A woman places a medical mask on her face.
Study finds that even a small increase in exposure to air pollution particulate matter called PM2.5, is associated with an increase in bone fractures among older adults. (For Spectrum Health Beat)

Exposure to air pollution can increase the risk for osteoporosis and broken bones in older adults, a new U.S. study suggests.

Researchers analyzed data on 9.2 million Medicare enrollees in the Northeast/Mid-Atlantic area who had been hospitalized for fractures from 2003 to 2010.

The investigators found that even a small increase in exposure to air pollution particulate matter called PM2.5 was associated with an increase in fractures among older adults. PM2.5 is the label for fine inhalable particles with a diameter of 2.5 micrometers or smaller, according to the U.S. Environmental Protection Agency.

The researchers also examined eight years of follow-up among 692 middle-aged, low-income adults in the Boston health survey.

The findings showed that people who lived in areas with higher levels of PM2.5 and black carbon—a type of air pollution from vehicle exhaust—had lower levels of an important calcium and bone-related hormone, and greater decreases in bone mineral density than did those exposed to lower levels of the two pollutants.

The study was published in The Lancet Planetary Health.

“Decades of careful research has documented the health risks of air pollution, from cardiovascular and respiratory diseases to cancer and impaired cognition [thinking skills], and now osteoporosis,” said senior author Dr. Andrea Baccarelli. He chairs environmental health sciences at Columbia University’s Mailman School of Public Health in New York City.

“Among the many benefits of clean air, our research suggests, are improved bone health and a way to prevent bone fractures,” he said in a school news release.

While the study found an association between air pollution and bone problems, it did not prove a direct cause-and-effect relationship.