Scattered UV radiation, shade structures and Vitamin D

Turnbull, David J. and Parisi, Alfio (2007) Scattered UV radiation, shade structures and Vitamin D. In: 12th Congress of the European Society for Photobiology, 1-6 Sep 2007, Bath, England.


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The health effects of solar UV radiation vary significantly, from assisting calcium absorption in humans due to the initiation of the synthesis of vitamin D3 to the severe degradation of body tissue. The good effects are relatively few, but they are essential to the well being of humans. It is well known that exposure to small amounts of UVB (280 to 315 nm) radiation are beneficial for the human body and important in the production of vitamin D3, whereas excessive exposure to UVB and UVA (315 to 400 nm) is known to cause skin cancer, DNA damage, immune suppression, erythema and sun-related eye disorders. It is estimated that approximately 90-95% of our vitamin D3 requirement comes from exposure to the sun. Studies on the levels of UV measured in the shade of different shade environments have shown that the ratios of UVB to UVA in the shade are significantly different to that in full sun. The ratio of UVB to UVA is higher in the shade than in full sun. These differences are due to the phenomena of Rayleigh scattering (-4) and Mie scattering (-1) in the atmosphere, which causes greater scattering at the shorter UVB wavelengths compared to that at the longer wavelength UVA. Therefore, certain shaded environments may hold the effective wavelengths needed for vitamin D3 production in the body, but not the high levels of UVA experienced in full sun. At certain latitudes and solar zenith angles, unprotected exposure for short periods to the UVB under shade structures may be the best course of action as it will contribute more toward vitamin D production than toward erythema compared to exposing the body to full sun UV due to the reduced relative component of the UVA in the shade.

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Item Type: Conference or Workshop Item (Commonwealth Reporting Category E) (Poster)
Refereed: No
Item Status: Live Archive
Faculty/School / Institute/Centre: Historic - Faculty of Sciences - Department of Biological and Physical Sciences (Up to 30 Jun 2013)
Faculty/School / Institute/Centre: Historic - Faculty of Sciences - Department of Biological and Physical Sciences (Up to 30 Jun 2013)
Date Deposited: 02 Nov 2007 11:19
Last Modified: 02 Jul 2013 22:49
Uncontrolled Keywords: Shade, vitamin D, ultraviolet radiation
Fields of Research (2008): 11 Medical and Health Sciences > 1117 Public Health and Health Services > 111705 Environmental and Occupational Health and Safety
10 Technology > 1002 Environmental Biotechnology > 100204 Environmental Biotechnology Diagnostics (incl. Biosensors)

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