Unregulated discharge of wastewater in the Mahanadi River Basin: Risk evaluation due to occurrence of polycyclic aromatic hydrocarbon in surface water and sediments

Exposure to polycyclic aromatic hydrocarbons (PAHs) through contaminated water may adversely affect human health and ecology. Water and sediment samples collected from the Mahanadi River Basin (MRB) were analyzed for the presence of sixteen priority PAHs. Results showed that the concentrations of sigma 16 PAHs in water and sediments ranged from 13.1 to 685.4 mu g/L and 302.6 to 728.2 ng/g. In river water samples, the highest mean concentrations were recorded for Acenaphthylene (18.73 +/- 11.61 mu g/L) and Benzo(a)Anthracene (10.11 & PLUSMN; 8 mu g/ L). On the contrary, the maximum concentration was recorded for Phenanthrene (96.18 +/- 50.66 ng/g) and Pyrene (76.69 +/- 22.73 ng/g) in sediment samples. Human health risk assessment suggests low risk, with in-cremental lifetime cancer risk (ILCR) being 37.44 x 10(-5) for children and 21.82 x 10(-5) for adults. In contrast, ecological risk assessment showed a high toxic equivalent quotient of 40.68 ng/g and mutagenic equivalent quotient of 39.74 ng/g suggesting elevated adverse risk to aquatic species.

Automated summary

This study found the presence of polycyclic aromatic hydrocarbons (PAHs) in water and sediment samples from the Mahanadi River Basin, with a wide range of concentrations. The human health risk assessment showed low risk, while the ecological risk assessment indicated elevated adverse risk to aquatic species.