Asian Smog Streams Across
Pacific - Is Now Polluting
The Western US
SAN FRANCISCO (Reuters) - Plumes of Asian smog and dust from powerful desert storms are streaming eastward across the Pacific Ocean, affecting air quality in the western United States, according to new studies presented Sunday.
``This is the first time that anybody has ever documented that pollution from one continent can be transported all the way to a downstream continent,'' said Dan Jaffe of the University of Washington in Seattle.
Jaffe and other environmental researchers told a meeting of the American Geophysical Union in San Francisco that on two separate occasions in 1997 and 1998, instruments in the United States picked up documented proof of Asian smog and dust cascading down through the atmosphere.
The 1998 event, sparked by a major dust storm in China's Gobi Desert, was serious enough to boost air pollution measurements in certain areas of the United States to as much as two-thirds of the safety standard set by the Environmental Protection Agency.
``We're still talking about a relatively small part of the pollution, but with the rapid industrial growth taking place in Asia we expect that the impacts will increase,'' Jaffe said.
Earlier studies of pollutants and weather patterns indicated that Asian smog was floating past Hawaii and could account for as much as 10 percent of the ozone and other pollutants found in the air along the U.S. West Coast.
At Sunday's meeting, researchers said these models had borne out by two closely studied events in the past two years. One, in March 1997, revealed that air blowing across Washington state from the Pacific contained carbon monoxide and particulate matter directly traceable to East Asia, sometimes making the journey in as little as four days.
The second, in April 1998, showed that a major dust storm in northwestern China sent enough material into the air that, for several days, the sky literally turned ``white'' over much of the western United States -- some 5,000 miles away.
``A large fraction of the United States was, in effect, covered by this,'' said Thomas Cahill of the University of California-Davis. ``If you looked up, you could see the sky was milky white.''
The scientists said advances in satellite monitoring of pollution streams had helped in development of new models for intercontinental pollution drift.
In the case of Asian smog and dust, it appears that low and high pressure patterns over the Pacific can sometimes combine to act like twin gears pulling Asian air flows through the troposphere directly toward the United States.
Other studies are currently underway to measure the possible flows of airborne pollution and dust from North America eastward toward Europe, Jaffe said, adding that the goal was to develop a global understanding of atmospheric interrelationships.
``As scientists we're not into finger-pointing,'' Jaffe said. ``We're trying to understand what it is we're doing to the planet. We're all in this together.''