THE CUTTING EDGE OF ENDOCRINE DISRUPTING CHEMICALS IN FRESHWATER FISHES
Résumé
In recent decades, industrial, agricultural and urban waste has been discharged into rivers, streams, lakes and estuaries causing a considerable increase in pollution and the progressive degradation of freshwater ecosystems. The effluents from most cities and industrial plants contain a large variety of pollutants including polycyclic aromatic hydrocarbons (PAHs), surfactants and persistent organic pollutants (POPs). The twelve worst POPs defined by the Stockholm Convention have been clustered into three main classes: pesticides, industrial chemicals such as PCBs, and dioxin-like PCBs (PCDD/PCDF). These last compounds are responsible for high chronic toxicity, hydrophobicity, and are also well-known to interfere with endocrine systems; so called endocrine disrupting compounds (EDs). Even low concentrations of EDs in freshwater environments represent a significant threat to wildlife and ultimately to human health. In the present study, we investigate the impact of EDs in freshwater fishes and review the cutting edge of the principal molecular tools (biomarkers such as vitellogenin, cathepsin D, aromatase and spiggin) commonly used to assess their impact. Finally, we highlight examples of the growing contribution made by DNA microarray technology to ecotoxicology studies and monitoring.