Getting exposed every day to certain kinds of air pollution can lead to a higher risk of premature death if you’re over 65.

That's the finding of a new study in the Journal of the American Medical Association. Francesca Dominici is a professor of biostatistics at the Harvard T. H. Chan School of Public Health and an author of the study.

She and her team studied daily exposure to ozone pollution and fine particulate matter. Those are tiny particles that can lodge deep in your lungs.

“So for example, if you experience a small change in fine particulate matter from yesterday to today, we see an increase in the daily mortality risk on the following day from this increase in exposure," Dominici says.

She says they found that to hold true for even low levels of air pollution below current national standards.

“We’re learning by breathing this small level of fine particulate matter, that penetrates deep into the lung, and activates all series of inflammation processes that can affect both our cardiovascular system and our respiratory system," says Dominici.

Dominici says they found African Americans, women, and low-income elderly people were the most at risk. Previous work by Dominici and her colleagues found that long-term air pollution exposure also increases the risk of premature death in older people.

She says it’s good for doctors to be aware of these risks. But she says it also highlights the role our government plays in continuing to reduce air pollution.