Transport of Suspended-Sediment-Bound Toxaphene in the Mississippi River

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• 作者：Jonathan D. Raff and Ronald A. Hites
• 刊名：Environmental Science & Technology
• 出版年：2004
• 出版时间：May 15, 2004
• 年：2004
• 卷：38
• 期：10
• 页码：2785 - 2791
• 全文大小：271K
• 年卷期：v.38,no.10(May 15, 2004)
• ISSN：1520-5851

文摘

Suspended sediment samples from ~30 locations alongthe Mississippi River and six of its major tributaries werecollected during July and August 2002 and March 2003to investigate the distribution and transport of toxaphenein the Mississippi River. The concentration of toxaphene wasmeasured, and the load of toxaphene carried by theriver at each site was calculated using water dischargeand suspended sediment concentrations. Results indicatethat toxaphene is widespread throughout the MississippiRiver Basin with the highest concentrations and loadsobserved for samples collected in the Lower MississippiRiver. Among the tributaries, the Yazoo River carried thelargest load, amounting to ~21% of the estimated load carriedby the Mississippi River just below Vicksburg, MS. Themajority of the contamination is most likely from nonpointsource runoff from agricultural lands. We also foundevidence of a localized toxaphene source in the vicinityof Memphis, perhaps coming from the Wolf River. From ourdata we estimate that between 200 and 1000 kg oftoxaphene were released into the Gulf of Mexico in 2002from the main stem of the Mississippi River.