DALLAS, Texas — Living on a busy road could trigger heart failure, especially among women, a new study warns. A team with the American Heart Association finds that traffic and noise pollution weaken the organ, reducing its blood-pumping power. Additionally, a small rise in toxic fumes increases the risk of heart failure by almost a fifth, rising to 72 percent in those with a history of smoking.
“We found long-term exposure to specific air pollutants and road traffic noise increased the risk of incident heart failure, especially for former smokers or people with hypertension, so preventive and educational measures are necessary. To minimize the impact of these exposures, broad public tactics such as emissions control measures should be implemented. Strategies like smoking cessation and blood pressure control must be encouraged to help reduce individual risk,” says study lead-author Dr. Youn-Hee Lim of Copenhagen University in a media release.
The findings were based on more than 22,000 Danish nurses aged 44 or over. They were recruited between 1993 and 1999 and tracked for up to 20 years. Researchers collected data on levels of fine particulate matter (PM2.5s) and nitrogen dioxide (NO2) from cars, trucks, and buses around their homes. Road traffic noise was also measured in decibels (dBs).
For every 5.1 and 8.6 µg/m3 (microgram per cubic meter squared) increase in PM2.5s and NO2 over three years, the risk of heart failure rose by 17% and 10%, respectively. For every 9.3 dB increase in road traffic noise in the same period, the risk rose by 12%.
“We were surprised by how two environmental factors — air pollution and road traffic noise — interacted,” Dr. Lim adds.
High blood pressure a major factor in pollution’s impact
Study authors found that air pollution was a stronger contributor to heart failure incidence compared to road traffic noise. However, the women encountering high levels of both air pollution and road traffic noise showed the highest increase in heart failure risk.
Additionally, only 12 percent of the participants had hypertension at the start of the study. Unfortunately, 30 percent of the nurses with heart failure incidence had a history of hypertension and they were the most susceptible group to air pollution exposure.
Each participant completed a questionnaire on body mass index (BMI), smoking history, alcohol consumption, physical activity, and dietary habits. They were also asked about pre-existing illnesses, reproductive health, and working conditions. Heart failure diagnoses throughout the follow-up period were identified through the Danish National Patient Register, which includes records on all care provided at hospitals.
The women lived in rural, urban, and suburban areas. Study authors measured pollution exposure through individual residences, including any moves up until the end of 2014. Yearly average concentrations of PM2.5, NO2, and dB levels were calculated using computer modeling systems.
More than 10 million people die each year from air pollution, estimates show. Heart failure causes tiredness, fatigue, and breathlessness, making even simple chores difficult. Over six million adults suffer from heart failure.
Last year, an international team of experts also linked environmental hazards to cardiovascular disease. They said noise pollution can make a person feel annoyed or angry. This can result in increased oxidative stress and inflammation. It can disrupt sleep cycles, which are important for good cardiovascular health. The scientists added air pollution stiffens the arteries which can lead to blood clots, increasing the risk of heart attacks and strokes.
The study was published in the Journal of the American Heart Association.