Association Between Air Pollution and Case-Specific Mortality in North-Eastern Part of Poland. Case-Crossover Study with 4,500,000 Person-Years of Follow-Up (PL-PARTICLES Study)

Abstract

Background: Recent studies have reported associations between air pollution and daily mortality. The majority of them are conducted in highly polluted areas. Therefore, we aimed to assess the short-term impact of air pollution on cardiovascular (CVD)-, coronary artery-related (CAD)-, and cerebrovascular-related (CbVD) mortality in moderately polluted cities. Methods: The analysis with a time-stratified case-crossover design was performed. Findings: The interquartile range (IQR) increase in PM2.5 (OR 1×036, 95%CI 1×016–1×056, P<0×0001) and PM10 concentration (OR 1×034, 95%CI 1×015–1×053, P<0×0001) was associated with increased CVD mortality on lag 0 and this effect persisted on following days. The effects of PMs were more expressed in association with CAD-related mortality (OR for PM2.5 =1×045, 95%CI 1×012–1×080, P=0×01), (OR for PM10 =1×044, 95%CI 1×010–1×078, P=0×01). Additionally, IQR increase in NO2 concentration was associated with increased CAD-related mortality at lag 0-1 (OR=1×055, 95%CI .1×004–1×108, P=0×03). This effect is no longer observed when using the multi-pollutant model. The highest OR for PMs was noted in Suwalki compared to Bialystok and Łomza. In a comparison of seasons, we noted higher CVD mortality OR in the cold season for PM10 in Suwalki (P=0×047) and Bialystok (P=0×001). However, the impact of PM10 (P=0×03) on CAD-related mortality was higher in the warm season. Interpretation: The impact of PMs on CVD mortality is also observed in moderately polluted areas. This adverse health effect was more apparent in CAD mortality. Differences in effect size and seasonality may depend on the source of air pollution. Funding: None to declare. Declaration of Interest: None to declare. Ethical Approval: This study was approved by the ethics committee of the Medical University of Bialystok (R-1-002/18/2019) and was registered at ClinicalTrials.gov (NCT04541498).