Little information is available on the environmental occurrence and ecotoxicological effects of pharmaceutical gestagens released in the aquatic environment. Since eighteen different gestagens were found to be used in France, preliminary exposure and hazard assessment were done. Predicted environmental concentrations (PECs) suggest that if parent gestagens are expected to be found in the ng l−1 range, some active metabolites could be present at higher concentrations, although limited data on metabolism and environmental fate limit the relevance of PECs. The biological effects are not expected to be restricted to progestagenic activity. Both anti-androgenic activity (mainly for cyproterone acetate, chlormadinone acetate and their metabolites) and estrogenic activity (mainly for reduced metabolites of levonorgestrel and norethisterone) should also occur. All these molecules are likely to have a cumulative effect among themselves or with other xenoestrogens. Studies on occurrence, toxicity and degradation time are therefore needed for several of these compounds. Gestagens exposure and hazard assessment for the aquatic environment.

[Departement_IRSTEA]Eaux [TR1_IRSTEA]BELCA | Little information is available on the environmental occurrence and ecotoxicological effects of pharmaceutical gestagens released in the aquatic environment. Since eighteen different gestagens were found to be used in France, preliminary exposure and hazard assessment were done. Predicted environmental concentrations (PECs) suggest that if parent gestagens are expected to be found in the ng l−1 range, some active metabolites could be present at higher concentrations, although limited data on metabolism and environmental fate limit the relevance of PECs. The biological effects are not expected to be restricted to progestagenic activity. Both anti-androgenic activity (mainly for cyproterone acetate, chlormadinone acetate and their metabolites) and estrogenic activity (mainly for reduced metabolites of levonorgestrel and norethisterone) should also occur. All these molecules are likely to have a cumulative effect among themselves or with other xenoestrogens. Studies on occurrence, toxicity and degradation time are therefore needed for several of these compounds.

The importance of earthworms to ecosystem functioning has led to many studies on the impacts of metals on earthworms. Far less attention has been paid to the impact that earthworms have on soil metals both in terms of metal mobility and availability. In this review we consider which earthworms have been used in such studies, which soil components have been investigated, which types of soil have been used and what measures of mobility and availability applied. We proceed to review proposed reasons for effects: changes in microbial populations, pH, dissolved organic carbon and metal speciation. The balance of evidence suggests that earthworms increase metal mobility and availability but more studies are required to determine the precise mechanism for this. We review the impact of earthworms on metal mobility and availability and suggest areas for further investigation.

The importance of earthworms to ecosystem functioning has led to many studies on the impacts of metals on earthworms. Far less attention has been paid to the impact that earthworms have on soil metals both in terms of metal mobility and availability. In this review we consider which earthworms have been used in such studies, which soil components have been investigated, which types of soil have been used and what measures of mobility and availability applied. We proceed to review proposed reasons for effects: changes in microbial populations, pH, dissolved organic carbon and metal speciation. The balance of evidence suggests that earthworms increase metal mobility and availability but more studies are required to determine the precise mechanism for this. (C) 2009 Elsevier Ltd. All rights reserved.

Community structure and microcystin accumulation of freshwater molluscs were studied before and after cyanobacterial proliferations, in order to assess the impact of toxic blooms on molluscs and the risk of microcystin transfer in food web. Observed decrease in mollusc abundance and changes in species richness in highly contaminated waters were not significant; however, relative abundances of taxa (prosobranchs, pulmonates, bivalves) were significantly different before and after cyanobacterial bloom. Pulmonates constituted the dominant taxon, and bivalves never occurred after bloom. Microcystin accumulation was significantly higher in molluscs from highly (versus lowly) contaminated waters, in adults (versus juveniles) and in pulmonates (versus prosobranchs and bivalves). Results are discussed according to the ecology of molluscs, their sensitivity and their ability to detoxify.

International audience | Community structure and microcystin accumulation of freshwater molluscs were studied before and after cyanobacterial proliferations, in order to assess the impact of toxic blooms on molluscs and the risk of microcystin transfer in food web. Observed decrease in mollusc abundance and changes in species richness in highly contaminated waters were not significant; however, relative abundances of taxa (prosobranchs, pulmonates, bivalves) were significantly different before and after cyanobacterial bloom. Pulmonates constituted the dominant taxon, and bivalves never occurred after bloom. Microcystin accumulation was significantly higher in molluscs from highly (versus lowly) contaminated waters, in adults (versus juveniles) and in pulmonates (versus prosobranchs and bivalves). Results are discussed according to the ecology of molluscs, their sensitivity and their ability to detoxify.

Guidelines provided by the OECD and EPPO allow the use of single-species tests performed in greenhouses to assess the risk of herbicides to non-target terrestrial plant communities in the field. The present study was undertaken to investigate the use of greenhouse data to determine effects of herbicides with a different mode of action on the biomass, seed production and emergence of field-grown plants. In addition, a single species approach was compared with a mixed species approach. Effects on the biomass of greenhouse and field-grown plants were found to be related at different effect levels, indicating that it might be possible to translate results from greenhouse studies to field situations. However, the use of single-species tests may not be valid. The response of a single plant species to sublethal herbicide dosages differed to the response of the same species grown in a mixture with other species. The use of single-species greenhouse tests in the ecological risk assessment of crop protection products may only be valid for single species in the field, not for vegetations.

Guidelines provided by the OECD and EPPO allow the use of single-species tests performed in greenhouses to assess the risk of herbicides to non-target terrestrial plant communities in the field. The present study was undertaken to investigate the use of greenhouse data to determine effects of herbicides with a different mode of action on the biomass, seed production and emergence of field-grown plants. In addition, a single species approach was compared with a mixed species approach. Effects on the biomass of greenhouse and field-grown plants were found to be related at different effect levels, indicating that it might be possible to translate results from greenhouse studies to field situations. However, the use of single-species tests may not be valid. The response of a single plant species to sublethal herbicide dosages differed to the response of the same species grown in a mixture with other species. The use of single-species greenhouse tests in the ecological risk assessment of crop protection products may only be valid for single species in the field, not for vegetations. Keywords: Non-crop terrestrial plants; Tepraloxydim; Greenhouse; Field; Biomass

Among the numerous PCB congeners, most of the dioxin-like PCBs (DL-PCBs) need to be characterized by hyphenated techniques. It has been shown in several instances that these congeners are well related to the total PCB content in fish. We examined datasets collected mainly in France, on freshwater and marine fish and sediments. A statistical model linking DL- and indicator PCBs was developed for a dataset composed of freshwater fishes, and proved to predict well DL-PCBs from indicator PCBs in all other fish sets, including marine ones. Type II error rates remained low in almost all fish sets. A similar correlation was observed in sediments. Non-dioxin-like PCBs elicit various adverse effects and represent 95% of the total PCBs. A European guideline for them is needed; the correlation between DL- and indicator PCBs could help develop this standard in the future. Dioxin-like PCBs in fish and maybe sediments are rather well predicted by indicator PCBs.

Among the numerous PCB congeners, most of the dioxin-like PCBs (DL-PCBs) need to be characterized by hyphenated techniques. It has been shown in several instances that these congeners are well related to the total PCB content in fish. We examined datasets collected mainly in France, on freshwater and marine fish and sediments. A statistical model linking DL- and indicator PCBs was developed for a dataset composed of freshwater fishes, and proved to predict well DL-PCBs from indicator PCBs in all other fish sets, including marine ones. Type II error rates remained low in almost all fish sets. A similar correlation was observed in sediments. Non-dioxin-like PCBs elicit various adverse effects and represent 95% of the total PCBs. A European guideline for them is needed; the correlation between DL- and indicator PCBs could help develop this standard in the future. (C) 2009 Elsevier Ltd. All rights reserved.

[Departement_IRSTEA]Eaux [TR1_IRSTEA]BELCA | Among the numerous PCB congeners, most of the dioxin-like PCBs (DL-PCBs) need to be characterized by hyphenated techniques. It has been shown in several instances that these congeners are well related to the total PCB content in fish.We examined datasets collected mainly in France, on freshwater and marine fish and sediments. A statistical model linking DL- and indicator PCBs was developed for a dataset composed of freshwater fishes, and proved to predict well DL-PCBs from indicator PCBs in all other fish sets, including marine ones. Type II error rates remained low in almost all fish sets. A similar correlation was observed in sediments. Non-dioxin-like PCBs elicit various adverse effects and represent 95% of the total PCBs. A European guideline for them is needed; the correlation between DL- and indicator PCBs could help develop this standard in the future.