Differential respiratory health effects from the 2008 northern California wildfires: A spatiotemporal approach.
We investigated health effects associated with fine particulate matter during a long-lived, large wildfire complex in northern California in the summer of 2008. We estimated exposure to PM2.5 for each day using an exposure prediction model created through data-adaptive machine learning methods from a large set of spatiotemporal data sets. We then used Poisson generalized estimating equations to calculate the effect of exposure to 24-hour average PM2.5 on cardiovascular and respiratory hospitalizations and ED visits. We further assessed effect modification by sex, age, and area-level socioeconomic status (SES). We observed a linear increase in risk for asthma hospitalizations (RR=1.07, 95% CI=(1.05, 1.10) per 5µg/m(3) increase) and asthma ED visits (RR=1.06, 95% CI=(1.05, 1.07) per 5µg/m(3) increase) with increasing PM2.5 during the wildfires. ED visits for chronic obstructive pulmonary disease (COPD) were associated with PM2.5 during the fires (RR=1.02 (95% CI=(1.01, 1.04) per 5µg/m(3) increase) and this effect was significantly different from that found before the fires but not after. We did not find consistent effects of wildfire smoke on other health outcomes. The effect of PM2.5 during the wildfire period was more pronounced in women compared to men and in adults, ages 20-64, compared to children and adults 65 or older. We also found some effect modification by area-level median income for respiratory ED visits during the wildfires, with the highest effects observed in the ZIP codes with the lowest median income. Using a novel spatiotemporal exposure model, we found some evidence of differential susceptibility to exposure to wildfire smoke.
Environmental Health Sciences Division, School of Public Health, University of California, Berkeley, United States. Electronic address: coreid@hsph.harvard.edu.
Colleen E
CE
Reid
Environmental Health Sciences Division, School of Public Health, University of California, Berkeley, United States.
Michael
M
Jerrett
Epidemiology Division, School of Public Health, University of California, Berkeley, United States.
Ira B
IB
Tager
Epidemiology Division, School of Public Health, University of California, Berkeley, United States; Biostatistics Division, School of Public Health, University of California, Berkeley, United States.
Maya L
ML
Petersen
Environmental Health Sciences Division, School of Public Health, University of California, Berkeley, United States.
Jennifer K
JK
Mann
Environmental Health Sciences Division, School of Public Health, University of California, Berkeley, United States; Department of Medicine, University of California, San Francisco, United States.
John R
JR
Balmes
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000393:Air Pollutants / Q000032:analysis / Q000633:toxicity*; D002140:California / Q000453:epidemiology; D002318:Cardiovascular Diseases / Q000139:chemically induced / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D004190:Disasters; D004781:Environmental Exposure; D005260:Female; D005390:Fires; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis / Q000633:toxicity*; D016012:Poisson Distribution; D012140:Respiratory Tract Diseases / Q000139:chemically induced / Q000453:epidemiology*; D012307:Risk Factors; D012906:Smoke; D013997:Time Factors; D055815:Young Adult
D000393:Air Pollutants; D052638:Particulate Matter; D012906:Smoke
Air pollution; Asthma; Climate change; Vulnerable populations; Wildland fires