Pollution in the Arctic region has become an increasingly serious issue. The environment may look pristine, but its inhabitants contain surprisingly high levels of heavy metals, organic pollutants, and radiation.

The main culprits are industrial chemicals, pesticides, and new compounds such as flame retardants. These chemicals were designed to not break down (to lengthen their effectiveness), and they don't!

Once released into the environment, these resistant chemicals are picked up by water, air or organisms and move northward.

The Arctic Ocean sits in an enclosed basin and contaminants deposited there tend to stay. Low temperatures and limited sunlight slow their decay, and biological processes allow some of them to accumulate to dangerously high levels.

They're picked up by algae and plankton, which are then eaten by the fish, who pass it on to the seals. The pollutants accumulate in the seal's fat, and unlucky seals then provide a contaminated meal for both polar bears (the fat is the bear's favorite part) and humans.

These pollutants destroy the bear's immune system, and this damage can start early in life - the pollutants are passed on to the cubs through their mother's fat-rich milk.

Polar bears may look nice and white, but at the top of the Arctic food chain, they've become one of the most polluted animals on Earth.