Using bioanalytical tools to detect and track organic micropollutants in the Ganga River near two major cities

Major rivers in India are subject to ongoing impacts from urban drain discharges, most of which contain high levels of domestic and industrial wastewater and stormwater. The aim of the present study was to determine the levels of bioactive organic micropollutants at the discharge points of major urban drains in comparison to upstream and downstream sites. To achieve this, we employed a panel of in vitro bioanalytical tools to quantify estrogenic, androgenic, progestogenic, glucocorticoid and peroxisome proliferator-like activity in water extracts collected from two Indian cities in the Ganga Basin. Cytotoxicity of the water extracts in a human-derived cell line and the potential to cause oxidative stress in a fish cell line were also investigated. We found high levels of activity for all endpoints in samples directly receiving urban drain discharge and low levels at sites upstream from drain discharges. Estrogenicity was detected at levels equivalent to 10 ng/L 17β-estradiol, representing a high likelihood of biomarker effects in fish. Sites located downstream from drain discharges exhibited low to intermediate activity in all assays. This study demonstrates the importance of managing urban drain discharges and the utility of applying bioanalytical tools to assess water quality.