Groundwater quality evaluation and risk assessment of nitrate using monte carlo simulation and sensitivity analysis in rural areas of Divandarreh County, Kurdistan province, Iran

Abstract

ABSTRACT During farming practices in rural areas, various fertilizers are used, which can lead to the contamination of groundwater resources with nitrate and, consequently, can affect the health of consumers. This study aimed to investigate the drinking suitability of the groundwater resources in rural areas of Divandarreh County, Kurdistan province, Iran using drinking water quality index (DWQI) and also estimation of the non-carcinogenic health risk induced by nitrate due to the drinking route. Sixty groundwater samples collected (2018) from active dug-wells and twelve parameters (TDS, pH, TH, EC, HCO3 −, K+, Na+, Mg2+, Ca2+, Cl−, SO4 2-, and NO3 −) were measured to calculate DWQI. Also, non-carcinogenic risk assessment was carried out for four exposed groupsusing two different approaches: deterministic andprobabilistic by Monte Carlo simulation. The results of WQI showed that 61.66, 31.66, and 6.66% of samples fall within the class of excellent, good, and poor quality, respectively. The nitrate concentration in drinking water ranged from 36.06 ± 14.32 mg/L. The HQ mean for infants, children, teenagers, and adults were 0.90158, 1.17205, 0.90158, and 0.70436, respectively.Probability estimation showed the HQ values for the 5th, and 95th percentile in infants, children, teenagers, and adult groups were (0.52–2.53), (0.27–1.54), (0.25–1.40), and (0.15–0.71), respectively. Sensitivity analysis results showed that the most effective parameter in the non-carcinogenic risk in all exposed groups was NO3 − concentration. Generally, nitrate concentration was relatively high and required more attention especially in agriculture and management of the use of fertilisers.