September 30, 2009

Air pollutants transported from Asia

Pollutant plumes observed in the United States can be attributed unambiguously to Asian sources based on meteorological and chemical analyses, researchers say.

Charles Kolb -- president of Aerodyne Research Inc. and chairman of the committee that wrote the report on air pollution by the National Research Council -- said the report examines four types of air pollutants: ozone; particulate matter such as dust, sulfates, or soot; mercury; and persistent organic pollutants such as DDT.

The committee found evidence, including satellite observations, that these four types of pollutants can be transported aloft across the Northern Hemisphere, delivering significant concentrations to downwind continents -- from Asia to the United States and from the United States to Europe.

One study found that a polluted airmass detected at Mt. Bachelor Observatory in central Oregon took approximately eight days to travel from East Asia, the report said.

Modeling studies have estimated that about 500 premature cardiopulmonary deaths could be avoided annually in North America if ozone emissions were reduced by 20 percent in the other major industrial regions of the Northern Hemisphere.

For mercury and persistent organic pollutants, the main health concern is transport and deposition on land and water. For example, people may consume mercury by eating fish, the report said.