Impact of COVID-19 Transport Restrictions on Respiratory Admissions: Air Pollutants and Fungal Spores

Abstract Background This study investigated the impact of COVID-19 transport restrictions on hospitalisations for asthma and chronic obstructive airway disease (COAD), considering the role of fungal spores, seasonal variations, and lag effects. Methods Hospitalisation data from the Hospital In-Patient Enquiry (HIPE) system were analyzed alongside daily air pollutant concentrations (NO2, PM2.5, PM10) from the Environmental Protection Agency and fungal spore data from Dublin City University. Meteorological data were also included. Data from 2018-2019 were compared with the transport restriction period starting March 2020. Statistical methods included descriptive statistics, correlation, regression, and lag analyses. Results During the pandemic, significant reductions in NO2 and PM2.5 coincided with decreased hospital admissions for asthma (mean 4.01 to 2.86, p < 0.001) and COAD (mean 10.18 to 6.04, p < 0.001). NO2 showed positive correlations with asthma (r = 0.125, p < 0.01) and COAD admissions (r = 0.258, p < 0.01), and was a significant predictor in regression models. Fungal spores were not significantly correlated with asthma admissions but negatively correlated with COAD admissions (r = -0.160, p < 0.01). Seasonal analysis revealed higher NO2 and PM levels outside summer, whereas fungal spores peaked in summer. Lag analysis suggested delayed effects of NO2 and spores on hospitalisations. Conclusions COVID-19 transport restrictions improved air quality, particularly by reducing NO2, which was linked to fewer hospital admissions for asthma and COAD. Seasonal and lag effects are important in understanding these relationships. These findings support transport policies aimed at improving air quality to benefit respiratory health. Key messages • COVID-19 transport restrictions cut NO2 and PM2.5, reducing asthma and COAD hospital admissions, showing benefits of strong air pollution control policies. • NO2 predicts asthma and COAD admissions; fungal spores negatively link to COAD. Seasonal and lag effects highlight the need for dynamic air quality management.