The harmful effects of ultraviolet radiation

The light from the Sun that reaches Earth consists of 50% infrared (>700 nm), 40% visible (400-700 nm), and 10% ultraviolet (200-400 nm).

UV CHARACTERISTICS

UV radiation  is the most harmful radiation of the spectrum emitted by the sun. It is divided into three areas, UVA, UVB and UVC. The shorter the wavelength, the more harmful  is UV radiation. The shorter the wavelength of UV radiation, the less it enters  on the skin and stays more superficial.

UVA-UVB

Of the ultraviolet radiation that reaches the Earth, 95% is UVA, 5% is UVB. UVC is completely filtered by the atmosphere and does not reach the earth's surface.

UVA region(320-400nm): It is continuous and stable throughout the year. The percentage of radiation in this area increases during the summer months and reaches its maximum in the midday hours. 

UVB region (290-320nm): Most of the solar UVB radiation is absorbed by the atmosphere. UVB radiation is toxic to cells and  causes DNA mutations.

• Negative effects of UV radiation

  1. Sunburn. 
  2. Damage to collagen and elastin  of the skin.
  3. Skin aging and wrinkles. 
  4. Roughness, dryness, varicose veins, uneven pigmentation.
  5. Immunosuppression 
  6. Eye damage (cataract).
  7. Development of skin cancers and DNA damage (precancerous or malignant changes). 

• Positive effects of UV when exposure is done in moderation

  1. Production of vitamin D3 (bones, immune) 
  2. Psoriasis, vitiligo. 

CONCLUSIONS

It is necessary to use sunscreen products, which protect against all the negative effects of UV (not only from the various types of skin cancer but also from photoaging, sunburn, etc.