Effects of perfluorooctane sulfonate on mallard and northern bobwhite quail exposed chronically via the diet.

Adult mallard ducks and northern bobwhite quail were exposed to 0, 10, 50, or 150mg perfluorooctane sulfonate (PFOS)/kg in the diet for up to 21 weeks. Adult health, body and liver weight, feed consumption, gross morphology and histology of body organs, and reproduction were examined. Due to mortality, birds exposed to 50 or 150mg PFOS/kg feed were terminated by Week 7. In quail, the lowest observable adverse effect level (LOAEL) was 10mg PFOS/kg feed based on decreased survivorship of 14-day-old quail offspring. For adult female quail fed 10mg/kg feed, there was a slight but statistically significantly PFOS-related increase in liver weight when compared to controls. When liver weight was normalized to body weight, the statistically significant differences were still observed indicating that PFOS affected liver size. However, no other pathological effects were observed livers of quail from this treatment group which suggests that this enlargement may have been an adaptive response. For adult mallards, no treatment-related effects on feed consumption, body or liver weight, growth, or reproductive performance were observed. There was a slightly greater incidence of small testes (length) in adult male mallards and quail exposed to 10mg PFOS/kg, feed when compared to controls. However, spermatogenesis was not affected and there was no effect on the rates of egg fertilization. Due to transfer to eggs, concentrations of PFOS measured in the liver and blood at study termination were greater in male birds than female birds.