UV radiation is electromagnetic radiation whose wavelength ranges from the edge of the violet spectrum to the edge of X-rays. It is worth noting that the first mention of this phenomenon arose in the thirteenth century. It was then that Indian philosophers in their writings described the atmosphere, which contained violet rays, invisible to the naked eye.
At the end of the 17th century, when the infrared spectrum was discovered, scientists around the world began to study radiation at the opposite end of the light spectrum. This is how ultraviolet radiation was first discovered and studied. In 1801, J. W. Ritter discovered that silver oxide darkens faster when exposed to invisible light in the violet part of the spectrum.
About the same time, scientists came to the conclusion that light consists of three separate parts. This is the so-called visible light (or lighting component), infrared and ultraviolet radiation (it is also restorative). In the future, researchers actively investigated the effect of ultraviolet radiation on livingorganism, as well as its role in nature.
UV radiation: properties and classification
Today, ultraviolet rays are usually divided into three main types, each of which has its own characteristics:
- UV-C, better known as gamma rays. It should be noted right away that they are very dangerous for the he alth of the human body. Fortunately, such radiation is almost completely absorbed by oxygen, the ozone layer and water vapor while passing through the planet's atmosphere.
- UV-B is another type of radiation that is also almost completely absorbed by the Earth's gaseous envelope. No more than ten percent reaches the surface. By the way, it is under the influence of these rays that melanin is produced in human skin.
UV-A. This type of rays almost completely reaches the surface of the planet and is practically harmless to living organisms. Prolonged exposure causes accelerated skin aging
As for the properties, for starters it is worth noting that ultraviolet radiation is invisible to the naked eye. In addition, it has a high chemical activity and is a catalyst for many natural reactions. High concentrations of ultraviolet light have antibacterial properties. And, of course, we must not forget that in small doses it has a positive effect on the human body.
UV radiation and its effect on the human body
It is immediately worth noting that it is ultraviolet rays that contribute to the formation of vitamin D in human skin, which, in turn, ensures normal calcium metabolism in the body and a good condition of the skeletal system. In addition, the rays of this particular spectrum are responsible for the biological rhythms of a living organism. It has been proven that ultraviolet light increases the level of the so-called “energy hormone” in the blood, which ensures a normal emotional state.
Unfortunately, ultraviolet radiation is useful and only needed in small doses. Excessive exposure to these rays causes the opposite effect. For example, with prolonged exposure to the skin, ultraviolet accelerates the aging process, and in some cases causes burns. Sometimes radiation leads to cell mutations, which can subsequently degenerate into malignant tumors.
Enhanced ultraviolet radiation also adversely affects the retina, causing burns. Therefore, in the sunny season, it is simply necessary to use special protective glasses.
