Association between gaseous pollutants and emergency ambulance dispatches for asthma in Chengdu, China: a time-stratified case-crossover study

OBJECTIVES@#The association between concentrations of sulfur dioxide (SO), nitrogen dioxide (NO), carbon monoxide (CO), ozone (O), and emergency ambulance dispatches (EADs) for asthma was explored in the central Sichuan Basin of southwestern China for the first time.@*METHODS@#EADs for asthma were collected from the Chengdu First-Aid Command Center. Pollutant concentrations were collected from 24 municipal environmental monitoring centers and including SO, NO, CO, daily 8-h mean concentrations of O (O-8 h), and particulate matter less than 2.5 μm in aerodynamic diameter (PM). The climatic data were collected from the Chengdu Municipal Meteorological Bureau. All data were collected from years spanning 2013-2017. A time-stratified case-crossover design was used to analyze the data.@*RESULTS@#After controlling for temperature, relative humidity, and atmospheric pressure, IQR increases in SO (13 μg/m), NO (17 μg/m), and CO (498 μg/m) were associated with 18.8%, 11.5%, and 3.1% increases in EADs for asthma, respectively. The associations were strongest for EADs and SO, NO, and CO levels with 3-, 5-, and 1-day lags, respectively.@*CONCLUSIONS@#This study provides additional data to the limited body of literature for potential health risks arising from ambient gaseous pollutants. The results of the study suggest that increased concentrations of SO, NO, and CO were positively associated with emergency ambulance dispatches for asthma in Chengdu, China. Further studies are needed to investigate the effects of individual air pollutants on asthma.

Short-term effects of ambient air pollution and cause-specific emergency department visits in Guangzhou / 中华疾病控制杂志

Objective To understand the relationship between the concentration of air pollutants and daily emergency department visits for different diseases (circulatory system disease, digestive system disease, nervous system disease and respiratory system disease) in Guangzhou, Guangdong Province. Methods The daily average concentrations of sulfur dioxide (SO2), nitrogen dioxide (NO2, carbon monoxide (CO) and PM2.5 and the daily maximum 8-hour concentrations of O3, the daily average temperature, the relative humidity and cause -specific emergency department visits of the four major diseases from 2015 to 2017 were collected in Guangzhou. Semi-parametric generalized additive model was used to analyze the relationship between the concentration of pollutants and daily cause-specific emergency department visits. Results The daily average concentrations of SO2, NO2, CO, O3 and PM2.5 during the study period were 13.24 μg /m3, 45.96 μg /m3, 0.97 mg /m3, 123.77 μg /m3 and 36.22 μg /m3, respectively. For circulatory system disease，the independently significant associations of SO2 with emergency department visits in single-pollutant models (2.91%, 95% CI: 1.00%-4.85%), and multipollutant models (4.39%, 95% CI: 1.22%-7.67%) were observed. Conclusion The ambient SO2 increases the risk of emergency department visits due to circulatory diseases in Guangzhou. Comprehensive prevention and control measures should be taken to reduce the emission of SO2.