Collection, validation and generation of bitumen fumes for inhalation studies in rats

In this study, personal exposure samples were collected in order to validate bitumen fume condensate to be used for inhalation toxicity studies in rats. Three different laboratories analyzed personal and static samples taken at road paving worksites by different methods. Parameters determined were: Total Particulate Matter (TPM), Benzene Soluble Matter (BSM), Semivolatiles (SV), Total Organic Matter (TOM), Boiling Point Distribution (BPD), Polycyclic Aromatic Hydrocarbons (PAHs) and UV Fluorescence. Different sampling methods were used to allow comparison of the standard German sampling method for bitumen fumes with other commonly used methods. In order to collect a sufficient amount of bitumen fume condensate for the study, a collecting procedure was developed that allowed sampling of the fume from bitumen tanks in an operational asphalt mixing plant. The sampling procedure has been optimized to collect material that matches the composition of workplace samples as closely as possible. The validation procedure has been performed using parameters that could be analyzed in both the workplace samples and the bitumen fume condensate collected from the tanks. Boiling Point Distribution, UV Fluorescence intensity and content of individual PAHs were selected as parameters. As a result, approximately 16 liters of bitumen fume condensate with parameters very close to the workplace samples have been collected. A laboratory setup for regeneration of airborne fume at three different concentrations, but with a composition similar to that of the bitumen fume condensate was developed and successfully tested.