Ultraviolet light in solar radiation is responsible for more than 600,000 malignancies each year in the United States alone, making it the most efficient environmental carcinogen known. Ultraviolet radiation-induced direct DNA damage is thought to be responsible for its initiating properties, while the promotional aspects of such radiation are poorly defined and only recently gaining attention....

Bacterial spores have been considered as microbial life that could survive interplanetary transport by natural impact processes or human spaceflight activity. Deposition of terrestrial microbes or their biosignature molecules onto the surface of Mars could negatively impact life detection experiments and planetary protection measures. Simulated Mars solar radiation, particularly the ultraviolet...

In this issue, Bogh et al. report a study that begins to address the important public health question of skin surface area and UVB exposure dose, related to erythema, necessary to achieve a given level of vitamin D status. They demonstrate the importance of baseline vitamin D status in conducting such studies. A smaller substudy suggests that skin pigment is not a barrier to vitamin D photosynt...

Radiochromic film is tested for its broad-band response to ultraviolet (UV) B (290-320 nm) and A (320 nm400 nm), visible and infrared radiation produced by a solar simulator and examined for dosimetry in ultraviolet radiation. Results show that MD-55-2 radiochromic film in solar and fluorescent light sources responds almost exclusively to broad-band UVA radiation with negligible colouration fro...

Nutr 2007;85:755-61. 14 MacfarlaneGJ,PalmerB,RoyD,AfzalC,SilmanAJ,O’Neill T.Anexcess of widespread pain among South Asians: are low levels of vitamin D implicated? Ann Rheum Dis 2005;64:1217-9. 15 AllisonTR,SymmonsDPM,BrammahT,HaynesP, RogersA, RoxbyM, et al. Musculoskeletal pain is more generalised among people from ethnic minorities than among white people in Greater Manchester. Ann Rheum Dis...

OBJECTIVES Low ultraviolet-B (UVB) radiation causes hypovitaminosis D, which is a known risk factor for multiple sclerosis (MS) and associated with MS disease activity. Our objective is to test whether vitamin D supplementation is most effective in lowering disease activity during the period of the year with low UVB radiation and consequently low serum 25-hydroxyvitamin D3 (25(OH)D3) concentrat...

background: ultraviolet (uv) radiation is divided into three regions: uva, uvb, and uvc. both the quality and quantity of solar uv radiation vary with various factors including the elevation of the sun above the horizon, as well as absorption and scattering of uv photons by molecules in the atmosphere, notably ozone and clouds. it is clear that whereas a moderate amount of uv exposure is benefi...

chemical methods ( actinometry ) depend on the measurement of the extent to which a chemical reaction occurs under the influence of uv light. two chemical actinometers have been used in this research. in one method, the mixtures of potassium peroxidisuiphate butanol solutions were irradiated for various time intervals, and ph-changes were determined. a linear relationship was observed between t...

BACKGROUND from a clinical and public health perspective, it is important to understand the influence of seasonality on the serum vitamin D level to adequately assess and interpret an individual measurement. Therefore, the aim of this study was to analyse the effects of seasonal conditions on 25-hydroxyvitamin D (25(OH)D) serum levels in a population-based cohort of older people. METHODS betw...

Multiple sclerosis and vitamin D: don't (yet) blame it on the sunshine It is all but 50 years since Sir Donald Acheson proposed a relationship between solar radiation and multiple sclerosis (Acheson et al., 1960). The subsequent discovery of the link between sunlight and vitamin D raised the potential for dietary supplementation to prevent or ameliorate the most common chronic neurologic diseas...