Ni, Ruijing et al.One Earth, Volume 0, Issue 0
Science for society
Asthma is currently an incurable disease that severely impairs quality of life, with recurring symptoms such as wheezing, coughing, and shortness of breath. As of today, ∼4% of the world’s population suffers from asthma, with more than 30 million new cases arising annually. Evidence suggests that long-term exposure to fine particulate matter (PM2.5) may be an important risk factor for developing asthma. However, inconsistencies in findings from earlier epidemiological studies have left this potential health risk under debate. Drawing on evidence from ∼25 million participants worldwide, we demonstrate that long-term exposure to PM2.5 significantly increases asthma risk in both children and adults and is associated with ∼30% asthma cases globally. Our findings highlight the urgent need for policymakers to enforce stringent legislation to continuously combat air pollution, while personal maneuvers, such as wearing masks, can also help reduce individual exposure and mitigate asthma risk.
Highlights
Long-term exposure to PM2.5 increases asthma risk in both children and adults
In 2019, nearly one-third of global asthma cases were associated with PM2.5 exposure
Elaborate database for evaluating PM2.5-associated asthma risk and its confidence level
Exposure-response curves for assessing global burden of asthma attributable to PM2.5
Summary
Asthma affects more than 250 million people worldwide, making it a globally significant health threat. As one of the most important potential risk factors, the effects of long-term exposure to ambient fine particulate matter (PM2.5) on asthma, especially in adults, remains unclear. Here, we comprehensively addressed this issue by integrating a systematic review, meta-analysis, exposure-response analysis, and health impact assessment based on evidence that emerged until May 2023. We show that, for every 10 μg/m3 increment in PM2.5, the risk of childhood and adult asthma (i.e., prevalence, incidence, and mortality of all asthma types) increases by 21.4% (95% confidence interval [CI]: 11.4%–32.3%) and 7.1% (95% CI: 1.6%–12.9%), respectively. We estimate that, in 2019, nearly one-third of the global asthma cases are associated with PM2.5 exposure. These findings emphasize that long-term PM2.5 exposure significantly increases asthma risk in both children and adults. Continuous efforts regarding air pollution mitigation are therefore urgently needed.
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