Oct. 22, 2021 -- Exposure to air pollution and road traffic noise over several years may increase the risk of heart failure, according to new research from a large observational study.
The study examined more than 22,000 female nurses based in Denmark, aged 44 and older, over a period of 15 to 20 years to evaluate the impact of exposure to small particulate matter and nitrogen dioxide, as well as road traffic noise.
The results showed that increased exposure to these pollutants after just 3 years was tied to a substantially increased risk of new heart failure
Former smokers and hypertensive patients were most susceptible to the negative effects of fine particulate matter, says Youn-Hee Lim, PhD, lead author of the study and an assistant professor in the Section of Environmental Health in the Department of Public Health at the University of Copenhagen in Denmark.
In fact, former smokers exposed to fine particulate matter for extended periods had a 72% higher risk for heart failure. They were not able to examine longer exposure to fine particulate matter, Lim says, "therefore, we can’t say which is the pivotal number of years where the heart failure risk starts to set in."
Road traffic noise was estimated by measuring noise from roads within a 3-kilometer radius of participants' homes. Although the relationship for road noise was not as strong as with pollutants, it was still linked to a higher risk of heart failure.
The findings were published online in the Journal of the American Heart Association.
While previous studies have linked air pollution and cardiovascular disease, there has been little research before now on the association between extended air pollution exposure and heart failure, says Lim.
"As air pollutants and road traffic noise share a major source -- traffic -- it is important to consider the independent or interactive effects of the 2 exposures on health," the researchers wrote.
With emissions standards now in place to combat pollution, it is interesting that the researchers thought to explore air pollution as a heart failure risk, says Ileana L. Piña, MD, a heart failure transplant cardiologist and professor of medicine at Wayne State University.
"You think of respiratory illness in cities where there is a high level of pollution, but you don't think of heart failure," says Piña, who was not a part of this study. "Next I think we need to link up what it was in that polluted air that actually caused the trauma."
Each woman enrolled in the study completed a comprehensive questionnaire on body mass index; lifestyle factors including smoking, alcohol consumption, physical activity, and dietary habits; current health conditions; reproductive health; and working conditions. The study did not account for things like exposure to indoor air pollution or occupational noise, which may have affected the results.
Lim says broad public tactics like better emissions control measures can help lessen the impact of pollution exposure, as can things like stopping smoking and controlling blood pressure.