The Transmittance of UVA and UVB on Human Epidermis

Choi, Yoo Won; Kang, Hyung Chul

Abstract

BACKGROUND: Ultraviolet light induces sunburn, ageing of the skin, pigmentation and even promotes skin cancers. As there has been a recent decrease in the ozone layer surrounding the earth, increasing attention has been given to the effects of ultraviolet light on the skin. Through human epidermis, ultraviolet light is reflected, scattered, absorbed or transmitted. In caucacians, the rate of transmitted ultraviolet light A from the epidermis to the dermis is 50% and the rate of transmitted ultraviolet light B is below 10%.
OBJECTIVE
The purpose of this study was to evaluate the transmittance of UVA and UVB on Korean normal epidermis.
METHODS
Pure epidermis was obtained from normal human epidermis by suction of blisters in 12 patients with vitiligo. All specimens were irradiated respectively with UVA and UVB and the amount of transmitted energy was measured.
RESULTS
1. The transmittance of UVA energy density by normal epidermis was 47.7+11.2% of irradiated UVA energy. 2. The transmittance of UVB energy density by normal epidermis was 32.4+3.4% of irradiated UVB energy.
CONCLUSION
UVA energy transmission through normal epidermis of Korean is less than those of Caucacians but UVB energy transmission through nor mal epidermis of Korean is more than those of Caucacians. It is suggested that this could be an important basic data to study for photoaging and photoprotection in Korean population.