密歇根新闻广播 为什么微粒子污染会增加老年人死亡风险（在线收听）

Long-term exposure to certain kinds of air pollution increases the risk of premature death in Americans over 65 years old. That finding holds true even at levels of air pollution below national standards.

That’s according to a study in The New England Journal of Medicine from the Harvard T.H. Chan School of Public Health. Francesca Dominici is the study's principal investigator, and a professor of biostatistics at Harvard.

She and her team examined Medicare claims records for 60 million Americans over a seven year period. They focused on ozone and fine particulate matter (tiny particles of pollution that we can inhale).

“One of the important aspects of this study was to collect and link an enormous amount of very granular data on exposure to pollution which we were able to assess up to the zip code of residents of almost every U.S. citizen older than 65," she says.

Dominici says they compared that information with socio-economic status, health history and behavioral risk factors.

She says particulate matter can penetrate deep into the lungs and cause inflammation, and lead to cardiovascular and respiratory problems. Dominici says they found some people are more susceptible to health problems from air pollution than others.

“People that have lower income, African American[s] and also male[s] have a much higher risk of that; specifically among African Americans, which was pretty surprising to us. We found that the risk was three times higher than the general population,” she says.