[Nitrogen dioxide and ozone exposures in a population sample from Ile-de-France]

Individual exposure to NO(2)and O(3) has been estimated in an urban population sample in southern France and the determinants identified. The present study was conducted to evaluated individual exposure to NO(2) and O(3) and to identify the environmental determinants of exposure in a larger population living in different environmental conditions.

Two hundred ninety-four volunteers were recruited from the SUVIMAX sample in Ile-de-France. The study covered 2 periods of 5 consecutive days, one in winter and the other in the fall of 1998. Passive monitors were used to estimate individual exposure and indoor concentration at the participant's dwelling. Background atmosphere concentrations were obtained for the AIRPARIF surveillance network. Single and multiple ANOVA were used for statistical analysis.

Individual exposures were low, especially for O(3) in the considered periods of time. Mean NO(2) and O(3)concentrations were 41 microg/m(3)/h and 16 microg/m(3)/h, respectively. The NO(2) individual exposure increased with the time spent in traffic and indoor concentration. The correlation coefficient between indoor and individual levels was r=0.73, and indoor concentration explained 50% of the variance in individual exposure. The site of the dwelling with regard to high traffic street, and most strongly, the presence of a gas stove influenced indoor concentration. However, mechanical air extraction decreased the mean indoor NO(2) level of the dwellings.

This study allowed identification of the environmental determinants of NO(2) exposure in an urban sample. These data, together with those obtained previously, well be used to establish an exposure matrix for NO(2).