title: Concentrations of DDTs and dieldrin in Long Island Sound sediment.
abstract: The concentrations of three frequently detected organochlorine pesticides (OCPs) and one degradation product, p,p'-DDT, p,p'-DDD, dieldrin, and p,p'-DDE were determined in recently collected (2005-2006) and archived (1986-1989) surficial sediments and sediment cores from Long Island Sound (LIS). The concentration of dieldrin ranged from 0.05 to 5.27 ng g(-1) dry weight in the surficial sediments, and from 0.05 to 11.7 ng g(-1) dry weight in the sediment cores. Total DDXs (the sum of p,p'-DDE, p,p'-DDD and p,p'-DDT) concentrations ranged from 1.31 to 33.2 ng g(-1) in surficial sediments and 1.11 to 66.4 ng g(-1) in sediment cores. The results indicate that the three OCPs and DDE were still widely present in LIS surficial sediments two decades after the use of these pesticides in the United States was banned. In addition, the surficial concentrations did not decrease significantly when compared to the concentrations in archived samples collected two decades ago. Sediments in the western part of LIS were more contaminated (with concentrations in some western sites being still above probable effect levels) than those in the eastern part, probably as a result of the net westward sediment transport in LIS. The three OCPs and DDE were detected at all depths (down to ~50 cm) in the sediment cores, and concentration profiles indicated a depositional sedimentary environment with significant sediment mixing. Such mixing may redistribute OCPs deposited earlier (deeper in sediment bed) to the sediment surface and lead to enhanced persistence of OCP concentrations in surficial sediments.
authors.affiliation: Department of Chemistry, City College of New York, CUNY, New York, New York 10031, USA.
authors.forename: Lijia
authors.initials: L
authors.lastname: Yang
authors.forename: Xiqing
authors.initials: X
authors.lastname: Li
authors.forename: Pengfei
authors.initials: P
authors.lastname: Zhang
authors.forename: Michael E
authors.initials: ME
authors.lastname: Melcer
authors.forename: Youxian
authors.initials: Y
authors.lastname: Wu
authors.forename: Urs
authors.initials: U
authors.lastname: Jans
mesh_terms: D003634:DDT / Q000032:analysis*; D004026:Dieldrin / Q000032:analysis*; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry*; D009518:New York; D010575:Pesticides / Q000032:analysis; D012623:Seawater / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014877:Water Pollution, Chemical / Q000706:statistics & numerical data
chemical_list: D010575:Pesticides; D014874:Water Pollutants, Chemical; D003634:DDT; D004026:Dieldrin