Anthropogenic nitrate in groundwater and its health risks in the view of background concentration in a semi arid area of Rajasthan, India

Abstract

An increased nitrate (NO3−) concentration in groundwater has been a rising issue on a global scale in recent years. Different consumption mechanisms clearly illustrate the adverse effects on human health. The goal of this present study is to assess the natural and anthropogenic NO3− concentrations in groundwater in a semi arid area of Rajasthan and its related risks to human health in the different groups of ages such as children, males, and females. We have found that most of the samples (n = 90) were influenced by anthropogenic activities. The background level of NO3− had been estimated as 7.2 mg/L using a probabilistic approach. About 93% of nitrate samples exceeded the background limit, while 28% of the samples were beyond the permissible limit of 45 mg/L as per the BIS limits. The results show that the oral exposure of nitrate was very high as compare to dermal contact. With regard to the non-carcinogenic health risk, the total Hazard Index (HITotal) values of groundwater nitrate were an average of 0.895 for males, 1.058 for females, and 1.214 for children. The nitrate health risk assessment shows that about 38%, 46%, and 49% of the samples constitute the non-carcinogenic health risk to males, females, and children, respectively. Children were found to be more prone to health risks due to the potential exposure to groundwater nitrate.

Comparative health risk assessment of nitrate in drinking groundwater resources of urban and rural regions (Isfahan, Iran), using GIS

“…Statistical analysis revealed that there was a minor significant relationship between groundwater NO 3 − content and Cl − ions in rural groundwater samples (p < 0.001 and r = 0.169), while it was not significant in urban samples (p = 0.848). Previous observations reported positive correlations between nitrate and chloride in rural groundwater (Iwar et al, 2021;Rahman et al, 2021;Yu et al, 2020). They reported that chemical fertilizers or the pollution of feces and livestock waste may elevate the concentration of chlorine ions in groundwater.…”

“…According to previous studies, the two main routes of nitrate exposure are drinking water and dermal exposure via bathing or swimming in nitrate-contaminated water (Yang et al, 2012). Given that we did not have information about swimming and bathing in the study area, and previous studies such as the study by Yu et al (2020) and Rahman et al (2021) showed that the risk of exposure to this route was very low, in the present study, only the risk assessment of drinking water contaminated with different amounts of nitrate has been investigated. Calculations for non-carcinogenic health risks associated with the consumption of groundwater containing nitrate by the residents were made based on the standard assumptions used in US-EPA risk analysis.…”

“…Other study results showed that health risk of nitrate in infant and children was higher than adults. Furthermore, infants and children were identified as a high-risk group (Chen et al, 2017;Rahman et al, Sadler et al, 2016;Wongsanit et al, 2015;Yu et al, 2020). Also, Su et al (2013) investigated the groundwater in the northern China and the associated health risks.…”

The Interplay of Environment and Biota in Assessing the Freshwater Quality in Karst

“…Nitrogen, one of the most frequent contaminants in freshwaters, is estimated to have a natural occurrence as nitrate (up to 10 mg/L), but values above this threshold reflect anthropogenic pollution [79][80][81][82]. The natural background of nitrate represents only a relative measure due to the interactions between the rock matrix and water, dissolutions, interactions between different water bodies, chemical and biological processes, retention time, and precipitation [82].…”

Hydrogeochemical factors controlling the fluoride concentration in spring/groundwater in Aso caldera in the volcanic region, Japan

“…Rahman et al (2021) summarized that the results may be good if the CBE is < ± 5%, and up to ± 10% is acceptable for groundwater. CBEs of most water samples were < ± 5%, although only one sample of N11 showed an acceptable CBE level of + 5.8%.…”