TOXICITY CHARACTERIZATION OF ORGANIC CONTAMINANTS IN RIVERWATER: A T.R.E. APPROACH USING ALGAL TESTS

The risk associated to the organic micropollutants was evaluated in surface waters from a contaminated river site, downstream from a highly antropized area in Northern Italy. The sensitivity of a chronic toxicity test toward organics was evaluated in a TRE approach by comparing the toxic effects of the concentrated organic-extract with the toxicity detected in the original mixture. The river water collected during a one-year sampling was treated by SPE extraction with Lichrolut resin and EDTA addition, while Selenastrum capricornutum growth inhibition test was used as ecotoxicological model. While the results were suggesting the organic micropollutants as primary toxicants in the riverwater, the relationship found between the Toxicity Reduction, as evaluated by the resin-EDTA treatment, and the toxicity of the organic mixture, as actually measured in the organic-extracts, was further supporting the predictive capacity of the adopted procedure to monitor the organic pollution in surface waters.