What are UV rays?

20 Nov 2016

Ultraviolet radiation or UV radiation is referred to electromagnetic radiation whose wavelength is between approximately 400 nm (4 x 10-7 m) and 15 nm (1.5 x 10-8 m). Its name comes from the fact that its range starts from shorter wavelengths than humans identify as the violet color, but that light or wavelength is invisible to the human eye as it is above the visible spectrum. This radiation is an integral part of the solar rays and produces several health effects because it`s a radiation between non-ionizing and ionising.

They are harmful ?

Most of the ultraviolet radiation that reaches Earth is in the UV-C, UV-B and UV-A Mainly the last one,because of the absorption by the Earth`s atmosphere. These ranges are associated to the damage they cause in humans: UV-C radiation (the most damaging to life) does not reach the earth becaise it`s absorbed by the oxygen and the ozone in the atmosphere; UV-B radiation is partially absorbed by the ozone and only reaches the earth's surface by a minimum percentage, although it can damage the skin.

The damages that ultraviolet rays can cause include skin cancer,skin aging, irritation, wrinkles, skin spots or loss of elasticity, as well as corneal diseases.

UV radiation is highly mutagenic,in oder words it induces mutations. In DNA it causes damage by forming pyrimidine dimers (usually thymine dimers) that shorten the normal bond distance, causing a deformation,on the DNA strand.

UV rays are responsable for the typical burns from prolonged exposure to the sun. In moderate amounts, it can activate melanocytes in some people, producing a brownish pigmentation (what is known as "tanning").

Risk colour UV Index

█ Green: Low <2

█ Yellow: Moderate 3-5

█ Orange: High 6-7

█ Red: Very High 8-10

█ Violet: Extremely high> 11

What simple measures can be taken to protect you from the sun?

According to WHO (World Health Organization):

  • Shaded areas sunglasses, clothing and hats are the best protection. In addition, it is necessary to apply a sunscreen on the parts of the body that are exposed, such as the face and hands. Sunscreen should never be used to prolong sun exposure.
  • Avoid sun exposure ad midday. Solar UV rays are stronger between 10am and 4pm. Take special care during these hours.
  • Take the UV index,into consideration.This important information helps you plan your outdoor activities and avoid excessive exposure to the sun's rays. Sun protection is required if the UV index moderate to high exposure levels, for example a UV index of 3 or higher.
  • Take advantage of the shaded areas.Go to a shaded area when the UV rays are more intense, but do not forget that trees, umbrellas or awnings do not fully protect against solar radiation.
  • Wear clothing for protection. A wide-brimmed hat protects the eyes, ears, face and back of the neck properly. Sunglasses with a sun protection index of 99% -100% against UVA and UVB rays considerably reduce eye damage. Loose and dense fabrics that cover most of the body surface also protect against the sun.
  • Use sunscreen choose a broad-spectrum sunscreen with an SPF of 30 or higher. Extend it generously over the exposed skin and repeat application every two hours, or after working, swimming, playing or exercising outdoors.
  • Avoid sun lamps or tainning booths.These increase the risk of skin cancer and can damage the eyes if protection is not used. Its use should be completely avoided.
  • Protect children. Children are often more vulnerable to environmental hazards than adults. While outdoors, protect them from UV exposure as explained above. Babies should always remain in shaded areas.

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