Air pollution and noise can contribute to heart failure. Former smokers and people with hypertension are most at risk, according to a study involving women, published Wednesday in the Journal of the American Heart Association.
Scientists investigated the impact of road noise and air pollution on the risk of heart failure over 15-20 years. Data was collected until December 31, 2014.
A team of researchers collected data on more than 22,000 participants in another large nursing health study. At the beginning, the women living in Denmark were 44 years of age or older. They provided information on the BMI, smoking, alcohol consumption, physical activity, diet, health and working conditions, among others.
Participants lived in cities, suburbs and villages, and the researchers deduced exposure to pollution and noise from their addresses.
Ex-smokers and people with hypertension are at greatest risk
– We found that long-term exposure to specific air pollutants and road noise increases the risk of heart failure, especially in ex-smokers and people with hypertension. So we need preventive action and adequate education, said Professor Youn-Hee Lim of the University of Copenhagen, who led the study.
– To minimize the impact of these factors, extensive measures are needed in the public sphere, such as exhaust emissions control. To reduce individual risk in humans, measures such as smoking cessation and blood pressure control must also be encouraged, she added.
“We were surprised how the two factors worked together”
For every additional 5.1 micrograms per cubic meter (µg / m3) of particulate matter in the air, the risk of heart failure rose by 17 percent in three years. For each additional 8.6 µg / m3 of nitrogen dioxide, the risk rose by 10% for three years.
The increase in noise by 9.3 decibels (dB) increased the hazard by 12%.
Particulate exposure, combined with a history of smoking, increased the risk by as much as 72%.
– We were surprised how both these environmental factors – air pollution and road noise – interacted – said Prof. Lim.
– Air pollution contributed more to the development of heart failure than noise, but women exposed to high levels of pollution and noise were at the highest risk. Moreover, about 12 percent of the participants had high blood pressure at the start of the study. However, 30 percent of nurses with heart failure previously suffered from hypertension and they were the group most sensitive to the effects of polluted air, the expert explained.
The study had several limitations, the authors admit. Among other things, it did not cover additional factors such as exposure to indoor pollution, noise in the workplace, time spent outside, thickness of window glass, hearing condition or socio-economic status. One must also be careful about generalizing the results to men and the general population. However, as the researchers point out, previous studies have already linked polluted air to cardiovascular disease.
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