Pollutants from China detected

BEND, Ore. – The air atop Mount Bachelor is some of the cleanest in the Northwest, and to some scientists it’s a perfect place to study pollution.

And some of what they’re finding comes from China.

“It’s sort of ironic that we have to go to one of the cleanest locations to look for pollutants,” said Daniel Jaffe, a professor of atmospheric and environmental chemistry at the University of Washington, Bothell.

Since 2004, he and other scientists have been sampling air on the 9,065-foot mountain. Most days levels are low, they say, and come from local sources.

But occasionally, when the winds are right, pollution levels from overseas increase.

“You can’t blame other countries for most of your pollution,” Jaffe said. “That said, this long-range transport of pollution shows we live on one planet.”

The levels of overseas pollution aren’t dangerous, Jaffe said, but added that as China grows we could see more of it.

Nine years ago his group first detected Chinese pollution on the Washington coast. Other sci- entists have since confirmed it.

Jaffe’s group is focusing on mercury as well as gases, including carbon monoxide, ozone and nitrogen oxides.

Most of the devices work by shining different wavelengths of light through the air samples in tubes and identifying its composition based on which wavelengths are absorbed.

To find the source, Jaffe looks at various clues.

If there is a big fire or dust storm across the globe, he can see the pollution crossing the ocean on satellite data. In lesser cases computers trace the path of Northwest winds to find origins.

On Mount Bachelor, Jaffe is looking for a mercury fingerprint of Chinese pollution. China is the largest consumer of coal, he said, and its coal is rich in mercury.

While the foreign contaminants do not exceed local health standards, they could in combination with local sources, he said.