title: Distribution of organochlorine pesticides in sediments from Yangtze River Estuary and the adjacent East China Sea: implication of transport, sources and trends.
abstract: Thirty-eight surface sediments and two sediment cores were collected from Yangtze River Estuary (YRE) and adjacent East China Sea (ECS) to study the distribution patterns, origins, potential transport and burden of organochlorine pesticides (OCPs) in the marginal sea. Residues of OCPs ranged from 0.190 to 5.17 ng g(-1) dry weight with a distinct "band type" pattern under the control of Yangtze River inputs and ECS circulation system. Differences in transmission media and redox conditions in situ respectively resulted in the divergent distributions of α/β-HCH and DDD/DDE. The compositional pattern analysis implied that OCPs in the inner shelf of ECS were derived from both "weathered" and fresh sources, whereas those in the outer shelf of ECS had undergone high metabolism. Concurrent with the land-sea migration, vertical profiles of sediment cores showed increasing trends or rebound since the 1990s, characteristic of two evident "jumps" of DDE+DDD/DDT and DDT/DDE ratios. Moreover, the primary distribution pattern founded for HCHs and the considerable mass inventories calculated (6.20 metric tones for OCPs) together suggested that the contaminated sediments in the studied area to be a potential source of OCPs to the global ocean.
authors.affiliation: International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032, China; IJRC-PTS, MOE Key Laboratory of Environmental Remediation and Ecosystem Health, Zhejiang University, Hangzhou 310058, China.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Zhou
authors.affiliation: Environmental Protection Research Institute, Hangzhou Normal University, Hangzhou 310012, China.
authors.forename: Huayun
authors.initials: H
authors.lastname: Yang
authors.affiliation: International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032, China.
authors.forename: Anping
authors.initials: A
authors.lastname: Zhang
authors.affiliation: IJRC-PTS, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
authors.forename: Yi-Fan
authors.initials: YF
authors.lastname: Li
authors.affiliation: IJRC-PTS, MOE Key Laboratory of Environmental Remediation and Ecosystem Health, Zhejiang University, Hangzhou 310058, China. Electronic address: wliu@zju.edu.cn.
authors.forename: Weiping
authors.initials: W
authors.lastname: Liu
mesh_terms: D002681:China; D003634:DDT / Q000032:analysis; D063366:Estuaries; D019015:Geologic Sediments / Q000032:analysis*; D001556:Hexachlorocyclohexane / Q000032:analysis; D006843:Hydrocarbons, Chlorinated / Q000032:analysis*; D009792:Oceans and Seas; D010575:Pesticides / Q000032:analysis*; D045483:Rivers / Q000737:chemistry*; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D006843:Hydrocarbons, Chlorinated; D010575:Pesticides; D014874:Water Pollutants, Chemical; C040534:alpha-hexachlorocyclohexane; D001556:Hexachlorocyclohexane; D003634:DDT; C023888:beta-hexachlorocyclohexane
keywords: Chlordanes; DDTs; HCHs; Mass inventory; Pollution trend