Toxicity and estrogenic activity of a wastewater treatment plant in Northern Italy

Many xenobiotics, widely diffused in the environment, have the potential to disrupt the delicate endocrine system balance of wildlife and humans. Different ecotoxicological studies were applied to screen for the discharge of estrogenic and toxic substances into the aquatic environment from the effluent of a small industrial wastewater treatment plant based in Northern Italy. Untreated samples were assayed with two toxicity tests: MicrotoxTM and Daphnia magna and a proliferation test using human estrogen receptor– positive MCF-7 breast cancer cells (E-screen assay) was performed on the same samples after solid-phase extraction for the determination of total estrogenic activity. The results of the MicrotoxTM assay employing the marine bacterium Vibrio fischeri were compared with data obtained from whole-effluent toxicity testing methods employing D. magna. Toxicity was found only for The effluent samples were considered acceptable (taking into account only toxicity), but they had estrogenic activity indicating an input of estrogenic substances by way of the treatment plant into the recipient river.