Toxic pollutants in the Arctic poses great health threats to polar bears, leading to pseudo-hermaphrodites and brain damage, a recent study has showed.
Analyzing the effects of persistent organic pollutants (POPs) on species in the Arctic, researchers at the University of Milano Bicocca in Italy found that polar bears are exposed to greater health risks than seals, and their cubs are at the highest risk.
Widely used in industry after World War II, POPs are toxic chemicals that have negative health impact on humans, animals and the environment. They can be transported by wind and water, accumulate in the environment and pass between different species through the food chain.
Researchers in Norway observed in 1996 two cases of pseudo-hermaphrodite in polar bears. The animals had normal vaginal openings and a penis bone inside it. However, neither of them showed signs of having a Y chromosome which could determine they were male.
Such “intersex” polar bears may have risen as a result of hormonal disruptions caused by pollutants, scientists suggested.
Climate change is a change in the statistical distribution of weather patterns when that change lasts for an extended period of time (i.e., decades to millions of years). Climate change may refer to a change in average weather conditions, or in the time variation of weather around longer-term average conditions (i.e., more or fewer extreme weather events). Climate change is caused by factors such as biotic processes, variations in solar radiation received by Earth, plate tectonics, and volcanic eruptions. Certain human activities have also been identified as significant causes of recent climate change, often referred to as global warming.
Scientists actively work to understand past and future climate by using observations and theoretical models. A climate record—extending deep into the Earth’s past—has been assembled, and continues to be built up, based on geological evidence from borehole temperature profiles, cores removed from deep accumulations of ice, floral and faunal records, glacial and periglacial processes, stable-isotope and other analyses of sediment layers, and records of past sea levels. More recent data are provided by the instrumental record. General circulation models, based on the physical sciences, are often used in theoretical approaches to match past climate data, make future projections, and link causes and effects in climate change.