INDUCTION OF MICRONUCLEI IN CULTURED-MAMMALIAN-CELLS BY FUME CONDENSATES OF ROOFING ASPHALT

A considerable number of workers in the United States are employed in asphalt industries and are potentially exposed to asphalt fumes. The i nformation regarding the potential carcinogenic hazards of such fumes to exposed workers is still limited, Studies have been conducted to de termine the cytogenetic effects of roofing asphalt fume using cultured mammalian cells. Exponentially growing Chinese hamster lung fibroblas ts (V79 cells) were exposed to different concentrations of condensates of type I and type III roofing asphalt fumes, generated at temperatur es similar to actual roofing operation (316 +/- 10 degrees C). The fre quencies of micronucleated cells in the treated and control cultures w ere determined, Additionally immunofluorescent staining of kinetochore with human anti-kinetochore primary antibody and flouresceinated goat anti-human Ige was used to investigate the potential mechanism of mic ronucleus formation. The results show that both types of roofing aspha lt fume condensates caused a significant increase in the frequency of micronucleated cells, and that 70% of micronucleated cells induced by asphalt fume condensates carried kinetochore-positive micronuclei. The se findings indicate that both type I and type III roofing asphalt fum es are capable of causing principally cytogenetic damage by spindle ap paratus alterations in cultured mammalian cells. (C) 1996 Wiley-Liss, Inc.