Altered pulmonary function in children with asthma associated with highway traffic near residence (original) (raw)

The influence of neighborhood traffic density on the respiratory health of elementary schoolchildren

Environment International, 2012

Background: Several studies have found that living near major roadways is associated with an increase in respiratory illness but few studies have measured the volume and type of traffic. Objective: We investigated the relation between traffic volume and respiratory health of 2328 children 9 to 11 years old in the city of Windsor, Canada. Methods: We identified the roadways within a 200 meter radius of the child's neighborhood using the latitude and longitude of the residential postal code. Traffic exposure was defined as the sum of the annual volume of vehicles on all of these roadways. Volume was calculated using sensors to detect passing vehicles (simple traffic counts), and by counts and direction of traffic at intersections (turning movement counts). Ventilatory lung function was measured by spirometry and airway inflammation by exhaled nitric oxide (eNO). Results: The odds ratio between an interquartile increase in truck turning movement counts and chest congestion was 1.20 (1.06-1.35). The percentage of predicted FVC declined 0.68%, (95% CI 1.32, 0.03) for an interquartile increase in simple traffic counts (33,787 vehicles daily). Among those with self-reported asthma, effect sizes were larger. Percentage predicted FEV 1 declined 1.84% (95% CI 0.07, 3.61) associated with an interquartile range increase in turning movement counts. No statistically significant change was detected between traffic measures and exhaled nitric oxide. Conclusions: Our findings provide further support for the hypothesis that neighborhood exposure to traffic-related air pollution increases respiratory symptoms and reduces ventilatory function in children, especially those with self-reported asthma.

Effect of vehicular particulate matter on the lung function of asthmatic children in Fresno CA

Unpublished Manuscript

Exposure to particulate matter (PM) is associated with adverse respiratory health effects. Vehicles traveling along a highway represent a significant source of fine particulates that contribute to the aggravation and possibly to the development of asthma in children. Residential history information and lung function data from 89 children involved in the Fresno Asthmatic Children's Environment Study were used to quantify the impact of PM exposure from vehicles on lung health. The forced expiratory flow volume in one second (FEV1) was collected for each child using a spirometer during office visits between November 2000 and December 2001. Individual-level demographic and socioeconomic data as well as the exact locations of the children's residences were gathered during home interviews. Residential address data were incorporated into a geographic information system to determine the distances of each residence to the closest highway in Fresno, CA. The distances to only highway 99 were also calculated. The categorical distances reported by the study participants were also used to estimate exposure to vehicular PM. Using three stepwise linear regression models, the effects of proximity to a vehicular source of PM on the mean FEV1 values were evaluated. After adjustment for sex, household income level, race, standing height, parental smoking, mother smoking during pregnancy, time lived in residence, and time of FEV1 test, the measures of absolute distances to the highways were found to be insignificant in predicting changes in mean FEV1 values. The regression model using self-reported distance variables indicated that children who lived one to three blocks from the source of vehicular PM experienced a 10% increased in mean FEV1 values, as compared to children who resided immediately next to the pollution source. These results indicate that living in an area with high traffic density may negatively affect the lung function of children with asthma.

Childhood Asthma and Exposure to Traffic and Nitrogen Dioxide

Epidemiology, 2005

Background: Evidence for a causal relationship between trafficrelated air pollution and asthma has not been consistent across studies, and comparisons among studies have been difficult because of the use of different indicators of exposure. Methods: We examined the association between traffic-related pollution and childhood asthma in 208 children from 10 southern California communities using multiple indicators of exposure. Study subjects were randomly selected from participants in the Children's Health Study. Outdoor nitrogen dioxide (NO 2 ) was measured in summer and winter outside the home of each child. We also determined residential distance to the nearest freeway, traffic volumes on roadways within 150 meters, and model-based estimates of pollution from nearby roadways. Results: Lifetime history of doctor-diagnosed asthma was associated with outdoor NO 2 ; the odds ratio (OR) was 1.83 (95% confidence interval ϭ 1.04 -3.22) per increase of 1 interquartile range (IQR ϭ 5.7 ppb) in exposure. We also observed increased asthma associated with closer residential distance to a freeway (2.22 per IQR; 1.36 -3.63) and with model-based estimates of outdoor pollution from a freeway (1.89 per IQR; 1.19 -3.02). These 2 indicators of freeway exposure and measured NO 2 concentrations were also associated with wheezing and use of asthma medication. Asthma was not associated with traffic volumes on roadways within 150 meters of homes or with model-based estimates of pollution from nonfreeway roads.