Date of Completion

Spring 5-1-2014

Thesis Advisor(s)

Milton Levin; Paulo Verardi

Honors Major



Environmental Public Health | Veterinary Preventive Medicine, Epidemiology, and Public Health


This study investigated the effects of environmental toxicants on the immune system of two pinniped species, grey seals (Halichoerus grypus) and hooded seals (Cystophora cristata). The toxicants included two perfluorinated compounds (PFC), perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), compounds commonly found in a wide variety of household consumer products, including Scotchguard and Teflon. Although corporations such as 3M curtailed the use of these chemicals in the past decade, concentrations of these chemicals are increasing in the arctic aquatic ecosystem and have been measured in the tissues and blood of arctic pinnipeds. However, the effects of these chemicals on the immune system are poorly understood in marine mammals. The hypothesis was tested, “PFOA and PFOS are equally immunotoxic in arctic pinniped species,” using the following specific aims, 1) quantify and assess changes in mitogen-induced lymphocyte proliferation upon increasing concentrations of PFOA and PFOS and 2) compare changes in lymphocyte proliferation between two pinniped species. This was the first study to demonstrate the immunotoxic effects of PFOA and PFOS in two pinniped species; however, the effects were not always similar between the species. Importantly, the concentrations tested represent the range found in the blood of free-ranging animals, suggesting that free-ranging animals may be at risk for immunotoxic effects.