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The Impact of Solar Radiation on the Human body

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Exposure to solar radiation can have positive effects on the human body, but it can also cause damages and melanoma is the most significant among those. The aim of the present study was to gather …

Exposure to solar radiation can have positive effects on the human body, but it can also cause damages and melanoma is the most significant among those. The aim of the present study was to gather information about the effects of solar radiation on the human body and to update available knowledge in accordance with new international data. A systematic literature review took place and included both Greek and international books, articles, studies and related papers on the internet (PubMed, Cinahl, Scopus and Iatrotek databases), published from 1998 to this day. Dissertations and “gray literature” (e.g. conference proceedings) were not included in this study. The following terms (“Ultraviolet radiation, skin cancer, sun, sun exposure, electromagnetic spectrum, conjunctiva, cataract, squamous cell cancer , basal cell cancer, cutaneous melanoma”) were used as key-words. UVR may have an impact on the human body according to wavelength. UVA and UVB exposure may cause photoaging and sunburns, and UVC may induce DNA mutations leading to skin cancer. Ozone is the main protective mechanism since it absorbs most of UVR. Ozone layer depletion in the last decades has lead to increased rates of sun-related damages. Most significant damages include cataract and skin damages such as photoaging and skin cancers. Among skin cancers, melanoma has the highest incidence in ever younger ages reducing life expectancy.
A good part of the international literature focuses on primary prevention measures and interventions that include mole monitoring.

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  • 1. WORLD ACADEMIC JOURNAL OF BUSINESS & APPLIED SCIENCES-MARCH-SEPTEMBER 2013 EDITION Journal of Health Science (JHS) SEPTEMBER 2013 VOL.1, No.7 The impact of solar radiation on the human body Saridi Maria (Corresponding author) Papakonstantinou Elpida & Rekleiti Maria General Hospital of Korinthos, Greece, 33 Sina str, GR-20100, Korinthos, Greece Accepted 3 September 2013 Abstract Exposure to solar radiation can have positive effects on the human body, but it can also cause damages and melanoma is the most significant among those. The aim of the present study was to gather information about the effects of solar radiation on the human body and to update available knowledge in accordance with new international data. A systematic literature review took place and included both Greek and international books, articles, studies and related papers on the internet (PubMed, Cinahl, Scopus and Iatrotek databases), published from 1998 to this day. Dissertations and “gray literature” (e.g. conference proceedings) were not included in this study. The following terms (“Ultraviolet radiation, skin cancer, sun, sun exposure, electromagnetic spectrum, conjunctiva, cataract, squamous cell cancer , basal cell cancer, cutaneous melanoma”) were used as key-words. UVR may have an impact on the human body according to wavelength. UVA and UVB exposure may cause photoaging and sunburns, and UVC may induce DNA mutations leading to skin cancer. Ozone is the main protective mechanism since it absorbs most of UVR. Ozone layer depletion in the last decades has lead to increased rates of sun-related damages. Most significant damages include cataract and skin damages such as photoaging and skin cancers. Among skin cancers, melanoma has the highest incidence in ever younger ages reducing life expectancy. A good part of the international literature focuses on primary prevention measures and interventions that include mole monitoring. Key Words: Ultraviolet radiation, skin cancer, sun, sun exposure, electromagnetic spectrum, melanoma 1. Introduction Solar radiation can have both positive and negative effects on the human body. Several essential procedures such as vitamin D synthesis are triggered by solar radiation. Also sun exposure can have beneficial effects on several diseases (Gies et al, 1998a). Both UVA and UVB are important for human health. Low levels of solar radiation are crucial for the synthesis of vitamin D, while overexposure may lead to acute and chronic damage to the skin, the eyes or the immune system (Zepp et al, 2011a; Lemus-Deschamps & Makin, 2012a). Ozone layer depletion has lead to increased UVB radiation-induced damages to humans, animals, deep-sea organisms and plants. It has been estimated that a further 10% depletion of the ozone layer in the following years could cause 300 000 new skin cancer cases (squamous and basal cell cancer), 4 500 new melanomas and 1.6-1.75 million cases of cataract each year worldwide (Tourpali et al, 2009a; Aucamp et al, 2010a). Aim: The aim of the present study was to gather information about the effects of solar radiation on the human body and to update available knowledge in accordance with new international findings. 303
  • 2. WORLD ACADEMIC JOURNAL OF BUSINESS & APPLIED SCIENCES-MARCH-SEPTEMBER 2013 EDITION 2. Literature review A comprehensive literature review took place by using Greek and international databases (PubMed, Cinahl, Scopus, Ιatrotek), relevant books and other relevant sources (WHO, CDC). The survey of the related literature included material published between 1998-2012, and the following key-words were used: Ultraviolet radiation, skin cancer, sun, sun exposure, ozon, electromagnetic spectrum, conjunctiva, cataracts, Squamous cell cancer, Basal cell cancer and melanoma. All related literature includes an abundance of research findings from all over the world regarding the effects of solar radiation on humans. Australia, USA and New Zealand, due to high incidence of sun-related health conditions have launched health education programs that stand as an example for other countries (including Greece) to follow. 2.1 Ultraviolet radiation (UVR) The Sun is a star in our galaxy that emits energy in the form of electromagnetic radiation, and has a surface temperature of about 6000 degrees Celsius. The electromagnetic radiation emitted by the photosphere ranges from very short wavelengths (gamma rays) to long wavelengths and for the most part it reaches the external layers of the Earth's atmosphere. The radiations that have an effect on human skin are just a fraction of the solar spectrum. Those radiations are the Infra-Red radiation, visible light, Ultra Violet radiation, gamma and X rays, radio waves and microwaves (Gies et al, 1998b). Ultraviolet radiation is a fraction of the electromagnetic spectrum and it has three sub-types (UVC, UVB, UVA), (Table 1) according to wavelengths (in nanometers) and effects on human skin. UVC rays (wavelength 100 280 nm) are absorbed by ozone, oxygen and carbon dioxide, while UVA (wavelength 315 - 400 nm) and 10% of UVB (wavelength 280 - 315 nm) reach the surface of the Earth, but not in the same degree, because rays are absorbed at different rates by the Earth's atmosphere (Zepp et al, 2011b). 2.2 Natural Factors affecting Solar Radiation There are several factors affecting the intensity of solar radiation (Table 2) (Gies et al, 1998c). The UVR intensity reaches its peak at noon rather than in the morning, in the summer rather than the winter, and in equatorial countries rather than Europe (Tourpali et al, 2009b; Aucamp et al, 2010b; Lemus-Deschamps & Makin, 2012b). UVR is more intense when the sky is clear. Clouds generally decrease the UVR intensity, but that depends mainly on the clouds' thickness and type. Thin and scattered clouds decrease UVR intensity by a mere 10%, while low and thick clouds reflect UVR significantly (almost by 80%). When the solar disc is visible, then UVR reflection is almost negligible. UVR becomes more intense the farther away from the sea level one moves, since the atmospheric elements that absorb most of it decrease by height. It has been estimated that 1000 meters from the ground, UVR increases by 10%. Almost 95% of UVR can penetrate water (e.g. the sea) and almost 50% of it can reach a depth of about 3 meters. Consequently when one swims their body is just a few centimeters above sea surface; hence they are virtually unprotected against UVR. When the sky is clear, UVR is more intense at noon rather than in the morning or afternoon. When the Sun is at its peak, radiation is also more intense (because solar rays reach the Earth directly). This is why solar radiation is more intense in the summer rather than the winter (Zerefos et al, 2000a; Lemus-Deschamps & Makin, 2012c). An object or an individual receives solar radiation directly (from the sky) and indirectly (radiation reflected on the ground). The amount of the reflected radiation depends on the type of the surface. Trees, grass and water reflect less than 10% of UVR; on the other hand, fresh snow reflects up to 80% of UVR and dry sand almost 20% of solar radiation. Consequently, those who are in snowy areas or sandy beaches receive more solar radiation. Some reflection levels according to the surface type: Grass reflects a mere 3%, sea water 5%, sand 304
  • 3. WORLD ACADEMIC JOURNAL OF BUSINESS & APPLIED SCIENCES-MARCH-SEPTEMBER 2013 EDITION 17% and snow 85% (Table 3). Clouds absorb 30-80% of solar radiation (according to height, thickness, etc) but not all of it (Aucamp et al, 2011c; Lemus-Deschamps & Makin, 2012d). 2.3 Ozone as a Protective Mechanism against Solar Radiation 12-15 km above the surface of the Earth, namely in the stratosphere, a thick layer of ozone exists, a gas that its molecule consists of three oxygen atoms. Ozone is formed by atmospheric oxygen and ultraviolet radiation from the Sun. The ozone layer virtually shields the Earth from the damaging effects of solar radiation (Zerefos et al, 2000b; Garane et al, 2006a). Ozone absorbs the solar radiation and transforms it to heat. Solar light gets filtered while traveling through the atmosphere and dangerous wavelengths (cosmic radiation, gamma and X rays, UVC) are blocked. Should this protection mechanism cease to exist, life as we know it (flora, fauna, bacteria and viruses), would perish (Isaksen et al, 2005a). The role of ozone is twofold: (a) It absorbs part of UVR and transforms it to heat; and (b) It blocks the dangerous types of UVR that otherwise would have had a devastating impact on the ecosystem. The depletion of the ozone layer mainly because of chemical agents such as chlorofluorocarbons (CFCs) in the last decades of the 20th century is a globally acknowledged problem that has alarmed scientists, governments and the public. It has been estimated that when ozone decreases by 1% and UVB increases by 2%, squamous and basal cell cancers and melanomas increase by 1-3% (Zerefos et al, 2000c; Isaksen et al, 2005b; Garane et al, 2006b). The ozone hole in the southern hemisphere increases every years, although its size varies according to season. It has been estimated that in the winter ozone decreases by 10% every ten years. Ozone generally increases in the summer because of higher temperatures that speed up chemical reactions involving volatile hydrocarbons and nitrogen oxides from factories and cars that help increase the amount of ozone. On the other hand, lower temperatures slow down the chemical reactions and thus the photochemical smog is a rare incidence. Thus, the synthesis of tropospheric ozone is favoured during the warmer months of the year (late spring and summer) (Isaksen et al, 2005c; Garane et al, 2006c). Ozone levels in Greece, according to daily measurements from November 1978 to April 1993, have increased –mainly in late winter and early spring. On the contrary no significant increase has been established for summer months. Nevertheless, in Greece overall ozone levels have not changed dramatically, as in other countries such as Australia or New Zealand, a fact that could explain also the lower skin cancer incidence in Greece compared to those countries (Varotsos, 1998; NASA's TOMS, 2005). 2.4 Biological Effects of Solar Radiation The organs most exposed to sun rays are the skin and the eyes. Exposure to solar radiation could result in direct or chronic disorders of the skin, the eyes and the immune system (Haake & Holbrook, 1999a; Lagerlund et al, 2002). Exposure to solar radiation may have sunburns or photokeratitis as a direct impact. Cancer and premature skin aging are among the chronic effects. UVA affects the subcutaneous tissue and can alter collagen and elastin structure. Cataract, pterygium and keratopathy are also among chronic conditions due to exposure to solar radiation. UVR can lead to the restructuring of DNA, something that can lead to mutations. The ability of the human body to heal and restore solar radiation-induced damages decreases by age. As a rule of thumb, the shorter the wavelength, the higher the risks associated with UVR exposure (Haake & Holbrook, 1999b). 2.5 The Beneficial Effects of Solar Radiation 305
  • 4. WORLD ACADEMIC JOURNAL OF BUSINESS & APPLIED SCIENCES-MARCH-SEPTEMBER 2013 EDITION Moderate sun exposure can have several positive effects on the human health and mood. The sun is vital for life on Earth. It activates provitamin D3, which exists on the skin, to vitamin D3 which regulates calcium and phosphorus metabolism; D3 deficiency can cause rickets, especially in children. Solar radiation can also ameliorate some skin diseases, such as psoriasis and acne, and it also activates the synthesis of melanin, a procedure that thickens the keratin layer and consequently is seen as the most important protection mechanism against sunburns (Haake & Holbrook, 1999c). Sun exposure can also affect in a positive way the autonomic nervous system by activating several vitamins, hormones and enzymes. It stimulates blood circulation, boosts hemoglobin synthesis and lowers blood pressure. It also makes the body less prone to some bacterial and fungal infections because of its drying effects on the skin. Moderate sun exposure improves mood and creates positive and optimistic feelings (Gies et al, 1998d; Zepp et al, 2011a). The sun is also a well-known heat source and an exploitable source of energy; it also is a key-factor for photosynthesis, a process vital for plants and animals and for the water cycle the procedure responsible for the continuous movement of water on the Earth and provides fresh water to rivers, lakes and underground water reservoirs. Consequently, running water can be used as a source of hydroelectric energy, and solar radiation may be used as a sustainable alternative source of energy (photovoltaic systems) (Zepp et al, 2011b). 2.6 Adverse effects of solar radiation 2,6,1 Effects of Solar Radiation on the Eyes Ultraviolet radiation can lead to several eye conditions. More than 99% of UVR is absorbed by the outer eye layers and only a fraction can reach the photo-sensitive retina (Haake & Holbrook, 1999d; Lucas, 2010a; Zepp et al, 2011c). Prolonged exposure to UVR can damage the eye and even lead to sight loss. Scientific findings have established that everyone, both children and adults, are susceptible to such risks. UVA can also damage the retina, since it penetrates much deeper into the eye although it has lower energy. Increased exposure of the eye to the sun increases the risk of sun-related eye damage. Persons that are exposed to the sun for long periods of time because of their profession or other activities are running a higher risk of eye damage (Fitzpatrick et al, 2003a; Lucas, 2010b). The most significant harmful effects of solar radiation on the eye are the following: Cataract is one of the most important causes of poor eye sight and sight loss worldwide. Laboratory studies have shown that UVR can cause cataract. Macular degeneration is the main cause of poor eye sight in people over 55 years of age. Laboratory experiments have shown that exposure to UVR and visible spectrum radiation can cause damage to the retina. Pterygium is a tissue-like formation on the white of the eye that extends to the cornea and can hinder eye-sight. It usually affects people that work outside and are exposed to the sun; its presence is related to the amount of ultraviolet radiation a person has been exposed to. It can be surgically removed but it frequently recurs and could cause sight loss if not properly treated. Photokeratitis is in essence a burn of the cornea which is caused because of excessive UVB exposure. It is reversible and treatable. It usually affects people who spend much time at the beach or in snowy areas without protecting their eyes. It can cause acute pain for 1-2 days and temporary sight loss. 2.6.2 Effects of Solar Radiation on the Skin The skin protects the human body from damaging factors. The skin’s surface performs two main functions: keratinopoiesis and melanogenesis. Keratinopoiesis is the formation of the hard keratin layer, and melanogenesis is the synthesis of the skin pigment, melanin. Melanin not only sets the skin colour but it also protects the cells by absorbing UVR. When the skin is under exposure to the sun, melanin production increases and the skin colour gets darker (Lucas, 2006 & 2010c). 306
  • 5. WORLD ACADEMIC JOURNAL OF BUSINESS & APPLIED SCIENCES-MARCH-SEPTEMBER 2013 EDITION The reactions of the skin after prolonged sun exposure are acute or chronic. Acute or direct effects are noticeable within hours or days after exposure; chronic effects are usually the result sun exposure for prolonged periods of time (Berg & Allan, 2001). Skin redness is usually a short-term, temporary skin condition. It is caused by expansion of the skin capillaries and becomes apparent 2-3 hours after sun exposure, reaching its peak 12-14 hours later. More intense redness accompanied by pain, itchiness, swelling, blisters or even fever and nausea is considered to be a sunburn. Sunburn is an acute temporary skin inflammatory reaction due to exposure to solar radiation or non-natural sunlight (solarium). It causes damage on the ‘gatekeepers’ of the skin, the squamous layer cells. It is a temporary condition that leaves no scars and at the final stages leads to skin resurfacing. Simple redness that is no longer exposed to the sun disappears after 24-36 hours, while more serious sunburns may take 4-8 days to heal. The existence of at least one serious sunburn during childhood or adolescence is a risk factor for skin cancer later in life. Solar dermopathy – Photo-ageing. A recurrent skin damage due to the sun over many years can lead to a syndrome called solar dermopathy. It is the result of excessive or prolonged sun exposure over many years. This syndrome is in fact the result of the cumulative results of sun exposure. Thin and deep wrinkles appear mainly around the mouth, above the upper lip, the cheeks and the neck. The skin appears to be yellow actinic elastosis. Solar lentigo. These are benign brown to black blemishes in white people. There are three types of such localized blemishes: freckles, juvenile lentigo and solar lentigo. Sun exposure may increase their number and cause them to become darker. If there is no sun exposure, they become lighter and in the winter they may disappear altogether. Juvenile lentigo appears in childhood; the spots do not increase in number, they do not change size or get darker after sun exposure. Actinic Hyperkeratosis is a premalignant condition and is usually the result of lont-term sun exposure. Actinic keratosis usually appears in groups in people of fair complexion. Fair complexion and long-term sun exposure are the main risk factors for actinic keratosis. The lesions appear usually on the face, the arms, the hands, the skin of the head, and rarely on the shoulder blade, the shoulders, the legs and the feet. Clinically, actinic keratosis appears as a ragged, thick lesion covered by yellow wing-like formations. Melanocytic nevi (Moles). These benign lesions are so common that no white person without even one nevus exists. Apart from the common nevi, there are also several clinical-histological varieties. Since melanocytic nevi can change into a melanoma, correct diagnosis is substantial for a person’s life. Some nevi have a greater risk of changing into a melanoma. Dysplastic nevi (atypical moles) are among those that carry a high risk of changing into a melanoma. Studies have shown that both genetic and environmental factors (e.g. solar radiation) are involved in these cases. It has been suggested that the existence of a large number of moles can increase the risk of melanoma. Estimates vary but the risk increases by 10-60 times (Habif, 2002a; Alexandrescu, 2009a). Not all changes in the appearance of a mole indicate a malignant condition. But a thorough examination by an experienced pshysician is necessary. The ABCD rule is a well-established method to monitor melanocytic nevi (Table 4). Basal Cell Carcinoma (BCC). BCC is a malign skin tumor that damages and penetrates locally the skin, rarely metastasizes, and is considered to be the most common skin cancer in white people. It usually affects adults and it appears on the skin excluding palms and sole. BCCs are generally considered to be more benign than SCCs since they develop slowly and are localized. BCC incidence in males is higher than that of females, although in the last decades females have increasing incidence rates as well. Annual BCC incidence in the USA is 146 cases out of 100 000 persons, and in Europe 132 cases per 100 000 persons. Worldwide there are significant fluctuations in BCC incidence rates (Haake & Holbrook, 1999e; Lemus-Deschamps & Makin, 2012e). In recent 307
  • 6. WORLD ACADEMIC JOURNAL OF BUSINESS & APPLIED SCIENCES-MARCH-SEPTEMBER 2013 EDITION years, BCC frequency has increased considerably in Europe, Australia (5%) and the US (4.5%). Data from Greece have shown a similar trend. BCCs usually develop after the age of 40 and their frequency increases by age. In recent years BCCs have been shown to increase alarmingly in younger ages too (Armstrong & Kricker, 2001; Lucas, 2010d). Although solar radiation has been assumed to be the main factor for the development of BCCs, the causal relation between them remains rather vague compared to the one between solar radiation and SCCs. It seems that after an upper limit of accumulated radiation, further sun exposure does not increase the risk for the development of BCCs (Habif, 2002b; Alexandrescu, 2009b). Squamous Cell Carcinoma (SCC). SCCs develop due to a malign growth of skin keratocytes, affecting both the skin and the mucous membrane. Consequently, SCCs can affect the mouth (tongue, palate, mouth angle, and inner buccal surface), the genitals and the anus. Its most common site is the lower lip semi-mucous membrane (Zepp et al, 2011d). In the USA alone, more than 1.000.000 persons are affected by some kind of skin cancer every year. The frequency of SCC varies considerably from country to country. Its highest rate is in Australia with an incidence of 250 cases per 100.000 people. It is noteworthy that within five years SCC incidence went up by 50% and males doubled SCC frequency compared to females. The risk of SCCs has been linked to the accumulated solar radiation over the years and a person’s phototype (Habif, 2002c; Alexandrescu, 2009c). Thus, people of fair complexion who have freckles, ginger or blond hair, blue eyes and do not tan, but sunburn easily are considered to be skin cancer-prone. People that are exposed to the sun because of their profession (e.g. farmers, sailors) and fail to take sun-protection measures are in dramatically higher risk of developing SCC (English et al, 1998a; Karagas et al, 1999a; American Cancer Society, 2002). Malign Melanoma (MM). Epidemiological studies focus regularly on melanomas because of their exceptional interest. The fact that melanoma affects more and more white persons and its relation to solar radiation, has attracted scientific interest. According to epidemiological studies, melanoma is an extraordinary neoplasm, of rapidly increasing incidence in Western countries, and some authors suggest that it is an epidemiological phenomenon. The most common risk factors for melanoma are: fair complexion with many moles or dysplastic moles, excesive and prolonged dun exposure and esxesive exposure during childhood or adolescence (Siegel et al, 2012). It has been observed that cases of melanoma have been increasing for all age-groups and both genders, although this increase is higher for people 20 to 40 years old. In Europe, almost 26.000 men and 33.300 women are diagnosed every year with melanoma and almost 8.300 men and 7.600 women die from it. The highest incidence rates are in Northern and Western Europe, although mortality rates do not show any significant variations (English et al, 1998b; Karagas et al, 1999b). In Greece, melanoma-related studies are scarce. Moreover, a well-coordinated record of all diagnosed cases is virtually nonexistent (Karagas et al, 1999c; Downard et al, 2007). Since 2000, when Greece joined the European campaign 'Euromelanoma', public information programs have been launched and also all newly diagnosed skin cancer cases are being recorded (Gies et al, 1998e; de Vries et al, 2003). Between 2000 and 2004, 2.723 persons had been examined, the majority being less than 50 years old and females (59%) (MacKie et al, 2002; Roussaki-Schulze et al, 2005). Most of the participants (76%) had had phototypes II and III. 47% of the participants reported at least one sunburn during childhood, while 5% had had individual or family history of melanoma. The clinical examination showed actinic keratosis (14.45%), dysplastic nevi (31.2%), and possiple skin cancer other than melanoma in 6.4% of the participants. Melanoma is an aggressive tumor that metastasizes early, being characterized by an uncontrollable increase in the number of the melanocytes. It can appear suddenly on its own, or at the site of an old mole. Its clinical appearance may vary since it can develop on the face, on the upper surface of arms and on the shank (Fitzpatrick et al, 2003b). The lesion is characteristically multicoloured, 308
  • 7. WORLD ACADEMIC JOURNAL OF BUSINESS & APPLIED SCIENCES-MARCH-SEPTEMBER 2013 EDITION ranging from dark brown or black to reddish or purple. It develops slowly and the lesion does not have well-defined borders (WHO, 2003). Melanomas that arise in pre-existing moles are also quite common. Some basic diagnostic criteria for melanomas include: a lesion that changes size; skin adjacent to the mole becomes brown; the lesion is multi-coloured; local infiltration; itchiness; the existence of a surrounding inflammatory halo; pain; ulceration (Table 4) (CDC, 2003). 3. Conclusions It is evident that the most substantial way to prevent skin cancer is to avoid sun exposure as much as possible. Since this is not always a realistic option, protection measures, such as sunscreen, staying in the shade and appropriate clothing, are essential. The general population should be kept continuously informed about skin cancer prevention and early detection methods, so that any lesion can be examined or diagnosed as early as possible. Besides primary and secondary prevention campaigns, health education programs and the adoption of healthier behaviours from an early age are also absolutely necessary. References Alexandrescu, D.T. (2009) “Melanoma costs: a dynamic model comparing estimated overall costs of various clinical stages”. Dermatology Online Journal 15 (11) article 1. American Cancer Society. Cancer Facts and Figures. Available from: http://www.cancer.org/docroot/stt/content/stt_1x_cancer_facts__figures_2002.asp [March 2003] Armstrong, B.K., Kricker, A. (2001) “The epidemiology of UV induced skin cancer”. Journal of Photochemistry and Photobiology B, 63 (1–3) 8–18. Aucamp, P.J., Björn, L.O., Lucas, R. (2011) “Questions and answers about the environmental effects of ozone depletion and its interactions with climate change: 2010 assessment”. Photochem Photobiol Sci 10 (2) 301-16. Berg, A.O., D. Allan, J.D. U.S. (2001) “Preventive Services Task Force. Screening for skin cancer; recommendations and rationale”. Am J Prev Med 20 (3S) 44–46. CDC. (2003) “Counseling to prevent skin cancer: recommendations and rationale of the US Preventive Services Task Force”. MMWR 52 (No.RR-15) 13–17. De Vries, E., Tyczynski, J.E, D. Parkin D.M. (2003) “Cutaneous Malignant Melanoma in Europe”. ENCR Cancer fact sheets No. 4. Downard, C.D., Rapkin, L.B., Gow, K.W. (2007) “Melanoma in children and adolescents”. Surg Oncol 16 (3), 215–220. English, D., Armstrong, B., Kricker, A., Winter, M., Heenan, P., Randell, P. (1998) “Case control study of sun exposure and squamous cell carcinoma of the skin”. International Journal of Cancer (77) 347-53. Fitzpatrick, T., Johnson, R., Wolf, K., Suurmond, D. (2003) Dermatology Clinic, Greek Edition Andreas Katsampas, Athens, 181-275. Garane, K., Bais, A., Tourpali, K., Meleti, C., Zerefos, C., Kazadzis, S. (2005) “Variability of spectral UV irradiance at Thessaloniki, Greece, from 15 years measurements,” In Ultraviolet Ground- and Space-based Measurements, Models and Effects V, G. Bernhard, J.R. Slusser, J.R. Herman, and W. Gao, Eds., vol. 5886 of Proceedings of SPIE, San Diego, Calif, USA. Gies, P.H., Roy, C.R., Toomey, S., McLennan, A. (1998) “Protection against solar UV radiation”. Mutat Res 422 (1) 15–22. Haake, A.R., Holbrook, K. (1999) The structure and development of skin. Ch.7, In Fitzpatrick’s Dermatology in General Medicine, 5th ed., Edited by I.Freedberg et al, Mc Graw-Hill, 70-114. Habif T.P. (2002) Skin Diseases. Diagnosis and Treatment. Greek Edition Andreas Katsampas, Athens, 298-321, 309
  • 8. WORLD ACADEMIC JOURNAL OF BUSINESS & APPLIED SCIENCES-MARCH-SEPTEMBER 2013 EDITION 360-397, 398-421. Isaksen, S.A., Zerefos, C., Kourtidis, K., Meleti, C., Dalsøren, S.B., Sundet, J.K., et al. (2005) “Tropospheric ozone changes at unpolluted and semipolluted regions induced by stratospheric ozone changes”. Journal of Geophysical Research D 110 (2) 1–15. Karagas, M.R., Greenberg, E.R., Spencer, S.K., Stukel, T.A., Mott, L.A. (1999) “Increase in incidence rates of basal cell and squamous cell skin cancer in New Hampshire, USA. New Hampshire Skin Cancer Study Group”. Int J Cancer 81 (4) 555–559. Lagerlund, M., Dixon, H.G., Simpson, J.A., Spittal, M., Taylor, H.R., Dobbinson, S.J. (2006) Observed use of sunglasses in public outdoor settings around Melbourne, Australia: 1993 to 2002”. Prev Med 42 (4) 291-6. Lemus-Deschamps, L., Makin, J.K. (2012) “Fifty years of changes in UV Index and implications for skin cancer in Australia”. Int J Biometeorol 56 (4) 727-735. Lucas, R.M., McMichael, A., Smith, W., Armstrong, B. (2006) Solar Ultraviolet Radiation: Global Burden of Disease from Solar Ultraviolet Radiation, Environmental Burden of Disease Series 13, World Health Organization, Geneva, Switzerland. Lucas, R.M. (2010) Solar Ultraviolet Radiation: Assessing the Environmental Burden of Disease at National and Local Levels, Environmental Burden of Disease Series 17, World Health Organization, Geneva, Switzerland. MacKie, R.M., Bray, C.A., Hole, D.J., Morris, A., Nicolson, M., Evans, A., et al (2002) “Incidence of and survival from malignant melanoma in Scotland: an epidemiological study”. Lancet 360 (9333) 587-591. NASA's Total Ozone Mapping Spectrometer, TOMS, 2005. Available from: http://eospso.gsfc.nasa.gov/missions/total-ozone-mapping-spectrometer-earth-probe [Aug 2011] Purdue, M.P., Freeman, L.E.B., Anderson, W.F., Tucker, M.A. (2008) “Recent trends in incidence of cutaneous melanoma among US caucasian young adults”. Journal of Investigative Dermatolog 128 (12) 2905–2908. Roussaki-Schulze, A.V., Rammos, C., Rallis, E., Terzis, A., Archontonis, N., Sarmanta, A., et al. (2005) “Increasing incidence of melanoma in central Greece: a retrospective epidemiological study”. Int J Tissue React 27 (4) 173-9. Siegel, R., Naishadham, D., Jemal, A. (2012) “Cancer statistics, 2012,” CA: A Cancer Journal for Clinicians 62 (1) 10–29. Tourpali, K., Bais, A.F., Kazantzidis, A., Zerefos, C.S., Akiyoshi, H., Austin J., et al (2009) “Clear sky UV simulations for the 21st century based on ozone and temperature projections from Chemistry-Climate Models”. Atmos Chem Phys 9 1165-1172. Varotsos, C.A. (1998) “Total ozone depletion over Greece as deduced from satellite Observations”. Laboratory of Meteorology, Department of Applied Physics, University of Athens, Greece. World Health Organization. Sun Protection and Schools: How to Make a Difference. Geneva: World Health Organization, 2003. Available from: http://www.who.int/phe/uv [Oct 2012] Zepp, R.G., Erickson, D.J.3rd., Paul, N.D., Sulzberger, B. (2011) “Effects of solar UV radiation and climate change on biogeochemical cycling: interactionsand feedbacks”. Photochem Photobiol Sci 10 (2) 261-79. Zerefos, C.S., Meleti, C., Balis, D.S., Bais, A.F., Gillotay, D. (2000) “On changes of spectral UV-B in the 90's in Europe”. Advances in Space Research 26 (12) 1971–1978. Appendix Table 1. UVR types (Source: Armstrong, B.K.et. al.) 310
  • 9. WORLD ACADEMIC JOURNAL OF BUSINESS & APPLIED SCIENCES-MARCH-SEPTEMBER 2013 EDITION Type Wavelength Characteristics UVA (400 - 320 nm) Long wavelength, low energy radiation. It can infiltrate human skin and reach the dermis. It can damage the collagen tissues and reduce skin elasticity and cause skin-ageing. (320 - 290 nm) Short wavelength, high energy radiation. It increases in the summer, reaching its peak at noon. It reaches the epidermis. Can cause sunburns and skin lesions. UVA UVC (290 - 200 nm) Short wavelength, high energy radiation. Can cause chemical and genetic changes in living organisms. Absorbed by stratospheric ozone. Table 2. Factors affecting solar radiation intensity FACTORS AFFECTING SOLAR RADIATION 1. Latitude 2. Season of the year 3. Time of the day (direct or abundant sun light) 4. Altitude 5. Reflection (sand, snow, water) 6. Skin phototype 7. Weather conditions (smog, clouds, humidity) 8. Transport of radiation in the atmosphere Table 3. Surface Reflection Coefficient Type of surface Reflection coefficient Fresh snow 0.87 Dry sand 0.18 Wet sand 0.09 Conifer forest 0.05 New Cement 0.33 Old cement 0.23 Table 4. The ABCD Rule (Source: Gies,et al) ABCD rule A (Asymmetry) Asymmetrical lesion. If divided in the middle, the two halves are not identical. B (Border irregular) Not well-defined lesion borders. They may be elevated, vague, blurry, irregular; adjacent skin may turn brown. C (Color Varied) Multi-coloured lesion. There are several shades of black, brown, even areas coloured white, grey, red, pink or blue. D (Diameter >6 mm) Usually the lesion diameter is over 6 mm. The lesion has changed its size, usually becomes bigger. 311

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