RESUMEN
Solid-phase extraction and ultra-high performance liquid chromatography-mass spectrometry were used to detect and analyze the contamination of nine typical endocrine disrupting chemicals (EDCs) in drains flowing into the Yellow River of Ningxia. Sources of these EDCs were analyzed, and their risks were assessed. The results showed that EDCs were detected in drains at all 33 sampling sites, with total concentrations ï¼ΣEDCsï¼ of 82.28-1730.09 ng·L-1. Among phenolic compounds, bisphenol A (BPA) and nonylphenol (NP) were two that were more commonly detected EDCs, with the detection rates above 90%; estrone (E1) and estriol (E3) were more commonly detected estrogenic compounds, both with detection rates of 79%. On a spatial scale, the average concentrations of ΣEDCs in the drains in Shizuishan and Yinchuan were much higher than those in Wuzhong and Zhongwei. Concentrations of ΣEDCs at the sampling sites before flowing into Yellow River ranged from 82.28 to 979.82 ng·L-1. The source analysis showed that industrial wastewater and domestic sewage were two primary sources for BPA, whereas industrial wastewater was the primary source for OP. The primary sources of E1 and E3 were livestock and poultry breeding wastewater and domestic sewage, respectively. Risk assessment results showed that EDCs in drains flowing into the Yellow River posed low or moderate ecological risk but high risk for estrogenic activity at all sampling sites.