Table 3.

Studies evaluating adult onset asthma on exposure to air pollution

Castro-Giner et al. [43]	Sweden, UK, Spain Barcelona, Germany, France, Paris, Belgium	Exposures to NO2 at each of the participants’ addresses were determined using air pollution maps using focal sum techniques in a global information system model.	20–44 years	NO2	No significant association between NO2 exposure and development of asthma. Significant association between development of asthma and NO2 exposure in those carrying NQO1 rs2917666 genotype.
Lindgren et al. [44]	Sweden	Self-reported exposure to traffic, traffic intensity within 100 m, modeled exposure to NOxusing modified Gaussian dispersion model.	18–77 years	NOx	Asthma diagnosis was associated with living within 100 m of a road with greater than 10 cars/min. Participants with high exposure to NOx (> 19 μg/m3) had increased odds ratio for asthma symptoms but not diagnosis.
Lindgren et al. [45]	Sweden	Self-reported exposure to traffic, traffic intensity within 100 m, modeled exposure to NOx using modified Gaussian dispersion model.	18–77 years	NOx	Increased prevalence of allergic asthma was seen for participants living within 100 m of a road with greater than 10 cars/min but not for non-allergic asthma. No statistical significance of allergic and non-allergic asthma prevalence on exposure to NOx at various concentrations.