Low levels of air pollution increase the risk of heart and lung disease

Air pollution elevates the risk of heart and lung disease over time, even at low levels, according to a study published by the American Heart Association. The researchers found that for people aged 65 and older, long-term exposure to air pollution can increase the risk of heart attack, stroke, atrial fibrillation, and pneumonia.

Study lead author Dr. Mahdieh Danesh-Yazdi is a postdoctoral researcher at the Harvard T.H. Chan School of Public Health.

“People should be conscious of the air quality in the region where they live to avoid harmful exposure over long periods of time, if possible,” said Dr. Danesh-Yazdi.

“Since our study found harmful effects at levels below current U.S. standards, air pollution should be considered as a risk factor for cardiovascular and respiratory disease by clinicians, and policy makers should reconsider current standards for air pollutants.”

The experts analyzed the addresses of 63 million older adults to evaluate the extent of their exposure to particulate matter, nitrogen dioxide (NO2), and ozone (O3). The team also analyzed the hospital records of the individuals from between 2000 and 2016.

In addition, the experts investigated the potential link between the average yearly levels of each of the three pollutants and hospitalization rates for non-fatal heart attacks, ischemic strokes, atrial fibrillation and flutter, and pneumonia.

By conducting statistical analyses, the experts determined that thousands of annual hospital admissions were tied to air pollution. In particular, the researchers found that the increased risk of heart attack, stroke, atrial fibrillation, and pneumonia were associated with long-term exposure to particulate matter.

“Long-term exposure to air pollution was associated with an increased risk of hospital admissions with cardiovascular and respiratory outcomes on an additive scale among the elderly population of the United States,” wrote the researchers.

“Each unit increase in levels of particulate matter, nitrogen dioxide, and ozone were associated with thousands of additional admissions each year.”

“Air pollution should be considered as a risk factor for cardiovascular and respiratory disease. The risk persists even at levels below current national and international guidelines.”

In particular, nitrogen dioxide was associated with an increased risk of stroke and atrial fibrillation, while stroke rates were most strongly tied to annual levels of fine particulate matter

Pneumonia was the only health outcome examined that seemed to be impacted by long-term exposure to ozone.

“When we restricted our analyses to individuals who were only exposed to lower concentrations of air pollution, we still found increased risk of hospital admissions with all of the studied outcomes, even at concentration levels below current national standards,” said Dr. Danesh-Yazdi. 

“More than half of the study population is exposed to low levels of these pollutants, according to U.S. benchmarks, therefore, the long-term health impact of these pollutants should be a serious concern for all, including policymakers, clinicians and patients.”

The study is published in the American Heart Association journal Circulation.

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By Chrissy Sexton, Earth.com Staff Writer