Fate and distribution of pyrene in Ilyanassa obsoleta exposed through the diet

The ability of Eastern mud snails to bioaccumulate and biotransform a model polycyclic aromatic hydrocarbon (PAH), pyrene (PY), was investigated. The contaminant was added to fish at levels ranging from 2 to 5,000 ng/animal fed 20 mg/each and fed to snails. A linear relationship (p=0.03) was observed between the level of PY and the sum of metabolites consisting predominantly of 1hydroxypyrene and pyrene-1-sulfate detected in soft tissues of snails. In healthy animals, more PY than metabolites was detected, with more biotransformation relative to the parent compound apparent at lower levels of exposure. In ten snails fed together, the body burden of PY-related compounds displayed 49% variability as well as a similar mean and median. One snail within that group had five times more metabolites than PY and was retracted inside the shell, indicating that the animal was stressed. Radio-labelled PY was detected in the largest proportion in the kidney of the animals. Three snails that died during the exposure had also greater than five times more PY metabolites relative to live counterparts. This study is unique in the links that it establishes between stress and the balance of fates of anthropogenic chemicals in biota.