The Truth about
Ultraviolet Radiation
As I researched more about sun protection and ultraviolet radiation (UV radiation in short) I begin to realize how little I know about our sun.
What is Ultraviolet Radiation?
The sun give us light (visible radiation), warmth (infrared radiation) and another that cannot be seen nor felt by our senses - the ultraviolet radiation. Sunlight is the ultimate source of energy and also the greatest source of UV radiation. So is sunlight a friend or a foe?Actually UV rays is widely used in industrial processes and in medical and dental practices for a variety of purposes, such as killing bacteria, curing inks and resins, phototherapy, welding equipment and others. Some UV exposure is essential for good health. It stimulates vitamin D production in the body. In medical practice, UV lamps are used for treating psoriasis and jaundice in new born babies. But excessive exposure can damage the skin and eyes. The severity of the effect depends on the wavelength, intensity and duration of exposure. I came across a data that indicates that more than 50% of an individual's total lifetime UV radiation exposure occurs by 18 years of age. Come to think about it quite true, as I do was actively involved in outdoor sports and also we do enjoy the sunlight.
The Components of Ultraviolet Radiation
Ultraviolet rays are a form of invisible energy given off by the sun and is divided into 3 wavelength ranges:- UVA: Long wave UV radiation accounts for nearly 95 % of the UV radiation reaching the surface of the Earth. It can penetrate into the deeper layers of skin and causes immediate tanning effects. Recent research has found that UVA rays also contributes to skin cancer formation. UVA are involved in the aging of cells and produce some damage to cells' DNA. They are mostly link to long-term skin damage such as wrinkles.
- UVB: Medium wave UV radiation causes sunburns, erythma(reddening of the skin) and darkening of the skin. Prolong exposure increase the risk of skin cancer. UVB rays are largely responsible for direct damage to the DNA, and are the rays that cause sunburns.
- UVC: Short wave UV radiation poses the maximum risk but the UVC rays is absorbed by ozone, water vapour, oxygen and carbon dioxide in the atmosphere before reaching the earth.
Therefore the ultraviolet solar radiation that reaches the Earth's surface is mainly composed of UVA with a small UVB component. Environmental factors also influence the UV level or intensity.
But as the ozone layer is depleted, the protective filter ability of the atmosphere is reduced and more UV rays, in particular the more harmful UVB, reached the surface of our Earth. What causes ozone depletion? Man-made chemicals are released into the atmosphere and will continue until the use of chlorine and bromine compounds is drastically reduced.
Take a QUIZ! Are some people more at risk to sun damage? YES or NO?The answer is YES. Everyone's eyes and skin are prone to sun damage. Although individuals with light skin are more at risk to sun damage from radiation, darker skinned people can also be affected.
Related Article
Do you know that protecting the skin from the sun during childhood reduces skin cancer risk later in life?
How to take effective sun protection measures to reduce damage from sun exposure.
Health effects of ultraviolet radiation from sun exposure.
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