ABSTRACT
Objective To quantitatively evaluate the association of short-term exposure to ambient submicron particulate matter (PM1) with hospital admissions for angina in older adults. Methods A case-crossover study was conducted among 46 687 older adults hospitalized for angina from 2016 to 2019 in Guangzhou medical institutions. Grid data on ambient PM1 concentrations in Guangzhou were obtained from the ChinaHighAirPollutants (CHAP) dataset. Exposure to PM1 was assessed according to each subject's residential addresses. Conditional logistic regression model was used to analyze the the exposure-response association between PM1 and hospital admissions for angina. Results From 2016 to 2019, the average exposure level of PM1 on the same day of hospital admissions (lag 0) for angina was 21.0 ± 11.5 μg/m3. The results of main model analysis showed that lag 0 day exposure to ambient PM1 was significantly associated with a higher odds of hospital admissions for angina in older adults. Each 10 μg/m3 increase of PM1 exposure level was significantly associated with a 1.31% (95% CI: 0.05%, 2.59%) increased odds of angina admissions. Results from a two-pollutant model adjusting for O3 showed that the association between short-term exposure to PM1 and odds of hospitalization for angina remained stable. According to the results of the above model, it was estimated that the excess hospitalization attributable to ambient PM1 exposure accounted for 2.46% (95% CI: 0.09%, 4.76%) of the total admissions in Guangzhou during 2016-2019, corresponding to 1539 (95% CI: 54, 2976) admissions. No significant effect modification on the associations was observed by sex, age, or season. Conclusion Short-term exposure to ambient PM1 was significantly associated with an increased odds of hospital admissions for angina in older adults.
ABSTRACT
Objective To investigate the association between short-term exposure to ambient air pollution and hospital admission for ischemic stroke among older adults. Methods Using clinical monitoring data from China National Health Commission, we identified 124 297 individuals from Guangzhou, Guangdong province, China who were 60 years or older and were admitted to hospital for ischemic stroke in 2016-2019. We used a time-stratified case-crossover design and employed the conditional logistic regression model to investigate the exposure-response association between short-term exposure to air pollution and hospital admission for ischemic stroke. Based on each subject's residential address and pollutant data from its neighboring air quality monitoring stations, we used an inverse distance weighting method to assess individual-level exposure to PM2.5, PM10, SO2, NO2, CO and O3 on each of the case and control days. Results In single-pollutant models, each 10 µg/m3 increase of PM2.5, PM10, SO2, NO2, CO and O3 was associated with a 0.46% (95% confidence interval [CI]: 0.13-1.36%, lag 2 d), 0.66% (1.38-2.93%, lag 02 d), 3.39% (0.07-0.21%, lag 2 d), 1.47% (0.07-0.21%, lag 02 d), 0.06% (0.07-0.21%, lag 02 d) and 0.18% (0.07-0.21%, lag 3 d) increase in odds of hospital admission, respectively. The results of 2-pollutant models showed that the association of exposure to SO2, NO2 and O3 with hospital admission for ischemic stroke remained stable with adjustment for each of the other air pollutants. Conclusions Short-term exposure to ambient air pollution, especially SO2, NO2 and O3, was associated with increased risk of hospital admission for ischemic stroke in older adults.
ABSTRACT
Objective@#To identify the definition of heat wave based on mortality risk assessment in different regions of China.@*Methods@#Daily mortality (from China Information System for Disease Control and Prevention) and meteorological data (from National Meteorological Information Center in China) from 66 counties with a population of over 200 000 were collected from 2006-2011. With the consideration of climate type and administrative division, China was classified as seven regions. Firstly, distributed lag non-linear model (DLNM) was used to estimate community-specific effects of temperature on non-accidental mortality. Secondly, a multivariate meta-analysis was applied to pool the estimates of community-specific effects to explore the region-specific temperature threshold and the duration for definition of heat wave.@*Results@#We defined regional heat wave of Northeast, North, Northwest, East, Central and Southwest China as being two or more consecutive days with daily mean temperature higher than or equal to the P64, P71, P85, P67, P75 and P77 of warm season (May to October) temperature, respectively, while the thresholds of temperature were 21.6, 23.7, 24.3, 25.7, 28.0 and 25.3 ℃. The heat wave in South China was defined as five or more consecutive days with daily mean temperature higher than or equal to the P93 (30.4 ℃) of warm season (May to October) temperature.@*Conclusion@#The region-specific definition of heat wave developed in our study may provide local government with the guidance of establishment and implementation of early heat-health response systems to address the negative health outcomes due to heat wave.