Wastewater alters feeding rate but not vitellogenin level of Gammarus fossarum (Amphipoda).

Wastewater treatment plant (WWTP) effluents release complex mixtures of organic and inorganic micropollutants, including endocrine disrupting compounds, into receiving water bodies. These substances may cause adverse effects in aquatic communities as well as in ecosystem functions they provide. The aim of this study was to determine the potential impact of secondary treated wastewater released into a small Swiss stream on leaf litter decomposition based on feeding rates of the amphipod shredder Gammarus fossarum measured in situ. Additionally, endocrine disrupting effects downstream of the WWTP were investigated by measuring vitellogenin (vg) induction in male gammarids exposed in situ, as well as estrogen receptor activation using the Yeast Estrogen Screen (YES) involving passive sampler and grab water sample extracts. Extracts were also analysed for 424 organic micropollutants and selected transformation products. Gammarid feeding rate was significantly reduced 100, 200 and 400 m downstream of the WWTP effluent relative to the upstream site. While YES results showed significantly elevated estrogenicity at downstream sites, vg production in male gammarids was not induced. A laboratory experiment, in which gammarids were exposed to WWTP effluent, supported this observation. These results, hence, suggest that treated wastewater released into aquatic ecosystems impairs the ecosystem function of leaf litter decomposition. Vg levels in male gammarids measured by UPLC-MS/MS did, however, not alter.

The influence of particles on bioavailability and toxicity of pesticides in surface water.

Environmental risk assessment is an essential part of the approval process for pesticides. Exposure concentrations are compared with ecotoxicological data obtained from standardized laboratory studies and, if available, from field studies to determine the risk of a substance or formulation for aquatic communities. Predicted concentrations in surface waters are derived using, for example, the European FOrum for the Co-ordination of pesticide fate models and their USe (FOCUS) or the German Exposit models, which distinguish between exposure to dissolved and particle-associated pesticide concentrations, because the dissolved concentration is thought to be the best predictor of bioavailability and toxicity. Water and particle-associated concentrations are estimated based on the organic carbon-water partitioning coefficient (KOC ). This review summarizes published information on the influence of natural suspended solids on bioavailability and toxicity of pesticides to aquatic organisms (algae, invertebrates and fish), and the value of log KOC and log KOW (octanol-water coefficient) as sole predictors of the bioavailable fraction is discussed. The information showed that: 1) the quality and origin of suspended solids played an important role in influencing pesticide bioavailability and toxicity; 2) a decrease in toxicity due to the presence of suspended solids was shown only for pyrethroid insecticides with log KOW greater than 5, but the extent of this reduction depended on particle concentration and size, and potentially also on the ecotoxicological endpoint; 3) for pesticides with a log KOW less than 3 (e.g., triazines, carbamates, and organophosphates), the impact of particles on bioavailability and toxicity is small and species dependent; and 4) pesticide bioavailability is greatly influenced by the test species and their physiology (e.g., feeding behavior or digestion). We conclude that exposure of aquatic organisms to pesticides and environmental risk of many pesticides might be underestimated in prospective risk assessment, when predicted environmental concentration is estimated based on the KOC of a compound. Integr Environ Assess Manag 2017;13:585-600. © 2016 SETAC.

In vitro bioassays to screen for endocrine active pharmaceuticals in surface and waste waters.

In the context of the European Water Framework Directive (WFD) it is fully recognized that pharmaceuticals can represent a relevant issue for the achievement of the good chemical and ecological status of European surface water bodies. The recent European Directive on the review of priority substances in surface water bodies has included three pharmaceuticals of widespread use (diclofenac, 17α-ethinylestradiol (EE2), 17ß-estradiol (E2)) in the European monitoring list, the so-called watch list. Endocrine active pharmaceuticals such as EE2 and E2 (also occurring as natural hormone) can cause adverse effects on aquatic ecosystems at very low levels. However, monitoring of these pharmaceuticals within the watch list mechanism of the WFD and national monitoring programs can be difficult because of detection problems of most routine analytical methods. With proposed annual average Environmental Quality Standards (AA-EQS) of 0.035 ng/L and 0.4 ng/L, respectively, the estrogenic pharmaceutical EE2 and the natural hormone E2 are among those substances. Sensitive in vitro bioassays could reduce the current detection problems by measuring the estrogenic activity of environmental samples. In a short review article the application of this approach to screen and assess the risks of endocrine active pharmaceuticals with a focus on estrogenic pharmaceuticals in environmental waters is discussed.