VEHICLE EMISSIONS, URBAN AIR-QUALITY AND CURRENT ITALIAN LEGISLATION - THE CASE OF MESSINA .2.

In a continuing programme to evaluate the urban air quality of the cit y of Messina, a research has been carried out to determine polycyclic aromatic hydrocarbons by means of a continuous analyzer, sulphur dioxi de, nitrogen dioxide, ozone, benzene, toluene, nitrous acid and formal dehyde by Differential Optical Absorption Spectroscopy in order to con trol the compliance with the Italian legislation. These preliminary re sults arise some hygienic preoccupation due to the amount of carcinoge nic hydrocarbons obtained with the consequent possibility of stopping totally or partially urban traffic. The values obtained for sulphur di oxide and nitrogen dioxide were as expected, while ozone concentration was found much higher than earlier determination; the other pollutant s has been determined for the first time. A singular behaviour has bee n registered for nitrous acid which may be explained by considering th e effective operational conditions.