Small Particles Add Up to Big Disease Risk

Breathing polluted air may be nearly as bad for you as living with a cigarette smoker. A new study, the most extensive of its type, shows that long-term exposure to tiny particles of air pollution increases the risk of dying from heart or lung disease or lung cancer by about the same amount as long-term exposure to secondhand smoke. Although the mechanism by which the particles cause disease is still up for debate, the latest study supports existing U.S. air-quality standards that have been attacked by industry and state governments.