INVESTIGATION ON CARCINOGENIC BURDEN BY AIR-POLLUTION IN MAN .15. POLYCYCLIC AROMATIC-HYDROCARBONS IN AUTOMOBILE EXHAUST-GAS - INVENTORY

Abstract

Polycyclic aromatic hydrocarbons (PAH) emitted by 2 vehicles were separated by gas chromatography and characterized by mass spectrometry [MS] after enrichment from exhaust gas condensate. Gasoline was also investigated using this technique. The quantities of PAH with boiling points higher than 338.degree. C contained in the exhaust gas were compared to those present in the fuel. About 150 PAH were characterized by mass spectrometry; 75 of these were identified by comparison with authentic samples. Six compunds of the PAH group consisting of 4-7 rings, which are suspected of possessing carcinogenic activity, are described for the 1st time. Structures of these hitherto unidentified PAH are proposed by means of MS and UV spectral information (11H-cyclopenta(qrs)benzo(e)-pyrene, 10H-cyclopenta(mno)benzo(a)pyrene, benzo(ghi)cyclopenta(pqr)perylene and cyclopentenopyrene). According to the different PAH profiles of the fuel and exhaust gas, the main part of the PAH emitted is produced de novo during combustion in the engine and the PAH contained in the fuel are combusted for the most part.