B Nowack

..The authors conclude that it is not possible to assess the risks associated with the use of ENM by investigating only the pristine form of the ENM, without considering alterations and transformation processes...

..This indicates that there was little transfer of the chelates into the symplast and that the apoplastic pathway, which is important for the transport of chelants into the shoots, is efficiently blocked between shoots and seeds...

..It is also important to notice that most NP in technical applications are functionalized and therefore studies using pristine NP may not be relevant for assessing the behavior of the NP actually used...

..This suggests that plant activity kept the metals in a more soluble form...

..Such a role warrants further investigations into the use of biodegradable chelants such as ethylenediaminedisuccinic acid (EDDS)...

..The results show that different silver textiles release different forms of silver during washing and that among the textiles investigated AgCl was the most frequently observed chemical form in the washwater...

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..The combination of different life cycle concepts with the evolving knowledge from toxicology and risk assessment can mitigate uncertainties and can provide an early basis for informed decision making by the industry and regulators...

..g., water, sediments, soils). We conclude that probabilistic modeling is very useful for predicting environmental concentrations of ENMs given the current lack of substantiated data...

..Nano-TiO(2) median PECs ranged from 11 to 1'623 ng L(-1) (conservative scenario) and from 2 to 1'618 ng L(-1) (optimistic scenario). The equivalent values for nano-ZnO and nano-Ag were by factors of 14 and 240 smaller...

..The results indicate that functional textiles release some TiO(2) particles, but that the amounts are relatively low and mostly not in the nanoparticulate range...

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..In addition some experiments were performed in order to determine the effect of acidic pH and dissolved ions on the binding properties of the chelating resin...

..For the other environmental compartments for which ecotoxicological data were available, no risks to organisms are presently expected...

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..First results show that much of the ENM released from products is present in matrix-bound form, but that also some fraction is released as single, dispersed nanoparticles...

..The results of this study make it possible for the first time to carry out a quantitative risk assessment of nanoparticles in the environment and suggest further detailed studies of nano-TiO2...

..Our study shows that agricultural activities involving nitrogen fertilization can have a strong influence on metal leaching and speciation...

..These differences may be due to the higher moisture content and homogeneous nature of the soils used in the pot experiment...

..caerulescens ecotypes, postulated earlier...

..The use of experimental in situ methods is thus giving new information on contaminant mineral behavior under field conditions...

..This shows that synthetic chelating agents do not necessarily increase uptake of heavy metals, when soluble concentrations are equal in the presence and absence of chelates...

..Our results prove that heap leaching using EDDS is a promising approach to reduce the heavy metal content of polluted soils...

..The results show that IMAC is an effective tool for the fractionation of copper complexing ligands that are capable of forming ternary complexes...

..Dissolved organic matter is important for metal speciation at low EDDS concentrations. Our results show that even in polluted soils EDDS is degraded from a level of several hundred micromoles to below 1 microM within 50 days...

..The detection limit is 0.01 microM. The method is applicable to the determination of the compound in water, soil solution and plant material at trace levels...

..Plant uptake reduced the dissolved Zn concentration and transpiration reduced Cu and Zn leaching...

..The new method has the potential to be used in other environmental media such as sediments or water to study the reactions of a variety of particles larger than 20 microm...

..g. light, temperature, water, and nutrients. To some degree, such indetermination has to be expected as an inherent feature of the system and the concept of bioavailability...

..We conclude that the extraction with EDDS at pH 7 showed the best compromise between extraction efficiency for Cu, Zn, and Pb and loss of Ca and Fe from the soil...

..The discussion of the influence of chelates on metal availability and fate also has to include the potential presence of other aminopolycarboxylate chelating agents besides the well-known EDTA and NTA...