Evaluation du risque dʹexposition aux composés aromatiques en milieu extra-urbain à forte circulation routière

A study was performed to assess road traffic pollution under extra-urban conditions, in the Susa Valley (Turin Province, Italy) for the Piedmont Regional Authorities by I.P.L.A. and L.S.P. Grugliasco. It concerns air contamination by volatile organic compounds. The Turin-Frejus highway and two national roads to Mont Cenis (SS 25) and to Montgenèvre (SS 24) run across this valley. The use of road traffic data recorded, and of unit emissions given in the literature, allowed to assess daily emissions in a number of sites in the valley with respect to determined trip units. Toluene, benzene, total hydrocarbons (HC) were considered. At the same time, monitoring studies were performed to assess volatile organic compounds in the air using the following techniques: direct sampling bags; adsorption and concentration using activated charcoal cartridges; cryofocussing and chromatographic analysis. Cryofocussing was used to obtain a very high analytical sensitivity as related to individual compounds. Sampling sites were located as follows: four locations along the roads in the valley bottom and a reference location in altitude. In short the results seem to show: high concentrations of aromatic hydrocarbons in the air; significant correlation between measured concentration ratios for different pollutants; high exposure risk to benzene for resident population or people working in sites located near heavy traffic roads. The authors propose to develop this study using possible correlations between air quality and running vehicle characterization.