7.1 Effects
The data on PAH toxicity to wildlife (except in laboratory animals such as rats, mice, guinea pigs, etc.) are few. Some pertinent data from the literature are reviewed below.
Patton and Dieter (1980) exposed mallards (Anas platyrhynchos) to a diet containing 4 000 µg PAHs/g (mostly as naphthalenes, naphthenes, and phenanthrene) for 7 months. No visible signs of toxicity were evident during the exposure. Although food consumption was not measured, it was believed the toxicant effect was mediated through a decrease in the voluntary intake by the birds because of reduced food palatability.
Hoffman and Gay (1981) studied the embryotoxicity of various PAHs (in a synthetic petroleum mixture) applied to the surface of mallard eggs. 7,12-dimethylbenz[a]anthracene was the most toxic PAH tested. Approximately 0.002 µg/egg (~0.036 µg/kg fresh weight, assuming an average mass of 55 g/egg) of 7,12-dimethylbenz[a]anthracene caused 26% mortality in 18 days. Also, a reduction in the embryonic growth and an increase in the frequency of other anomalies were noted among survivors. Similar results were found with 0.015 µg chrysene/egg. Benzo[a]pyrene (0.002 µg/egg) did not affect mallard survival, but caused a reduction in the embryonic growth and an increased incidence of abnormal survivors.
7.2 Criteria from other jurisdictions
PAH criteria for wildlife were not found in the literature.
7.3 Recommended criteria
PAH criteria for wildlife are not recommended due to the lack of data.