[Air pollution in the daily environment: study of a school-children population]

To evaluate the annual distribution of personal exposure to NO2 in a sample of school children and to study the determinants of such exposure.

Exposure to NO2 has been evaluated using Palmes Tubes in 310 school-children (aged 5-14) in Novara. The possible differences in personal measurements by means of ANOVA and Tuckey test were evaluated. Information on the sources of potential exposure and on respiratory symptoms have been collected through a questionnaire and a clinical diary. The relative risk for these variables has been assessed using a multiple regression model (Logit).

The annual mean of the 6,200 measurements was 42.3 microgram/m3, with a significant difference among seasons and with higher values in winter. The only factor associated with a high exposure was identified for maternal school children living in houses close to high traffic density roads. Respiratory symptoms were non-related to NO2.

The use of gas cookers and heaters is not enough to explain the variability of personal exposure. Between other specific determinants, the importance of living along busy streets, of ETS and of seasons explains the level of personal exposure. The opportunity of personal, rather than environmental, monitoring is confirmed, even if we stress the necessity of studying the short-term exposure to rapidly find clinical damages in the general population.