High levels of certain environmental pollutants could impact the size of sexual organs in animals and probably humans, say scientists.
Christian Sonne and colleagues at National Environmental Research Institute at Denmark checked 55 male and 44 female East Greenland polar bears for a correlation between the pollutant levels in body tissue and the size of sexual organs.
Exposure to high levels of environmental pollutants called organohalogen compounds (OHCs) seems to reduce the size of sexual organs in male and female polar bears, the health portal Medical News Today quoted the researchers as saying.
OHCs include dioxins, polychlorinated biphenyls and some pesticides. Past studies have linked OHCs to various health effects in bears.
The researchers did the study to close gaps in knowledge about the possible effects of OHC on reproduction in polar bears, a vulnerable population because of their low reproductive rates.
The bears have elevated OHC levels due to a diet that includes seals, which accumulate large amounts of OHCs in their blubber.
The new study reports a connection between OHC levels and reduced size of the uterus in female bears and reduced size of the testis and baculum (penis bone) in males.
A large baculum is critical for successful mating in an Arctic climate, the researchers note, and even slight decreases may interfere with reproduction.
"Furthermore, similar physiological impacts from organohalogen-pollutant exposure may be manifested on the reproductive tract of humans relying on OHC-contaminated food resources," the study states.