Ambient air pollution triggers wheezing symptoms in infants

Thorax. 2008 Aug;63(8):710-6. Andersen ZJ, Loft S, Ketzel M, Stage M, Scheike T, Hermansen MN, Bisgaard H. Department of Biostatistics, Institute of Public Health, Copenhagen University, Øster Farimagsgade 5 Entr. B, P O Box 2099, 1014 Copenhagen K, Denmark.

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 microm in diameter (PM(10)) and the concentrations of ultrafine particles, nitrogen dioxide (NO(2)), nitrogen oxide (NO(x)) 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 PM(10), NO(2), NO(x), CO and wheezing symptoms in infants (aged 0-1 year) with a delay of 3-4 days. Only the traffic-related gases (NO(2), NO(x)) 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.




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