Short-term Associations between Ambient Air Pollutants and Pediatric Asthma Emergency Department Visits.
Am J Respir Crit Care Med. 2010 Apr 8 Strickland MJ, Darrow LA, Klein M, Flanders WD, Sarnat JA, Waller LA, Sarnat SE, Mulholland JA, Tolbert PE Department of Environmental and Occupational Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, United States.
RATIONALE: Certain outdoor air pollutants cause asthma exacerbations in children. To advance understanding of these relationships, further characterization of the dose-response and pollutant lag effects are needed, as are investigations of pollutant species beyond the commonly measured criteria pollutants.
OBJECTIVES: Investigate short-term associations between ambient air pollutant concentrations and emergency department visits for pediatric asthma.
METHODS: Daily counts of emergency department visits for asthma or wheeze among children age 5â17 were collected from 41 Metropolitan Atlanta hospitals during 1993â2004 (n = 91,386 visits). Ambient concentrations of gaseous pollutants and speciated particulate matter were available from stationary monitors during this time period. Rate ratios for the warm season (MayâOctober) and cold season (NovemberâApril) were estimated using Poisson generalized linear models in the framework of a case-crossover analysis.
MEASUREMENTS AND MAIN RESULTS: Both ozone and primary pollutants from traffic sources were associated with emergency department visits for asthma or wheeze; evidence for independent effects of ozone and primary pollutants from traffic sources were observed in multipollutant models. These associations tended to be of the highest magnitude for concentrations on the day of the emergency department visit and were present at relatively low ambient concentrations.
CONCLUSIONS: Even at relatively low ambient concentrations, ozone and primary pollutants from traffic sources independently contributed to the burden of emergency department visits for pediatric asthma.