Exposure to high levels of pollutants may reduce the size of sexual organs in polar bears.

A Danish study examined reproductive organs from 55 male and 44 female East Greenland polar bears to find the potential negative impact from organohalogen pollutants.

The industrial pollutants, called organohalogen compounds, have been affecting polar bears in several areas, LiveScience reported.

Polar bears from East Greenland, Svalbard, and the Western Russian Arctic are the most OHC-polluted species in the Arctic because they rely on blubber from mainly ringed seals and bearded seals, according to the study. LiveScience reported that the blubber of the seals accumulates high levels of organic pollutants, organohalogens (OHC), which act like hormones.

The shrinkage of the genitals could endanger polar bears by diminishing their sex lives, which in turn would cause their numbers to diminish.

A study showed a connection between OHC levels and a smaller uterus in female bears and smaller testis and baculum, or penis, in males, according to United Press International. UPI reported that a large penis is critical for successful mating in an arctic climate, noting that even a slight decrease may interfere with polar bears' reproduction.

LiveScience reported that the pollutants could affect all marine mammals, "especially the Arctic fox, killer whale and pilot whales," according wildlife veterinarian and toxicologist Christian Sonne at the National Environmental Research Institute of Denmark.

The study, published in the journal Environmental Science & Technology, suggests that the impact on the size of polar bear genitalia may pose a risk to the east Greenland polar bear subpopulation in the future because of reduced sperm and egg quality and quantity and uterus and penis size and robustness.

The life-span and adult survival of polar bears are among the highest for mammals in general, while the reproductive rates are among the lowest for terrestrial mammals.