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Workplaces of an Italian carbon electrode factory, exposed to petroleum pitch and petroleum coke, were studied using a coupled chemical and biological approach to evaluate occupational mutagenic/carcinogenic hazards. Analytical procedures for the determination of polycyclic aromatic hydrocarbons (PAH) and Salmonella/microsome mutagenicity tests (with TA98 and TA100 strains) were performed on both industrial ingredients (pitch and coke) and airborne particulate matter of the working environment, after fractionating by sequential Soxhlet extractions with four organic solvents of increasing polarity (benzene, chloroform, methanol and acetone). The results showed: (a) the presence of extraordinarily high PAH (carcinogenic and non-carcinogenic) contents in the benzene extracts of petroleum pitch (3.6 wt% of total PAH) and of airborne particulate samples (up to 0.35 wt% of total PAH), in correlation with very high indirect (after metabolic activation) mutagenic responses of benzene extracts with strain TA98; (b) very high indirect mutagenic responses in the other extracts of the airborne particulate samples (especially with strain TA98); (c) the production during the processing at high temperatures of directly acting mutagens (without metabolic activation) which were absent in the starting materials and their release in the air of workplaces. The comparison of chemical analytical and mutagenicity data has proved to be an interesting approach for better defining the relative health hazards due to occupational exposure to potentially mutagenic/carcinogenic petroleum products.

Environmental monitoring of mutagenic/carcinogenic hazards associated with occupational exposure to bitumen fumes was performed during road paving operations. Bitumen samples were collected and analysed for polycyclic aromatic hydrocarbons (PAH) content by HPLC and for mutagenicity by the Ames test. The exposure of sixteen road workers to bitumen fumes was studied. Time-weighted average values of bitumen fumes were determined by personal samplers. PAH concentration in the air and the mutagenicity of airborne particulates were also analysed. The results showed that bitumen samples contained low levels of total PAH (microgram/g) and were not mutagenic. Environmental monitoring showed a low level of exposure to bitumen fumes, which were found to contain only trace levels of PAH and not to be mutagenic. The authors suggest that these workers' exposure to mutagenic/carcinogenic agents is low.

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The authors carried out biological monitoring of the mutagenic/carcinogenic hazards associated with exposure to bitumen fumes during paving operations, analysing some biological parameters in the urine of a group of exposed workers. The urine samples were studied for mutagenicity by the Ames test and for thioethers concentration. D-Glucaric acid urine excretion was also determined to investigate the enzymatic induction potential of bitumens. Even though, in a previous environmental monitoring phase, a low content of mutagenic/carcinogenic compounds was found in bitumen and air samples, urinary mutagenicity data of exposed workers were statistically higher than those of a group of unexposed subjects. The urinary mutagenicity increased further if exposure to bitumens was associated with cigarette smoking. Thioethers were higher only in subjects exposed simultaneously to bitumens and cigarettes. D-Glucaric acid excretion did not increase significantly. The authors think that this type of coupled environmental and biological monitoring is a valid tool for a better evaluation of the mutagenic/carcinogenic exposure to bitumens or similar complex mixtures.