Why does sunlight damage our skin???

Question

...tom science

Answer 1

The skin shields the rest of the body from the sun's rays. Ultraviolet (UV) light, although invisible to the human eye, is the component of sunlight that has the most effect on skin. UV light is classified into three types, ultraviolet A (UVA), ultraviolet B (UVB), and ultraviolet C (UVC), depending on its wavelength.

UV light in small amounts is beneficial, because it helps the body produce vitamin D. However, larger amounts of UV light damage DNA (the body's genetic material) and alter the amounts and kinds of chemicals that the skin cells make. UV light also may break down folic acid, sometimes resulting in deficiency of that vitamin in fair-skinned people. Although UVA penetrates deeper into the skin, UVB is responsible for at least three quarters of the damaging effects of UV light, including tanning, burning, premature skin aging, wrinkling, and skin cancer.

The amount of UV light reaching the earth's surface is increasing, especially in the northern latitudes. This increase is attributable to chemical reactions between ozone and chlorofluorocarbons (chemicals in refrigerants and spray can propellants) that are depleting the protective ozone layer, creating a thinner atmosphere with some holes. UV light is more intense between 10 a.m. and 3 p.m., in the summer, and at higher altitudes.

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 (the pigment-producing skin cells) make increased amounts of melanin, which darkens the skin, resulting in a tan. Melanin absorbs the energy of UV light and prevents the light from penetrating deeper into the tissues.

Sensitivity to sunlight varies according to the amount of melanin in the skin. Darker-skinned people have more melanin and therefore greater protection against the sun's harmful effects, although they are still vulnerable to some extent. The amount of melanin present in a person's skin depends on heredity as well as on the amount of recent sun exposure. Some naturally pale people are able to produce large amounts of melanin in response to UV light, whereas others produce very little. People with albinism (see Pigment Disorders: Albinism) have little or no melanin at all.

Exposure to sunlight prematurely ages the skin. Exposure to ultraviolet light is responsible for the wrinkles, both fine and coarse; irregular pigmentation; brown and red spots; and leathery, rough texture of sun-exposed skin. Although fair-skinned people are most vulnerable, with enough exposure, anyone's skin will change.

The more sun exposure a person has, the higher the risk of skin cancers, including squamous cell carcinoma, basal cell carcinoma, and, to some degree, malignant melanoma (see Skin Cancers: Melanoma).

The key to minimizing the damaging effects of the sun is avoiding further sun exposure; damage that is already done is difficult to reverse. Moisturizing creams and makeup help hide wrinkles. Chemical peels, alpha-hydroxy acids, tretinoinSome Trade Names
RETIN-A
AVITA
RENOVA
creams, and laser skin resurfacing may improve the appearance of thin wrinkles and irregular pigmentation. Deep wrinkles and significant skin damage, however, are unlikely to be reversed.

Answer 2

the sun or any star is basically one giant nuclear reaction and they give off radioactive waves (UV) some of which can hurt us by causing certain cancerous growths while others can help us by supporting bone growth. or something like that

Answer 3

The sun emits UV rays which are what harms our skin.

Answer 4

because the UV rays are very strong and when you get a tan it is basically toasting you like marshmallow

Answer 5

Uh duh? The ultra violet raze.