Human health risk assessment
Nitrate (NO3-) is one of the world’s largest sources of groundwater contamination. The specific objective of this study is to assess the impact on human health of the continuous consumption of high nitrate water. Higher concentration of nitrate leads the adverse health effects and its category as non-carcinogenic risk for human (Gao et al., 2020). In the study area, hazards index for male varied from 1.20E-01 to 1.75E+00 with an average of 8.21E-01, for female varied from 1.42E-01 to 2.07E+00 with a mean of 9.71E-01, for children ranged from 1.63E-01 to 2.37E+00 with a mean of 1.11E+00. About 40 %, 50% and 53.33% of the sample location exceed the HQ value of greater than one for male, female, and children, respectively (Fig.9). It indicates children and women are at higher risk than male through drinking water ingestion. However, nature of groundwater is the major source for drinking water sources; especially children, have adverse health risk through the intake of contaminated groundwater. The conception diagram (Fig.10 a, b) shows that the aquifer lithological system and source of nitrate contamination in the study area. The major source for elevated concentration of nitrate in the study area is excess utilization of fertilizer, pesticides leaching of dumping waste and sewage disposal.