http://www.cnn.com/2000/NATURE/08/01/asian.pollution.enn/

Transpacific pollution leaves thicker and thicker trail August 1, 2000 Web posted at: 2:50 p.m. EDT (1850 GMT)

By Environmental News Network staff

Rising industrialization in Asia is discharging millions of tons of previously undetected contaminants annually into the winds that travel across the Pacific Ocean, researchers say.

The aerosols are killing crops and spreading illness in Asia. They're probably polluting waters in America. And they could dramatically alter global climate.

"Previous research has shown that every spring there are massive dust storms in Asia that transport soil eastward to Japan and across the Pacific to the United States. Now we've found that sulfate and organic aerosols are also present, and in roughly the same amounts," said Thomas Cahill, a professor emeritus of physics and atmospheric science at the University of California at Davis and an international authority on the atmospheric transport of pollutants.

Asia is the largest source of aerosols in the world, said Cahill, who presented new data at a conference in Seattle with colleagues from UC Davis. Asia burns millions of tons of coal annually from abundant coal deposits.

Aerosols are generated from coal-burning power plants and coal-fired locomotives; heavy industry such as metals production; automobile and truck exhaust; home heating; and overtilling of dry-area farmland.

The new findings are crucial for several reasons, Cahill said.

"First, the northern Pacific Ocean is one of the last really clean areas of the Northern Hemisphere. If we start to pollute the air above that ocean, we'll change the balance of heating and cooling of the ocean and that will produce changes in the weather.

"Second, there are increasing numbers of reports of what appear to be toxic Asian pollutants in the lakes and streams of North America.

"Finally, and perhaps most important, there is an established link between aerosol levels and rates of illness and death in people."

While releases of one key type of aerosol, sulfur dioxide, have been decreasing in the United States and Europe since tough air-pollution rules were enacted, the releases are increasing in Asia. Between 1990 and 2000, annual releases of sulfur dioxide into the atmosphere in the United States dropped from about 20 million tons to 13 million tons, but in Asia they climbed to about 45 million tons.

Once released into the air, aerosols ride the wind over land and sea, rising to altitudes of several miles, where their travel is sped by the dry atmosphere and swift winds.

Wherever they go, they retain a unique signature of their origins in their composition of trace elements, such as nickel, copper, zinc, arsenic and lead. Aerosols with these unique signatures from Asia have been detected all the way to the Rocky Mountains in the United States, Cahill said.

The new data is the result of a research project called the University of California Pacific Rim Aerosol Network. The project was started in 1998 with $67,000 from the university system.

Besides releasing results of the project, the researchers also described their role in the forthcoming ACE-Asia project. ACE-Asia, or Aerosol Characterization Experiment, will be the world's largest attempt to identify the exact sources and destinations of those tiny particles of dust, sulfate and organic matter.

Cahill outlined the strategy of the multimillion-dollar research project. In ACE-Asia, existing air samplers and some additions will gather data for six weeks in spring 2001. New samplers will be installed at sites in five Asian countries (China, Taiwan, the Philippines, South Korea and Japan), Mexico and the United States.

The heart of the network is the newly designed International Aerosol Sampler designed and built at UC Davis. It is inexpensive, lightweight and low-tech for producing reliable data in undeveloped regions with unreliable power supplies. It collects air samples that can be chemically checked for unique signatures and tracked as they move around the globe.

This method of developing chemical signatures has been put to intensive use at UC Davis since the early 1970s, when Cahill and colleagues conducted the first studies to identify the origins of view-blocking haze in U.S. national parks.

"Working with our Asian colleagues, we hope to help them efficiently address the causes of these aerosols and aid in developing mitigation. The findings may prompt Asian policymakers to restructure developmental mandates to take into account the devastating air-quality problem they have," Cahill said.

"The relationship between a smelter in Manchuria and aerosol pollution in Japan is not obvious. That's the understanding we're trying to achieve," he added.

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-- K (infosurf@yahoo.com), August 01, 2000