You are here:
Traffic-related air pollution and circulating levels of total and allergen-specific IgE among children in Detroit, Michigan
Citation:
JOHNSON, M. M., E. E. HUDGENS, B. HEIDENFELDER, L. Smith, R. Hamilton, S. MUKERJEE, C. Stallings, L. M. NEAS, H. A. OZKAYNAK, AND J. GALLAGHER. Traffic-related air pollution and circulating levels of total and allergen-specific IgE among children in Detroit, Michigan. Presented at International Society of Environmental Epidemiology Annual Conference, Pasadena, CA, October 12 - 14, 2008.
Impact/Purpose:
research results
Description:
Introduction: There is a growing body of literature suggesting a relationship between traffic-related air pollution and allergic health outcomes. Animal studies have demonstrated that air pollution, particularly diesel exhaust particles, may stimulate or enhance atopic responses. Epidemiologic studies have also suggested that traffic-related air pollution may have an adjuvant effect on allergic response. This study examined relationships between traffic pollution and clinical markers of atopy among asthmatic and non-asthmatic children (aged 9-12 years) in Detroit, Michigan. Methods: Total and allergen-specifc IgE levels were assessed in serum from 194 children participating in Mechanistic Indicators of Childhood Asthma (MICA) and the Detroit Children’s Health Study (DCHS). Traffic variables included distance to major roadways with 50,000 or more vehicles per day (vpd) and traffic intensity (vpd/km) within a 1500 meter buffer area around the home. Results: Increased exposure to traffic-related air pollution was associated with increased total- and allergen-specific IgE levels. Traffic intensity within 1500 meters (ranging from 14,745 to 169,607 vpd/km) was positively associated with total- and allergen-specific serum IgE. In multivariate models adjusting for age sex, parental education and ethnicity, log total serum IgE and log allergen-specific IgE increased by 0.078 (p-value = 0.024) and 0.11 (p-value = 0.024) per 10,000 vpd/km within a 1500 meter buffer area. Distance to major roadways (ranging from 5-5700 meters) was inversely associated with total serum IgE and allergen-specific IgE in multivariate models. Log total serum IgE and log allergen-specific IgE decreased by 0.21 (p-value = 0.039) and 0.26 (p-value =0.063) per 1000 meters, respectively. Models restricted to African-American children (N=167) were similar, with p values < 0.05. Effect estimates for traffic variables and atopy were similar among asthmatics (N=89) and non-asthmatics (N=105). Associations between traffic and serum IgE were not improved by considering tighter buffer areas. Conclusions: These results were consistent with previous studies suggesting that increased exposure to traffic-related air pollution may impact allergic responses in children. Although this work was reviewed by EPA and approved for publication, it may not reflect official Agency policy.