S6: Organic micro-pollutants in rural groundwater of China
Screening and health risk of Organic micro-pollutants in rural groundwater of China
School of Environmental Science & Technology, Dalian University of Technology, China
Xuehua Li1, Xiaochen Shang1, Qing Xie1, Jingwen Chen*1, Kiwao Kadokami*2
1 Key Laboratory of Industrial Ecological and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian 116024, China
2 Faculty of Environmental Engineering, The University of Kitakyushu, 1-1 Hibikino, Wakamatsu, Kitakyushu, Fukuoka 808-0135, Japan
Groundwater is one of the drinking water sources in China. More than 70% of the Chinese population use groundwater in their daily life, and the rural residents account for 95%. However, contaminated groundwater takes a heavy toll on human health due to private exploitation of the wells and directly drinking raw groundwater. Many organic compounds, referred to as organic micro-pollutants, are found to occur in a low to very low concentration (μg/L-ng/L) in groundwater, but with a nonnegligible potential biological toxicity. Comprehensive screening and risk assessment of organic micro-pollutants in rural groundwater are critical to ensure the drinking water security of the Chinese rural population.
The occurrence and health risk of organic micro-pollutants in rural groundwater from Liaodong Peninsula has been first studied. The groundwater samples were collected from 13 drinking water wells. An automated identification and quantification database system (AIQS) developed by Kadokami et al. was used to analyze more than 1300 organic micro-pollutants. A total of 80 organic micropollutants including 12 polycyclic aromatic hydrocarbons, 11 alkanes, 9 pesticides, 7 substituted phenols, 7 perfluoroalkyl acids, 6 heterocyclic compounds, 5 alcohols, 5 phthalic acid esters, 5 pharmaceutical and personal care products, 3 ketones, 2 polychlorinated biphenyls (PCBs), 2 alkylbenzenes and 2 chlorinated benzenes were detected, with their total concentration of 0.032-15μg/L. Noncarcinogenic and carcinogenic risks of a part of the pollutants were assessed by considering skin absorption and oral ingestion. Generally, the risks are within the acceptable limits, except for that the carcinogenic risk at two sites in Jinzhou is higher than 10-6. On this basis, the sampling has been extended to 88 drinking water wells distributed across 21 provinces of China. 99 organic micro-pollutants were detected at least once, and the detection frequencies are 2%-54%. Total concentrations of all the detected compounds at each site were 0.03-275 μg/L. Now, we are attempting to extend the sampling sites to cover all the provinces in China.