Influence of clouds on pre-vitamin D3 effective solar UV exposures

Parisi, Alfio V. and Turnbull, David J. and Turner, Joanna (2007) Influence of clouds on pre-vitamin D3 effective solar UV exposures. Environmental Health, 7 (3). pp. 75-83. ISSN 1444-5212

Abstract

Clouds are affected by aspects of climate change and are a major influencing factor on the pre-vitamin D3 effective solar UV (UVD3) exposures that humans receive. The aim of this research was to investigate the influence of clouds on the short wavelength cut-off of the spectral UVD3 irradiances, on the maximum of the UVD3 spectral irradiances and on the magnitude of the UVD3 irradiances. The spectral pre-vitamin D3 effective solar UV irradiances on a horizontal plane were calculated by weighting the spectral UV measured every five minutes by a spectroradiometer with the action spectrum for the synthesis of pre-vitamin D3. The short wavelength cut-off was defined as the wavelength at which the UVD3 irradiances were 0.1% of the maximum biologically damaging irradiance for that scan. Due to the higher relative effectiveness of the action spectrum at the shorter UV wavelengths, any variations will influence the UVD3 exposures and consequently has public health implications. The short wavelength cut-off, the magnitude of the irradiances and the maximum of the UVD3 spectral irradiances were investigated for a range of solar zenith angles for cloud free cases and cloudy cases. The results show that clouds do not influence the short wavelength cut-off or the wavelength at which the maximum spectral UVD3 irradiance occurs. However, cloud cover higher than 5.5 octa reduces the amount of biologically effective UV for pre-vitamin D3 production. Any changes in cloud cover will not significantly influence the short wavelength cut-off or the wavelength at which the maximum spectral UVD3 irradiance occurs. However any changes that cause the amount of cloud cover to vary between 5.5 and 8 octa or cause the cloud cover to increase above or decrease below 5.5 octa will have an effect on the UV for pre-vitamin D3 production.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Deposited in accordance with the copyright policy of the publisher (Australian Institute of Environmental Health)
Depositing User: Assoc Prof Alfio Parisi
Faculty / Department / School: Historic - Faculty of Sciences - Department of Biological and Physical Sciences
Date Deposited: 24 Oct 2007 04:37
Last Modified: 02 Jul 2013 22:52
Uncontrolled Keywords: cloud; vitamin D; climate change; UV spectral
Fields of Research (FOR2008): 11 Medical and Health Sciences > 1117 Public Health and Health Services > 111705 Environmental and Occupational Health and Safety
04 Earth Sciences > 0401 Atmospheric Sciences > 040106 Cloud Physics
04 Earth Sciences > 0401 Atmospheric Sciences > 040103 Atmospheric Radiation
Socio-Economic Objective (SEO2008): E Expanding Knowledge > 97 Expanding Knowledge > 970102 Expanding Knowledge in the Physical Sciences
URI: http://eprints.usq.edu.au/id/eprint/3419

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