Abstract Background Emerging evidence suggests a complex link between air pollution, mental health, and cardiovascular disease (CVD). While air pollution is a known risk factor for both CVD and mental disorders, initial small-scale studies indicate that its impact on mental health might also indirectly increase CVD risk. Purpose The aim of our study was a nationwide analysis of the long-term impact air pollution exposure on mental health and mortality, as well as identifying factors modifying its effects. Methods The study covered 38 million inhabitants of Poland in 2011-2020 Figure 1A and 1B. Air pollution data were processed using the GEM-AQ model with high-quality resolution for all 380 analyzed counties. Individual mortality presented as Standardized Mortality Rates (SMR) and mental health data were obtained from the Central Statistical Office. For statistical analysis, negative binomial regression was applied. To control for time effects, dummy variables for individual years were included, allowing for the adjustment of year-specific trends and confounders. Socioeconomic variables, incl. gross domestic product (GDP), as well as atmospheric conditions, were used as covariates. The model was evaluated for goodness-of-fit at each stage using the Akaike Information Criterion and the Likelihood Ratio test. Results We recorded 4,010,521 all-cause deaths, incl. 1,706,111 CVD-related deaths (42.5%). The most common causes of CVD-related deaths were ischemic heart disease (25.5%), heart failure (22.2%), and stroke (18.5%). Median age of CVD deaths was 81 (IQR 71-87) years (84.8% aged ≥65) with 53.6% female. There was a significant increasing trend for all-cause SMR over time (Kendall’s tau 0.689, p-value=0.004), but not for CVD-related SMR Figure 1C and 1D. An annual increase of 10 μg/m3 in PM2.5 (RR 1.023, 95%CI 1.012-1.035, p0.001), NO2 (RR 1.111, 95%CI 1.072-1.151, p0.001), SO2 (RR 1.081. 95% CI 1.03-1.134, p=0.002), and CO (RR 1.018, 95%CI 1.013-1.023, p0.001) concentrations was associated with an increase in CVD-related SMR, whereas none of these pollutants significantly increased all-cause SMR Figure 2A. Exposure to air pollution was also associated with an increased rates of mental health indicators Figure 2A, which then mediated particulate matter (PMs) effects on all-cause and CVD-related mortality Figure 2B. Socioeconomic status modified the air pollution effect, as an increase in GDP per capita by 100 USD (β -0.138, p-value 0.001) and urbanity (β -0.005, p-value 0.001) decreased the harmful effects of PMs. Conclusions Both long-term exposure to air pollution and mental health conditions increases CVD-related mortality. Mental health issues amplify the adverse effects of PMs on the cardiovascular system. In contrast, higher socioeconomic status offsets the harmful effects of PMs. Public health changes and interventions should primarily target regions with lower socioeconomic indicators.Characteristics of the analyzed region. Air pollution effects and its modifiers.
Święczkowski et al. (2025) studied this question.