ACCUMULATION OF HEXABROMOCYCLODODECANES (HBCDS) AND THEIR METABOLITES IN PUP AND ADULT HARBOUR SEALS FROM THE NORTHWEST ATLANTIC

摘要

The isomer-specific distribution of HBCDs was investigated in 56 liver samples of harbour seals (Phoca vitulina concolor; 50 pups and 6 adults) and 5 blubber samples of pups (n = 4) and one adult from the northwest Atlantic. In two liver samples, HBCDs were below the limit of quantification (< 1.5 ng/g lipid weight (lw) for each isomer). For all other samples, the sum of HBCDs ranged from 2.7 to 4805 ng/g lw in liver and from 2.0 to 25.3 ng/g lw in blubber. Median values were 23.5 ng/g lw and 11.1 ng/g lw for liver and blubber respectively. The α- HBCD isomer was the dominant isomer (mean percentage was 95%) in all liver samples. In blubber, γ-HBCD and β-HBCD were not found in any sample. Male pups and female pups were found to differ significantly in the concentration of α-HBCD in liver, however no statistical significant differences could be detected between male pups and adult males. Other factors, such as time of sampling, location, body length and body weight, were not able to explain the results found in the present study. Additionally, HO-HBCDs could be detected in some seal liver samples, indicating the capacity of harbour seals to (partially) metabolize HBCDs.