@article {Delfino189, author = {R J Delfino and S Brummel and J Wu and H Stern and B Ostro and M Lipsett and A Winer and D H Street and L Zhang and T Tjoa and D L Gillen}, title = {The relationship of respiratory and cardiovascular hospital admissions to the southern California wildfires of 2003}, volume = {66}, number = {3}, pages = {189--197}, year = {2009}, doi = {10.1136/oem.2008.041376}, publisher = {BMJ Publishing Group Ltd}, abstract = {Objective: There is limited information on the public health impact of wildfires. The relationship of cardiorespiratory hospital admissions (n = 40 856) to wildfire-related particulate matter (PM2.5) during catastrophic wildfires in southern California in October 2003 was evaluated. Methods: Zip code level PM2.5 concentrations were estimated using spatial interpolations from measured PM2.5, light extinction, meteorological conditions, and smoke information from MODIS satellite images at 250 m resolution. Generalised estimating equations for Poisson data were used to assess the relationship between daily admissions and PM2.5, adjusted for weather, fungal spores (associated with asthma), weekend, zip code-level population and sociodemographics. Results: Associations of 2-day average PM2.5 with respiratory admissions were stronger during than before or after the fires. Average increases of 70 μg/m3 PM2.5 during heavy smoke conditions compared with PM2.5 in the pre-wildfire period were associated with 34\% increases in asthma admissions. The strongest wildfire-related PM2.5 associations were for people ages 65{\textendash}99 years (10.1\% increase per 10 μg/m3 PM2.5, 95\% CI 3.0\% to 17.8\%) and ages 0{\textendash}4 years (8.3\%, 95\% CI 2.2\% to 14.9\%) followed by ages 20{\textendash}64 years (4.1\%, 95\% CI -0.5\% to 9.0\%). There were no PM2.5{\textendash}asthma associations in children ages 5{\textendash}18 years, although their admission rates significantly increased after the fires. Per 10 μg/m3 wildfire-related PM2.5, acute bronchitis admissions across all ages increased by 9.6\% (95\% CI 1.8\% to 17.9\%), chronic obstructive pulmonary disease admissions for ages 20{\textendash}64 years by 6.9\% (95\% CI 0.9\% to 13.1\%), and pneumonia admissions for ages 5{\textendash}18 years by 6.4\% (95\% CI -1.0\% to 14.2\%). Acute bronchitis and pneumonia admissions also increased after the fires. There was limited evidence of a small impact of wildfire-related PM2.5 on cardiovascular admissions. Conclusions: Wildfire-related PM2.5 led to increased respiratory hospital admissions, especially asthma, suggesting that better preventive measures are required to reduce morbidity among vulnerable populations.}, issn = {1351-0711}, URL = {https://oem.bmj.com/content/66/3/189}, eprint = {https://oem.bmj.com/content/66/3/189.full.pdf}, journal = {Occupational and Environmental Medicine} }