Multi-City Analysis of the Acute Effect of Polish Smog on Cause-Specific Mortality (EP-PARTICLES Study)

Abstract

Polish smog is a specific type of air pollution present in Eastern Poland, which may cause particularly adverse cardiovascular effects. It is characterized primarily by high concentrations of particulate matter (PM) and different favorable conditions of formation. Our study aimed to assess whether PM and nitrogen dioxide (NO2) have a short-term impact on mortality due to acute coronary syndrome (ACS) and ischemic stroke (IS). The study covered the years 2016–2020, a total of 6 million person-years from five main cities in Eastern Poland. To evaluate the association between air pollution and cause-specific mortality, a case-crossover study design with conditional logistic regression was used at days with LAG from 0 to 2. We recorded 87,990 all-cause deaths, including 9688 and 3776 deaths due to ACS and IS, respectively. A 10 μg/m3 increase in air pollutants was associated with an increase in mortality due to ACS (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) on LAG 0. 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 (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). There was a strong association between air pollution and cause-specific mortality 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 elderly (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). The negative influence of PMs was observed on mortality due to ACS and IS. NO2 was associated with only ACS-related mortality. The most vulnerable subgroups were women and the elderly.