Distribution And Risk Assessment Of Typical EDCs In Hun River Water System

Endocrine disrupting compounds (EDCs) is the trace organic contaminant with the character of extensive sources, potential harmfulness and long latency. Endocrine system, nervous system and other systems can even be jeopardized by minimal exposure concentration. The aquatic quality of Liao River Basin has been improved year by year, while specific tributaries are still in terrible environmental pollution status. As one of the economic center in Northeast of China, the sum of industrial wastewater and domestic sewage in Shenyang has soared with the fast urbanization. The typical EDCs pollution in Xi River (XR), Hun River and DaLiao River (HR-DLR). which are main rivers to receive effluents from city, are supposed to be studied in this research.Selected contaminants BPA, E1, E2 and EE2 are detected in water with the method of SPE-GC-MS and in surface sediment with the Ultrasonic-assisted extraction-GC-MS in freezing and unfreezing season; and risk assessment are made by estradiol equivalent (EEQ) and risk quotient (RQ). The conclusions are as follows:(1) In water, the pollution of selected EDCs in XR is more serious than those in HR-DLR. The ranges of concentration in XR are 159～1131ng/L for BPA, 1.20-1235ng/L for E1.<LOD～1254ng/L for E2 and <LOD～17112ng/L for EE2; the ranges of concentration in HR～DLR are 0.923-324ng/L for BPA,<LOD～25.0ng/L for El.<LOD-8.50ng/L for E2 and<LOD～650ng/L for EE1. The levels of BPA, E1 and E2 monitored in freezing season are generally greater than those in unfreezing season. It reveals that a positive and significant correlation between the amount of BPA in water and TDS, while negative and significant correlation is found between the BPA concentration and DO. pH and oxidation reduction potential (ORP).(2) In surface sediment, all targeted EDCs detected in both freezing and unfreezing season in XR are higher than those in HR-DLR, and the detective frequency are in ascending orders as E1 (13%). EE2 (17%), E2 (25%) and BPA (92%). In unfreezing season, the average levels of BPA and El are more than those in HR-DLR (9.80>1.03 ng/g,1.42>0.0550 ng/g), and no E2 and EE2 were found in HR-DLR. Positive and significant correlation was found between the concentrationsof BPA in sediment and the BPA level in water and the content of TOC in sediment, respectively. It also saw the positive correlation between the Kd of BPA and the TOC in sediment.(3) The proportion of sampling sites with obvious endocrine disrupting effects on the organism (EEQ>lng/L) made by selected EDCs in surface water were E1>EE2>E2>BPA. In XR, more sampling sites with EEQBPA、EEQE1、EEQEE2>1 ng/L were found than in HR-DLR; while the EEEQporcwater>1 ng/L were only calculated in sampling site XR3 and no sites with ΣEEQPorewater>lng/L were found in HR-DLR. The results of RQ showed that El and EE2 pollution in XR were in serious eco-disturbance status and the highest RQ level was up to 58293 at station XR3. The proportion ranges of RQE1>1.0, RQE2>1.0, RQEE2>1.0 were 28%、22%　and 33% respectively in HR-DLR, which were lower than those in XR. The ΣRQ of XR1、XR2 and XR3 were found in the range of 0.1 to 1.0, which are supposed to be observed further.