Childhood Incident Asthma and Traffic-Related Air Pollution at Home and School

Abstract

BackgroundTraffic-related air pollution has been associated with adverse cardiorespiratory effects, including increased asthma prevalence. However, there has been little study of effects of traffic exposure at school on new-onset asthma.ObjectivesWe evaluated the relationship of new-onset asthma with traffic-related pollution near homes and schools.MethodsParent-reported physician diagnosis of new-onset asthma (n = 120) was identified during 3 years of follow-up of a cohort of 2,497 kindergarten and first-grade children who were asthma- and wheezing-free at study entry into the Southern California Children’s Health Study. We assessed traffic-related pollution exposure based on a line source dispersion model of traffic volume, distance from home and school, and local meteorology. Regional ambient ozone, nitrogen dioxide (NO2), and particulate matter were measured continuously at one central site monitor in each of 13 study communities. Hazard ratios (HRs) for new-onset asthma were scaled to the range of ambient central site pollutants and to the residential interquartile range for each traffic exposure metric.ResultsAsthma risk increased with modeled traffic-related pollution exposure from roadways near homes [HR 1.51; 95% confidence interval (CI), 1.25–1.82] and near schools (HR 1.45; 95% CI, 1.06–1.98). Ambient NO2 measured at a central site in each community was also associated with increased risk (HR 2.18; 95% CI, 1.18–4.01). In models with both NO2 and modeled traffic exposures, there were independent associations of asthma with traffic-related pollution at school and home, whereas the estimate for NO2 was attenuated (HR 1.37; 95% CI, 0.69–2.71).ConclusionsTraffic-related pollution exposure at school and homes may both contribute to the development of asthma.

On-Roadway In-Cabin Exposure to Particulate Matter: Measurement Results Using Both Continuous and Time-Integrated Sampling Approaches

“…Exposure to traffic and traffic-related air pollution has been associated with adverse health, including respiratory responses such as decreased pulmonary function (Brunekreef et al 1997;Gauderman et al 2004;Sekine et al 2004;McCreanor et al 2007), increased respiratory symptoms (Bayer-Oglesby et al 2006;Vigotti et al 2007), and increased incidence of asthma or severity of asthma symptoms (Lwebuga-Mukasa et al 2004;Zmirou et al 2004;McConnell et al 2006McConnell et al , 2010, as well as with cardiovascular outcomes such as increased levels of atherosclerosis (Hoffmann et al 2007), alterations in heart rate variability (Riediker et al 2004;Schwartz et al 2005;Adar et al 2007), and increased incidence of myocardial infarction (Peters et al 2004;Lanki et al 2006;Rosenlund et al 2006;Tonne et al 2007). Toxicological evidence suggests these associations are related to both the size and composition of traffic-related particulate matter (PM) (Brook 2008;Valavanidis et al 2008;Møller et al 2010).…”

Family Hardships and Serum Cotinine in Children With Asthma

“…19 Socioeconomic hardships, day-to-day challenges faced by families living in poverty such as difficulties paying bills or finding work, have been proposed as potentially explanatory and alternative models or pathways through which poverty affects health. 10,20,21 Such hardships, rooted in financial strain, have also been shown to predict lower rates of smoking cessation among smokers. 22 Hardships that families face in the setting of low SES may be more easily affected by social, public health, and clinical interventions.…”

Exposure to Traffic-related Air Pollution and the Onset of Childhood Asthma: A Review of the Literature and the Assement Methods Used

“…On the other hand, Venn and co-workers found that the increased odds of childhood wheeze occurrence in relation to road proximity were local and only visible within 150 meters from the road. Similarly, McConnell et al (2006) and follow-up work in McConnell et al (2010) showed high risks of asthma in children residing at less than 75 meters from a major road, with susceptibility found to have significantly increased in long-term residents with no parental history of asthma. The authors also observed that these risks decreased to reach background rates at 150-200 meters from the road as illustrated in Fig .1.…”

“…As this metric cannot take meteorological conditions into account, it has a limited directional dependence, and automatically assumes that all pollutants disperse in a similar manner, which is inaccurate Six out of the sixteen collected studies used this metric, either in isolation or alongside other criteria. In five of these studies, there was little evidence for an effect of major roadway proximity alone, where weak local and no associations between proximity to major roads and asthma were reported (Gauderman et al, 2005;McConnell et al, 2010). The exception of this was in the study by Gauderman et al (2005) where the residential distance from the nearest freeway was the distance investigated.…”

“…Five out of the sixteen collected studies were found to have used dispersion models to assess the exposure, either in isolation (Nordling et al, 2008;Gruzieva et al, 2013), or alongside other metrics (Gauderman et al, 2005;McConnell et al, 2010;Lindgren et al, 2013). In these studies, the use of dispersion models to assess the exposure is advantageous over the previously described metrics as it allows a more accurate assessment of the impact of variable sources' emissions loads on ambient air quality, and provides outputs that are characterized by a relatively high temporal and spatial resolution.…”