THE PRODUCTION OF ERYTHEMA OF THE SKIN BY EXPOSURE TO X-RAY RADIATION

¹ School of Dentistry, University of Michigan, Ann Arbor, Mich.

Experiments performed on human skin irradiated with a modern dental x-ray machine indicate that an erythema of the skin on the flexor surface of the forearm can be produced by an exposure of 600 Ma.S. ("165 r in air"). Such exposure produced an erythema on three of four patients. The least exposure required to produce an erythema on anyone in these tests was 425 Ma.S. Recognizing that the skin of the face is less sensitive to x-ray radiation than the skin on the flexor surface of the forearm and utilizing this difference in sensitivity as a safety factor, it has been recommended that no single area of the face be exposed at a 7 inch target-skin distance to more than 400 Ma.S. ("110 r in air") in any two-week period.