New research suggests pollutants are weakening the penis bones of male polar bears in the Arctic. Photo by the U.S. Fish and Wildlife Service.
AARHUS, Denmark, Jan. 26 (UPI) -- Polar bears do more than just star in Coca-Cola commercials. Occasionally, they eat and mate (the two great joys of animals' lives). But according to a new study, mating has been getting a bit harder for polar bears in recent decades -- or more accurately, getting a bit softer.
New research suggests the bone in the penis of male polar bears has been weakening as a result of exposure to a variety of industrial contaminants known as polychlorinated biphenyls, or PCBs.
"These chemicals enter the atmosphere at lower latitudes where they were used, and are then deposited down from the cold polar air, so Arctic animals are more highly exposed than animals in more temperate or equatorial regions," Margaret James, a biologist at the University of Florida who wasn't involved in the study, told the New Scientist.
Researchers located the correlation after comparing the bone density of the baculum (penis bone) of several dozen polar bear specimens with concentrations of PCBs in the Arctic.
Contaminants like PCBs are always the most dangerous for large predators, like bears and humans, that feed upon a range of animals lower down on the food chain. PCBs are stored in animal fat and concentrate as they travel up the food chain towards the top predators. The same phenomenon explains why mature blue fin tuna often feature relatively high concentrations of mercury.
The new research was carried out by Christian Sonne and his colleagues at Aarhus University, in Denmark. The research team has previously found that polar bears with high concentrations of organohalogens, another type of industrial contaminant, featured smaller testes and penis bones.
The study was published this week in the journal Environmental Research.
