Ambient air pollution and emergency department visits for asthma: a multi-city assessment of effect modification by age.
Previous studies have found strong associations between asthma morbidity and major ambient air pollutants. Relatively little research has been conducted to assess whether age is a factor conferring susceptibility to air pollution-related asthma morbidity. We investigated the short-term relationships between asthma emergency department (ED) visits and ambient ozone (O3), carbon monoxide (CO), nitrogen dioxide (NO2), sulfur dioxide (SO2), and fine particulate matter (PM2.5) in Atlanta (1993-2009), Dallas (2006-2009), and St. Louis (2001-2007). City-specific daily time-series analyses were conducted to estimate associations by age group (0-4, 5-18, 19-39, 40-64, and 65+ years). Sub-analyses were performed stratified by race and sex. City-specific rate ratios (RRs) were combined by inverse-variance weighting to provide an overall association for each strata. The overall RRs differed across age groups, with associations for all pollutants consistently strongest for children aged 5-18 years. The patterns of association across age groups remained generally consistent when models were stratified by sex and race, although the strong observed associations among 5-18 year olds appeared to be partially driven by non-white and male patients. Our findings suggest that age is a susceptibility factor for asthma exacerbations in response to air pollution, with school-age children having the highest susceptibility.
Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA.
Brooke A
BA
Alhanti
Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA.
Howard H
HH
Chang
Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA.
Andrea
A
Winquist
School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia, USA.
James A
JA
Mulholland
Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA.
Lyndsey A
LA
Darrow
Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA.
Stefanie Ebelt
SE
Sarnat
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000367:Age Factors; D000368:Aged; D000393:Air Pollutants / Q000009:adverse effects* / Q000032:analysis; D000397:Air Pollution / Q000009:adverse effects* / Q000032:analysis; D000818:Animals; D001249:Asthma / Q000139:chemically induced* / Q000453:epidemiology*; D002248:Carbon Monoxide / Q000009:adverse effects / Q000032:analysis; D002648:Child; D002675:Child, Preschool; D002947:Cities; D004636:Emergency Service, Hospital; D004784:Environmental Monitoring; D005260:Female; D005845:Georgia / Q000453:epidemiology; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D008923:Missouri / Q000453:epidemiology; D009585:Nitrogen Dioxide / Q000009:adverse effects / Q000032:analysis; D010126:Ozone / Q000009:adverse effects; D010316:Particle Size; D052638:Particulate Matter / Q000009:adverse effects* / Q000032:analysis; D016012:Poisson Distribution; D012307:Risk Factors; D013458:Sulfur Dioxide / Q000009:adverse effects / Q000032:analysis; D013781:Texas / Q000453:epidemiology; D055815:Young Adult
D000393:Air Pollutants; D052638:Particulate Matter; D013458:Sulfur Dioxide; D010126:Ozone; D002248:Carbon Monoxide; D009585:Nitrogen Dioxide