Air pollution and respiratory admissions in Poland: a nationwide DLNM analysis of COPD and asthma

Poland relies heavily on coal for residential heating, resulting in seasonal variation in air pollution, Whether COPD and asthma exacerbations leading to urgent hospitalizations respond differently to these patterns—and whether effects are limited to the heating season—remains unclear. This study aimed to assess and compare short-term associations between air pollution and emergency hospitalizations for COPD and asthma, with a focus on seasonal variation and pollutant-specific effects. We analyzed daily emergency hospitalizations for COPD (n = 625,597) and asthma (n = 153,563; including 32,893 children) from the national registry (2012–2019). Air pollution data (PM10, PM2.5, NO2, SO2, PAHs, and heavy metals in PM10) were obtained from national monitoring systems, along with meteorological variables. Associations were assessed using distributed lag non-linear models (DLNM, quasi-Poisson, lag 0–10 days), stratified by heating (Nov–Mar) and non-heating seasons. Significant associations were observed only during the heating season. For COPD, the strongest effects on hospitalizations (RR per IQR) were for SO2 (1.055), PM2.5 (1.044), and PM10 (1.039). Among PM components, lead (RR = 1.072) and PAHs (e.g., benzo[a]anthracene RR = 1.057) showed the strongest associations. In adults with asthma, effects were stronger than for COPD (PM2.5 RR = 1.100; SO2 RR = 1.082; PM10 RR = 1.069). In children, particulate matter and SO2 were not significant; instead, arsenic (RR = 1.124) and ozone (RR = 1.115) were associated with increased risk independent of season. NO2 was not associated with increased risk in any group. Short-term respiratory risks in Poland are driven primarily by heating-season emissions and are underestimated in annual-average analyses. COPD and adult asthma reflect a coal-combustion pollution signature, while childhood asthma responds to distinct toxic components. These findings support the need for pollutant-specific monitoring and seasonally targeted public health strategies.

Key messages

• Emergency COPD and adult asthma hospitalisations are strongly linked to air pollution during the heating season, with SO2 and particulate matter showing the highest risks.

• Children’s asthma responds to different pollutants (arsenic, ozone), highlighting distinct mechanisms and the need for pollutant-specific, seasonally targeted public health strategies.