Tumours of mesothelial origin in rats following inoculation with biogenic silica fibres.

Pleural implant experiments using Sprague-Dawley rats have shown that those injected with the carcinogen 15,16-dihydro-11-methylcyclopenta[a]phenenthren-17-one (11-methyl-17-ketone) intraperitoneally followed by silica fibres intrapleurally develop mesotheliomas. These tumours were histologically similar to those induced by crocidolite alone. The intraperitoneal injection of 11-methyl-17-ketone also induced leukaemia.