Daily effects of air pollutants and pollen types on asthma and COPD hospital emergency visits in the industrial and Mediterranean Spanish city of Cartagena

ABSTRACT

Background: Associations found in time-series studies on hospital emergency room (ER) visits due to asthma and chronic obstructive pulmonary disease (COPD) with single air pollutants show some lack of consistency. The respiratory effects of aeroallergens in the air pollution mix are not well established. Non-linear relationships of different airborne pollen types with certain respiratory diseases have also been described. We aim to study the short-term effects of major air pollutants and aeroallergen pollen on asthma and COPD hospital ER visits in the industrial and Mediterranean Spanish city of Cartagena during1995-1998. Methods: The association of asthma and COPD to ER visits with mean levels of sulphur and nitrogen dioxides (SO2 and NO2), total suspended particles (TSP), ozone (O3), and the main allergenic airborne pollen types were analysed using Poisson regression with Generalised Additive Models, taking into account delayed effects and adjusting for long-term trends, seasonality, weather conditions, holidays and flu notifications. Results: Multipollutant models showed a similar relative risk (RR) increase (in %), of around 5% in asthma and COPD ER visits per 10 microg/m3 SO2 increments. The risk of an ER visit for the sameNO2 increment was 2.6% for asthma and 3.3% for COPD. Visits to the ER due to asthma showed a positive increase with both Urticaceae and Poaceae levels, but did not substantially modify the previous percentages(AU)