Study On The Analytical Method And Environment Risk Assessment Of The Typical Endocrine Disrupting Chemicals In Groundwater

Endocrine disrupting chemicals(EDCs)with high bioactive are harmful to environment and ecological health even at concentrations as low as 1 ng/L.Groundwater is the main source of drinking water in northern China.The detection,investigation and risk assessment of EDCs in groundwater are particularly important.In this study,EDCs analytical methods were established.The distribution characteristics and environmental risk assessment of EDCs in groundwater in a region were studied.The results of this work provide technical support for the safe utilization and risk control of groundwater.An analytical method for separating and determining eight selected EDCs(namely,estrone(E1),17α-estradiol(17α-E2),17β-estradiol(17β-E2),17α-ethinyl estradiol(EE2),estriol(E3),bisphenol A(BPA),4-n-nonylphenol(NP),and 4-t-octylphenol(OP)),in groundwater was developed.The method was based on solid-phase extraction and ultra-performance liquid chromatography tandem mass spectrometry.The correlation coefficient of the standard curves was greater than 0.999.The limit of detections for selected EDCs ranged from 0.02 ng/L to 0.17 ng/L.The limits of quantification ranged from 0.07 ng/L to 0.56 ng/L.The recovery rate ranged from 84% to 116%.The main endocrine disruptors detected in the groundwater of river alluvial fan were OP and BPA,and the detection frequency of OP in both dry and wet periods was 100%.In the dry and wet periods,the concentrations ranged from 13.10 ng/L to 41.33 ng/L and 23.42 ng/L to 72.34 ng/L,respectively.In surface water,the detection frequency of OP was 100% and the highest concentration was 133.50 ng/L.The detection of EDCs in surface waters was similar to that in groundwater.According to the ecological risk assessment,the highest risk entropies of OP in groundwater and surface water were 5.56 and 10.27,respectively.This indicated that OP was the major compound causing the high ecological risk of water.Thus,OP was selected as the preferentially controlled pollutant in surface water and groundwater.The ecological risk of OP in surface water was generally higher than that of groundwater.The four-step way of Health Risk Assessment was used to assess the risk of groundwater exposure under long-term OP conditions.The results showed that the risks were all acceptable and there were differences in the health risks of exposed populations in different age groups.The younger the age,the greater the risk.Drinking water ingestion was the main contact method for population exposure.