Chlorobornanes in Sediments and Fish 30 Years after Toxaphene Treatment of Lakes

Autor: Gary A. Stern, Derek C. G. Muir, Norbert P. Grift, David W. Schindler, Brenda M. Miskimmin
Rok vydání: 1995
Předmět:
Zdroj: Environmental Science & Technology. 29:2490-2495
ISSN: 1520-5851
0013-936X
Popis: Chlorobornanes (CHBs) were isolated from recent and older sediments as well as from rainbow trout muscle in two prairie lakes that were treated with toxaphene as a pesticide in the early 1960s. Cored sediments representing the years of treatment (1961/1962) contained high concentrations of hepta-, octa-, and nonachlorobornanes (ΣCHBs, 1602 and 500 ng g -1 ) with a similar gas chromatographic peak pattern to technical toxaphene. In contrast, negative ion mass spectrometry confirmed that the near-surface sediments contained hexa- and heptachlorobornanes at levels not normally observed in environmental samples. This suggests that some of the original toxaphene mixture had been dechlorinated and was redistributed by porewater diffusion and/or sediment focusing. Analyses of fish revealed a toxaphene fingerprint similar to that of the dechlorinated material in sediments, suggesting that the chemical was both water soluble and bioavailable. Significant residual CHBs in surface sediments and in fish indicate that other toxaphene-treated lakes should be reexamined.
Databáze: OpenAIRE