ISEE 2007 CONFERENCE ABSTRACTS SUPPLEMENT: Abstracts
In vitro studies, animal experiments, and human exposure studies have shown increased risks for atopic outcomes. However, results derived from observational studies are not consistent. We aim to assess the relationship between individual-based exposure to traffic-related air pollutants and allergic outcomes in a prospective birth cohort study during the first 6 years of life.
Material and Methods:
In a population-based cohort of 3577 newborns in the Munich metropolitan area, we followed-up 2860 children at the age of 4 years and 3061 children at the age of 6 years to investigate atopic diseases and allergic sensitization. Long-term exposure to fine particles with a 50% cutoff aerodynamic diameter of 2.5 μm (PM2.5), PM2.5 absorbance, and nitrogen dioxide (NO2) was assessed at residential addresses using geographic information systems-based regression models and air pollution measurements. In addition, the distance to the nearest main road was used as a surrogate for traffic-related air pollutants.
Strong positive associations were found between distances to the nearest main roads and asthmoid bronchitis, hay fever, eczema, and sensitization. A distance-dependent relationship could be identified with the highest ORs for children living less than 50 m from busy streets. For PM2.5, statistically significant effects were found for the symptoms of asthmoid bronchitis and eczema as well as for allergic sensitization to inhalant allergens due to pollen sensitization. PM2.5 absorbance was statistically associated with eczema and allergic sensitization to inhalant allergens. NO2 exposure was associated with hay fever only at 4 years of age, whereas no association was found for allergic sensitization.
In conclusion, there is a strong evidence for an increased risk of atopic diseases and allergic sensitization when children are exposed to traffic-related particulate matter during the first 6 years of life.