An excess of electromagnetic radiation in the ultraviolet waveband can cause severe damage to skin cells and their DNA. Fortunately, various natural protection mechanisms exist, but until recently, one has been almost entirely overlooked in the dosimetric literature. New details are revealed in the latest (July 2012) edition of the journal Radiation Protection Dosimetry, which features a paper from a cross faculty team at the University of Southern Queensland, Australia.
Explanatory note regarding the abbreviations below: UPF means ultraviolet protection factor, SZA means solar zenith angle, UVR means ultraviolet radiation,
“The longer hair provides a higher UPF at the smaller SZA, but the difference between the protection provided by the longer hair compared with the shorter hair reduces with increasing SZA. Protection from UVR is provided by the facial hair; however, it is not very high, particularly at the higher SZA.”
Also see: Solar Ultraviolet Protection Provided by Human Head Hair (Photochemistry and Photobiology, Volume 85, Number 1, January/February 2009 , pp. 250-254)
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