Moving persistence assessments into the 21st century: A role for weight-of-evidence and overall persistence.

Assessing the persistence of chemicals in the environment is a key element in existing regulatory frameworks to protect human health and ecosystems. Persistence in the environment depends on many fate processes, including abiotic and biotic transformations and physical partitioning, which depend on substances' physicochemical properties and environmental conditions. A main challenge in persistence assessment is that existing frameworks rely on simplistic and reductionist evaluation schemes that may lead substances to be falsely assessed as persistent or the other way around-to be falsely assessed as nonpersistent.

Temporal patterns of digestive enzyme activities and feeding rate in gammarids (Gammarus fossarum) exposed to inland polluted waters.

The aim of this study was to use digestive enzyme activities in Gammarus fossarum as biomarkers during active biomonitoring. Standardised gammarids were transplanted for 7 days to five sites in the Riou Mort watershed contaminated by polymetallic pollution. This experiment was conducted on seven different dates from February 2009 to June 2010.

Seasonal and PAH impact on DNA strand-break levels in gills of transplanted zebra mussels.

Genotoxicity endpoints are useful tools to biomonitor the physicochemical and biological quality of aquatic ecosystems. A caging study on the freshwater bivalve Dreissena polymorpha was planned to run over four seasons in the Seine River basin in order to assess whether DNA damage measured in transplanted mussels to polluted area vary according to seasonal changes. Three sites were chosen along the Seine River, one upstream from Paris and two downstream, corresponding to a chemical gradient of water contamination.

One-year monitoring of core biomarker and digestive enzyme responses in transplanted zebra mussels (Dreissena polymorpha).

A 12-month active biomonitoring study was performed in 2008-2009 on the Vesle river basin (Champagne-Ardenne, France) using the freshwater mussel Dreissena polymorpha as a sentinel species; allochthonous mussels originating from a reference site (Commercy) were exposed at four sites (Bouy, Sept-Saulx, Fismes, Ardre) within the Vesle river basin. Selected core biomarkers (acetylcholinesterase (AChE) activity, glutathione-S transferase (GST) activity, metallothionein concentration), along with digestive enzyme activities (amylase, endocellulase) and energy reserve concentrations (glycogen, lipids), were monitored throughout the study in exposed mussels. At the Fismes and Ardre sites (downstream basin), metallic and organic contamination levels were low but still high enough to elicit AChE and GST activity induction in exposed mussels (chemical stress); besides, chemical pollutants had no apparent deleterious effects on mussel condition.

In situ assessment of phytotechnologies for multicontaminated soil management.

Due to human activities, large volumes of soils are contaminated with organic pollutants such as polycyclic aromatic hydrocarbons, and very often by metallic pollutants as well. Multipolluted soils are therefore a key concern for remediation. This work presents a long-term evaluation of the fate and environmental impact of the organic and metallic contaminants of an industrially polluted soil under natural and plant-assisted conditions.

One-year monitoring of reproductive and energy reserve cycles in transplanted zebra mussels (Dreissena polymorpha).

A 12-month active biomonitoring study was performed in 2008-2009 on a northern French river system using the freshwater mussel Dreissena polymorpha as a sentinel species. Allochtonous mussels originating from a reference site (Commercy) were caged at four sites (Bouy, Sept-Saulx, Fismes, Ardre) within the Vesle River basin. The main objective of the study was to characterize the influence of biotic (sex, food availability) and abiotic (temperature, chemicals) factors on the reproductive and energy reserve (glycogen, lipids) cycles of exposed mussels.

Lessons from a transplantation of zebra mussels into a small urban river: An integrated ecotoxicological assessment.

It is often difficult to evaluate the level of contamination in small urban rivers because pollution is mainly diffuse, with low levels of numerous substances. The use of a coupled approach using both chemical and biological measurements may provide an integrated evaluation of the impact of micro-pollution on the river. Zebra mussels were transplanted along a metal and organic pollution gradient in spring 2008.

Effects of metals on feeding rate and digestive enzymes in Gammarus fossarum: an in situ experiment.

The feeding activity and afterward the assimilation of the products resulting of the food digestion, allow organisms to obtain energy useful for growth, maintenance and reproduction. These biological parameters may be studied to assess the impact of contaminants on the energy metabolism of organisms, which could induce potential effects at an individual level. The studied species was an amphipod Gammarus fossarum, which has a high ecological relevance since it is widespread in European streams and plays a major role in the breakdown of leaf litter.

Bioavailability of chemical pollutants in contaminated soils and pitfalls of chemical analyses in hazard assessment.

Decision-making for remediation of industrial wastelands are still based on the concentrations of pollutants of concern measured in soils. In this work, two soils polluted by polycyclic aromatic hydrocarbons (PAHs) and metals were investigated for their toxicity on earthworms (Eisenia fetida), collembolae (Folsomia candida), and higher plants (Brassica chinensis, Lactucca sativa and Avena sativa) in order to study the relationships between chemical contamination and biological effects. Although the level of contamination by PAHs was elevated and commensurate in the two soils, their toxicity profile was quite different.