Air Pollution and Acute Respiratory Response in a Panel of Asthmatic Children along the U.S.–Mexico Border

Abstract

Background: Concerns regarding the health impact of urban air pollution on asthmatic children are pronounced along the U.S.–Mexico border because of rapid population growth near busy border highways and roads.Objectives: We conducted the first binational study of the impacts of air pollution on asthmatic children in Ciudad Juarez, Mexico, and El Paso, Texas, USA, and compared different exposure metrics to assess acute respiratory response.Methods: We recruited 58 asthmatic children from two schools in Ciudad Juarez and two schools in El Paso. A marker of airway inflammation [exhaled nitric oxide (eNO)], respiratory symptom surveys, and pollutant measurements (indoor and outdoor 48-hr size-fractionated particulate matter, 48-hr black carbon, and 96-hr nitrogen dioxide) were collected at each school for 16 weeks. We examined associations between the pollutants and respiratory response using generalized linear mixed models.Results: We observed small but consistent associations between eNO and numerous pollutant metrics, with estimated increases in eNO ranging from 1% to 3% per interquartile range increase in pollutant concentrations. Effect estimates from models using school-based concentrations were generally stronger than corresponding estimates based on concentrations from ambient air monitors. Both traffic-related and non–traffic-related particles were typically more robust predictors of eNO than was nitrogen dioxide, for which associations were highly sensitive to model specification. Associations differed significantly across the four school-based cohorts, consistent with heterogeneity in pollutant concentrations and cohort characteristics. Models examining respiratory symptoms were consistent with the null.Conclusions: The results indicate adverse effects of air pollution on the subclinical respiratory health of asthmatic children in this region and provide preliminary support for the use of air pollution monitors close to schools to track exposure and potential health risk in this population.

Airway inflammation and oxidative potential of air pollutant particles in a pediatric asthma panel

“…43 Another cohort panel study at the US–Mexico border towns of Ciudad Juarez, Mexico, and El Paso, Texas, found positive associations between FE NO in children with asthma and both black carbon and PM 2.5 measurements at school sites. 44 Our null PM 2.5 results were consistent with a longitudinal study of FE NO in children with asthma in Windsor, Canada, with lower levels of PM 2.5 (median 6.5 μ g/m 3 ). 45 The Canadian study instead found a positive association between a biomarker of oxidative stress in exhaled breath condensates and both PM 2.5 and NO 2 .…”

Local variability in the impacts of residential particulate matter and pest exposure on children’s wheezing severity: a geographically weighted regression analysis of environmental health justice

“…El Paso County had a lower median household income (2011 US $36,333) than the State of Texas (2011 US $49,391) and the US (2011 US $50,502) with a poverty rate of 24%, which was higher than the national rate (16%). In previous studies in this city, researchers have found relatively modest associations between air pollutants (including PM 2.5 ) and respiratory health effects (Grineski, et al, 2011; Sarnat et al, 2011; Svendsen et al, 2012; Zora et al, 2013). …”

Exposure to traffic pollution, acute inflammation and autonomic response in a panel of car commuters

“…Given the relatively short follow-up period for this study, however, inferences relating to the temporality of any of the endpoints should be viewed cautiously. Numerous studies have reported associations between air pollution and acute eNO response utilizing panel based designs (Adamkiewicz et al, 2004; Buonanno et al, 2013; Delfino et al, 2006; Greenwald et al, 2013; Sarnat et al, 2012). …”