Epidemiological, clinical and laboratory studies have implicated solar ultraviolet (UV) radiation as a tumor initiator, tumor promoter and complete carcinogen, and their excessive exposure can lead to the development of various skin disorders including melanoma and nonmelanoma skin cancers. Sunscreens are useful, but their protection is not adequate to prevent the risk of UV-induced skin cancer...

Only small amounts of vitamin D come from dietary sources as it is mainly synthesised in the skin from the ultraviolet B (UVB) fraction of sunlight if the person is sufficiently exposed to direct sunlight. Vitamin D deficiency has been well documented in Oman. The "2004 Oman National Micronutrients Survey" and other recent studies revealed that vitamin D3 stores are low among healthy Omani fema...

Exposure to ultraviolet radiation is an important risk factor for skin cancer. The Global Solar Ultraviolet Index (UVI) was developed as a tool to visualize the amount of harmful radiation and to encourage people to use sun protection. We conducted a systematic review of the effectiveness of the UVI. We employed a comprehensive search strategy to explore the impact of the UVI on five outcome ca...

An atmospheric radiation model is used to study the combined effects of ozone depletions/redistributions and particulate clouds on atmospheric heating/photolysis rates and ultraviolet radiation reaching the biosphere. Four types of particulate clouds prevalent in the summertime Arctic are considered: stratospheric aerosols, tropospheric aerosols (Arctic haze), cirrus clouds, and stratus clouds....

Multiple sclerosis (MS) is a chronic disease of the central nervous system, pathologically characterized by inflammation, demyelination, and axonal damage, presumably auto-immune in nature. Complex interactions between genetic susceptibility and environmental factors, such as vitamin D status and primary Epstein-Barr virus infection in adolescence or later in life, probably determine the MS ris...

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....

Sun exposure is today well recognized as having an adverse effect on human skin. Part of sun radiation, ultraviolet radiation A (UVA) and B (UVB), can modify skin structures and induce short-term skin changes (sunburn, tanning, hyperkeratinization, brown spots) and long-term skin damages (accelerated skin aging and skin cancers). Protection against both UVA and UVB is very important, therefore ...

Radiation pressure cross-sections for clumps of hollow bacterial grains with thin coatings of graphite are calculated using rigorous Guttler formulae. The carbonized skins are expected to form through exposure to solar ultraviolet radiation, but a limiting thickness of about 0.03 μm is determined by opacity effects. The ratios of radiation pressure to gravity P/G are calculated for varying size...

this paper presents the current activities on radiation protection in iran. according to the atomic energy organization law of iran the radiological safety is ascribed to the atomic energy organization of iran (a e o i) and the radiation protection department (r p d) is the responsible organ within aeoi. r p d since it's establishment in 1975, with the aim to ensure the protection of man and hi...