Rationale: Evidence concerning the acute health effects of air pollution caused by fine particulate matter (PM_2.5) in developing countries is quite limited. Objectives: To evaluate short-term associations between PM_2.5 and daily cause-specific mortality in China. Methods: A nationwide time-series analysis was performed in 272 representative Chinese cities from 2013 to 2015. Two-stage Bayesian hierarchical models were applied to estimate regional- and national-average associations between PM_2.5 concentrations and daily cause-specific mortality. City-specific effects of PM_2.5 were estimated using the overdispersed generalized additive models after adjusting for time trends, day of the week, and weather conditions. Exposure–response relationship curves and potential effect modifiers were also evaluated. Measurements and Main Results: The average of annual mean PM_2.5 concentration in each city was 56 μg/m³ (minimum, 18 μg/m³; maximum, 127 μg/m³). Each 10-μg/m³ increase in 2-day moving average of PM_2.5 concentrations was significantly associated with increments in mortality of 0.22% from total nonaccidental causes, 0.27% from cardiovascular diseases, 0.39% from hypertension, 0.30% from coronary heart diseases, 0.23% from stroke, 0.29% from respiratory diseases, and 0.38% from chronic obstructive pulmonary disease. There was a leveling off in the exposure–response curves at high concentrations in most, but not all, regions. The associations were stronger in cities with lower PM_2.5 levels or higher temperatures, and in subpopulations with elder age or less education. Conclusions: This nationwide investigation provided robust evidence of the associations between short-term exposure to PM_2.5 and increased mortality from various cardiopulmonary diseases in China. The magnitude of associations was lower than those reported in Europe and North America.

Background: Few large multicity studies have been conducted in developing countries to address the acute health effects of atmospheric ozone pollution. Objective: We explored the associations between ozone and daily cause-specific mortality in China. Methods: We performed a nationwide time-series analysis in 272 representative Chinese cities between 2013 and 2015. We used distributed lag models and over-dispersed generalized linear models to estimate the cumulative effects of ozone (lagged over 0–3 d) on mortality in each city, and we used hierarchical Bayesian models to combine the city-specific estimates. Regional, seasonal, and demographic heterogeneity were evaluated by meta-regression. Results: At the national-average level, a 10-μg/m3 increase in 8-h maximum ozone concentration was associated with 0.24% [95% posterior interval (PI): 0.13%, 0.35%], 0.27% (95% PI: 0.10%, 0.44%), 0.60% (95% PI: 0.08%, 1.11%), 0.24% (95% PI: 0.02%, 0.46%), and 0.29% (95% PI: 0.07%, 0.50%) higher daily mortality from all...

The COVID-19 epidemic, caused by the SARS-CoV-2 virus, has resulted in 3352 deaths in China as of April 12, 2020. This study aimed to investigate the associations between particulate matter (PM) concentrations and the case fatality rate (CFR) of COVID-19 in 49 Chinese cities, including the epicenter of Wuhan. We used the Global Moran's I to analyze spatial distribution and autocorrelation of CFRs, and then we used multivariate linear regression to analyze the associations between PM2.5 and PM10 concentrations and COVID-19 CFR. We found positive associations between PM pollution and COVID-19 CFR in cities both inside and outside Hubei Province. For every 10 μg/m3 increase in PM2.5 and PM10 concentrations, the COVID-19 CFR increased by 0.24% (0.01%-0.48%) and 0.26% (0.00%-0.51%), respectively. PM pollution distribution and its association with COVID-19 CFR suggests that exposure to such may affect COVID-19 prognosis.

Background: Short-term exposure to ambient air pollution has been linked with daily hospitalization and mortality from acute coronary syndrome (ACS); however, the associations of subdaily (hourly) levels of criteria air pollutants with the onset of ACS and its subtypes have rarely been evaluated. Methods: We conducted a time-stratified case-crossover study among 1 292 880 patients with ACS from 2239 hospitals in 318 Chinese cities between January 1, 2015, and September 30, 2020. Hourly concentrations of fine particulate matter (PM _2.5 ), coarse particulate matter (PM _2.5–10 ), nitrogen dioxide (NO ₂ ), sulfur dioxide (SO ₂ ), carbon monoxide (CO), and ozone (O ₃ ) were collected. Hourly onset data of ACS and its subtypes, including ST-segment–elevation myocardial infarction, non–ST-segment–elevation myocardial infarction, and unstable angina, were also obtained. Conditional logistic regressions combined with polynomial distributed lag models were applied. Results: Acute exposures to PM _2.5 , NO ₂ , SO ₂ , and CO were each associated with the onset of ACS and its subtypes. These associations were strongest in the concurrent hour of exposure and were attenuated thereafter, with the weakest effects observed after 15 to 29 hours. There were no apparent thresholds in the concentration–response curves. An interquartile range increase in concentrations of PM _2.5 (36.0 μg/m ³ ), NO ₂ (29.0 µg/m ³ ), SO ₂ (9.0 µg/m ³ ), and CO (0.6 mg/m ³ ) over the 0 to 24 hours before onset was significantly associated with 1.32%, 3.89%, 0.67%, and 1.55% higher risks of ACS onset, respectively. For a given pollutant, the associations were comparable in magnitude across different subtypes of ACS. NO ₂ showed the strongest associations with all 3 subtypes, followed by PM _2.5 , CO, and SO ₂ . Greater magnitude of associations was observed among patients older than 65 years and in the cold season. Null associations of exposure to either PM _2.5–10 or O ₃ with ACS onset were observed. Conclusions: The results suggest that transient exposure to the air pollutants PM _2.5 , NO ₂ , SO ₂ , or CO, but not PM _2.5–10 or O ₃ , may trigger the onset of ACS, even at concentrations below the World Health Organization air quality guidelines.

Although air pollution has been frequently linked to a range of cardiometabolic diseases, its association with the onset, progression, and prognosis of cardiometabolic multimorbidity (CMM) has never been studied. We conducted this prospective analysis based on the UK Biobank cohort. CMM was defined as the coexistence of at least two cardiometabolic diseases, including type 2 diabetes, ischemic heart disease and stroke. Multi-state model was used to analyze the association between air pollution and the trajectory of CMM. 410,494 middle- and old-age participants were included. During a median follow-up of 12.0 years, 56,877 participants developed first cardiometabolic disease (FCMD), 8616 developed CMM, and 22,423 died. The risks of transitions from baseline to FCMD, from FCMD to CMM, and transitions from baseline and FCMD to all-cause mortality increased by 3% (2%, 5%), 3% (1%, 6%), 5% (2%, 7%) and 2% (−1%, 6%), respectively, per interquartile range increase of fine particulate matter. The corresponding increases were 3% (2%, 5%), 6% (3%, 9%), 4% (2%, 7%) and 6% (2%, 10%), respectively, for nitrogen dioxide. Older participants, males, and individuals with excessive alcohol drinking and lower economic levels were more likely to experience these risks. Air pollution exposures could play important roles in almost all transition phases of CMM development. Our results highlight clean air as an upstream approach to mitigate both initiation and progression of CMM, especially in vulnerable populations. Shanghai Municipal Science and Technology Commission (21TQ015); The National Natural Science Foundation of China (92143301 and 92043301).