According to new research published today in Circulation, the leading journal of the American Heart Association, prolonged exposure to what is regarded as modest levels of air pollution can raise the risk of heart attack, stroke, atrial fibrillation, and pneumonia in persons 65 and older.
Due to its impact on inflammation in the heart and throughout the body, air pollution can affect the cardiovascular and respiratory systems. The focus of more recent research on the impacts of air pollution on health is on understanding the possible harm brought on by prolonged exposure, as well as investigating the effects of several air pollutants at once.
Informing suggestions for national environmental and health guidelines requires research on air pollution.
“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 Mahdieh Danesh Yazdi, Pharm.D., M.P.H., Ph.D., a post-doctoral research fellow at the Harvard T.H. Chan School of Public Health and lead author of the study.
“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 policymakers should reconsider current standards for air pollutants.”
In order to determine how long-term exposure to air pollution affects hospital admissions for particular cardiovascular and respiratory disorders, researchers looked at hospitalization records for more than 63 million Medicare members in the contiguous United States from 2000 to 2016.
Three elements of air pollution were examined in the study: ozone (O3), nitrogen dioxide (NO2), and fine particulate matter (PM2.5). Researchers determined the study participants’ exposure to the pollutants based on their residence zip code by using hundreds of predictors, such as meteorological variables, satellite observations, and land use to estimate daily amounts of pollutants.
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.
Mahdieh Danesh Yazdi
The effects of each pollutant’s average annual quantities on hospitalization rates for non-fatal heart attacks, ischemic strokes, atrial fibrillation and flutter, and pneumonia were also examined.
Numerous hospital admissions per year were determined to be related to air pollution by statistical analysis. Specifically:
Long-term exposure to particulate matter was linked to an increased risk of heart attacks, strokes, atrial fibrillation and flutter, pneumonia, and other conditions.
Additionally, data showed that for all of the health outcomes examined, hospital admissions increased with each extra unit of particle matter. For each extra ug/m3 (micrograms per cubic meter of air) rise in fine particulate matter per year, stroke rates specifically increased by 2,536, according to the study.
Long-term exposure to nitrogen dioxide was linked to an elevated risk of stroke and atrial fibrillation.
The only health outcome in the study that appeared to be affected by prolonged exposure to ozone was pneumonia; however, the researchers point out that there are no national recommendations in place at the moment that would indicate what amounts of ozone are safe or harmful.
“When we restricted our analyses to individuals who were only exposed to lower concentrations of air pollution, we still found an increased risk of hospital admissions with all of the studied outcomes, even at concentration levels below current national standards,” added 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 results were then divided by patient subgroups, including gender, race or ethnicity, age, and socioeconomic characteristics, to determine the cardiovascular and respiratory risks linked to each of the pollutants.
Due to the limits of the data that were provided, which may not have included other recognized CVD risk factors, the causation in the study could only be interpreted and not conclusively demonstrated. The Medicare database may also contain coding errors, which would affect the analyses.
