Air Pollution and Outpatient Visits for Cardiovascular and Cerebrovascular Diseases: A Time-Series Analysis in Luoyang, China

Abstract

Background: Previous studies have shown that air pollution has a great impact on cardiovascular and cerebrovascular diseases (CCD), but there is a lack of research on low and medium pollution areas. This study was the first time to explore the effects of air pollutants on the outpatient visits of CCD in Luoyang, which is located in low and medium pollution areas.Methods: 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 O3 on the outpatient visits of CCD within a week.Results: The results of single pollutant model showed that PM2.5, PM10, SO2, NO2, CO and O3 all had significant effects on the outpatient visits of CCD with a lag effect, interquartile range (IQR) increased in their concentration, the outpatient visits with CCD increased by 2.8%(95%CI:1.7%-4.0%), 3.0%(95%CI:1.8%-4.1%), -4.2% (95%CI: -5.5%- -2.9%), 20.5%(95%CI:18.2%-22.7%), 10.4%(95%CI:8.8%-12.1%), 2.3%(95%CI:0.8%-3.9%). The multi-pollutant model showed that there may be complex interactions among pollutants. The results of 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 of CCD in spring and summer, while NO2 and O3 had a greater influence on the outpatient visits of CCD in autumn and winter.Conclusion: The results showed that air pollutants significantly affected the outpatient visits of CCD, among which NO2 had the greatest influence, and seasonal effects and the combined effects of various pollutants should be considered in the prevention of CCD.