Surface Water Quality and Health Risk Assessment of Some Potentially Toxic Metals in Ogun River, Nigeria

Freshwater resources face global threats from anthropogenic pollution, posing human health and ecological risks. The water quality of Ogun River was assessed using the Weighted Arithmetic Water Quality Index (WWQI), The Canadian Water Quality Index (CWQI), the Heavy Metals Pollution Index (HPI), and the Comprehensive Pollution Index (CPI); the Carcinogenic and Non-Carcinogenic risk assessment of some toxic metals through oral and dermal exposures was carried out. The heavy metals were measured with the Microwave Plasma Atomic Emission Spectrometer (MP-AES). The results from all the evaluation indices show that the River is highly polluted at all sampling stations and in all seasons. WWQI and HPI show that the water quality decreased from the dry to the rainy season due to a rise in heavy metal levels. At the same time, WQI indicates that the level of the physicochemical parameters decreased from the dry to the rainy season. Cd and Pb posed significant non-carcinogenic risk (HQ > ۱) through oral exposure to adult and children populations at all locations, accounting for ۹۸.۲۷ % of the total risk. There was a significant cancer risk (CR >۱۱۰-۴) through oral exposure to Pb and Cr for the adult populations at ۳۱.۲۵ % and ۶۲.۵۰ % of the sampling locations respectively, while oral and dermal exposure to Cd posed a significant cancer risk for the adult and children populations at all the sampling locations. The river's water quality is impacted mainly by heavy metals, which pose significant human health risks.

کلیدواژه ها:

heavy metals ، Water Quality Index ، Risk Assessment ، pollution ، carcinogenic