Acute short‐term effects of the inhalation of CO2 laser smoke on Syrian hamsters

Abstract. Nahhas WA, Connelly PJ, Giron DJ, Agostini HJ. Acute short-term effects of the inhalation of CO2 laser smoke on Syrian hamsters. Int J Gynecol Cancer 1991; 1: 259–262. The carbon dioxide laser is frequently used for the treatment of Human Papilloma Virus infections and intraepithelial neoplasia of the lower genital tract. There has been mounting concern about possible health hazards from inhaling the CO2 laser plume or from contact with particles of tissue or liquid produced during vaporization procedures. Five healthy young-adult female Syrian hamsters were housed in individual cages. Hamsters were selected because they were readily available, easy to maintain, lacked appreciable indigenous viral flora or infections, and were susceptible to oncogenic viruses. A special cage was constructed which allowed the hamsters to be bathed in a high concentration of lazer smoke which they were forced to inhale. Ninety-three patients underwent laser therapy for intraepithelial neoplasia or condylomata acuminata. The hamsters were exposed to laser fumes once every 11 days. At the end of the study, all animals were autopsied and samples of grossly abnormal tissue were obtained. When no gross abnormal findings were present the cheek pouches and entire respiratory tracts were removed. One animal developed an angiosarcoma. None of the hamsters had light microscopic changes of Human Papilloma Virus infection. None of the viral DNA probes used hybridized to nuclear DNA in the epithelial cells. Electron microscopy did not detect any viral inclusions. The present study did not show histopathologic changes in the exposed hamster respiratory tracts suggesting carcinogenesis, Human Papilloma Virus infection or any other acute process. The development of angiosarcoma in one animal may be viewed with concern, but is most likely incidental.