How Does The Sun Affect Your Skin? Benefits & Harmful Effects of Sunlight Exposure Animation Video
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8 سال پیش
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Sun’s effect on skin: The
Sun’s effect on skin: The skin uses sunlight to help manufacture vitamin D, which is important for normal bone formation. But sometimes its ultraviolet light can be very detrimental.
Within the skin's epidermal (outer) layer are cells that contain the pigment melanin. Melanin protects skin from the sun’s ultraviolet rays, which can burn the skin, and over time, could reduce its elasticity and cause a person to age prematurely. Suntanning occurs because exposure to sunlight causes the skin to produce more melanin and to darken. The tan fades as these cells move toward the surface and are sloughed off.
Health effects of sunlight exposure. The ultraviolet radiation in sunlight has both positive and negative health effects, as it is both a principal source of vitamin D3 and a mutagen. A dietary supplement can supply vitamin D without this mutagenic effect, but bypasses natural mechanisms that would prevent overdoses of vitamin D generated internally from sunlight. Vitamin D has a wide range of positive health effects, which include strengthening bones and possibly inhibiting the growth of some cancers. UV exposure also has positive effects for endorphin levels, and possibly for protection against multiple sclerosis. Visible sunlight to the eyes gives health benefits through its association with the timing of melatonin synthesis, maintenance of normal and robust circadian rhythms, and reduced risk of seasonal affective disorder.
Long-term sunlight exposure is known to be associated with the development of skin cancer, skin aging, immune suppression, and eye diseases such as cataracts and macular degeneration. Short-term over-exposure is the cause of sunburn, snow blindness, and solar retinopathy.
UV rays, and therefore sunlight and sunlamps, are the only listed carcinogens that are known to have health benefits, and a number of public health organizations state that there needs to be a balance between the risks of having too much sunlight or too little. There is a general consensus that sunburn should always be avoided.
Too much exposure to ultraviolet or UV rays can cause sunburn. UV rays penetrate the outer skin layers and pass into the deeper layers, where they can damage or kill skin cells. People who do not have much melanin and sun burn easily should protect themselves by covering up sensitive areas, wearing sun block, limiting their total exposure time, and limiting their sun exposure between the hours of 10 a.m. and 2 p.m.
Frequent and prolonged exposure to ultraviolet rays over many years is the chief cause of skin cancer. Examine skin regularly for development of suspicious growths or changes in an existing skin lesion. Early detection and treatment are key in increasing the cure rate for skin cancer.
Risks to skin: Ultraviolet (UV) irradiation present in sunlight is an environmental human carcinogen. The toxic effects of UV from natural sunlight and therapeutic artificial lamps are a major concern for human health. The major acute effects of UV irradiation on normal human skin comprise sunburn inflammation erythema, tanning, and local or systemic immunosuppression. The most deadly form, malignant melanoma, is mostly caused by indirect DNA damage from UVA radiation. This can be seen from the absence of a direct UV signature mutation in 92% of all melanoma. UVC is the highest-energy, most-dangerous type of ultraviolet radiation, and causes adverse effects that can variously be mutagenic or carcinogenic.
Despite the importance of the sun to vitamin D synthesis, it is prudent to limit the exposure of skin to UV radiation from sunlight and from tanning beds. According to the National Toxicology Program Report on Carcinogens from the US Department of Health and Human Services, broad-spectrum UV radiation is a carcinogen whose DNA damage is thought to contribute to most of the estimated 1.5 million skin cancers and the 8,000 deaths due to metastatic melanoma that occur annually in the United States. Lifetime cumulative UV exposure to skin is also responsible for significant age-associated dryness, wrinkling, elastin and collagen damage, freckling, age spots and other cosmetic changes. The American Academy of Dermatology advises that photoprotective measures be taken, including the use of sunscreen, whenever one is exposed to the sun. Short-term over-exposure causes the pain and itching of sunburn, which in extreme cases can produce more-severe effects like blistering.
Cosmetic Procedures: Sun Exposure and Skin Cancer
The sun's rays make us feel good, and in the short term, make us look good. But our love affair isn't a two-way street. Exposure to sun causes most of the wrinkles and age spots on our faces. Consider this: One woman at age 40 who has protected her skin from the sun actually has the skin of a 30-year-old!
Within the skin's epidermal (outer) layer are cells that contain the pigment melanin. Melanin protects skin from the sun’s ultraviolet rays, which can burn the skin, and over time, could reduce its elasticity and cause a person to age prematurely. Suntanning occurs because exposure to sunlight causes the skin to produce more melanin and to darken. The tan fades as these cells move toward the surface and are sloughed off.
Health effects of sunlight exposure. The ultraviolet radiation in sunlight has both positive and negative health effects, as it is both a principal source of vitamin D3 and a mutagen. A dietary supplement can supply vitamin D without this mutagenic effect, but bypasses natural mechanisms that would prevent overdoses of vitamin D generated internally from sunlight. Vitamin D has a wide range of positive health effects, which include strengthening bones and possibly inhibiting the growth of some cancers. UV exposure also has positive effects for endorphin levels, and possibly for protection against multiple sclerosis. Visible sunlight to the eyes gives health benefits through its association with the timing of melatonin synthesis, maintenance of normal and robust circadian rhythms, and reduced risk of seasonal affective disorder.
Long-term sunlight exposure is known to be associated with the development of skin cancer, skin aging, immune suppression, and eye diseases such as cataracts and macular degeneration. Short-term over-exposure is the cause of sunburn, snow blindness, and solar retinopathy.
UV rays, and therefore sunlight and sunlamps, are the only listed carcinogens that are known to have health benefits, and a number of public health organizations state that there needs to be a balance between the risks of having too much sunlight or too little. There is a general consensus that sunburn should always be avoided.
Too much exposure to ultraviolet or UV rays can cause sunburn. UV rays penetrate the outer skin layers and pass into the deeper layers, where they can damage or kill skin cells. People who do not have much melanin and sun burn easily should protect themselves by covering up sensitive areas, wearing sun block, limiting their total exposure time, and limiting their sun exposure between the hours of 10 a.m. and 2 p.m.
Frequent and prolonged exposure to ultraviolet rays over many years is the chief cause of skin cancer. Examine skin regularly for development of suspicious growths or changes in an existing skin lesion. Early detection and treatment are key in increasing the cure rate for skin cancer.
Risks to skin: Ultraviolet (UV) irradiation present in sunlight is an environmental human carcinogen. The toxic effects of UV from natural sunlight and therapeutic artificial lamps are a major concern for human health. The major acute effects of UV irradiation on normal human skin comprise sunburn inflammation erythema, tanning, and local or systemic immunosuppression. The most deadly form, malignant melanoma, is mostly caused by indirect DNA damage from UVA radiation. This can be seen from the absence of a direct UV signature mutation in 92% of all melanoma. UVC is the highest-energy, most-dangerous type of ultraviolet radiation, and causes adverse effects that can variously be mutagenic or carcinogenic.
Despite the importance of the sun to vitamin D synthesis, it is prudent to limit the exposure of skin to UV radiation from sunlight and from tanning beds. According to the National Toxicology Program Report on Carcinogens from the US Department of Health and Human Services, broad-spectrum UV radiation is a carcinogen whose DNA damage is thought to contribute to most of the estimated 1.5 million skin cancers and the 8,000 deaths due to metastatic melanoma that occur annually in the United States. Lifetime cumulative UV exposure to skin is also responsible for significant age-associated dryness, wrinkling, elastin and collagen damage, freckling, age spots and other cosmetic changes. The American Academy of Dermatology advises that photoprotective measures be taken, including the use of sunscreen, whenever one is exposed to the sun. Short-term over-exposure causes the pain and itching of sunburn, which in extreme cases can produce more-severe effects like blistering.
Cosmetic Procedures: Sun Exposure and Skin Cancer
The sun's rays make us feel good, and in the short term, make us look good. But our love affair isn't a two-way street. Exposure to sun causes most of the wrinkles and age spots on our faces. Consider this: One woman at age 40 who has protected her skin from the sun actually has the skin of a 30-year-old!
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در تاریخ 1395/01/29 منتشر شده
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