Kannan, K, JC Franson, WW Bowerman, KJ Hansen, PD Jones, and JP Giesy. 2001. Perfluorooctane Sulfonate in Fish-Eating Water Birds Including Bald Eagles and Albatrosses. Environmental Science and Technology 35: 3065 -3070.
Kannan et al. measured perfluorooctane sulfonate (PFOS) contamination in samples of fish-eating birds from diverse locations in the US and the central Pacific Ocean and determined that PFOS contamination is very widespread in fish-eating birds, including eagles, ospreys, albatrosses, gulls, herons, loons, ibises and gannets.
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Sites from which samples were obtained for measurement
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 from Kannan et al. |
Samples came from diverse sources and involved different types of tissue and fluid. In all, 161 samples from 21 species of water bird were characterized.
Most samples obtained from birds across the United States contained PFOS levels about the limits of detection. "The greatest concentration of PFOS (1780 ng/g, wet wt) was determined in the liver of a Brandt's cormorant from San Diego, CA. PFOS concentra tions greater than 1000 ng/g, wet wt, were measured in livers of some individuals of red-throated loon from North Carolina, great egret from Florida, and white pelican from California."
The lowest concentrations were observed in Franklin's gulls. All species except Franklin's gull in this study are fish-eating birds. Franklin's in contrast, eats insects.
Birds in more urbanized regions tended to have higher contamination levels than those in more remote regions. Nestlings contained significant amounts of PFOS. For example, PFOS was found in all but one sample of blood plasma from nestling bald eagles collected from the midwestern United States. This result suggested contamination of eggs and/or diet; analysis of the eggs of both double crested cormorants and ring-billed gulls revealed significant PFOS contamination.
Of particular note were results obtained from two species of albatross living in the central Pacific. Both Laysan and black-legged albatross sera had measurable PFOS contamination, albeit significantly lower than that of fish eating birds in the Great Lakes region. "The occurrence of PFOS in albatrosses suggests the widespread distribution of sulfonated perfluorochemicals in remote marine locations." This is consistent with a study of PFOS in marine mammals.
Contamination levels observed were beneath those currently understood to be sufficient to cause harm in wildlife. Relatively little toxicological testing has been undertaken for PFOS, however, particularly for subtle, low level effects.