Health Risk Assessment of Groundwater in Omu-Aran, Nigeria

Abstract

Pollution of groundwater by bathroom, laundry and kitchen effluent has been documented to have non-desirable health and environmental effects. There is little information about the quality of groundwater and associated health effects in Omu-Aran. The present research therefore meets the need to investigate the levels of heavy metals, the pollution effects, and the long term human health risk effect on local inhabitants in Omu-Aran. Thirty water samples were collected from five hand dug wells (HWs) in different parts of Omu-Aran spanning a period of three months and the heavy metal parameters were determined using standard protocol. The non-carcinogenic risk was evaluated using hazard index (HI) according to United States Environmental Protection Agency (USEPA) risk assessment method. Data analysis were carried out by the use of descriptive statistics. From the result, mean values and SD of heavy metals in the water samples obtained from selected HWs ranged from 0.16 ± 0.13 to 0.29 ± 0.18 mg/L, 0.29 ± 0.02 to 1.36 ± 0.07 mg/L, 0.00 ± 0.00 to 0.72 ± 0.04 mg/L, 0.00 ± 0.00 to 0.51 ± 0.09 mg/L, 0.01 ± 0.01 to 5.26 ± 0.07 mg/L, and from 0.03 ± 0.01 to 12.96 ± 2.82 mg/L for Al, Fe, Mn, Cr, Cu, and Zn respectively. The heavy metals were all above the WHO limits except Pb and Fe. The hazard index values ranged from 1.406 to 10.075 indicating significant non-carcinogenic risk. The findings of the study, has shown that there is considerable amount of heavy metal pollution which stems from anthropogenic sources. There was no observable risk via dermal pathways based on hazard quotient values while non-carcinogenic risk via ingestion was observed for all the locations. There is therefore a need to bring awareness to the community for the purpose of ensuring safety of its active water sources.