ORIGINAL ARTICLE

NO₂, as a marker of air pollution, and recurrent wheezing in children: a nested case-control study within the BAMSE birth cohort

G Emenius¹, G Pershagen², N Berglind¹, H-J Kwon², M Lewné¹, S L Nordvall³, M Wickman¹

¹ Department of Environmental Health, Stockholm County Council, Sweden
² Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden
³ Department of Women’s and Children’s Health, Uppsala University, Sweden

Correspondence to:
Correspondence to:
Dr G Emenius
Department of Environmental Health, Norrbacka 3rd floor, Karolinska Hospital, SE-171 76 Stockholm, Sweden; gunnel.emenius{at}smd.sll.se

Aims: To investigate the association between air pollution, including with NO₂, and recurrent wheezing during the first two years of life.

Methods: A birth cohort (BAMSE) comprised 4089 children, for whom information on exposures, symptoms, and diseases was available from parental questionnaires at ages 2 months, and 1 and 2 years. NO₂ was measured during four weeks in and outside the dwellings of children with recurrent wheezing and two age matched controls, in a nested case-control study (540 children).

Results: Conditional logistic regression showed an OR of 1.60 (95% CI 0.78 to 3.26) among children in the highest quartile of outdoor NO₂ exposure in relation to those in the lowest quartile, adjusted for potential confounders. The corresponding OR for indoor NO₂ was 1.51 (95% CI 0.81 to 2.82). An interaction with environmental tobacco smoke (ETS) was indicated with an OR of 3.10 (95% CI 1.32 to 7.30) among children exposed to the highest quartile of indoor NO₂ and ETS. The association between NO₂ and recurrent wheezing appeared stronger in children who did not fulfil the criteria for recurrent wheezing until their second year.

Conclusions: Although the odds of increased recurrent wheezing are not statistically significantly different from one, results suggest that exposure to air pollution including NO₂, particularly in combination with exposure to ETS, increases the risk of recurrent wheezing in children.

Keywords: NO2, wheezing, asthma, air quality

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

• Jacquemin, B., Sunyer, J., Forsberg, B., Aguilera, I., Bouso, L., Briggs, D., de Marco, R., Garcia-Esteban, R., Heinrich, J., Jarvis, D., Maldonado, J. A., Payo, F., Rage, E., Vienneau, D., Kunzli, N. (2009). Association between modelled traffic-related air pollution and asthma score in the ECRHS. Eur Respir J 34: 834-842 [Abstract] [Full Text]  
• Weichenthal, S., Dufresne, A., Infante-Rivard, C. (2007). Review: Indoor Nitrogen Dioxide and VOC Exposures: Summary of Evidence for an Association with Childhood Asthma and a Case for the Inclusion of Indoor Ultrafine Particle Measures in Future Studies. Indoor and Built Environment 16: 387-399 [Abstract]  
• Osman, L. M., Douglas, J. G., Garden, C., Reglitz, K., Lyon, J., Gordon, S., Ayres, J. G. (2007). Indoor Air Quality in Homes of Patients with Chronic Obstructive Pulmonary Disease. Am. J. Respir. Crit. Care Med. 176: 465-472 [Abstract] [Full Text]  
• Houston, D., Ong, P., Wu, J., Winer, A. (2006). Proximity of Licensed Child Care Facilities to Near-Roadway Vehicle Pollution. AJPH 96: 1611-1617 [Abstract] [Full Text]  
• (2004). Lucina. Arch. Dis. Child. 89: 592-592 [Full Text]