UVB rays, the primary sunburn ray, are largely blocked by glass; but more than 50 percent of UVA rays, the main cause of premature skin aging, can penetrate glass. Consider installing professional protective window film both in your car and in your home , but check local regulations first. In fact, this sun exposure may be stronger than the exposure you get on the ground more on that in a bit. UVA rays can penetrate through clouds, rain and fog, leaving you exposed.
Also keep in mind that summer storms can pass quickly, so when the sky clears, you might be caught unexpectedly in the sun. Heading to the nail salon for a mani-pedi? UV light also causes damaging effects such as premature skin aging and wrinkling. There is no safe level of UV light.
The amount of UV light reaching the earth's surface is increasing, especially in the northern latitudes. This increase is caused by depletion of the protective ozone layer high in the atmosphere. Ozone, a naturally occurring chemical, blocks much UV light from reaching the surface of the earth.
Chemical reactions between ozone and chlorofluorocarbons chemicals in refrigerants and spray can propellants are depleting the amount of ozone in the protective ozone layer. The amount of UV light reaching the earth's surface also varies depending on other factors. UV light is more intense between 10 AM and 3 PM, during the summer, and at high altitudes and low latitudes such as at the equator.
Glass, heavy clouds, smoke, and smog filter out much UV light, but UV rays may pass through light clouds, fog, and about 1 foot of clear water, potentially causing severe burns. The skin undergoes certain changes when exposed to UV light, to protect against damage.
The epidermis the skin's uppermost layer thickens, blocking UV light. The melanocytes pigment-producing skin cells make increased amounts of melanin, a brownish-colored pigment that darkens the skin, resulting in a tan. Tanning provides some natural protection against future exposure to UV radiation because melanin absorbs the energy of UV light and helps prevent the light from damaging skin cells and penetrating deeper into the tissues.
Otherwise, tanning has no health benefits. Tanning for the sake of being tanned is hazardous to health see Are Tans Healthy? Are Tans Healthy?
Sunburn results from a brief acute overexposure to ultraviolet UV light. Sensitivity to sunlight varies according to the amount of melanin Overview of Skin Pigment Melanin is the pigment that produces the various shades and colors of human skin, hair, and eyes.
Coloration pigmentation is determined by the amount of melanin in the skin. Without melanin Darker-skinned people have more melanin and therefore greater built-in protection against the sun's harmful effects. However, darker-skinned people are still vulnerable to sun damage and the long-term effects of exposure to UV light. Darker-skinned people are still vulnerable to sun damage and the long-term effects of exposure to UV light.
The amount of melanin present in a person's skin depends on heredity as well as on the amount of recent sun exposure. Some people are able to produce large amounts of melanin in response to UV light, whereas others produce very little.
People with blonde or red hair are especially susceptible to the short-term and long-term effects of UV radiation, because they are not able to produce enough melanin. The melanin in their skin can also become distributed unevenly, resulting in freckling. People with vitiligo Vitiligo Vitiligo is a loss of melanocytes that causes patches of skin to turn white.
Patches of whitened skin are present on various parts of the body. Doctors usually base the diagnosis on the appearance People with albinism Albinism Albinism is a rare hereditary disorder in which little or none of the skin pigment melanin is formed. The skin, hair, and eyes, or sometimes just the eyes, are affected. Typically, the hair Exposure to sunlight prematurely ages the skin. Damage to the skin caused by prolonged exposure to sunlight is known as photoaging.
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