Association between long-term exposure to fine particulate matter from sand dust storms and small airway dysfunction: A national cross-sectional study.

Despite growing concern on the health effects of dust-sourced fine particulate matter (dust PM2.5), especially in the context of climate change, but the respiratory health effect has not been well characterized. Investigating the impact of dust PM2.5 on small airway dysfunction (SAD) is important for early prevention, since SAD represents an early stage of airway obstruction. This study evaluated the dose-response associations and effect modifications of long-term dust PM2.5 exposure with risks of SAD on a national scale. SAD was identified based on lung function data from the China Pulmonary Health Study (N = 50,326). An interquartile range (IQR, 5.76 μg/m3) increment in long-term dust PM2.5 concentration was associated with higher risk of SAD (Odds ratio [OR]:1.18, 95 % confidence interval [CI]:1.08, 1.28) and SAD without airflow obstruction (OR: 1.24, 95 % CI: 1.10, 1.39). Long-term dust PM2.5 exposure was significantly associated with decrease in pre- and post-bronchodilator lung function. Individuals with lower levels of education were found to be more vulnerable. This finding provided much-needed evidence on why and when air pollution leads to irreversible airway obstruction, calling for greater awareness on the harm of fine dust particle on early-stage lung impairment. Studies on the countermeasures of respiratory hazard caused by SDS are warranted.