Exposure to traffic pollution: comparison between measurements and a model.

French researchers from the Building Scientific and Technical Center have produced a traffic-exposure index. To achieve this, they used an air pollution dispersion model that enabled them to calculate automobile pollutant concentrations in front of subjects' residences and places of work. Researchers used this model, which was tested at 27 Paris canyon street sites, and compared nitrogen oxides measurements obtained with passive samplers during a 6-wk period and calculations derived from the model. There was a highly significant correlation (r = .83) between the 2 series of values; their mean concentrations were not significantly different. The results suggested that the aforementioned model could be a useful epidemiological tool for the classification of city dwellers by present-or even cumulative exposure to automobile air pollution.

[Development of an exposure index of air pollution caused by motor vehicles for use in epidemiological studies]. / Elaboration d'un indice d'exposition a la pollution atmospherique d'origine automobile a l'usage des etudes epidemiologiques.

Air pollution due to motor vehicles is a worrying issue, in particular in the urban environment, all the more as a number of pollutants such as benzene and PAH are known to have carcinogenic effects. Epidemiological studies seem to be required, so a cumulated score of exposure must be developed. A correlation with pathology should be investigated. The calculation of an index of exposure to motor vehicle-related pollution requires a good assessment of pollutant emissions and a precise knowledge of pollutant transfer mechanisms by advection and spreading in built-up areas. In this study, it is proposed to use current theoretical and experimental knowledge to develop a calculation algorithm for this index. The following issues will be addressed in the presentation: an analysis of epidemiological requirements and of constraints of data acquisition using questionnaire surveys; a model for assessing, for each residential area, the average annual concentration of gaseous pollutants from motor vehicles. It will consider the environment geometry, traffic emissions and wind distributions. The model CALINE3 is used for open areas near roads and highways and the Danish model OSPM is introduced for street canyon environments.