Emanation of Hydroxyl Radicals From Human Skin

Hydroxyl radicals (OH) that emanated from the skin on the palm of the hand were detected using a novel laser-induced fluorescence system, which consisted of an ultraviolet laser system, a chamber with a sample entrance, and a detection system with a photomultiplier. When a subject placed the palm of their hand over the sampling entrance, the resultant excitation spectrum exhibited a specific increase in the region representing the resonance fluorescence signal for OH radicals. By examining seven volunteers using the system, we found that the ingestion of a vitamin C solution significantly decreased the palm to background signal ratio from 1.16±0.04 (SD) to 1.03±0.03 and that vitamin E significantly reduced the ratio from 1.14±0.09 to 1.00±0.04. These results strongly suggest that OH radicals emanate from the skin surface.