NARRAGANSETT, R.I. July 14, 2008 The outlook for air quality in Beijing during the Olympics is borderline, and there's little that the Chinese government can do to improve it. That's the conclusion drawn by a University of Rhode Island atmospheric chemist who analyzed pollution data collected regularly for the last five years by Chinese scientists.
"There is both a local component and a regional component to the pollutants that cause unhealthy air in Beijing, and the severity of their effects are driven by weather fronts and winds," said Kenneth Rahn, a retired URI professor who travels to China several times a year to help scientists at Tsinghua University interpret their data. "Since it's controlled by the weather, it will be a matter of luck whether the bad air periods correspond with days of outdoor Olympic events."
Locally generated pollutants in Beijing consist primarily of organic matter from transportation, factories and cooking, while regional sources of pollution include ammonium sulfates and ammonium nitrates from coal-burning power plants, industry and transportation sources, which are easily transported long distances in the atmosphere, according to Rahn.
"The air pollution pattern in Beijing is unusual, with high and low concentrations that can differ by a factor of 50 to 100," Rahn said. "When the winds shift to the north and bring in clear air from Mongolia, the air can be relatively clean, though that's not the norm during the summer. But when winds are from the south, where there is a large population and lots of industrial activity, the air can be particularly hazardous."
When air quality in Beijing is at its worst, Rahn says, most of the pollutants come from distant sources, making it virtually impossible for local efforts to lead to the kind of improvements that the government would like.
"It's one thing to take steps to try to clean up a big city, but unless they also clean up the s
|Contact: Todd McLeish|
University of Rhode Island