with a minimum soluble concentration observed around pH 6–8. This pH dependency can be successfully described with the LCD model and it is attributed mainly to the synergistic effects from Ca adsorption. The solubility of phosphate is much lower than that of arsenate. This big difference cannot be sufficiently explained by the reduction of small amount of As(V) into As(III), neither by slow desorption/adsorption. The difference between phosphate and arsenate in their solid-solution distribution becomes larger with the increase of aluminum (hydr)oxides (Al-oxides) contribution to the total amount of metal (Al and Fe) (hydr)oxides. The influence of Al-oxides is much larger than its relative amount extracted from the soils. When Al-oxides account for >40% of the soil oxides, the whole adsorbents behave apparently similarly to that of pure Al-oxides. These results indicated that surface coating and substitution may have modified significantly oxyanion adsorption to Fe-oxides in soils, and how to account for this complexity is a challenge for geochemical modeling.
    Risks associated with the transfer of toxic organo-metallic mercury from soils into the terrestrial feed chain
    Henriques, B. ; Rodrigues, S.M. ; Coelho, C. ; Cruz, N. ; Duarte, A.C. ; Romkens, P.F.A.M. ; Pereira, E. - \ 2013
    Environment International 59 (2013). - ISSN 0160-4120 - p. 408 - 417.
    oryza-sativa-l. - atomic-absorption-spectrometry - inorganic mercury - heavy-metals - chloralkali plant - asturias spain - food-chain - part i - rice - methylmercury
    Although the transfer of organo-metallic mercury (OrgHg) in aquatic foodwebs has long been studied, it has only been recently recognized that there is also accumulation in terrestrial systems. There is still however little information about the exposure of grazing animals to OrgHg from soils and fHenriqueseed as well as on risks of exposure to animal and humans. In this study we collected 78 soil samples and 40 plant samples (Lolium perenne and Brassica juncea) from agricultural fields near a contaminated industrial area and evaluated the soil-to-plant transfer of Hg as well as subsequent trophic transfer. Inorganic Hg (IHg) concentrations ranged from 0.080 to 210 mg kg-1 d.w. in soils, from0.010 to 84 mg kg-1 d.w. in roots and from0.020 to 6.9 mg kg-1 d.w. in shoots.OrgHg concentrations in soils varied between 0.20 and 130 µg kg-1 d.w. representing on average 0.13% of the total Hg (THg). In root and shoot samples OrgHg comprised on average 0.58% (roots) and 0.66% (shoots) of THg. Average bioaccumulation factors (BAFs) for OrgHg in relation to soil concentrations were 3.3 (for roots) and 1.5 (for shoots). The daily intake (DI) of THg in 33 sampling sites exceeded the acceptable daily intake (ADI) of THg of both cows (ADI = 1.4 mg d-1) and sheep (ADI = 0.28 mg d-1), in view of food safety associated with THg in animal kidneys. Estimated DI of OrgHg for grazing animals were up to 220 µg d-1 (for cows) and up to 33 µg d-1 (for sheep). This study suggested that solely monitoring the levels of THg in soils and feedmay not allow to adequately taking into account accumulation of OrgHg in feed crops and properly address risks associatedwith OrgHg exposure for animals and humans. Hence, the inclusion of limits for OrgHg in feed quality and food safety legislation is advised.
    Safety of Novel Protein Sources (Insects, Microalgae, Seaweed, Duckweed, and Rapeseed) and Legislative Aspects for Their Application in Food and Feed Production
    Spiegel, M. van der; Noordam, M.Y. ; Fels-Klerx, H.J. van der - \ 2013
    Comprehensive Reviews in Food Science and Food Safety 12 (2013)6. - ISSN 1541-4337 - p. 662 - 678.
    culturing aquatic organisms - cross-reactive allergen - sludge-grown algae - lemna-minor l. - heavy-metals - chemical-composition - atopic-dermatitis - edible insects - oilseed rape - turnip rape
    Novel protein sources (like insects, algae, duckweed, and rapeseed) are expected to enter the European feed and food market as replacers for animal-derived proteins. However, food safety aspects of these novel protein sources are not well-known. The aim of this article is to review the state of the art on the safety of major novel protein sources for feed and food production, in particular insects, algae (microalgae and seaweed), duckweed, and rapeseed. Potential hazards for these protein sources are described and EU legislative requirements as regard to food and feed safety are explained. Potential hazards may include a range of contaminants, like heavy metals, mycotoxins, pesticide residues, as well as pathogens. Some safety aspects of novel protein sources are intrinsic to the product, but many potential hazards can also be due to production methods and processing conditions. These aspects should be considered in advance during product development. European law is unclear on several issues regarding the use of novel protein sources in food and feed products. For food product applications, the most important question for food producers is whether or not the product is considered a novel food. One of the major unclarities for feed applications is whether or not products with insects are considered animal-derived products or not. Due to the unclarities in European law, it is not always clear which Regulation and maximum levels for contaminants apply. For market introduction, European legislation should be adjusted and clarified.
    Biovailability of copper and zinc in pig and cattle slurries
    Jakubus, M. ; Dach, J. ; Starmans, D.A.J. - \ 2013
    Fressenius Environmental Bulletin 22 (2013)4. - ISSN 1018-4619 - p. 995 - 1002.
    sequential extraction procedures - heavy-metals - soils - fractionation - speciation - sediments - manganese - sludge - nickel - lead
    Slurry is an important source of macronutrients, micro-nutrients and organic matter. Despite the considerable fertilizer value of slurry, it may be abundant in amounts of copper and zinc originating from dietary. The study presents quantitative changes in copper and zinc in individual slurries (pig and cattle slurries). The bioavailability of copper and zinc was estimated on the basis of amounts of the metals in isolated fractions using the sequential extraction method. Sequential techniques identify fractions which describe different connections of metals with the compost solid phase beginning with those that are easiest soluble up to those that dissolve with the greatest difficulties.Pig slurry was characterized by 2-fold higher amounts of copper and zinc in comparison to the levels detected in cattle slurries. Quantitative changes of the elements in the sequentially isolated fractions of analyzed slurries differed. First of all, this was dependent on the chemical character of a given metal, followed by the animal species, or the type of management. Irrespective of the type of slurry, 40-56% of the total amounts of copper were found in hardly available combinations, while available copper forms accounted for only 6.6–10.9%. Zinc was found predominantly in com-binations with iron and manganese oxides which, irrespective of the tested slurry, ranged from 130.64 mg·kg-1 to 293.60 mg·kg-1. Bioavailable metal contents, potentially introduced to soil with slurry doses, calculated as 170 kg total N/ha/year, ranged from 63.6 to 124.5 g for copper, and from 349.5 to 696.4 g for zinc. The estimated amounts of metal inputs to agricultural land demonstrate that soils are potentially at risk of heavy metal accumulation from the application of pig and cattle slurries.
    Incorporating availability/bioavailability in risk assessment and decision making of polluted sites, using Germany as an example
    Kördel, W. ; Bernardt, C. ; Derz, K. ; Hund-Rinke, K. ; Harmsen, J. ; Peijenburg, W. ; Comans, R.N.J. ; Terytze, K. - \ 2013
    Journal of Hazardous Materials 261 (2013). - ISSN 0304-3894 - p. 854 - 862.
    polycyclic aromatic-hydrocarbons - solid-phase microextraction - polychlorinated-biphenyls - terrestrial environments - contaminated sediments - tenax(r) extraction - organic-compounds - soil extraction - heavy-metals - trace-metals
    Nearly all publications dealing with availability or bioavailability of soil pollutants start with the following statement: the determination of total pollutant content will lead to an over-estimation of risk. However, an assessment of contaminated sites should be based on the determination of mobile fractions of pollutants, and the fractions with potential for mobilisation that threaten groundwater and surface water, and the actual and potential fractions available for uptake by plants, soil microflora and soil organisms. After reviewing the literature for method proposals concerning the determination of available/bioavailable fractions of contaminants with respect to leaching, plants, microorganisms (biodegradation) and soil organisms, we propose a testing and assessment scheme for contaminated sites. The proposal includes (i) already accepted and used methods, (ii) methods which are under standardisation, and (iii) methods for which development has just started in order to promote urgently needed research. (C) 2013 Elsevier B.V. All rights reserved.
    Predicting zinc bioavailability to wheat improved by integrating pH dependent nonlinear root suface adsorption
    Duffner, A. ; Hoffland, E. ; Weng, L.P. ; Zee, S.E.A.T.M. van der - \ 2013
    Plant and Soil 373 (2013)1-2. - ISSN 0032-079X - p. 919 - 930.
    donnan membrane technique - ion activity model - dtpa soil test - heavy-metals - trace-metals - chemical speciation - contaminated soils - calcareous soils - aquatic systems - organic-matter
    Aim Our aim was to improve the prediction of Zn bioavailability to wheat grown on low-Zn soils. The classical approach that directly relates Zn in a certain soil extract to Zn uptake has been shown to be inadequate in many cases. We tested a stepwise approach where the steps of the uptake process are characterized with, respectively, Zn solid-solution distribution, adsorption of Zn to root surface, Zn uptake into root and Zn translocation to shoot. Methods Two pot experiments were done with wheat grown on nine low-Zn soils varying widely in pH, clay and organic matter content. Soluble Zn concentrations in two soil extracts (DTPA and CaCl2) were measured. Free Zn ion concentrations in CaCl2 soil extracts were determined with the Donnan Membrane Technique. These Zn concentrations were then related to plant Zn uptake following both the direct and the stepwise approach. Results In the direct approach, Zn in the DTPA extract was a better predictor for shoot Zn uptake than Zn in the CaCl2 extract. In the stepwise approach, the relationship between Zn in CaCl2 extracts and the root surface adsorbed Zn was pH-dependent and nonlinear. Root surface adsorbed Zn was linearly related to root Zn uptake, and the latter was linearly related to the shoot Zn uptake. The stepwise approach improved the Zn uptake prediction compared to the direct approach and was also validated for different wheat cultivars. Conclusions The adsorption of Zn on the root surface is pH dependent and nonlinear with respect to the soil Zn concentration, and a useful proxy for bioavailable Zn over a wide range of soils.
    Metal exposure and accumulation patterns in free-range cows (Bos taurus) in a contaminated natural area: Influence of spatial and social behavior
    Roggeman, S. ; Brink, N.W. van den; Praet, N. van; Blust, R. ; Bervoets, L. - \ 2013
    Environmental Pollution 172 (2013). - ISSN 0269-7491 - p. 186 - 199.
    hedgehog erinaceus-europaeus - potentially-toxic metals - dry-matter intake - heavy-metals - cadmium accumulation - trace-elements - environmental exposure - modeling cadmium - soil ingestion - mining area
    Possible effects of spatial metal distribution, seasonal-, ecological- and ethological parameters, on the metal exposure of cows were investigated. Therefore the habitat use, vegetation selection and foraging behavior of two free ranging Galloway herds in a metal polluted nature reserve were observed. Metal concentrations in soil, vegetation, hair, blood and feces were measured. Although both herds lived in the same reserve, their metal exposure differed significantly. A high consumption of soft rush by herd 1 during winter for instance was responsible for a large increase in daily Cd intake. The results of this study suggest that the exposure and health risks of large grazers can probably not only be predicted by general monitoring of soil and vegetation pollution. Also detailed information about the occurring vegetation types, spatial habitat use together with the social- and foraging behavior and diet selection of the species need to be studied.
    A meta-database comparison from various European research networks dedicated to forests sites
    Danielewska, A. ; Clarke, N. ; Olejnik, J. ; Hansen, K. ; Vries, W. de - \ 2013
    iForest : Biogeosciences and Forestry 6 (2013). - ISSN 1971-7458 - p. 1 - 9.
    nitrogen deposition - terrestrial ecosystems - anthropogenic sources - air-pollutants - climate-change - united-states - heavy-metals - carbon - ozone - pollution
    Of a wide variety of international forest research and monitoring networks, several networks are dedicated to the effects of climate change on forests, while the effects of anthropogenic pollutants on forests have been a major area for both monitoring and research for decades. The large amounts of data already obtained within existing monitoring programmes and large-scale international projects can be used to increase understanding of the state and potential of forest mitigation and adaptation to climate change in a polluted environment, and a major challenge now is to evaluate and integrate the presently available databases. We present a meta-database with the main goal to highlight available data and integrate the information about research and monitoring of selected European Research and Monitoring Networks (ERMNs). Depending on the selected ERMNs, the list of variables and the measurement units differ widely in the databases. As a result, activities related to the identification, evaluation and integration of the presently available databases are important for the scientific community. Furthermore, and equally important, the recognition of current knowledge gaps and future needed research is made easier. This analysis suggests that: ground-level ozone is under-investigated, although it is one of the pollutants of greatest concern to forests; in addition to CO2, long-term other greenhouse gasses (GHG) flux measurements should be carried out; there is still a need of improving links between monitoring of atmospheric changes and impacts on forests; research-oriented manipulative experiments in the forests are missing.
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