Problem Statement: Comparisons between air pollutant concentrations measured at fixed monitoring stations and personal exposures measured over short periods show weak correlations. Nevertheless, air quality monitoring data are frequently used in epidemiological studies to characterize the exposure of urban populations. The objective of this study is to propose a method for utilizing measurements from air quality monitoring networks to estimate the exposure of groups of children whose living environments are more or less influenced by vehicle emissions. Methods: Personal exposure to PM2.5 and NO₂ was measured over 48 hours in 66 to 184 children across four French metropolitan areas (Grenoble, Nice, Toulouse, and Paris). The method involves correcting the average values of air quality monitoring network measurements using a translation coefficient. This approach is applied to contrasting groups of children, based on the amount of time they spend in urban areas more or less affected by vehicle traffic. Results: NO₂ ambient concentration measurements, on average, overestimate personal exposures; however, children living in areas affected by vehicle traffic emissions have, on average, higher exposure levels. For particulate matter, average ambient concentrations are closer to personal exposures. The translation coefficients therefore vary depending on the pollutant, the city, and the population subgroups studied. Conclusion: The results suggest that fixed sensors can be used to estimate the exposure of populations living in urban areas differently influenced by local sources of pollution. However, the use of these ambient concentration data must be adapted to the characteristics of the urban environment, the population profile, and the types of pollutants under consideration.