Erythema induced by quartz-halogen sources

The erythemal effect of 100-W quartz-halogen sources, previously predicted from radiation measurements, was directly measured on humans at a distance of 10 cm. Minimal erythema was produced in 15 min for skin type I. These data show that normal use of a desktop lamp should not usually lead to erythema in one day, but that long-term effects cannot be ignored, because for lifetime use at work, the relative risk for squamous cell carcinoma on the back of the hands is 3.4.