A new study suggests that Americans who live and work in countries with dirty air have a shorter life expectancy and are more likely to die from a stroke.

For this study, researchers analyzed the health and air pollution data collected from nearly 1,600 counties in the United States between 2005 and 2010. The study focused on adults aged 35 and over.

The type of air pollution studied is called PM 2.5. It contains inhalable particles produced by diesel engines and the combustion of coal, biomass and kerosene. It has been shown that these fine particles enter the circulatory system and are harmful to health.

In 51% of the countries surveyed, average annual PM 2.5 exceed federal standards.

The results showed that the more dirty the air, the higher the rate of stroke deaths and the shorter life expectancy, both for men and women. The threat to health was greatest in areas of high poverty and fewer health providers.

The largest exposure to polluted air occurred in the south, suggesting that PM 2.5 could contribute to the region's high rate of strokes. Poverty, diet, smoking, inadequate control of risk factors for stroke and reduced availability of health services are other contributing factors.

The study is to be presented Feb. 6 at a conference of the American Stroke Association in Honolulu. Research presented at meetings is generally considered preliminary until it is published in a peer-reviewed journal.

"To reduce the risk of stroke, clinicians must take into account the potential exposure of their patients to air pollution as well as other risk factors," said Dr. Longjian Liu. , lead author of the study, in a press release of the association. Liu is an associate professor of epidemiology and biostatistics at Drexel University in Philadelphia.

Liu suggested to health care providers to ask patients if they lived or worked in an industrial area and knew the sources of pollution nearby.

"Clinicians can then encourage at-risk patients to take steps to minimize their exposure, for example by avoiding highways during rush hours, keeping the car windows closed and letting the air conditioner circulate. indoor air, "said Liu.

Researchers are currently examining the links between higher levels of PM 2.5 pollution and the risk of other leading causes of death, including heart disease, heart failure and cancer.