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NWT - Scientists say pollution from around the world is coming home to roost in the NWT, but it's no reason to panic just yet.

Representatives from INAC's Environmental Contaminants Program said they have found increasing levels of mercury in caribou from around the NWT.

But even with the increase, no one is sounding the alarm.

"The levels are actually very low, particularly in (meat)," said environmental scientist Jason Stow, who works with the program.

The average level is 0.06 parts per million, well below the Health Canada threshold for commercial sale (0.5 parts per million).

To compare, the GNWT has issued an advisory for Giauque Lake, which is contaminated with mercury from the former Discovery mine. In 2005, fish in that lake tested at 1.5 parts per million. The advisory warned that fishers shouldn't eat more than one meal of fish from the lake a week.

In high, persistent doses, mercury can affect the heart, brain and immune system.

"I wouldn't deter anyone from eating caribou here based on these mercury levels," said Kami Kandola, deputy chief medical officer of the NWT. She said caribou is still the healthiest country food available in the NWT.

Studies are based on samples donated by hunters from around the North, including NWT communities Fort Smith, Yellowknife and Inuvik, taken from the Bathurst, Beverly and Bluenose East caribou herds. The studies also include sea mammals such as seals and narwhal.

"(These studies) are one of the ways in which we are contributing to the implementation of international agreements," said Stow.

These agreements, such as the UN's Stockholm Convention, limit the amount of harmful substances that participating countries expel - substances like DDT, PCBs and various others.

Stow said most of the mercury that finds its way into the NWT comes from abroad. Coal-fired power plants are the main culprit, he said, and the developing world's increased reliance on coal is pushing more of the element into the air.

"Mercury is quite volatile - it can stay in the atmosphere for a year," Stow said. "That's plenty of time to travel the globe."

He said the substance settles in grasses and plants, which are then eaten by caribou. In sea mammals, mercury contacts sea water and plankton, entering the food chain at that stage.

While mercury is a concern, Stow said the program is watching newly-recognized pollutants, such as brominated flame retardants (used in circuit boards and wiring) and PFOS, the key ingredient in Scotchguard. He said information from the Environmental Contaminants Program could develop further regulations around mercury and other harmful pollutants

"If levels (of these substances) are not going down, it indicates that we need to do more."