Known effects of UVA and UVB on people with more melanin

Rays emitted by the sun reaches the earth and aid in the natural processes that go on all around us. Of the rays emitted by the sun, the UVC doesn’t reach the earth as it is absorbed by the ozone layer. However, the UVA and UVB reach the earth and are the focus of this article. When you hear about ultraviolet rays causing skin damage in one way or the other, the UVA and UVB rays are at work. It is interesting to note that in the early 1980s, the UVA was considered to be a good ray and tanning beds were encouraged. Today it is known to be a more damaging sun ray.

UVA and UVB

There are two types of sun rays that reach the earth, Ultraviolet A or UVA with a long wavelength and Ultraviolet B with a short wavelength.  UVA is of the same strength through the year regardless of how far or near the sun is from the earth.

Repeated exposure to sun rays of the type UVA will result in photo damage of the skin. Since UVA has longer wavelengths, it penetrates the skin deeper and scatters in the dermis where it helps to accelerate the aging process. The dermis is made up of collagen and other substances like elastin. Due to continuous exposure to sunlight, the UVA cause the collagen to shrink and skin loses its elastic property and starts aging. When the damage caused by this ray reaches the cells, cell DNA is also affected leading to a severe type of skin cancer known as melanoma.

The UVB ray is now considered the ray for tanning and varies in strength throughout the year. It is strongest when the sun is closest to the sun’s orbit. This ray that is strong enough to penetrate the epidermis is the main cause of sunburn. Melanocytes that produce melanin are stimulated by UVB to produce more melanin. Continuous exposure will cause unpleasant looking skin and also result in sunburn.

Interestingly, even people with dark skin will also suffer from sun burn. The difference between having dark skin and having fair skin is that it may take longer periods of exposure to the sun for a dark skin to show sunburn. Notwithstanding they still suffer from sunburn. When it comes to skin cancer, the rays that cause it will penetrate dark skin as well as fair skin.

The only way to ensure that the harmful effects caused by these rays are kept to a bare minimum is to wear sun protection at all times in winter as well as in summer. There are many sun protection creams and lotion that can be used the most common of which is sunscreen. Sunscreen is only as good as its SPF value so use the right one for your skin. There are also sun protection clothing that can be worn to help reduce the effects of the sun’s rays. Always try to stay away from the sun or if you have to stay under the sun, use a good sun protection.

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by admin

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