River runoff as a considerable pathway for terrigenous organic matters to the ocean, their persistent organic pollutants (POPs) pollution is of particular concern. In order to understand the pollution characteristics of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs, including hexachlorocyclohexane, dichlorodiphenyltrichloroethane and chlordane, abbreviated as HCHs, DDTs and CHLs, respectively) in water of the Yangtze River, surface water samples were collected at the Datong Station in the Yangtze River during November 2017 to November 2018. Concentrations of dissolved and particulate PCBs, HCHs, DDTs and CHLs were determined by Gas Chromatography-Triple Quadrupole Tandem Mass Spectrometer (GC-MS/MS), to discuss compound composition, phase distribution and source. The fluxes were estimated and illustrated by the changes of concentration, annual runoff and sediment load. The results showed that the dissolved concentrations of ∑41
PCBs and ∑9
OCPs in surface water of the Datong Station ranged from 0.059-0.29 and 0.21-0.52 ng/L, respectively. Moreover, the particulate ones ranged 0.26-0.88 for ∑41
PCBs and 0.34-0.89 ng/L for ∑9
OCPs, respectively. Combined with the comparison of concentration levels in different regions, compound composition and ratio results indicate that HCHs, DDTs and CHLs were dominated by the historical application of pesticides, but there were new inputs for PCBs. The estimated fluxes of PCBs, HCHs and DDTs by the river runoff were 0.57, 0.35 and 0.29 t/a, respectively. The results of this study indicated that the pollution characteristics of dissolved and particulate PCBs and OCPs in water of the Datong Station were different and the fluxes of PCBs, HCHs and DDTs were significantly lower than those from 2009 to 2015 reported by previous studies, due to the overall reduction in pollutant concentration, annual runoff and sediment load of the Yangtze River over the past decade, and reduced dissolved concentration of PCBs, HCHs and DDTs in water was an essential factor. It can be said that ‘to set up conservation of the Yangtze River and stop its over development’ proposed during the 13th
Five-Year Plan period, as well as the implementation of the Stockholm Convention on Persistent Organic Pollutants in the past 20 years have jointly contributed to the decline of flux. In the future, further studies should focus on the profile distribution of POPs and exchange fluxes at the different media interface from Datong to the Yangtze River estuary, to systematically reveal the role of the Yangtze River runoff output and its implications for regional POPs cycle.