Enantiomers of methylhexachlorocyclohexane and hexachlorocyclohexane in fish, shellfish, and waters of the Mersey estuary

✍ Scribed by A. S. McNeish; T. Bidleman; R. T. Leah; M. S. Johnson

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 116 KB
• Volume: 14
• Category: Article
• ISSN: 1520-4081
• DOI: 10.1002/(sici)1522-7278(1999)14:4<397::aid-tox4>3.0.co;2-3

✦ Synopsis

Biota of the Mersey Estuary are contaminated by a number of methylhexachlorocyclohexane compounds, of which the most abundant analyte is 1␣ ,2 ␣ ,3 ␤,4␣ ,5␤,6 ␤-hexachloro-1-methyl-( ) ( ) cyclohexane ␣-MHCH . The soft tissues of blue mussels Mytilus edulis and liver tissue of dab ( ) ( ) ( ) Limanda limanda , flounder Platichthys flesus , and plaice Pleuronectes platessa from the estuary ( ) (

) show enantiomeric ratios ERs for chiral ␣-MHCH of 0.88 " 0.01 -1.10 " 0.02 mean " SD , a range which departs from the unity value expected for the racemic mixture of the two enantiomers if no metabolic or abiotic transformations occur. This reflects biologically mediated degradation which is enantiomer selective, though the differences in ER values are subtle given the contrasting behavioral and feeding strategies of the species analyzed. The ecotoxicological risk of MHCH isomers is unknown; but as a result of enantioselective metabolism, the chiral structure of ␣-methyl HCH may influence the bioaccumulation and toxicological potential of this group of compounds to marine biota.