[Short-term effects of ozone on respiratory health of children in Armentières, North of France].

Background: We studied short-term respiratory effects of ozone in a panel of 91 ten-year old children from a school in Armentières, North of France.

Methods: Each child reported twice daily peak expiratory flow rate measurements (mini-Wright) and daily occurrence of respiratory symptoms, from April 1, 1996 to June 30, 1996. Outdoor ozone measurements were obtained from a continuous fixed monitor, located at 850 meters from the school. Ozone effect was examined by regression models, using generalized estimating equations (GEE), with time and weather covariates.

Results: A 30 mg/m(3) increase in the daily maximum 8-hour mean level of ozone was associated with a 1.91 L x min(-1) decrement in evening peak expiratory flow (95% confidence interval [-0.02; 3.84]) and with increased daily prevalence of cough (odds ratio=1.17, 95% confidence interval [0.97; 1.40]), whereas ozone levels stayed moderate (1-hour level<180 microg/m(3)) during the study period.

Conclusion: These results suggest that moderate levels of ozone have still an effect on children's lung.