Air pollution and respiratory symptoms among children with asthma: Vulnerability by corticosteroid use and residence area

Abstract

Rationale Information on how ambient air pollution affects susceptible populations is needed to ensure protective air quality standards. Objectives To estimate the effect of community-level ambient particulate matter (PM) and ozone (O3) on respiratory symptoms among primarily African-American and Latino, lower-income asthmatic children living in Detroit, Michigan and to evaluate factors associated with heterogeneity in observed health effects. Methods A cohort of 298 children with asthma was studied prospectively from 1999 to 2002. For 14 days each season over 11 seasons, children completed a respiratory symptom diary. Simultaneously, ambient pollutant concentrations were measured at two community-level monitoring sites. Logistic regression models using generalized estimating equations were fit for each respiratory symptom in single pollutant models, looking for interactions by area or by corticosteroid use, a marker of more severe asthma. Exposures of interest were: daily concentrations of PM<10 μm, <2.5 μm, and between 10 and 2.5 μm in aerodynamic diameter (PM10, PM2.5, and PM10–2.5, respectively), the daily 8-hour maximum concentration of O3 (8HrPeak), and the daily 1-hour maximum concentration of O3 (1HrPeak). Results Outdoor PM2.5, PM10, 8HrPeak, and 1HrPeak O3 concentrations were associated with increased odds of respiratory symptoms, particularly among children using corticosteroid medication and among children living in the southwest community of Detroit. Similar patterns of associations were not seen with PM10–2.5. Conclusions PM2.5 and O3 at levels near or below annual standard levels are associated with negative health impact in this population of asthmatic children. Variation in effects within the city of Detroit and among the subgroup using steroids emphasizes the importance of spatially refined exposure assessment and the need for further studies to elucidate mechanisms and effective risk reduction interventions.

Asthmatic symptoms and air pollution: a panel study on children living in the Italian Po Valley

“…We found statistically significant increases for occurrence of at least one symptom, cough and phlegm. Our results are consistent with previous studies showing an increase in asthma symptoms for urban areas, (Yu et al, 2000;Escamilla-Nunez et al, 2008;Lewis et al, 2013).…”

Outdoor air pollution and asthma

“…123,124 Patients with severe asthma might be the most likely to have respiratory symptoms with exposure to air pollutants, despite treatment with steroids. 125 Because of the potential interactive effects of air pollutants with allergens or secondhand smoke, avoidance of these exposures is prudent, especially during high pollution days, which may be concurrent with exposure to seasonal aeroallergens.…”

Multifactorial airborne exposures and respiratory hospital admissions — The example of Santiago de Chile

“…Lippmann et al found that spatial inhomogeneity of air pollutant concentrations may hide negative associations with human health (Lippmann et al, 2000). Generally, odds for respiratory symptoms may be increased by O 3 exposure but result in application of appropriate medicaments and not hospitalization (Altug et al, 2014; Lewis et al, 2013). Therefore, we assume that unidentified factors and/or the negative correlation between concentrations of O 3 and the other investigated pollutants may mask rather small adverse health effects of ozone.…”