Shallow groundwater quality and health risk assessment of fluoride and arsenic in Northwestern Jiangsu Province, China

Abstract

Assessing groundwater quality is critical to regional water resource conservation and human health safety, especially in areas with co-existence of toxic constituents fluoride (F−) and arsenic (As). In this study, fourteen groundwater samples were collected in Feng County, Northwestern Jiangsu Province to identify dominant contaminants and their spatial distribution and health risk. The composition and variation characteristics of major ions (K+, Na+, Ca2+, Mg2+, Cl−, SO42−, HCO3−, and NO3−) and trace elements (F−, As, and Mn) were analyzed. The hydrochemical results revealed that high F− groundwater was mainly distributed in the northern areas whereas As-riched groundwater was primarily distributed in southern areas. Notably, over 85.7% and 21.4% of the shallow groundwater samples exceeded the drinking water quality standard of 1.5 mg/L for F− and 10 µg/L for As, respectively. Based on the water quality index (WQI) appraisal result, 71.4% of the groundwater in the study area is classified as “poor”, and thus unsuitable for drinking directly. We assessed the human non-carcinogenic health risk of F− (HQFluoride) and As (HQArsenic) and the carcinogenic health risk of As (CRArsenic). The calculated hazard quotient (HQ) for F− indicated nearly all groundwater samples have an unacceptable risk (HQ > 1) for each age group. However, HQArsenic values revealed that 28.6%, 21.4%, 21.4%, and 21.4% of groundwater samples posed potential non-carcinogenic health risks for infants, children, females, and males, respectively. The calculated results of CRArsenic showed that 0%, 21.4%, 28.6%, and 28.6% of groundwater samples posed unacceptable health risks (CR > 1.0 × 10−4) to infants, children, females, and males, respectively. The groundwater irrigation suitability assessment results showed that 21.4% of samples were doubtful to unsuitable for irrigation, and 85.7% owed magnesium hazards. The findings of this study will assist policymakers in formulating proper remedial policies and mitigation strategies to ensure the safety of drinking and irrigation water.