Short-term Associations between Ambient Air Pollutants and Pediatric Asthma Emergency Department Visits

Abstract

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 aged 5 to 17 years were collected from 41 Metropolitan Atlanta hospitals during 1993-2004 (n 5 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 (May to October) and cold season (November to April) 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.Keywords: ambient particulate matter; asthma; minors; ozone A broad literature supports associations between ambient air pollutant concentrations and asthma exacerbations (1-3). Children are thought to be particularly susceptible to ambient air pollutants, because their lungs and immune systems are not fully developed, they breathe more air per unit body weight and are typically more active than adults, and their peripheral airways are anatomically smaller than adults so that inflammation results in proportionally greater airway obstruction (4-6). To help advance understanding of the relationships between ambient air pollutant concentrations and asthma exacerbations in children, further characterization of the dose-response and pollutant lag effects are needed, as are investigations of pollutant species beyond the commonly measured urban air pollutants (3, 7). Further investigation of pollutant mixtures and effect modification may also provide insights (8, 9); for example, there have been reports of stronger pollution effects during the warm season (10-15) even though pediatric asthma rates peak during the cold season (16). To lessen concerns about uncontrolled confounding, aggressive control for variables, such as meteorology and seasonal asthma trends, is required.In the present study, we analyzed data from the Study of Particles and Health in Atlanta (SOPHIA) (14,(17)(18)(19)(20)(21), one of...

Impact of air pollution with PM10 on primary health care consultations for respiratory diseases in children in Zasavje, Slovenia: a time-trend study

“…The hypothesis that a positive temporal relationship exists between the daily number of first consultations for respiratory diseases and the daily concentration of PM 10 was thus certainly confirmed in the Zagorje and Trbovlje municipalities. Moreover, these results are consistent with the results of many similar studies (23,(48)(49)(50) that also confirmed the positive association between respiratory diseases and PM 10 concentration.…”

Air Pollution, Allergic Co-morbidity, and Emergency Department Visit for Pediatric Asthma in Taiwan

“…Ozone can diffuse freely into cells and lead to sulfhydryl oxidation and inflammation (Frischer et al, 2001). An increased risk of asthma exacerbation associated with O 3 at levels ranging from 24.3 ppb to 60.0 ppb has been reported in previous studies (Jalaludin et al, 2008;Strickland et al, 2010).…”

“…Epidemiologic studies on school-age children have shown that exposure to ambient air pollutants were associated with increases in emergency department visits (Norris et al, 1999;Babin et al, 2007;Jalaludin et al, 2008;Strickland et al, 2010;Li et al, 2011) and hospital admissions for asthma (Lin et al, 2002(Lin et al, , 2003Tsai et al, 2006;Yang et al, 2007;Bell et al, 2008).…”

Clearing the Air: A Review of the Effects of Particulate Matter Air Pollution on Human Health

“…Large pediatric studies demonstrate increased asthma ED visits for increases in PM [68] and that PM 10 increases of 6.5 μg/m 3 are associated with a 15% (95% CI, 2-30%) increase in respiratoryrelated hospital admissions [69] (Table 3).…”