Short-term associations between fine and coarse particles and hospital admissions for cardiorespiratory diseases in six French cities.

TLDR: The results indicate that the coarse fraction may have a stronger effect than the fine fraction on some morbidity endpoints, especially respiratory diseases.

Abstract: Objectives: Little is known about the potential health effects of the coarse fraction of ambient particles The aim of this study is to estimate the links between fine (PM25) and coarse particle (PM25210) levels and cardiorespiratory hospitalisations in six French cities during 2000–2003 Methods: Data on the daily numbers of hospitalisations for respiratory, cardiovascular, cardiac and ischaemic heart diseases were collected Associations between exposure indicators and hospitalisations were estimated in each city using a Poisson regression model, controlling for confounding factors (seasons, days of the week, holidays, influenza epidemics, pollen counts, temperature) and temporal trends City-specific findings were combined to obtain excess relative risks (ERRs) associated with a 10 mg/m 3 increase in PM25 and PM25210 levels Results: We found positive associations between indicators of particulate pollution and hospitalisations for respiratory infection, with an ERR of 44% (95% CI 09 to 80) for PM25210 and 25% (95% CI 01 to 48) for PM25 Concerning respiratory diseases, no association was observed with PM25, whereas positive trends were found with PM25210, with a significant association for the 0– 14-year-old age group (ERR 62%, 95% CI 04 to 123) Concerning cardiovascular diseases, positive associations were observed between PM25 levels and each indicator, although some did not reach significance; trends with PM25210 were weaker and non-significant except for ischaemic heart disease in the elderly (ERR 64%, 95% CI 16 to 114) Conclusions: In accordance with other studies, our results indicate that the coarse fraction may have a stronger effect than the fine fraction on some morbidity endpoints, especially respiratory diseases