Anthropogenic pollution and its cytotoxic effects in an Iranian river, Zayandehrood river

Zayandehrood River located in central Iran have been suffering from pollution by municipal, industrial and agricultural wastewater. The research investigates the occurrence of five pharmaceuticals including amoxicillin, paracetamol, metronidazole, ranitidine and diphenhydramine and two estrogenic compounds consisting estradiol and ethynilestradiol contamination in Zayandehrood River. Water samples were collected in five stations including upstream and downstream receiving sewage water treatment effluents. The concentration of compounds in the upstream was below the detection limit up to 2 ng/l and reached its highest level about 6-46 ng/l in downstream. Also, the cytotoxicity of water samples was evaluated using two human cell lines (HepG2, HEK293T) and one fish cell line (RTG2). No cytotoxic effects were observed but cell viability decreased in cells exposed to river water receiving waste waters. Residues of pharmaceutical and steroid compounds were detected in water samples of Zayandehrood river and these compounds can enter the drinking water sources and affect its quality if not properly treated.