Atmospheric chemist Kenneth Rahn regularly travels to China to consult with scientists there about the country's air pollution problem. Rahn took your questions about pollution in Beijing during the run-up to the Olympic Games.
Does pollution stay in the lungs or get flushed out over time?
John Shaughnessy of Fairfield, Va. asks
Will the pollution breathed by those attending the 2008 Games stay in their lungs or will it be flushed out over time? Please compare to tobacco smoke, asbestos, farmer's lung, etc.
Kenneth Rahn responds:
It gets flushed out pretty fast. Most of the fine particles are soluble, and will simply be excreted in the normal course of things.
Tobacco smoke is far worse than Beijing's pollution. Asbestos is a wholly different kind of problem, and I have no idea whether China is using asbestos today or has used it extensively in the past. Don't know about farmer's lung. Sorry.