Ozone measurement with passive samplers: Validation and use for ozone pollution assessment in Montpellier, France

The objective of this pilot study was to determine a way of assessing personal exposure to ozone (O-3) for use in a study of O-3 effects on health. Passive samplers (Passam, AG) were used to measure pollution levels in Montpellier, France. They were standardized using an O-3 analyzer. Blanks and duplicates were tested to evaluate sensitivity (6.6 mu g/ m(3)) and imprecision (2 mu g/m(3)). They were validated by comparing on-site measurements with those of the automatic UV absorption analyzers of the regional air quality network (AMPADI-LR). The correlation coefficient was r = 0.9, p < 10(-3), and the regression coefficient was close to 1. The on-site measurements provided information about local pollution. Distance from NO2 sources turban traffic) and sunlight intensity were identified as environmental determinants of O-3 pollution. Residential microenvironmental concentrations and personal exposure were measured for 110 subjects. The indoor/outdoor ratio is higher than in Mexico City and higher than in Toronto in summer but comparable with that in Toronto in winter. The relationship between personal exposure and indoor home measurements is closer than that between personal exposure and outdoor home environment measurements. This is especially true for the spring and summer months, when the correlation between indoor and outdoor measurements is low (r = 0.23, p < 0.05). At the workplace, on the other hand, there is a close correlation between indoor and outdoor ozone measurements in summer (r = 0.80, p < 0.001), as there is between personal exposure and outdoor measurements (r = 0.60, p < 0.001).