Assessment of the environmental health and human exposure risk of emerging contaminants in groundwater of a typical agricultural irrigation area in the North China Plain.

Emerging contaminants in groundwater have attracted widespread attention, particularly pesticide and antibiotic residuals may lead to considerable environmental health risk and human exposure risk through drinking water. This study aims to investigate the concentration level of emerging contaminants in the groundwater of an agricultural irrigation area located in the North China Plain, and to assess its exposure risks to ecosystem and human health. The groundwater samples were collected across different crop growing stages, and four antibiotics, five pesticides, and three fluorine compounds were analyzed. The human exposure risk was evaluated using a Monte Carlo simulation method. The fluorine compounds were basically below the detection limit of 0.1 ng/L, while the detected maximum mixture concentrations of antibiotics and pesticides were 538 ng/L. Sulfonamides (SAs) and atrazine derivatives (ATZs) were the predominant contaminants with the maximum concentrations of 43 and 507 ng/L, respectively. The average detection rates of different pesticides and antibiotics across three field sampling campaigns varied in the range of 37.0-100 % and 27.5-88.3 %, respectively. The region with a long-term history of wastewater irrigation had the highest average total mixture concentrations of 316 ng/L, which is 3.5-17.1 times that in the other regions. ATZs and SAs posed moderate to high ecological risks to the environment. However, no significant health risks to humans were observed from any of the pollutants at current concentrations. The findings of this study provide important insights into the occurrence, distribution, and exposure risks of groundwater pollutants in the agricultural irrigation areas of the North China Plain.