Clearance of Benzo[a]pyrene From Hamster Lunis After Administration on Coated Particles2

Abstract

The persistence of benzo[a] pyrene (BP) in the respiratory tract of hamsters was determined after intratracheal instillation of the particulate dusts carbon, aluminum oxide, and ferric oxide (in the 4 size ranges 0.5–1, 2–5, 5–10, and 15–30µ), each coated with BP. Because the 2% dust-2% carcinogen preparations were prepared on a weight basis, density differences required that more particles of carbon than of aluminum oxide or ferric oxide be given. Analysis of the BP content of hamster lungs immediately after instillation showed that the carbon reparations contained more carcinogen. BP was cleared much more slowly from lungs of carbon-treated animals, and there was a positive correlation between particle size and retention rate. The particles of aluminum oxide and ferric oxide retarded the clearance of the carcinogen, but retention rates did not correlate with particle size. These results were discussed in relation to the pathogenesis of lung cancer in hamsters treated by intratracheal instillations.