- 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.
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- ``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.
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- 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.
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- 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.
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- ``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.
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- 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.
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- 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.
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- 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.
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- ``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.''
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- The scientists said advances in satellite
monitoring of pollution streams had helped in development of new models
for intercontinental pollution drift.
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- 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.
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- 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.
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- ``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.''
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