Heavy metal contamination and risk assessment on ecological and public health in a tropical estuarine river

Heavy metals contamination of water is one of the most severe environmental and public health issues. The present study was conducted to assess the levels of lead (Pb), chromium (Cr), cadmium (Cd), arsenic (As), copper (Cu) and zinc (Zn) in surface water of the Pasur River estuary in Bangladesh along with their health risk through the ingestion and dermal exposure. The decreasing order of studied metals was Cr > Pb >Cu > Zn > As > Cd with the mean value of 0.050 > 0.024 > 0.021 > 0.014 > 0.012 > 0.006 mg/L respectively. Pb, Cr, Cd and Zn concentration in water samples exceeded the safe limits of drinking water and thereby not safe for drinking. The multivariate analysis identified the common anthropogenic source and existence of studied metals. Heavy metal pollution index (HPI) and heavy metal evaluation index (HEI) indicated significant contamination of water. The HQ and HI through ingestion and dermal contact were 1 indicating an unacceptable risk of non-carcinogenic effects on public health. Carcinogenic risk through ingestion (CRing) indicated that consumption of water from Pasur River estuary may develop cancer risk of Cd. Therefore, strict rules and regulations must be adopted to reduce water contamination of this tidal river from anthropogenic sources for improving the health of this riverine ecosystem.