Short-term effects of gaseous air pollutants on outpatient visits for respiratory diseases: a case-crossover study in Baotou, China

Abstract

Air pollution is a major public health problem throughout the world. Although there have been several studies in this field, most of them have focused on particulate matter and only covered a few key cities. This study aimed to assess a potential association between exposure to gaseous air pollutants and outpatient visits for respiratory diseases in Baotou, China. Daily outpatient visits for respiratory diseases and daily averages of air pollutants and meteorological parameters from 2015 to 2020 were obtained. Time-stratified case-crossover design and restricted cubic splines were used to perform the analyses. Stratified analyses were performed in different hospital departments and districts. Significant association between the concentrations of air pollutants and outpatient visits for respiratory diseases was observed. The odds ratios of outpatient visits for respiratory diseases associated with per 10 μg/m 3 increases in concentrations of NO 2 and SO 2 , and per 10 mg/m 3 increases in concentrations of CO were 1.033 (95% CI: 1.018 to 1.049), 0.965 (95% CI: 0.954 to 0.976), and 1.038 (95% CI: 1.006 to 1.071), respectively. Short-term exposure to NO 2 , SO 2 , and CO was positively associated with outpatient visits for respiratory diseases, with stronger effects among children. The relationship between O 3 and respiratory diseases varied at different concentrations.

Interactive effects of atmospheric oxidising pollutants and heat waves on the risk of residential mortality

“…In contrast to the results of previous studies of highly polluted areas [ 34 , 35 ], the results of this study reveal the interaction of heat waves and oxidising pollutants in cities with relatively low pollution levels and relatively high temperatures in China. However, there are non-significant results, may not be sufficiently persuasive, and we will continue to observe and improve our study in subsequent studies.…”

“…Fuzhou is one of China’s hottest provincial capitals according to data from the Chinese Meteorological Agency and has been called an ‘oven’ city because of its extremely hot summers [ 33 ]. In comparison to some of the more polluted towns in northern China [ 34 , 35 ], Fuzhou has higher air quality, and many of its air pollutants are below the Chinese National Ambient Air Quality Standard (CAAQS) standard I [ 36 ]; this city is considered a low-concentration control site for the National Air Pollution Health Impacts Monitoring Project. Given that China’s air quality is improving as a result of ongoing interventions and that there will be more days with high heat as a result of climate change, Fuzhou was selected as the research location to examine how heat waves and oxidising pollutants in the atmosphere interact.…”