Background: Short-term exposure to air pollution has adverse effects among patients with asthma, but whether long-term exposure to air pollution is a cause of adult-onset asthma is unclear.

Objective: We aimed to investigate the association between air pollution and adult onset asthma.

Methods: Asthma incidence was prospectively assessed in six European cohorts. Exposures studied were annual average concentrations at home addresses for nitrogen oxides assessed for 23,704 participants (including 1,257 incident cases) and particulate matter (PM) assessed for 17,909 participants through ESCAPE land-use regression models and traffic exposure indicators. Meta-analyses of cohort-specific logistic regression on asthma incidence were performed. Models were adjusted for age, sex, overweight, education, and smoking and included city/area within each cohort as a random effect.

Results: In this longitudinal analysis, asthma incidence was positively, but not significantly, associated with all exposure metrics, except for PM_coarse. Positive associations of borderline significance were observed for nitrogen dioxide [adjusted odds ratio (OR) = 1.10; 95% CI: 0.99, 1.21 per 10 μg/m³; p = 0.10] and nitrogen oxides (adjusted OR = 1.04; 95% CI: 0.99, 1.08 per 20 μg/m³; p = 0.08). Nonsignificant positive associations were estimated for PM₁₀ (adjusted OR = 1.04; 95% CI: 0.88, 1.23 per 10 μg/m³), PM_2.5 (adjusted OR = 1.04; 95% CI: 0.88, 1.23 per 5 μg/m³), PM_{2.5absorbance} (adjusted OR = 1.06; 95% CI: 0.95, 1.19 per 10^–5/m), traffic load (adjusted OR = 1.10; 95% CI: 0.93, 1.30 per 4 million vehicles × meters/day on major roads in a 100-m buffer), and traffic intensity (adjusted OR = 1.10; 95% CI: 0.93, 1.30 per 5,000 vehicles/day on the nearest road). A nonsignificant negative association was estimated for PM_coarse (adjusted OR = 0.98; 95% CI: 0.87, 1.14 per 5 μg/m³).

Conclusions: Results suggest a deleterious effect of ambient air pollution on asthma incidence in adults. Further research with improved personal-level exposure assessment (vs. residential exposure assessment only) and phenotypic characterization is needed.

Citation: Jacquemin B, Siroux V, Sanchez M, Carsin AE, Schikowski T, Adam M, Bellisario V, Buschka A, Bono R, Brunekreef B, Cai Y, Cirach M, Clavel-Chapelon F, Declercq C, de Marco R, de Nazelle A, Ducret-Stich RE, Ferretti VV, Gerbase MW, Hardy R, Heinrich J, Janson C, Jarvis D, Al Kanaani Z, Keidel D, Kuh D, Le Moual N, Nieuwenhuijsen MJ, Marcon A, Modig L, Pin I, Rochat T, Schindler C, Sugiri D, Stempfelet M, Temam S, Tsai MY, Varraso R, Vienneau D, Vierkötter A, Hansell AL, Krämer U, Probst-Hensch NM, Sunyer J, Künzli N, Kauffmann F. 2015. Ambient air pollution and adult asthma incidence in six European cohorts (ESCAPE). Environ Health Perspect 123:613–621;  http://dx.doi.org/10.1289/ehp.1408206

Address correspondence to B. Jacquemin, CREAL–Centre for Research in Environmental Epidemiology, Parc de Recerca Biomèdica de Barcelona, Doctor Aiguader, 88, 08003 Barcelona, Spain. Telephone: 34 93 2147359. E-mail: benedicte.jacquemin@inserm.fr

The research leading to these results was funded by the European Community’s Seventh Framework Program (FP7/2007-2011) under grant agreement no. 211250.

The cohort-specific funding and acknowledgments are listed in the supplemental material.

The authors declare they have no actual or potential competing financial interests.

Received: 31 January 2014 Accepted: 20 February 2015 Advance Publication: 24 February 2015 Final Publication: 1 June 2015

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