Long-Term Exposure to Air Pollution Linked with Heart Attack Risk

Long-term exposure to air pollution can lead to an increased risk of heart attacks, a new study has found.

The study, conducted by researchers at Helmholtz Zentrum München and colleagues, also found that the link between particulate matter and heart health is present even when the exposure is below European limit values, meaning that people living in areas that are currently designated as 'low air pollution zones' might also be at risk for several health problems.  

For the study, researchers looked at population groups in Finland, Sweden, Denmark, Italy and Germany. They found that levels of particulate matter near their homes co-related with the risk of coronary heart disease.

Particulate matter (PM) is a mixture of small particles and water droplets. PM may have several other chemicals including nitrates, sulfates, organic compounds and soil particles. According to the United States Environmental Protection Agency, particles between 2.5 and 10 micrometers in diameter pose significant health hazards as they can be easily inhaled and can disrupt heart and lung function. Particles smaller than 2.5 micrometer are classified as "fine particles". They are found in smoke and haze.

In the present study, researchers looked at data from 100,000 participants. At the start of the study, none of them had any kind of heart disease.

During the study period, 5,157 individuals suffered from a condition called angina pectoris or a heart attack. Both conditions occur due to hardening of arteries.

Researchers found that a rise of 5 µg/m³ of annual concentration of PM2.5 was associated with 13 percent increase in heart attack and a 10 µg/m³ of PM10 in the air was tied 12 percent increased heart attack risk.

Current EU limit values for particulate matter are 25 µg/m³ for PM2.5 and 40 µg/m³ for PM10

"Our results show that exposure to particulate matter poses a significant health risk -- and an even greater risk than previously thought," Dr. Annette Peters, lead author of the study, according to a news release. "The adverse health effects that occurred at exposure levels below the current specified limits are particularly alarming. The study therefore supports the demands to lower these limits."

The study is published in the British Medical Journal.

Recently, The International Agency for Research on Cancer had announced that it has classified outdoor air pollution as carcinogenic to humans. A related study had found that two million people die annually due to health complications from air pollution. Previous research by MIT, too, had found that more people in the U.K. die from air pollution than road accidents. This study appeared in the journal Environment Science and Technology.