Bioaccumulation and biotransformation of 1-hydroxypyrene by the marine whelk Neptunea lyrata

Abstract

In the marine environment, organisms can be exposed to oxidised forms of polycyclic aromatic hydrocarbons. Bioaccumulation and biotransformation of these derivatives has rarely been investigated and would lead to a better understanding of the overall fate of polycyclic aromatic hydrocarbons and that of other phenolic contaminants. The marine whelk Neptunea lyrata was exposed to 1-hydroxypyrene through its diet over 35 days. Extracts from the muscle and visceral mass of each animal were analysed by liquid chromatography with fluorescence detection. The quantified compounds included 1-hydroxpyrene and the phase II metabolites pyrene sulphate, pyrene glucuronide and one isomer of pyrenediol disulphate. The hydroxylated hydrocarbon was highly retained with 78% of the exposure amount recovered primarily from the visceral mass of the whelks, while the muscle accounted for 4% of the body burden. Whelks efficiently biotransformed 1-hydroxypyrene with a mean of 81% of the compound detected as phase II metabolites. The novel biotransformation product, pyrenediol disulphate, accounted for the largest proportion of the 1-hydroxypyrene derivatives detected at body burdens below 200 ng. At higher body burdens, bioaccumulation increased. Control animals showed trace levels of pyrene derivatives with 76% represented by metabolites. This study highlights the importance of investigating the multiple fates of reactive chemicals in order to interpret exposure.

Keywords:

• PAH
• biotransformation
• metabolite
• bioaccumulation
• whelk
• pyrene

Acknowledgements

The authors would like to thank B. Macdonald and M. Lundy (DFO, Dartmouth, NS, Canada) for collection of field samples. We also acknowledge Dr Haidrun Anke (Institute of Biotechnology and Drug Research, Kaiserslautern, Germany) for the sample of 1,6-PYDS. Daniel also acknowledges that this research was performed as part of his MSc thesis in the Chemistry Department at Dalhousie University. This research was funded by the National Sciences and Engineering Research Council and the Department of Fisheries and Oceans.

Notes

Note

1. Log K_ow and solubility values calculated using Advanced Chemistry Development (ACD/Labs) Software v8.14 © 1994–2007.