GIS-modeled indicators of traffic-related air pollutants and adverse pulmonary health among children in El Paso, Texas.

Investigators examined 5,654 children enrolled in the El Paso, Texas, public school district by questionnaire in 2001. Exposure measurements were first collected in the late fall of 1999. School-level and residence-level exposures to traffic-related air pollutants were estimated using a land use regression model. For 1,529 children with spirometry, overall geographic information system (GIS)-modeled residential levels of traffic-related ambient air pollution (calibrated to a 10-ppb increment in nitrogen dioxide levels) were associated with a 2.4% decrement in forced vital capacity (95% confidence interval (CI): -4.0, -0.7) after adjustment for demographic, anthropomorphic, and socioeconomic factors and spirometer/technician effects. After adjustment for these potential covariates, overall GIS-modeled residential levels of traffic-related ambient air pollution (calibrated to a 10-ppb increment in nitrogen dioxide levels) were associated with pulmonary function levels below 85% of those predicted for both forced vital capacity (odds ratio (OR) = 3.10, 95% CI: 1.65, 5.78) and forced expiratory volume in 1 second (OR = 2.35, 95% CI: 1.38, 4.01). For children attending schools at elevations above 1,170 m, a 10-ppb increment in modeled nitrogen dioxide levels was associated with current asthma (OR = 1.56, 95% CI: 1.08, 2.50) after adjustment for demographic, socioeconomic, and parental factors and random school effects. These results are consistent with previous studies in Europe and California that found adverse health outcomes in children associated with modeled traffic-related air pollutants.

Mechanistic indicators of childhood asthma (MICA) study: piloting an integrative design for evaluating environmental health.

BACKGROUND: Asthma is a common complex disease responsible for considerable morbidity and mortality, particularly in urban minority populations. The Mechanistic Indicators of Childhood Asthma study was designed to pilot an integrative approach in children's health research. The study incorporates exposure metrics, internal dose measures, and clinical indicators to decipher the biological complexity inherent in diseases such as asthma and cardiovascular disease with etiology related to gene-environment interactions. METHODS/DESIGN: 205 non-asthmatic and asthmatic children, (9-12 years of age) from Detroit, Michigan were recruited. The study includes environmental measures (indoor and outdoor air, vacuum dust), biomarkers of exposure (cotinine, metals, total and allergen specific Immunoglobulin E, polycyclic aromatic hydrocarbons, volatile organic carbon metabolites) and clinical indicators of health outcome (immunological, cardiovascular and respiratory). In addition, blood gene expression and candidate SNP analyses were conducted. DISCUSSION: Based on an integrative design, the MICA study provides an opportunity to evaluate complex relationships between environmental factors, physiological biomarkers, genetic susceptibility and health outcomes. PROJECT APPROVAL: IRB Number 05-EPA-2637: The human subjects' research protocol was reviewed by the Institutional Review Board (IRB) of the University of North Carolina; the IRB of Westat, Inc., the IRB of the Henry Ford Health System; and EPA's Human Subjects' Research Review Official.

A participant-based approach to indoor/outdoor air monitoring in community health studies.

Community health studies of traffic-related air pollution have been hampered by the cost and participant burden associated with collecting household-level exposure data. The current study utilized a participant-based approach to collect indoor and outdoor air monitoring data from 92 asthmatic and nonasthmatic children (9-13 years old) enrolled in two concurrent health studies in Detroit, Michigan (Mechanistic Indicators of Childhood Asthma and Detroit Children's Health Study) conducted by the US Environmental Protection Agency (EPA). Passive samplers were shipped to participating households and deployed by parents of study participants to collect indoor and outdoor measurements of nitrogen dioxide (NO(2)), volatile organic compounds (VOCs), and polycyclic aromatic hydrocarbons (PAHs) including naphthalene. Half of the households deployed VOC and NO(2) samplers for 7 days; the other half deployed PAH and NO(2) samplers for 2 days and additional PAH samplers for 1 day. Approximately 88% of the households that received air sampling kits completed the air monitoring. Compliance was significantly higher among participants asked to deploy all samplers for 7 days (85%) compared with participants asked to deploy some samplers for 2 days and others for 1 day (56%). The 7-day homes were also more likely to provide usable data (96%) compared with the 1- and 2-day homes (73%). Compliance and providing usable data did not vary between parents of asthmatic versus nonasthmatic study participants and were not reduced among households deploying duplicate samplers. These results suggest that participant-based sampling may be a feasible and cost-effective alternative to traditional exposure assessment approaches that can be applied in future epidemiological and community-based health studies.