Long‐Term PM _2.5 Exposure and Risks of Ischemic Heart Disease and Stroke Events: Review and Meta‐Analysis

Abstract

Background Fine particulate matter <2.5 µm in diameter (PM 2.5 ) has known effects on cardiovascular morbidity and mortality. However, no study has quantified and compared the risks of incident myocardial infarction, incident stroke, ischemic heart disease (IHD) mortality, and cerebrovascular mortality in relation to long‐term PM 2.5 exposure. Methods and Results We sought to quantitatively summarize studies of long‐term PM 2.5 exposure and risk of IHD and stroke events by conducting a review and meta‐analysis of studies published by December 31, 2019. The main outcomes were myocardial infarction, stroke, IHD mortality, and cerebrovascular mortality. Random effects meta‐analyses were used to estimate the combined risk of each outcome among studies. We reviewed 69 studies and included 42 studies in the meta‐analyses. In meta‐analyses, we found that a 10‐µg/m 3 increase in long‐term PM 2.5 exposure was associated with an increased risk of 23% for IHD mortality (95% CI, 15%–31%), 24% for cerebrovascular mortality (95% CI, 13%–36%), 13% for incident stroke (95% CI, 11%–15%), and 8% for incident myocardial infarction (95% CI, −1% to 18%). There were an insufficient number of studies of recurrent stroke and recurrent myocardial infarction to conduct meta‐analyses. Conclusions Long‐term PM 2.5 exposure is associated with increased risks of IHD mortality, cerebrovascular mortality, and incident stroke. The relationship with incident myocardial infarction is suggestive of increased risk but not conclusive. More research is needed to understand the relationship with recurrent events.

Analysis of long- and medium-term particulate matter exposures and stroke in the US-based Health Professionals Follow-up Study

“…Our findings are generally consistent with several previous studies. However, our HR = 1.05 (95% CI: 0.88, 1.25) for 12-month average PM 2.5 and total stroke is lower than a recent meta-estimate (RR = 1.13, 95% CI: 1.11, 1.15) 21 of other studies. Compared with a previous study by Puett et al 28 in the HPFS, we observed generally larger estimates of effect with a longer study period and more cases; however, the results still did not reach statistical significance.…”

“…Our HR = 1.17 (95% CI: 0.76, 1.81) for PM 2.5 and hemorrhagic stroke is somewhat higher than a recent meta-estimate (RR = 1.10, 95% CI: 1.05, 1.16) 21 ; however, our HR = 0.99 (95% CI: 0.79, 1.25) for PM 2.5 and ischemic stroke is much lower than a recent meta-estimate (RR = 1.18, 95% CI: 1.14, 1.22). 21 …”

Global urban temporal trends in fine particulate matter (PM2·5) and attributable health burdens: estimates from global datasets

“… 1 , 2 Long-term exposure to PM 2·5 is associated with premature mortality from a variety of diseases, including cardiovascular disease, respiratory disease, lung cancer, and lower respiratory infection. 3 , 4 , 5 PM 2·5 is now the leading environmental contributor to the global burden of disease, rising from being the fifth leading contributor among environmental risk factors in 1990, in part driven by declines in household air pollution and unsafe water and sanitation. 1 Recent estimates of PM 2·5 -attributable disease burdens describe global, regional, and national trends, and do not focus on the city scale where 55% of the world's population resides; a figure that is expected to increase.…”

A National-Scale 1-km Resolution PM2.5 Estimation Model over Japan Using MAIAC AOD and a Two-Stage Random Forest Model

“…PM 2.5 is considered more toxic than PM 10 because of its smaller diameter, meaning it can deposit into the alveolar region of the lungs and induce a series of immune responses [2]. Many epidemiological studies reported that exposure to PM 2.5 is associated with adverse health outcomes, such as allergic respiratory diseases, asthma, cardiovascular diseases, neuropsychological diseases, and mortality [3][4][5][6][7]. The major sources of PM 2.5 in Japan include sea salt, biomass combustion, soil dust, and secondary aerosols, which are derived from local emission sources and long-range transportation [8].…”