Persistent Chlordane Concentrations in Long Island Sound Sediment: Implications from Chlordane, 210Pb, and 137Cs Profiles

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• 作者：Lijia Yang ; Xiqing Li ; John Crusius ; Urs Jans ; Michael E. Melcer ; Pengfei Zhang
• 刊名：Environmental Science & Technology
• 出版年：2007
• 出版时间：November 15, 2007
• 年：2007
• 卷：41
• 期：22
• 页码：7723 - 7729
• 全文大小：297K
• 年卷期：v.41,no.22(November 15, 2007)
• ISSN：1520-5851

文摘

Concentrations of chlordane, a banned termiticide andpesticide, were examined in recently collected surficialsediment (10 sites) and sediment cores (4 sites) in LongIsland Sound (LIS).The highest chlordane concentrationswere observed in western LIS, near highly urbanized areas.Chlordane concentrations did not decrease significantlyin the past decade when compared to the data collectedin 1996, consistent with the observation of near-constant chlordane levels in blue mussel tissues collectedduring the same time period. Chlordane concentrationsin many of the sites exceeded levels above which harmfuleffects on sediment-dwelling organisms are expected tofrequently occur. Chlordane concentrations in two of the foursediment cores showed a peak below the sedimentsurface, suggesting reduced chlordane inputs in recentyears. The lack of a chlordane concentration maximum belowthe sediment surface in the other two cores, coupledwith the lack of a well-defined ¹³⁷Cs peak, indicated significantsediment mixing. Simulations of ¹³⁷Cs and ²¹⁰Pb profilesin sediment cores with a simple sediment-mixing model wereused to constrain both the deposition rate and thebioturbation rate of the sediment. Simulations of thechlordane profiles indicated continued chlordane input toLIS long after chlordane was phased out in the U.S.Continued chlordane input and significant sediment mixingmay have contributed to the persistent chlordaneconcentrations in surficial sediment, which poses long-term threats to benthic organisms in LIS.