Ambient air levels and occupational exposure to benzene, toluene, and xylenes in northwestern Italy.

The purpose of this study was to determine benzene, toluene, and xylenes air pollution in two cities in Italy (Biella and Torino) having different traffic intesities and to investigate whether new environmental conditions occurred consequent to the changes of gasoline composition in Europe during the last 20 yr. Furthermore, three types of urban occupational exposure (petrol pump attendants, traffic policemen, and municipal employees) to the same hydrocarbons were compared to verify three different expected levels of exposure. Results in Biella demonstrate a direct relationship between traffic density and level of human exposure to these pollutants. Air concentrations for benzene were 2.3 micrograms/m3 in a suburban area having low traffic and 10.3 micrograms/m3 in the central area having high traffic. The comparison to trend analysis recently carried out in Torino indicates it is possible to improve the situation in the central area of Biella by adopting the same traffic limitations imposed in Torino. Personal sampling devices demonstrated that only the petrol pump attendants show, by means of a multivariate analysis, statistically significant higher levels of benzene compared to the other two professional categories, in both winter and summer. Values found in the present study for petrol pump attendants were around 1 mg/m3. Environmental and occupational exposure to benzene, toluene, and xylenes could be largely lowered by adopting preventive measures including traffic restrictions, the reduction of aromatic chemical content in gasoline, and the recovery of gasoline vapors at petrol pump stations.