Ancient Bones Give Clues to Modern Pollution

WebPosted Nov 15 2002 09:48 AM CST

WHITEHORSE, YUKON - Ancient ice patches in the Yukon are providing researchers with startling insights into airborne contaminants around the world.

Recent test results show lead levels in modern caribou have risen dramatically, and point to the internal combustion engine as the culprit.

Scientists tested pieces of caribou bone found in 6,000-year-old ice patches in the territory. They say the ice acted like a huge freezer, preserving the bone for millennia and allowing them to compare heavy metals found in the bones with modern caribou.

Yukon biologist Pat Roach says says their tests found a four-fold increase in lead levels.

Further tests proved the source of lead was from gasoline made in the U.S., and sold around the world.

"So the question is, is it strictly [lead from] the United States and a lag effect, or is it something thats being blown in from other parts of the world where they are still using tetra ethyl lead, like Asia?" he says.

Leaded gasoline has been banned in America for the past 20 years. While that same lead is still working it's way through the northern food chain, Roach says the implications are not so clear.

"If this is a leaded gas problem, the tap has already been turned off and it's a question of how long we're going to have to live with it, and that is a whole new field of research one step farther than we are right now," he says.

Roach says ongoing research will provide insights into windblown contaminants and the effect on ecosystems around the globe