Occurrence and Health Risks of Organic Micro-Pollutants and Metals in Groundwater of Chinese Rural Areas

This study investigated the occurrence and health risks of organic micropollutants (OMPs) and metals in 166 groundwater samples collected from rural areas across 28 provinces in China. The research aimed to provide a benchmark for monitoring and improving groundwater quality, which serves as a primary drinking water source for many rural residents. The methods involved comprehensive screening of 1,300 OMPs and 25 metals using GC-MS, LC-QTOF/MS, and ICP-MS analysis. To assess noncarcinogenic and carcinogenic risks, missing toxicity threshold values were extrapolated using quantitative structure-activity relationship (QSAR) models, and Monte Carlo simulation was employed to account for uncertainties in exposure parameters and toxicity thresholds. The study detected 233 OMPs and 25 metals, with total OMP concentrations ranging from 2.9 to 1.7 × 10^5 ng/L. While cumulative noncarcinogenic risks for OMPs were negligible, high metal risks were found in 23% of the sites. Forty-two carcinogens (38 OMPs) were identified, with cumulative carcinogenic risks exceeding 10^-4 in 34% of the sites, primarily attributed to metals (79% contribution). The findings highlight significant metal contamination and the need for improved groundwater monitoring and management in rural China.

This study investigated the occurrence and health risks of organic micropollutants (OMPs) and metals in 166 groundwater samples collected from rural areas across 28 provinces in China. The research aimed to provide a benchmark for monitoring and improving groundwater quality, which serves as a primary drinking water source for many rural residents. The methods involved comprehensive screening of 1,300 OMPs and 25 metals using GC-MS, LC-QTOF/MS, and ICP-MS analysis. To assess noncarcinogenic and carcinogenic risks, missing toxicity threshold values were extrapolated using quantitative structure-activity relationship (QSAR) models, and Monte Carlo simulation was employed to account for uncertainties in exposure parameters and toxicity thresholds. The study detected 233 OMPs and 25 metals, with total OMP concentrations ranging from 2.9 to 1.7 × 10^5 ng/L. While cumulative noncarcinogenic risks for OMPs were negligible, high metal risks were found in 23% of the sites. Forty-two carcinogens (38 OMPs) were identified, with cumulative carcinogenic risks exceeding 10^-4 in 34% of the sites, primarily attributed to metals (79% contribution). The findings highlight significant metal contamination and the need for improved groundwater monitoring and management in rural China. Research Background and Significance Groundwater serves as a critical source of drinking water for millions of rural residents in China. However, contamination by organic micropollutants (OMPs) and heavy metals poses a significant threat to public health and environmental safety. OMPs, which include pesticides, pharmaceuticals, personal care products, and industrial chemicals, are of particular concern due to their persistence, bioaccumulation potential, and diverse toxicological profiles. Metals, often deriv