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Cancer
Published in Sally Robinson, Priorities for Health Promotion and Public Health, 2021
Ultraviolet (UV) radiation, from the sun (solar radiation) or sunbeds, causes skin cancer. The radiation damages the skin cells and the mutated cells replicate. Sunburn means the skin may feel tender or itchy, and fair skin may turn pink or red – a tan is a sign of damage. If someone gets sunburnt once every two years, it triples their risk of developing skin melanoma (Cancer Research UK, 2019).
Introduction to Cancer
Published in David E. Thurston, Ilona Pysz, Chemistry and Pharmacology of Anticancer Drugs, 2021
The UV band, which is invisible to the human eye, constitutes one component of the spectrum of sunlight and represents approximately 3% of all the solar radiation reaching the Earth’s surface. Three types of UV light have been identified. One of these, UV-C (200 to 290 nm), is generally thought to be the most carcinogenic. UV-B (290 to 320 nm) causes the most sunburn, and UV-A (320 to 400 nm), which can be up to 1,000 times stronger than UV-B, is able to penetrate underlying tissues of the skin leading to “photo-aging” damage. For many years it was thought that UV-A could not cause any lasting damage. However, more recent studies strongly suggest that it may also enhance the development of skin cancers. Fortunately, the ozone layer absorbs most of the more carcinogenic UV-C radiation, although there is presently concern that depletion of the ozone layer through the release of chlorofluorocarbons used in the air conditioner and refrigeration industries and in the production of Styrofoam insulation may increase the intensity of UV-C at the Earth’s surface in the future. UV radiation occurs at a similar wavelength to the region of maximum absorbance by DNA (i.e., 260 nm), and the major damage is intrastrand covalent linkage of adjacent pyrimidines (usually thymines) to form so-called thymine dimers. These thymine dimers create distortions in the DNA helix and can block replication and transcription, thus leading to tumorigenesis.
The Integumentary (Dermatologic) System and Its Disorders
Published in Walter F. Stanaszek, Mary J. Stanaszek, Robert J. Holt, Steven Strauss, Understanding Medical Terms, 2020
Walter F. Stanaszek, Mary J. Stanaszek, Robert J. Holt, Steven Strauss
A number of skin changes and disorders are caused by exposure to ultraviolet radiation from the sun. The sunburn reaction is a complex inflammatory process, including swelling and capillary leakage. Skin cancer is also known to be caused by solar radiation, as are degenerative changes of the skin such as wrinkling, keratoses, telangiectasia, and atrophy. Cutaneous photosensitivity is a general term for any abnormal reaction of the skin to the stimulus of light. A large number of chemicals, including many drugs, also can produce this reaction.
Occupational variation in the incidence of lip cancer in the Nordic countries
Published in Acta Oncologica, 2023
Rayan Mroueh, Timo Carpén, Antti Mäkitie, Johnni Hansen, Sanna Heikkinen, Elsebeth Lynge, Jan Ivar Martinsen, Jenny Selander, Ingrid Sivesind Mehlum, Jóhanna Eyrún Torfadottir, Tuula Salo, Eero Pukkala
The most obvious risk factor for the increased risk associated with these outdoor occupations is the carcinogenic effect of the UVA and UVB components of ultraviolet radiation, as seen in non-melanoma skin cancer [26]. This rationale is also supported by the observation that lip cancer occurs rarely on the upper lip, and most frequently on the lower lip which receives considerably more direct sunlight than the upper lip [8,12,27]. An excess incidence of lip cancer has been observed in rural areas, where the proportion of outdoor workers is higher [27–30]. In Finland, a three-fold risk of lip cancer was described for people living in municipalities where agricultural livelihood contributed to more than 70% of livelihood when compared to areas where less than 2% of livelihood stemmed from agriculture [30]. Still, the disease risk could emanate from an interplay of chronic solar radiation along with cumulative carcinogenic exposure to other potential risk factors, such as tobacco. Corroborative of this theory is the study by Lindqvist et al. [14] who evaluated 290 lip cancer patients employing a questionnaire survey. While the RRs of lip cancer for outdoor workers and smokers were 1.4 and 2.0, respectively, when compared to other patients with skin squamous cell carcinoma of the head and neck, together these two risk factors induced a significant 15.4-fold increased risk of lip cancer.
Photoprotective effect of solid lipid nanoparticles of rutin against UVB radiation damage on skin biopsies and tissue-engineered skin
Published in Journal of Microencapsulation, 2022
Rodrigo Molina Martins, Silvia de Siqueira Martins, Gustavo Luis Ferreira Barbosa, Maria José Vieira Fonseca, Patrick J. Rochette, Véronique J. Moulin, Luis Alexandre Pedro de Freitas
Excessive solar radiation exposure can lead to skin cell DNA damage by ultraviolet rays’ action (280–400 nm) being able to cause photoaging and carcinogenesis (Gromkowska-Kępka et al. 2021). Ultraviolet B (UVB) radiation (280–315 nm) can cause acute problems, such as skin inflammation, photodamage, and photoaging (Chen et al. 2019, Mhamdi-Ghodbania et al. 2021). UVB radiation is directly absorbed by the DNA leading to the formation of covalent bonds between adjacent pyrimidines. This induces the formation of cyclobutane pyrimidine dimers (CPDs), which activate multiple cell signalling pathways protecting cells from their deleterious effect (Marabini et al. 2020, Hegedűs et al. 2021). Repeated UVB exposure to the epidermis elicits a fail-safe mechanism as evidenced by the formation of sunburn cells, representing keratinocytes undergoing apoptosis (Ferreira et al. 2020, Soetrisno et al. 2020). UVB radiation can also induce lipid peroxidation, which in turn leads to the formation of reactive aldehydes that attack several inter- and intracellular targets (Daré et al. 2020, Jastrząb et al. 2021). Moreover, the UV-induced reactive oxygen species (ROS) can stimulate extracellular matrix degradation through the activation of matrix metalloproteinases (MMPs) (Gao et al. 2018, Kim et al. 2022).
Plants growing in Colombia as sources of active ingredients for sunscreens
Published in International Journal of Radiation Biology, 2021
Jorge Luis Fuentes, Diego Armando Villamizar Mantilla, Silvia Juliana Flores González, Luis Alberto Núñez, Elena E. Stashenko
Overexposure to solar radiation in humans is a public health problem due to carcinogenicity (Linos et al. 2009). The damaging biological effects of solar radiation depending on its energy ranging from minor skin damage like erythema to more severe ones such as burns, aging, or skin cancer (Narayanan et al. 2010). The UV component of solar radiation comprises long [ultraviolet A (UVA), 320–400 nm], medium [ultraviolet B (UVB), 280–320 nm], and short [ultraviolet C (UVC), 100–280 nm] wavelengths. UVC rays are absorbed by the ozone layer, while UVB (5%) and UVA (95%) rays reach the Earth's surface (Schuch et al. 2013). Thus, it is considered that only UVB and UVA rays have biological relevance (Ganesan and Hanawalt 2016). Both UVA and UVB rays cause DNA damages, being the cyclobutane pyrimidine dimers (CPDs) the most frequent (Tewari et al. 2012). UVB radiation also triggers the formation of pyrimidine (6-4) pyrimidone photoproducts as a second major class of DNA photoproducts (Cadet and Douki 2018). CPDs cause mutations including predominant CC→TT tandem base substitutions and C→T transversions at dipyrimidine sites of p53 gene (Brash et al. 1991), known as UV genetic fingerprints, which initiate inflammatory processes, immunosuppression, and skin cancer (Vink and Roza 2001). The CPDs constitute an obstacle to DNA replication (Setlow et al. 1963; Yeeles et al. 2013), therefore, this DNA damage must be repaired so that the cell restores genome replication and survives.