A RECEPTOR MODEL ADAPTED TO REACTIVE SPECIES - POLYCYCLIC AROMATIC-HYDROCARBONS - EVALUATION OF SOURCE CONTRIBUTIONS IN AN OPEN URBAN SITE .1. PARTICLE COMPOUNDS

Contributions from three urban sources of PAHs: domestic heating, petrol vehicles and diesel vehicles, were evaluated for various times of year and various times of day. Contributions were calculated by chemical mass balance from histograms of six PAHs that are present in the atmosphere only in particle form. The urban site studied (Paris, France) is an open site well suited to the use of a piston reactor model. This model has been modified to take into account the differences in reactivity between the particle PAHs and adapted to conserve its linearity. The correction is brought to bear upon the histograms from measurements taken at the receptor site, and leads to the construction of virtual profiles from which the contributions of the various sources are calculated. Evidence of seasonal and hourly variations is brought out. The results are very realistic and can be compared with information about vehicle traffic density and about energy consumption. They also show that the difference observed between summer and winter concentrations is mainly due to variations in production, and not to the decay of PAHs. © 1990.