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NEAR-ROADWAY EXPOSURE AND CHILDREN'S RESPIRATORY HEALTH: IRRITANT OR ALLERGY
Citation:
NEAS, L. M. NEAR-ROADWAY EXPOSURE AND CHILDREN'S RESPIRATORY HEALTH: IRRITANT OR ALLERGY. Presented at 10th International Inhalation Symposium, Hannover, GERMANY, June 01 - 03, 2006.
Impact/Purpose:
research results
Description:
A series of epidemiologic studies since 1993 have suggested that exposure to traffic may be associated with an increased prevalence of asthma. This talk will review several different biologic hypotheses that have been advanced to explain the apparent association between traffic and asthma and will also review the wide variety oftraffic exposure metrics used in these epidemiologic studies, including measured levels ofindicator pollutants, such as volatile organic compounds or nitrogen dioxide; self-reported perceptions ofneighborhood traffic; many different geographic indicators of proximity to roadways of different traffic volume, vehicle types, or flow patterns; and more sophisticated land-use regression models. After this background, I will present and discuss the results ofEPA's El Paso Children's Health Study, a prevalence survey ofchildren's respiratory conditions and lung function. The study used a land¬ use regression model for exposure assessment based on repeated measurements of several indicator pollutants and geographic variables for point, line and area sources in the largely Hispanic community of E1 Paso, Texas. The primary indicator pollutant, nitrogen dioxide, was associated with consistent decrements in lung function, but was only associated with current asthma in the less dense, up-land portion ofthe city. However, the El Paso study provided a clear demonstration that the indicator pollutant for traffic, nitrogen dioxide, was not the etiologic agent and that traffic exerts an adverse effect beyond a narrow roadway buffer. I also will provide a status report on the design and development ofthe Detroit Children's Health Study, a case-cohort study ofchildren's respiratory conditions, lung function, and exhaled nitric oxide. Finally, I will briefly discuss the varying degrees of support for each ofthe reviewed biologic hypotheses from recent epidemiologic studies. This is an abstract ofa presentation and does not necessarily reflect EPA policy.