The Wild Male Mink as a Sentinel for Endocrine-Disrupting Chemicals and Reproductive Toxicity

Increasing evidence indicates that pollutants may affect the hormone system of humans and wildlife. These endocrine-disrupting chemicals are related to an increased risk of a variety of diseases and disorders, including adverse effects on the reproductive system. By using a sentinel wildlife species, an early warning of adverse health effects due to pollutants in the environment may be provided. This is also relevant for humans, as wildlife and humans can be exposed to similar mixtures of pollutants. With this in mind, the aim of this thesis is to investigate the possibility of establishing the wild mink (Neovison vison) as a sentinel species in Sweden, for both exposure to pollutants and effects of pollutants on the reproductive system. Mink were collected from local hunters and necropsies were performed focusing on the male reproductive system. The collected mink provided an insight in how to handle the variation in data due to sample season, age and nutritional status. These factors significantly influenced many, but not all, of the concentrations of chlorinated, brominated and perfluorinated compounds and also some reproductive organ variables. In addition, the results offer information on how to optimize the design of future studies, and some baseline data for reproductive organ measurements were compiled. Considerable concentrations of PCBs were found in some areas and the concentrations of PFOS were among the highest ever recorded in mink. Associations were found between measurements on the reproductive organs and pollutant concentrations. The anogenital distance was inversely associated with concentrations of some perfluoroalkyl acids and DDE. Several associations were also found between some PCB congeners and measurements on the penis and baculum. In conclusion, the wild mink males may serve as an indicator for environmental exposure to pollutants in Sweden. In addition, the wild mink seems to be a suitable sentinel species that may provide an early warning of alterations in the male reproductive organs related to environmental pollution.