Document Detail


Organochlorine compounds in Lake Superior: chiral polychlorinated biphenyls and biotransformation in the aquatic food web.
MedLine Citation:
PMID:  14740721     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The enantiomeric composition of seven chiral PCB congeners was measured in the Lake Superior aquatic food web sampled in 1998, to determine the extent of enantioselective biotransformation in aquatic biota. All chiral PCB congeners studied (CBs 91, 95, 136, 149, 174, 176, and 183) biomagnified in the Lake Superior aquatic food web, based on biomagnification and food web magnification factors greater than unity. PCB atropisomers were racemic in phytoplankton and zooplankton, suggesting no biotransformation potential toward PCBs for these low trophic level organisms. However, Diporeia and mysids had significantly nonracemic residues for most chiral congeners studied. This observation suggests that these macrozooplankton can stereoselectively metabolize chiral congeners. Alternatively, macrozooplankton obtained nonracemic residues from feeding on organic-rich suspended particles and sediments, which would imply that stereoselective microbial PCB biotransformation may be occurring in Lake Superior sediments at PCB concentrations far lower than that previously associated with such activity. Widely nonracemic PCB residues in forage fish (lake herring, rainbow smelt, and slimy sculpin) and lake trout suggest a combination of both in vivo biotransformation and uptake of nonracemic residues from prey for these species. Minimum biotransformation rates, calculated from enantiomer mass balances between predators and prey, suggest metabolic half-lives on the order of 8 yr for CB 136 in lake trout and 2.6 yr for CB 95 in sculpins. This result suggests that significant biotransformation may occur for metabolizable PCB congeners over the lifespan of these biota. This study highlights the potential of chiral analysis to study biotransformation processes in food webs.
Authors:
Charles S Wong; Scott A Mabury; D Michael Whittle; Sean M Backus; Camilla Teixeira; David S DeVault; Charles R Bronte; Derek C G Muir
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.    
Journal Detail:
Title:  Environmental science & technology     Volume:  38     ISSN:  0013-936X     ISO Abbreviation:  Environ. Sci. Technol.     Publication Date:  2004 Jan 
Date Detail:
Created Date:  2004-01-26     Completed Date:  2004-03-30     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0213155     Medline TA:  Environ Sci Technol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  84-92     Citation Subset:  IM    
Affiliation:
Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada.
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MeSH Terms
Descriptor/Qualifier:
Animals
Biotransformation
Environmental Pollutants / analysis,  metabolism*,  pharmacokinetics*
Fishes
Food Chain*
Geologic Sediments / chemistry
Great Lakes Region
Half-Life
Molecular Conformation
Particle Size
Phytoplankton
Polychlorinated Biphenyls / analysis,  metabolism*,  pharmacokinetics*
Tissue Distribution
Zooplankton
Chemical
Reg. No./Substance:
0/Environmental Pollutants; 0/Polychlorinated Biphenyls

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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