"The long term survival of polar bears is being threatened by man-made pollution that is reaching the Arctic.

This conclusion comes from a major review of research into how industrial chemicals such as mercury and organochlorines affect the bears.

The review suggests that such chemicals have a range of subclinical effects.

When added together, these can have a dramatic and potentially fatal impact on the bears' bones, organs and reproductive and immune systems.

The review, an analysis of more than a decade's research into the effect of pollution on bears, is published in the journal Environment International."

Matt Walker reports for BBC Earth News January 14, 2010. [2]