JAMA Netw Open: A study of residents of one of the most polluted cities in the United States has revealed that air pollution increases the risk of stroke from atrial fibrillation.

Air pollution, especially fine particulate matter (PM2.5), has been a major global environmental and public health problem.
, a study published in the international journal JAMA Network Open found that excessive exposure to fine particulate matter of up to 2.5 m may increase the risk of stroke in patients with atrial fibrillation.
these results suggest a dose-dependent relationship between air pollution and stroke events, and emphasize the importance of air pollution for cardiovascular outcomes associated with atrial fibrillation.
In the cohort study, researchers analyzed data from 31,414 patients with atrial fibrillation (average age 74 years old, 50 percent female) from the Pittsburgh-area health care system and used data from space-saturated air pollution monitoring activities in Allegne County, in southwestern Pennsylvania, an area with a history of focused industrial activity.
, Pennsylvania, is the largest city in the region and is listed as one of the 10 most polluted cities in the United States by the American Lung Association's 2019 Air Condition Report.
researchers geocoded the subjects' addresses to determine annual estimates of particulate exposure at residential levels, while collecting data on residents' income and education levels.
of the study was the average annual exposure of each residential area to fine particulate matter of 2.5 m (PM2.5).
result is hospitalization for ischemic stroke, the date of which is considered to be the original date of hospitalization.
time of the event is defined as the beginning of observation, or the earliest detection of atrial fibrillation in electronic health records, to the first stroke event during the study period.
follow-up time is 3.5 years.
study period, the average annual exposure of PM2.5 was 10.6 μg/m3.
the correction of clinical and demographic variables, each additional standard deviation of PM2.5 was associated with an increased risk of stroke (HR=1.08; 95% CI 1.03-1.14).
was also observed after a comprehensive multivariable adjustment of educational levels and household income (HR=1.07; 95% CI 1-1.14).
risk of stroke in the highest quarterile (HR=1.36; 95% CI 1.18-1.58) was increased compared to the lowest quarterile of PM2.5 exposure level.
after adjusting for clinical covariates, educational levels, and income, the risk of stroke increased, although decreasing, persisted (HR=1.21; 95% CI 1.01-1.45).
future research needs to address factors at the individual and community levels that exacerbate the relevance identified by the Institute.
results have contributed to an understanding of the public health costs of air pollution and have highlighted the importance of continuing advocacy efforts to control pollution exposure.
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