Acute Effect of Ambient Air Pollution on Stroke Mortality in the China Air Pollution and Health Effects Study

Abstract

Background and Purpose— There have been no multicity studies on the acute effects of air pollution on stroke mortality in China. This study was undertaken to examine the associations between daily stroke mortality and outdoor air pollution (particulate matter <10 μm in aerodynamic diameter, sulfur dioxide, and nitrogen dioxide) in 8 Chinese cities. Methods— We used Poisson regression models with natural spline-smoothing functions to adjust for long-term and seasonal trends, as well as other time-varying covariates. We applied 2-stage Bayesian hierarchical statistical models to estimate city-specific and national average associations of air pollution with daily stroke mortality. Results— Air pollution was associated with daily stroke mortality in 8 Chinese cities. In the combined analysis, an increase of 10 μg/m 3 of 2-day moving average concentrations of particulate matter <10 μm in aerodynamic diameter, sulfur dioxide, and nitrogen dioxide corresponded to 0.54% (95% posterior intervals, 0.28–0.81), 0.88% (95% posterior intervals, 0.54–1.22), and 1.47% (95% posterior intervals, 0.88–2.06) increase of stroke mortality, respectively. The concentration–response curves indicated linear nonthreshold associations between air pollution and risk of stroke mortality. Conclusions— To our knowledge, this is the first multicity study in China, or even in other developing countries, to report the acute effect of air pollution on stroke mortality. Our results contribute to very limited data on the effect of air pollution on stroke for high-exposure settings typical in developing countries.

Fusing Observational, Satellite Remote Sensing and Air Quality Model Simulated Data to Estimate Spatiotemporal Variations of PM2.5 Exposure in China

“…Severe PM 2.5 pollution in China has attracted considerable public attention [10][11][12] and inspired numerous epidemiological studies to investigate the health effects of air pollution in China since 2013 [13][14][15][16][17][18]. Accurately assessing PM 2.5 exposure is critical for estimating its health risks in such epidemiological studies.…”

“…Accurately assessing PM 2.5 exposure is critical for estimating its health risks in such epidemiological studies. However, due to the limited number of ground monitors in China, previous studies generally ignored the spatial variation of PM 2.5 and assessed the ambient exposure uniformly using one monitor or averages of several monitors located within a city or a municipality [13][14][15][16], which causes exposure misclassification. Therefore, accurately estimating the fine-scale spatiotemporal variation of ground PM 2.5 may lay a foundation for future health-related studies of PM 2.5 in China.…”

Association of chemical constituents and pollution sources of ambient fine particulate air pollution and biomarkers of oxidative stress associated with atherosclerosis: A panel study among young adults in Beijing, China

“…However, airborne particles are a mixture of different chemical constituents with different potentials to induce toxicological effects (Costa and Dreher, 1997;Valavanidis et al, 2008). Airborne particles may also originate from different pollution sources, which could affect the total toxicity of the particles and partially account for the heterogeneous particle-related cardiovascular effects observed in different study locations (Wong et al, 2002;Chen et al, 2013). Toxicological studies have revealed several possible biological mechanisms through which airborne particles may affect the cardiovascular system (Sun et al, 2010).…”

Acute nitrogen dioxide (NO2) exposure enhances airway inflammation via modulating Th1/Th2 differentiation and activating JAK-STAT pathway

“…The purpose of this study is to study the mechanism of airway inflammation induced by NO 2 exposure. Previous study have showed that peak levels of NO 2 can reach up to 0.4 ppm are encountered in the outdoors, particularly along kerbsides in downtown areas with heavy motor vehicular traffic, peak levels in the indoor environment can reach up to 4 ppm in garages, ferries, skating ice rinks, and kitchens with gas cookers (Pathmanathan et al, 2003), and peak levels about occupational exposure to NO 2 can reach up to 7.6 mg/m 3 (Chen et al, 2013). Studies by other investigators have confirmed that 5 mg/m 3 are the peak level encountered outdoor and indoor, which is similar with the lowest effect value in humans (Hesterberg et al, 2009).…”