[Effect of radiation emitted from personal computer terminal on urethan-induced lung tumors in mice]

Female SHR mice were injected intraperitoneally 0.2 ml of 1% solution of urethan on days 1, 8, 54 and 61 of the experiment. Beginning from day 1, they were exposed to radiation emitted from the video terminal of the EGA/PC/AT-286 (personal computer), for 1 hr, 5 times a week. The exposure was conducted with or without the Ergostar G-14 protective filter. The distance between the PC screen and the cage bottom was 38 cm. It was found during the 12 months of the experiment that the lifespan of urethan-injected animals was somewhat shorter as a result of the exposure. A significantly higher frequency of all or only malignant tumors of the lung and uterine polyps was recorded in urethan- and irradiation-treated mice than in non-irradiated controls. However, irradiation of urethan-treated animals from a filter-protected screen was followed by a significant decrease in frequency of incidence of all neoplasms and multiple tumors of the lung, as compared with those exposed to unfiltered radiation. It is suggested that long-term exposure to PC-emitted irradiation may cause slight stimulation of urethan-induced carcinogenesis of the lung. The Ergostare filter was found to make no contribution to carcinogenesis. It is also thought that the urethan dose was too large and the entire model--too rigid to adequately assess the PC influence on neoplastic formation.