LAUSR

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Science Center. According to WHO reports, cardiovascular diseases (CVD) are responsible for almost 18 million deaths worldwide annually. The harmful effect of air pollution on human health in highly polluted regions is well documented. However, Eastern Poland is a region with so-called "Polish smog" – air pollution causing exceptionally adverse cardiovascular effects. The aim of our study was to assess whether "Polish smog" has an impact on mortality due to CVD,. All-cause deaths from 5 main cities in Eastern Poland in 2016-2020 were analyzed. Mortality data was obtained from Central Statistical Office, while air pollution concentrations (PM2.5, PM10, and NO2) were attained from Voivodeship Inspectorate for Environmental Protection. The analysis with almost 6 million person-years of follow-up with a time-stratified case-crossover design was performed. Results are reported as odds ratio (OR) and 95% Confidence Intervals (95%CI) associated with an increase of 10 μg/m3 in a daily concentration of air pollutants. The study was financed from the funds of the National Science Center granted under the contract number UMO-2021/41/B/NZ7/03716. We recorded 87990 all-cause deaths, including 34907, 9688, and 3776 deaths due to CVD, acute coronary syndromes (ACS), and ischemic stroke (IS) respectively. A 10 μg/m3 increase in all analyzed air pollutants was associated with an increase in mortality due to CVD on the day of exposure (PM2.5 OR 1.034, 95%CI 1.027-1.041, p<0.001; PM10 OR 1.033, 95% CI 1.027-1.039, p<0.001; NO2 OR=1.083, 95%CI 1.073-1.094, p<0.001) [Figure 1]. Moreover, a similar effect was also noted on LAG 1 and LAG 2 (LAG 1: PM2.5 OR 1.028, 95%CI 1.021-1.036, p<0.001; PM10 OR 1.025, 95% CI 1.02-1.031, p<0.001; NO2 OR=1.082, 95%CI 1.069-1.094, p<0.001 and LAG 2: PM2.5 OR 1.024, 95%CI 1.017-1.032, p<0.001; PM10 OR 1.023, 95% CI 1.017-1.029, p<0.001; NO2 OR=1.075, 95%CI 1.063-1.087, p<0.001). An increase in PM level caused increased mortality due to ACS on LAG 0 [(PM2.5 OR=1.029, 95%CI 1.011-1.047, p=0.002; PM10 OR=1.015, 95%CI 1-1.029, p=0.049)] [Figure 2]. On LAG 1 we recorded an increase in both IS- (PM2.5 OR=1.03, 95%CI 1.001-1.058, p=0.04) and ACS-related mortality (PM2.5 OR=1.028, 95%CI 1.01-1.047, p=0.003; PM10 OR=1.026, 95%CI 1.011-1.041, p=0.001; NO2 OR=1.036, 95%CI 1.003-1.07, p=0.04). These effects were the most noticeable in women (ACS: PM2.5 OR=1.032, 95%CI 1.006-1.058, p=0.01; PM10 OR=1.028, 95%CI 1.008-1.05, p=0.01) and in older adults (ACS: PM2.5 OR=1.03, 95%CI 1.01-1.05, p=0.003; PM10 OR=1.027, 95% CI 1.011-1.043, p<0.001 and IS: PM2.5 OR=1.037, 95%CI 1.007-1.069, p=0.01; PM10 OR=1.025, 95%CI 1.001-1.05, p=0.04). "Polish smog" has a significant impact on CVD-related mortality. The negative influence of PMs was observed on mortality due to ACS and IS, whereas NO2 affected only ACS-related mortality. The most vulnerable subgroups to air pollution were women and people over 65 years old.