Short‑term effects of air pollution and aeroallergens on respiratory admissions

Background

Short‑term fluctuations in ambient air pollution are established triggers of respiratory morbidity, yet few European studies integrate air pollutants, aeroallergens, and meteorology to inform city‑level public health action.

Methods

Daily hospital admissions for asthma, chronic obstructive airways disease (COPD), and all respiratory conditions were obtained from the Hospital In‑Patient Enquiry (HIPE) system for Dublin. Ambient NO₂, PM₂.₅, and PM₁ data were sourced from the Environmental Protection Agency, fungal spore counts from the Dublin City University aerobiology programme, and meteorological data from Met Éireann. Time‑series analyses using negative binomial regression assessed short‑term and lagged (0–7 days) associations, adjusting for meteorology and seasonality.

Results

NO₂ showed consistent positive associations with asthma, COPD, and all respiratory admissions, with relative risks of approximately 3–5% per unit increase across multiple lags (p < 0.01). Particulate matter effects were outcome‑specific. Fungal spore concentrations displayed strong seasonal patterning but no independent short‑term associations after adjustment.

Conclusions

Integrating air pollution, aeroallergen, and meteorological data supports urban respiratory health surveillance. Traffic‑related NO₂ is a consistent driver of short‑term respiratory admissions in Dublin, while fungal spores provide important environmental context.

Key messages

• Traffic‑related NO₂ was consistently associated with increased asthma, COPD, and overall respiratory admissions, with effects persisting across multiple short‑term lag periods.

• Fungal spores showed strong seasonal patterning but no independent short‑term effect on respiratory admissions after adjustment, improving interpretation of seasonal respiratory risk.