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The Fitzpatrick scale is not sufficient to precisely estimate the minimum radiation dose needed for sunburn. Research has found broad variation within and between populations, e.g. for skin type V subjects the MED in the US is 60–100 mJ/cm 2 vs. 120–240 mJ/cm 2 in Taiwan. [ 29 ]
UVA can generate highly reactive chemical intermediates, such as hydroxyl and oxygen radicals, which in turn can damage DNA. The DNA damage caused indirectly to skin by UVA consists mostly of single-strand breaks in DNA, while the damage caused by UVB includes direct formation of thymine dimers or cytosine dimers and double-strand DNA breakage ...
The UVA seal used in the EU A tube of SPF 15 sun lotion. As part of revised guidelines for sunscreens in the EU, there is a requirement to provide the consumer with a minimum level of UVA protection in relation to the SPF. This should be a UVA protection factor of at least 1/3 of the SPF to carry the UVA seal. [87]
The Fitzpatrick scale (also Fitzpatrick skin typing test; or Fitzpatrick phototyping scale) is a numerical classification schema for human skin color. It was developed in 1975 by American dermatologist Thomas B. Fitzpatrick as a way to estimate the response of different types of skin to ultraviolet (UV) light. [ 2 ]
Scale; Wavelength pm picometer 1 ... UVA, UVB, and UVC. UV is the lowest energy range energetic enough to ionize atoms, separating electrons from them, ...
UV swimwear. Sun protective clothing is clothing specifically designed for sun protection and is produced from a fabric rated for its level of ultraviolet (UV) protection. A novel weave structure and denier (related to thread count per inch) may produce sun protective properties.
UVA is the safest of the three spectra of UV light, although high exposure to UVA has been linked to the development of skin cancer in humans. The relatively low energy of UVA light does not cause sunburn. It can damage collagen fibers, so may accelerate skin aging and cause wrinkles. It can also degrade vitamin A in the skin.
Skin darkening from UVA exposure does not lead to significantly increased production of melanin or protection against sunburn. [9] In the second process, triggered primarily by UVB, there is an increase in production of melanin (melanogenesis), [ 10 ] which is the body's reaction to direct DNA photodamage (formation of pyrimidine dimers ) from ...