Historical Trends in Organochlorine Compounds in River Basins Identified Using Sediment Cores from Reservoirs

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• 作者：Peter C. Van Metre ; Edward Callender ; and Christopher C. Fuller
• 刊名：Environmental Science & Technology
• 出版年：1997
• 出版时间：August 1997
• 年：1997
• 卷：31
• 期：8
• 页码：2339 - 2344
• 全文大小：184K
• 年卷期：v.31,no.8(August 1997)
• ISSN：1520-5851

文摘

This study used chemical analyses of dated sedimentcores from reservoirs to define historical trends in waterquality in the influent river basins. This workappliestechniques from paleolimnology to reservoirs, and in theprocess, highlights differences between sediment-core interpretations for reservoirs and natural lakes.Sedimentcores were collected from six reservoirs in the centralandsoutheastern United States, sectioned, and analyzed for¹³⁷Cs and organochlorine compounds. ¹³⁷Csanalyses wereused to demonstrate limited post-depositional mixing, toindicate sediment deposition dates, and to estimatesedimentfocusing factors. Relative lack of mixing, highsedimentationrates, and high focusing factors distinguish reservoirsediment cores from cores collected in natural lakes.Temporal trends in concentrations of PCBs, total DDT(DDT+ DDD + DDE), and chlordane reflect historical use andregulation of these compounds and differences in land usebetween reservoir drainages. PCB and total DDT coreburdens, normalized for sediment focusing, greatly exceedreported cumulative regional atmospheric fallout of PCBsand total DDT estimated using cores from peat bogs andnatural lakes, indicating the dominance of fluvial inputsof both groups of compounds to the reservoirs.