Summary and conclusions

Luftforureningen og luftvejseffekter hos fynske børn

This investigation was conducted on the temporal variation in admissions for respiratory disorders at the children’s hospital in Odense and their dependency on air pollution components measured in the City center of Odense during the time period 1994-99. The results show that the levels of air pollution encountered in Denmark, which are relatively low compared to central European areas, are sufficient to cause respiratory health effects in children, after controlling for season, pollen pressure, flue episodes, temperature and humidity.

For a 10 µg/m³ increase in PM₁₀ levels we observed an increase in admission for respiratory diseases of 0.99%. For NO₂ and SO₂ the corresponding figures were 1.23% and 1.49%, respectively. All these values are for the Greater Odense population with a delay (Lag time) of 3 days. For the entire population at Funen we only observed an effect for PM₁₀ and SO₂. We did not find any association to ozone in any of the analyses.

The investigation covers all admissions for respiratory disorders at the children’s hospital in Odense, which includes all children living in Funen. A weakness of the investigation is that only one measuring station is applied to the whole area. Better results are therefore expected for the population residing closest to the center of Odense.

However, many pollution components have a significant contribution from emissions far away, which are evenly distributed over large areas, when it reaches Denmark, and this will increase the usability of the pollution data for the total Funen population.

Time series studies have been used for a wide range of air pollution studies globally. The studies have usually been conducted to investigate the effect on adults, and only a few such studies have been conducted on children.

The results of the study is a weak, although significant effect of the different air pollution components TSP, NO, NO₂, NO_x og SO₂on the morbidity of children at Funen. The effect is greatest for the children living in Greater Odense, probably because of the proximity to the measuring stations. Since the yearly mean of PM₁₀ in Denmark is approximately 30µg/m³ a reduction to 20µg/m³ would be associated to a reduction of 7 to 19 saved admissions for asthma per year at Funen and accordingly 70 to 189 saved admissions nationwide, see table 25. Such a reduction in particle concentration will be associated to a reduction in acute bronchitis and phlegm with a magnitude of 97 to 193 yearly episodes at Funen and accordingly 970 to 1.931 yearly admissions nationwide.

For asthma attacks (spells of wheezing with breathlessness) the figures are in the range from 145 to 302 yearly attacks at Funen and accordingly 1.447 to 3.016 yearly admissions nationwide.