Validation of biomarkers for impact evaluation of aqueous industrial waste in mesocosms

The use of exposure biomarkers in measuring the impact of aqueous waste holds promise because such tools have short response times, are flexible in use and may give an indication about the type of pollution. However, their ecological significance has not yet been demonstrated. It is necessary to validate these responses under controlled conditions before using such biomarkers for biomonitoring. The TotalFinaElf company has developed a pilot scheme incorporating such controlled conditions. This pilot is a dynamic open mesocosm (16 channels 40 m in length supplied with river water). The research programme currently carried out in the “Pilot Rivers” aims at validating biochemical parameters (components of phases I and II (de)toxication metabolism and propionylcholinesterase activity), measured in a fresh water bivalve Corbicula fluminea as a biomarker of water quality. The comparison between biomarker responses and community ones (reference) gives information about the precocity and sensitivity of these biomarker responses. Pure substances (trichloroethylene (TCE), cadmium (CD) and anthracenic oil (AO)) have been injected during one month. Biomarker responses are as sensitive as the most sensitive community response in the presence of CD and AO. With TCE, community responses are more sensitive. Precocity of biomarker response is observed only in the presence of CD.