Air pollution and the development of asthma, allergy and infections in a birth cohort.
Eur Respir J. 2007 Jan 24; Brauer M, Hoek G, Smit HA, de Jongste JC, Gerritsen J, Postma DS, Kerkhof M, Brunekreef B. School of Occupational and Environmental Hygiene, Vancouver, BC, Canada.
Few studies have addressed associations between traffic-related air pollution and respiratory disease in young children. We assessed the development of asthmatic/allergic symptoms and respiratory infections during the first four years of life in a birth cohort study (n approximately 4, 000).
Outdoor concentrations of traffic-related air pollutants (NO2, PM2.5 and "soot") were assigned to the birthplace home addresses with a land-use regression model. They were linked by logistic regression to questionnaire data on doctor-diagnosed asthma, bronchitis, influenza and eczema and to self-reported wheeze, dry nighttime cough, ear/nose/throat infections and skin rash. Total and specific IgE to common allergens were measured in a subgroup (n=713).Adjusted odds ratios per interquartile pollution range were elevated for wheeze (1.2, 95% CI=1.0-1.4 for "soot"), doctor-diagnosed asthma (1.3, 1.0-1.7), ear/nose/throat infections (1.2, 1.0-1.3) and flu/serious colds (1.2, 1.0-1.4). No consistent associations were observed for other endpoints. Positive associations between air pollution and specific sensitization to common food allergens (1.6, 1.2-2.2 for "soot"), but not total IgE, were found in the subgroup with IgE measurements.
Traffic-related pollution was associated with respiratory infections and some measures of asthma and allergy during the first four years of life.