Distribution of organochlorine pesticides in sediments from Yangtze River Estuary and the adjacent East China Sea: Implication of transport, sources and trends

• Published in: Chemosphere (Oxford) 2014-11, Vol.114, p.26-34
• Main Authors: Zhou, Shanshan, Yang, Huayun, Zhang, Anping, Li, Yi-Fan, Liu, Weiping
• Format: Article
• Language: English
• Subjects: Applied sciences; Brackish; China; Chlordanes; DDT; DDT - analysis; DDTs; Estuaries; Exact sciences and technology; Geologic Sediments - analysis; HCHs; Hydrocarbons, Chlorinated - analysis; Lindane - analysis; Mass inventory; Oceans and Seas; Pesticides; Pesticides - analysis; Pollution; Pollution sources. Measurement results; Pollution trend; Rivers; Rivers - chemistry; Sediments; Soil and sediments pollution; Transport; Trends; Water Movements; Water Pollutants, Chemical - analysis
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2014.03.100

•OCP residues were at the low or comparable levels of the global range presently.•Distribution of OCPs showed a “band type” pattern and controlled by ocean current.•Distribution of OCPs also influenced by transmission media and redox conditions.•Fresh sources and increasing contaminant trends of OCPs existed in the coastal area.•OCPs in YRE and adjacent ECS are active sources of these chemicals to global sea. 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 5.17ngg−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.