Effects of Mode of Generation on the Composition of Asphalt Fumes

Abstract

Abstract Asphalt is used as the binder (cement) in road paving, and in the manufacture and application of roofing materials. At the elevated temperatures used in these industries, asphalt emits fumes. Concerns about the possible presence of carcinogenic PACs in asphalt fumes prompted the National Institute of Occupational Safety and Health (NIOSH) to sponsor two mouse skin-painting bioassays[1,2] of roofing asphalt fumes laboratory generated at 232° and 316°C. The studies showed that the whole fume condensates and two of five HPLC subfractions of the higher temperature fume were carcinogenic. The present investigation was designed to determine the extent to which NIOSH's mode of fume generation affected their composition, and hence biological activity. The results show that minor changes in generation mode produce marked differences in fume composition. Relative to field fumes, the laboratory-generated fumes were significantly enriched in higher molecular weight PACs associated with carcinogenicity in animal studies.