Distribution and Risk Assessment of Endocrine-Disrupting Pesticides in Drinking Water Sources from Agricultural Watershed

Occurrences and exposure risk of 21 target endocrine-disrupting pesticides (EDPs) were investigated in the eight typical drinking water sources (including six rivers and two reservoirs) with different hydraulic characteristics and intensive agricultural activities in agricultural watershed over a year. A multi-residue analytical methodology was developed for screening 21 target compounds in water sources based on gas chromatography- mass spectrometry (GC-MS), and the results showed that within the 21 EDPs, only trifluralin was occasionally detected (27.1 %), indicative of widespread occurrences of EDP residues in these areas. Dominant detected EDPs of dicofol and cypermethrin accounted for more than 20 % of the total EDPs (37.9 to 2948.9 ng 1(-1)) in the eight sites, which were both currently used in abundance. Clustering analysis indicated that the obvious spatial difference appeared among river basins with different agricultural aeras, and the levels of detected EDPs in the two reservoirs were also much lower than other sites due to the less intensive of agricultural activities. Besides, results of temporal distribution analysis showed that occurrences of EDPs decreased in winter and spring mainly because of the decline in the usage of cypermethrin and dicofol, and the temporal variation of organics was similar with that of EDPs. It might be concluded that the agricultural intensive was the main factor affecting the occurrence of EDPs. The EDPs risk assessment revealed that the high ecological risk are existing at polluted drinking water sources in Eastern China after a long-term influence, and it is very necessary to remedy polluted natural waters.