Investigations of Laser Skin Hazards.
Final rept. 16 Mar 70-11 Jan 71,
BATTELLE MEMORIAL INST COLUMBUS OHIO
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The report considers the effect of four lasers, the argon, the Q-switched neodymium, the carbon dioxide and the Q-switched ruby laser on human skin. Two Negro and two Caucasian volunteers were exposed to each laser. Each subject received 3 or 4 different dose levels of irradiation. These dose levels were preselected by the Sponsor to explore the threshold of effect to produce minimal erythema and discomfort. After irradiation skin biopsies were taken in the first experiment - the argon laser - no change was seen immediately after exposure but some changes were evident 24 hours after the exposure. In subsequent experiments samples were taken 24 and 48 hours postirradiation. In general, changes in the skin structure were observed at 24 hours but these changes had generally disappeared at 48 hours postirradiation. Negro and Caucasian subjects were examined because the darker skin reflects less light and therefore absorbs more of the lasers energy. The degree of pigmentation was measured as reflectance prior to exposure to the laser. Author