Air pollution and outpatient visits for cardiovascular and cerebrovascular diseases: A time-series analysis in Luoyang, China

Previous studies have shown that air pollutants have a significant impact on cardiovascular and cerebrovascular diseases (CCD), but these studies have focused more on provincial capitals or large cities. This study was the first time to explore the effects of air pollutants on CCD in Luoyang. In this study, the generalized additive model (GAM) was used to establish a single-pollutant model, a multi-pollutant model and stratified modes of age, sex and season to evaluate the effects of PM2.5, PM10, SO2, NO2, CO and O-3 on outpatient visits for CCD within a week. The results of the single-pollutant model showed that PM2.5, PM10, SO2, NO2, CO and O-3 all had significant effects on the outpatient visits for CCD with a lag effect. The multi-pollutant model showed that there might be complex interactions among pollutants. The results of the stratified model showed that there was no significant difference in the effects of different pollutants on different genders and ages, and the results of seasonal stratification showed that PM2.5, PM10, SO2 and CO had a greater influence on the outpatient visits for CCD in spring and summer, while NO2 and O-3 had a greater influence on the outpatient visits for CCD in winter and summer, respectively. The results showed that air pollutants significantly affected outpatient visits for CCD, among which NO2 had the greatest influence, and seasonal effects and the combined effects of various pollutants should be considered in strategies for the prevention of CCD.