Use of personal passive samplers for measurement of NO2, NO, and O3 levels in panel studies

We measured personal exposure to nitrogen dioxide (NO2), nitrogen monoxide (NO), and ozone (O-3), using personal passive samplers during three 4-day periods, in a panel study of asthmatics continuing the normal activities of everyday life, Fifty-five adults, mean age 42 years, 53% men, and 39 children, mean age 11 years, 67% boys,wore two Ogawa passive samplers simultaneously: one for O-3, the other for NO2 and NO. Mean outdoor pollution was measured at a regional monitoring network, Personal exposure levels were scattered; they were (on average) higher than stationary-site levels for NO and lower for NO2 and O-3. In adults, 41% of the variance of personal exposure to NO2 was explained by mean stationary-site measurement levels (P < 0.0001), Twenty-one percent additional variance was explained by living near a main road, not having an extractor fan over the cooker, older age, and male sex. NO and O-3 personal exposures correlated poorly with stationary-site measurements. In panel studies of the health effects of air pollution, personal exposure to NO2 and NO can be measured satisfactorily by passive samplers: such measurements are necessary for NO but not for NO2, For O-3, accurate personal exposure measurement remains a challenge and further technical development is required. (C) 1999 Academic Press.