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

Miskimmin, Brenda M.; Muir, Derek C. G.; Schindler, D. W.; Stern, Gary A.; Grift, Norbert P.

doi:10.1021/es00010a006

Cited by 43 publications

(46 citation statements)

References 39 publications

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“…The general hierarchy for individual CHB concentrations was B7-1001 ~ B6-923> B8-2229 -B8-786 > B7-515 ~ B9-1025. The predominance of B7-1001 and B6-923 in our samples was consistent with the pattern seen in sediments and fish from toxaphene-treated Canadian lakes (7,14). B8-1413 and B9-1679 were found to be the 2 major residue components in marine mammals (17) and fish (18).…”

Section: Chlorobornane Identification and Estimated Concentrationssupporting

confidence: 87%

“…In contrast, profiles of CHBs were found to be much more complex in media from toxaphene-treated lakes (7) or those in close proximity to known point sources, such as the Terry/Dupree tidal creek system in Brunswick (8, this study) and Lake Nicaragua, the site of another Hercules toxaphene plant (9). In this study, we characterized the profiles and computed estimated concentrations of toxaphene residues in sediments and biota from the Brunswick site, focusing on the identification of prominent CHBs in these samples and a comparison of source (sediment) and receptor (marsh biota) profiles/levels.…”

mentioning

confidence: 75%

“…Toxaphene was produced by reacting chlorine gas with technical camphene (a derivative of a-pinene extracted from pine resin) in the presence of ultraviolet radiation and catalysts. The resulting formulation was composed mostly of chlorobornanes (CHBs), compounds with 5 to 11 chlorine atoms on a saturated CIO bicyclic hydrocarbon skeleton (7). The average chlorine content of toxaphene was 68-70%.…”

mentioning

confidence: 99%

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Selective Persistence and Bioaccumulation of Toxaphene in a Coastal Wetland

Maruya

Vetter

Wakeham

et al. 2000

ACS Symposium Series

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Section: Chlorobornane Identification and Estimated Concentrationssupporting

confidence: 87%

mentioning

confidence: 75%

mentioning

confidence: 99%

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Selective Persistence and Bioaccumulation of Toxaphene in a Coastal Wetland

Maruya

Vetter

Wakeham

et al. 2000

ACS Symposium Series

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“…Octach‐lorobornanes were below the detection limit in all samples. The shift of the CTT pattern toward shorter retention times and lower degree of chlorination [6,28] was confirmed.…”

Section: Resultsmentioning

confidence: 90%

“…Stern et al [4] showed that these two compounds of technical toxaphene (CTTs) accounted for approximately 60% of the total toxa‐phene concentration. Miskimmin et al [6] and Stern et al [7] described time profiles of toxaphene in sediment cores and showed that CTT patterns can vary with time. It is noteworthy that the major CTTs present in sediments from a toxaphene treated lake (i.e., B6‐923 and B7‐1001) are not observed in marine mammals and, conversely, B8‐1413 and B9‐1679, two of the major CTTs in biota, have been found to be only minor components in sediments.…”

Section: Introductionmentioning

confidence: 99%

Enantioselective determination of two persistent chlorobornane congeners in sediment from a toxaphene‐treated yukon lake

Vetter

Bartha

Stern

et al. 1999

Enviro Toxic and Chemistry

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The composition of toxaphene residuesand the enantiomeric ratios of the major congeners were studied in the top 10 slices (1935–1992) of a sediment core collected from Hanson Lake in the Yukon Territories (Canada). This lake was treated with toxaphene as a picsicide in July 1963. Electron‐capture negative ion mass spectrometry and electron‐capture detection were applied in combination with enantioselective gas chromatography using modified cyclodextrin columns. Of the 10 toxaphene peaks identified in each of the sediment slices, two congeners, 2‐exo,3‐endo,6‐exo,8,9,10‐hexachlorobornane (B6‐923 or Hx‐Sed) and 2‐endo,3‐exo, 5‐endo,6‐exo, 8,9,10‐heptachlorobornane (B7‐1001 or Hp‐Sed), were the most abundant. Each of the three chiral stationary phases used in this study was successful at resolving the enantiomers in at least of one of the two congeners. Among them was permethylated β‐cyclodextrin (Chirasil‐Dex), which, up until now, has never been used for enantiomer separation of compounds of technical toxaphene. B6‐923 and another less abundant, as of yet unknown, hexachlorobornane were racemic in all sediment core slices. For B7‐1001, the latter eluting enantiomer was always more predominant. Furthermore, the enantiomeric ratio was found to consistently decrease with time from approximately 0.8 in the early slices (∼1950) to 0.7 in the slice representing 1992, implying that the first eluted B7‐1001 enantiomer is less persistent than the second. B6‐923 and B7‐1001 are most likely metabolites of the more highly chlorinated congeners. A structural evaluation provided evidence that reductive dechlorination at carbons with geminal chlorine atoms is the primary microbial degradation pathway in sediments from Hanson Lake.

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Spatial trends and bioaccumulation of organochlorine pollutants in marine zooplankton from the Alaskan and Canadian Arctic

Hoekstra

O’Hara

Teixeira

et al. 2002

Enviro Toxic and Chemistry

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Planktonic copepods (Calanus glacialis and C. hyperboreus; n = 37) and water (n = 19) were collected to examine the spatial distribution and bioaccumulation of organochlorine contaminants (OCs) in the Alaskan and Canadian Arctic. The rank order of total OC (sigma OC) group concentrations in Calanus samples was toxaphene > or = sigma polychlorinated biphenyls (PCBs) > sigma hexachlorcyclohexane (HCH) > sigma DDT > sigma chlordane-related compounds (CHLOR) > sigma chlorobenzenes (ClBz). The dominant analyte was alpha-HCH in all water and zooplankton samples. The most abundant toxaphene congener in water and zooplankton samples was the hexachlorobornane B6-923. Organochlorine contaminant group concentrations in Alaskan zooplankton and water samples were lower than those in samples collected from sites in the eastern Canadian Arctic. Comparison of PCB and toxaphene congener profiles in zooplankton and water samples suggests that biotransformation by cytochrome P-4502B isozymes is low in Calanus, and limited phase I metabolism may occur. The log relationship of bioaccumulation factor (log BAF) versus octanol-water partition coefficient (log Kow) relationship was near 1:1 for OCs within the log Kow range of 3 to 6. A curvilinear model provided a better relationship between these two variables when OC compounds with log Kow > 6 were included. These results suggest that hydrophobic OCs (log Kow 3-6) in Calanus species are at equilibrium with the water concentrations and that physical partitioning, rather than biotransformation, is the major factor governing OC profiles in marine zooplankton.

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

Cited by 43 publications

References 39 publications

Selective Persistence and Bioaccumulation of Toxaphene in a Coastal Wetland

Selective Persistence and Bioaccumulation of Toxaphene in a Coastal Wetland

Enantioselective determination of two persistent chlorobornane congeners in sediment from a toxaphene‐treated yukon lake

Spatial trends and bioaccumulation of organochlorine pollutants in marine zooplankton from the Alaskan and Canadian Arctic

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