Ultraviolet Rays

The Electromagnetic Spectrum

Have you ever wondered by looking up the sky and thinking about what causes the deep blue color? You may not realize but electromagnetic waves play a major role in this.


The electromagnetic spectrum is the combination of radio waves, microwaves, infrared waves, visible light, UV light, and also X-rays and gamma rays. The interesting thing is, electromagnetic waves travel through the empty space and it travels very quickly to be about 3 x 108 m/s. 


Electromagnetic Spectrum - Ultraviolet Rays

Ultraviolet rays are the part of the Electromagnetic Spectrum ranging from the end of the visible light range to the X-ray region. It is harmful rays as a continuous effect on humans can cause skin and eye disorders. Moreover, it is the source of Vitamin D, plays an important role in human growth.


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A large amount of UV rays comes from the sun is absorbed by the ozone layer in the atmosphere. Some other sources of UV rays are black lights, mercury lamps, and tanning lights.


Wavelength and Frequency of Ultraviolet rays

Since all the electromagnetic waves travel at different speeds through the vacuum, their wavelength and frequency vary.


The frequency of a wave is defined as the number of times it repeats in a second. Its unit is Hertz. In the case of electromagnetic waves, the wavelength is measured in units of nanometres.


Ultraviolet rays have a shorter wavelength when compared with visible light and so we are not able to see in our naked eyes.


Ultraviolet rays were present in the wavelength range from around 10 nm to around 400 nm. It has a frequency ranging between the 800 THz to 30 PHz.


According to physics, UV radiation is divided into four regions - 

Near (400 – 300 nm)

Middle (300 – 200 nm)

Far (200 – 100 nm)

Extreme (below 100 nm)


On the interaction of ultraviolet radiation wavelength with biological materials, it is divided into three divisions - 

UVA (400nm – 315 nm) 

UVB (315nm – 280 nm) 

UVC (280nm – 100 nm)


Uses of UV Rays

UV light is found in nature from sunlight and the application of sunlight is present in every field. It is present in both commercial and industrial purposes. Generally, it is used in purifying air, water treatment, skin treatment, indoor gardening, things identifying, and more uses by UV lamps.


UV rays are used in a wide range, ranging from medical therapy to photography. 


UV Light in Tanning

When your body skin is exposed to UVB rays, your body produces a pigment called melanin, which absorbs UV rays and results in heat in your skin.


When the body sends this melanin into besides cells, your body goes black.

In the same way, tanning booths use man-made UV light lamps, which pass an electric current through a gas (vaporized mercury gas ).


UV Light in Chemistry

In chemistry, UV light is used to analyze the compound's chemical structure through its color change. A spectrophotometer is a machine used here, it passes a UV light beam into the solution. It shows how much of the UV radiation is absorbed with the observation of color change in the solution. It is widely used in the testing of water quality, and also in hospitals, food industry. 


Ultraviolet Light in Indoor Gardening

UV light plays a major role in the production of polyphenols. It is a plant used in the prevention of cancer and also for a young look. Moreover, it helps in improving the medicinal properties of cannabis.


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UV lights are used in the production of polyphenols. It is a very beneficial plant and is said to prevent cancer. It can also make you look young. It can help in raisin production as well. It can also help in the production of medical cannabis. In fact, the UV light helps in improving the medicinal properties of cannabis.


Uses of Ultraviolet Rays in Biology

Ultraviolet Rays in Killing Cells

UV light kills cells of the human body by damaging their DNA. When a UV light falls on the body, it initiates a reaction between two molecules of thymine, which is responsible for making DNA.


Then remove the two bases and nucleotides are filled in between the gaps.

In case the UV light is exposed for a longer time, the more thymine dimers are formed in the DNA.


The risk of getting incorrect repair also increases. If it happens, the cell cannot continue its actual work. Depending upon the location of damage, cells are created from healthy cells, or else it will die if it undergoes widespread damage.


UV Radiation in Clinical

UV radiation is used in the treatment of psoriasis, and in recent years UV rays are used for the treatment of dermatological conditions.


In chronic open wounds, UV is used as an occasional component. Usually, UV rays are used in the treatment of skin disorders.

FAQ (Frequently Asked Questions)

1. What is Solar UV Radiation (UVR)?

Answer. Solar radiation is a form of electromagnetic radiation that comes from the sun. When it reaches the Earth's surface, it has visible light and infrared radiation. Visible light is seen by us whereas IR is felt as heat in our skin. Ultraviolet radiation is also present, but it is invisible and having higher energy. It can cause damage to our organisms.

2. How to get Enough Vitamin-D from the Sunlight Without Having much Exposure?

Answer. The UV rays present in the sun is the key factor for both, in skin cancer and in getting vitamin-D. We have to expose our skin to sunlight in order to get vitamin-D, but for a certain limited time only. The total time of exposure to sunlight is varied by, time of year, location of sunlight, surrounding factors. 


The sun's UVR is both the major cause of skin cancer and the best source of vitamin D. In Australia, we need to balance the risk of skin cancer from too much sun exposure with maintaining adequate vitamin D levels. Sensible sun protection does not put people at risk of vitamin D deficiency. In more cases, people get their vitamin-D from the sun by their day-to-day regular activities and some people have to take care of exposure to sunlight.