NEOPLASTIC TRANSFORMATION OF NEONATAL HUMAN FIBROBLASTS EXPOSED IN-VITRO TO RADIATION FROM A QUARTZ-HALOGEN LAMP

The use of unfiltered quartz-halogen lamps exposes human skin to radia tion that spans much of the ultraviolet (UV) spectrum. Reports indicat e that exposure to quartz-halogen lamps is erythemogenic, mutagenic, a nd carcinogenic. To compare the carcinogenic potential of quartz-halog en lamps with that of other UV sources, we determined the dose depende nce for cytotoxicity and neoplastic transformation in neonatal human f ibroblasts exposed in vitro to: a 15 W germicidal lamp (primarily 254 MI radiation), a 15 W Cool White fluorescent lamp, and an unfiltered 2 0 W quartz-halogen lamp. Fluence-survival relationships were multiphas ic with linear dose response below about 40% survival, and all three s ources produced fluence-dependent transformation as indicated by induc tion of anchorage-independent growth. Maximum transformation frequenci es were observed at fluences of 5-8 J/m(2) for the germicidal lamp, 6. 3 kJ/m(2) for the fluorescent lamp, and 300 J/m(2) for the quartz-halo gen lamp. These data confirm the carcinogenic potential of the quartz- halogen lamp.