Potential health risk assessment of nitrate in groundwater of Tonk district in Rajasthan, north western India

Abstract

ABSTRACT Anthropogenic activities like adding synthetic nitrogenous fertilisers in agriculture fields, animal and human waste are the main factors responsible for the increase in nitrate concentration in groundwater of any area. Groundwater is the main source of not only irrigation but also dependency for drinking which has increased on it with decreasing surface sources. Today, increase in such anthropogenic activities has resulted in upsurge of the natural nitrate concentration to the extent of crossing its acceptable limit in drinking water. The Bureau of Indian Standard (BIS, 2012) 1 has prescribed the limit of 45 mg/L, whereas for WHO (2011) 2 the limit of nitrate is 50 mg/L. The goal of this present study is to assess the natural and anthropogenic NO3 concentrations in groundwater in a semi arid area of Rajasthan in Tonk District and its related risks to human health in the different groups of ages, such as children, males, and females. Being immune adults has little less effect on its continuous exposure than children. Even though these risks are non-carcinogenic, incessant exposure can create several health issues. In juveniles, it is known to cause methemoglobinemia, in adults it causes gastric and other stomach issues on prolonged consumption as well as dermal contact. The results show that the oral exposure of nitrate was very high compared to dermal contact. On the basis of non-carcinogenic health risk, the total Hazard Index (HITotal) values of groundwater nitrate were an average of 1.16 for males, 1.37 for females, and 1.58 for children. The nitrate health risk assessment shows that about 39%, 44%, and 51% of the samples constitute the non-carcinogenic health risk to males, females, and children, respectively.