Mounting Evidence Indicts Fine-Particle Pollution

摘要

Particle air pollution clearly causes substantial deaths and illness, but what makes fine particles so toxic—the size, the chemical compound, or both? Talk about heart-stopping news: Spending time in traffic may triple some people's risk of having aheart attack an hour later. That's what German researchers reported last October in the New England Journal of Medicine (NEJM), based on responses from 691 heart attack survivors about their activities in the days before they fell ill. The study seemed to support the notion that tiny air pollution particles from tailpipes, along with stress, could help trigger a heart attack. Yet in another recent study in which volunteers in upstate New York breathed in lungfuls of these so-called ultraf ines, particles less than 0.1 micrometer (nm) in diameter, the effects were minimal. If ultraf ines were the main culprit, "you would have expected to see something more," says Daniel Green-baum, president of the Health Effects Institute (HEI) in Cambridge, Massachusetts.