Ambient air pollution triggers wheezing symptoms in infants
- 1Department of Biostatistics, University of Copenhagen, Copenhagen, Denmark
- 2Department of Environmental and Occupational Health, Copenhagen University, Copenhagen, Denmark
- 3Department of Atmospheric Environment, National Environmental Research Institute, Aarhus University, Denmark
- 4Danish Paediatric Asthma Centre, Copenhagen University Hospital, Gentofte, Copenhagen
- Mrs Z J Andersen, Department of Biostatistics, Institute of Public Health, Copenhagen University, Øster Farimagsgade 5 Entr. B, P O Box 2099, 1014 Copenhagen K, Denmark; zorana{at}cancer.dk
- Received 12 June 2007
- Accepted 16 January 2008
- Published Online First 11 February 2008
Abstract
Background: There is limited evidence for the role of air pollution in the development and triggering of wheezing symptoms in young children. A study was undertaken to examine the effect of exposure to air pollution on wheezing symptoms in children under the age of 3 years with genetic susceptibility to asthma.
Methods: Daily recordings of symptoms were obtained for 205 children participating in the birth cohort study Copenhagen Prospective Study on Asthma in Children and living in Copenhagen for the first 3 years of life. Daily air pollution levels for particulate matter <10 μm in diameter (PM10) and the concentrations of ultrafine particles, nitrogen dioxide (NO2), nitrogen oxide (NOx) and carbon monoxide (CO) were available from a central background monitoring station in Copenhagen. The association between incident wheezing symptoms and air pollution on the concurrent and previous 4 days was estimated by a logistic regression model (generalised estimating equation) controlling for temperature, season, gender, age, exposure to smoking and paternal history of asthma.
Results: Significant positive associations were found between concentrations of PM10, NO2, NOx, CO and wheezing symptoms in infants (aged 0–1 year) with a delay of 3–4 days. Only the traffic-related gases (NO2, NOx) showed significant effects throughout the 3 years of life, albeit attenuating after the age of 1 year.
Conclusions: Air pollution related to traffic is significantly associated with triggering of wheezing symptoms in the first 3 years of life.
Footnotes
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Funding: The statistical analyses were supported by the Danish Research Council grant number 2052-03-16, AIRPOLIFE (Air Pollution in a Life Time Health Perspective) and the Danish Environmental Protection Agency. The COPSAC cohort study is funded by research funds from the Pharmacy Foundation of 1991; the Lundbeck Foundation; the Augustinus Foundation; Ronald McDonald House Charities; the Danish Medical Research Council; the Danish Pediatric Asthma Center; Direktør, cand. pharm. K Gad Andersen og Hustrus Familiefond; Aage Bangs Fond; Danish Lung Association; Kai Lange og Gunhild Kai Langes Fond; Direktør Ib Henriksens Fond; Gerda og Aage Hensch’s Fond; Rosalie Petersens Fond; Hans og Nora Buchards Fond; Dagmar Marshalls Fond; Foundation of Queen Louise Children Hospital; the Danish Hospital Foundation for Medical Research, Region of Copenhagen, the Faroe Island and Greenland; Gangsted Fond; Højmosegård-Legatet; Fonden til Lægevidenskabens Fremme; A P Møller og Hustru Chastine Mc-Kinney Møllers Fond til almene Formaal; The Danish Ministry of the Interior and Health’s Research Centre for Environmental Health. The study received support from the following pharmaceutical companies: AstraZenaca; LEOpharma; Pharmacia-Pfizer and Yamanouchi Pharma.
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Competing interests: None.
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Ethics approval: The COPSAC study was conducted in accordance with the Declaration of Helsinki and approved by the Copenhagen Ethics Committee and the Danish Data Protection Agency.
