Evaluation of Groundwater Quality and Health Risk Assessment During the Dry Season in the Xin’an River Basin, China

A total of 162 groundwater samples were collected during November and December 2022 in the Xin’an River Basin during the dry season. In this research, the concentrations of various indicators in most samples did not exceed the prescribed standards. The indicators with the largest number of exceedances were iodine and manganese, with 22 and 23 samples, respectively. Overall, the groundwater quality in the Xin’an River Basin was generally good, with only 7 samples with the EWQI values greater than 150, which exhibited poor groundwater quality. The primary factors influencing groundwater quality were the concentrations of I, Mn, and Al, which were predominantly affected by water–rock interactions. Groundwater quality in the Xin’an River Basin was mainly influenced by natural factors rather than anthropogenic activities. Both the carcinogenic and non-carcinogenic health risks posed by groundwater in the Xin’an River Basin were higher for children than for adults. The long-term chronic cumulative effect was the most important factor contributing to both carcinogenic and non-carcinogenic health risks. Iodine presented the highest non-carcinogenic health risks for both adults and children. In regions where high-iodine groundwater was distributed, it is recommended to enhance the monitoring of iodine concentrations in the groundwater.