Occurrence, distribution and ecological risks of organophosphate esters and synthetic musks in sediments from the Hun River.

The Hun River is an important main tributary of the Liao River system. It is located in northeast China, and provides water resources for agriculture and industry. A man made reservoir (Dahuofang Reservoir, DHF) has been constructed mid-stream in the Hun River, supplying drinking water to surrounding cities. Pollution from organic contaminants is of great concern. In the present study, 40 sediment samples were collected and analyzed for the occurrence and distribution of two groups of emerging organic pollutants; namely, organophosphate esters (OPs) and synthetic musks (SMs). In all samples taken from upstream of the Hun River (UHR), downstream of the Hun River (DHR), and from DHF, the following concentrations were recorded: 0.141-4.39, 1.21-245, and 0.117-0.726 µg/kg galaxolide (HHCB), and 0.098-3.82, 2.79-213, 0.430-0.956 µg/kg tonalide (AHTN), respectively. For OPs, seven target analytes were detected in most of the sediment samples, with chlorinated OPs Tris-(2-chloroethyl) phosphate and Tris(2-chloro-isopropyl) phosphate being the dominant components, at levels varied in the range of LOD-0.810, ND-49.6, and 0.532-3.18 µg/kg, and LOD-0.786, ND-60.1, and 0.352-1.32 µg/kg from UHR, DHR and DHF, respectively. The elevated levels of these target compounds were detected in DHR, including its two main tributaries, Xi River and Pu River, which drain through cities with industrial development and dense populations. Our results indicate that domestic and industrial wastewater contributed to OPs and SMs sediment pollution, posing low to medium ecological risks to sediment dwelling organisms.