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In many countries, the fox (Vulpes vulpes), predator of small mammals, is particularly affected by anticoagulant rodenticides such as bromadiolone due to secondary poisoning. Nevertheless, to date, no method of exposure monitoring is applicable in the field over large areas, and no toxicological data are available concerning sensitivity of foxes to bromadiolone. The aim of this work was to compare excretion kinetics of bromadiolone in fox faeces with clinical and haemostatic effects after repeated exposure to intoxicated voles. A sensitive method for the quantification of bromadiolone excretion in fox faeces and plasma was developed, using liquid chromatography combined with electrospray ionisation mass spectrometry (LC/ESI-MS). The LoD was 0.9microg/kg and 0.15microg/L, and the LoQ was 3.0microg/kg and 0.5microg/L, in faeces and in plasma, respectively. Four captive foxes were fed for 2 or 5 days with water voles (Arvicola terrestris Sherman) spiked with bromadiolone at concentrations close to those measured in the field. Faeces and blood were collected for bromadiolone titration, and blood-clotting tests were performed to monitor fox health daily during 10 days and then every 3-4 days until the end of the experiment (D28). Then, after euthanasia, a complete necropsy was performed, and levels of bromadiolone residues in the liver were determined. Bromadiolone residues were detected in faeces 15h after the first exposure. They increased dramatically during the exposure period and then gradually decreased, but they remained detectable at the end of the experiment, i.e., 26 days after the last exposure. Bromadiolone residues in plasma showed a similar pattern but were no longer detectable 7-24 days after the last exposure. Two foxes presented very severe external haemorrhages, requiring the administration of the antidote vitamin-K1. Bromadiolone residues in faeces and their relationships with exposure and other direct-markers that were measured are discussed. Liver residues and the toxicity data of our study will help to interpret data from fox carcasses collected by wildlife disease surveillance networks. These findings provide a basis for programs aiming to monitor the exposure of wild fox populations to bromadiolone using non-invasive methods based on standard sampling and analysis of residues in faeces., (Copyright 2010 Elsevier Inc. All rights reserved.)

This paper documents the exposure pattern of a population of small mammals to bromadiolone over time in a field-scale follow up. This is the first assessment of the field-scale effect of such control operation on the availability of bromadiolone-exposed A. terrestris prey to nontarget predator species. It indicates that an important risk of poisoning of nontarget species does exist during large-scale field control operations with bromadiolone, which is contradictory to results obtained from laboratory experiments in the early 1980s and consistent with the secondary poisoning hazards due to repeated exposure regularly reported during the past 20 years.

The effects of metal mixture (Cd+Cu) versus single-metal exposure on total MT response and bioaccumulation were investigated in the freshwater bivalve Dreissena polymorpha. A two-month exposure period, including two levels of contamination, was chosen for each of the two metals: 5, 10 microg/L for Cu, and 2, 20 microg/L for Cd, with mixtures of, respectively, 5 microg/L Cu+2 microg/L Cd, 5 microg/L Cu+20 microg/L Cd, 10 microg/L Cu+2 microg/L Cd, and 10 microg/L Cu+20 microg/L Cd. Total MT contents were assessed by an Ag-saturation method, and metals contents were determined by atomic absorption spectrometry. Results at the whole-organism level showed a significant and early increase of total MT biosynthesis after exposure to Cd. This increase was significantly correlated with Cd bioaccumulation. By contrast, Cu did not modify total MT response, and mussels limited Cu bioaccumulation. The mixture either did not influence or only weakly influenced metal accumulation and MT response to Cu and Cd after long-term exposure. Our results suggest that the form of MT existing in D. polymorpha was not Cu-inducible. This could limit the use of MT in D. polymorpha as a biomarker of heavy metal pollution in freshwater ecosystems.

Zebra mussels are common freshwater mollusks in many European lakes and rivers. Their abundance, wide distribution, and filtering activity make them good candidates to evaluate the contamination of freshwaters with environmental contaminants. The purpose of this work was to determine the kinetics of lindane in zebra mussels and compare laboratory results with in situ measurements. Exposure was conducted in small tanks, under controlled experimental conditions. Our results indicated that mussels accumulated lindane with a bioconcentration factor around 10. They generally reached equilibrium within 4 days. Elimination was rapid but biphasic and the terminal elimination half-life was long (> 168 h). Age of the mussels and temperature also affected the kinetics of lindane in mussels. In the Lake of Geneva, zebra mussels were sampled and showed that mussels accumulated it to significant values (up to 900 ng/g fresh weight) depending on the site and period of sampling. The in situ results, together with the laboratory exposures, showed that freshwater mussels could be used to monitor point sources of pollutants such as lindane over short periods of time (< 1 week).