Summary and conclusion

Trafik og luftvejssymptomer hos småbørn

Asthma and allergy are major public health problems. Around 7% of all Danish children suffer from asthma at school age and 15-20% suffer from asthmatic symptoms in early childhood. Internationally, air pollution, in particular from traffic, has been found to aggravate such symptoms. E.g. residence near busy roads has been found to be a risk factor

In this study we investigated possible associations between residence near busy road and incidence of lower airway symptoms in terms of wheezing, breathlessness, shortness of breath, and persistent, troublesome cough. For this we used the COPSAC (Copenhagen Prospective Study of Asthma in Childhood) cohort of 411 children followed from birth. These children have increased risk of asthma because their mothers suffer from asthma. We could relate daily symptoms recorded by the parents in the first three years of life in 338 children to presence of roads with more than 10,000 vehicles within 50 or 100 m of the residence and with the daily vehicle load within 50 or 100 m of the residence.

We found increased incidence of symptoms within these distances although with great uncertainty because of the small number of children and most associations were not statistically significant.

We have previously reported from this cohort that the incidence of symptoms is higher on days following days with high measured levels of traffic related air pollutants in the first 18 months of life among children living relatively close to the Copenhagen monitoring stations, whereas such associations were not present among children living in the periphery and outside Copenhagen County. These findings jointly support that there are relevant associations between traffic generated air pollution and lower airway symptoms and small children. Moreover, we have also found that hospital admissions for asthma among school age children appear to be associated with traffic generated air pollution. Such associations between asthma and similar symptoms among small and school age children are consistent with international findings.

Conclusion

Traffic generated air pollution appears to have health effects in children in terms of increased occurrence of asthma admissions and asthmatic symptoms in Copenhagen. However, there is still a lot of uncertainty and more research is required.