Ultraviolet radiation, also referred to in the literature as UV radiation, is emitted by the sun, and among them, it is the most energetic. It is a type of electromagnetic radiation with a wavelength between 200 and 400 nm and a frequency greater than that of visible light. This fact derives its name since violet is the color that has the highest frequency among those that human eyes can see.
The electromagnetic radiation called UV is the strongest and therefore poses many dangers to living beings present on Earth. However, the Earth’s surface receives a lower incidence of these rays thanks to the ozone layer, which ends up protecting us from their harm. The layer is between 12 and 32 km in the Earth’s atmosphere, acting as a shield.
The three different types of classification of ultraviolet rays have different characteristics and, therefore, it is necessary, when talking about them, to divide them.
UVA: with a wavelength between 320 and 400 nm, UVA rays are the ones that most affect the Earth’s surface. This happens because the ozone layer does not absorb these. Lightning of this type strikes equally during seasons of the year, days, and climatic differences; that is, the rays strike the same way on a sunny day and a rainy day.
UVB: the ozone layer partially absorbs UVB rays and, with a wavelength between 280 and 320 nm, are more incident during the summer. Furthermore, in regions of high altitudes and close to the equator and between the hours between 10 am and 4 pm. That’s why we often hear on summer days that you shouldn’t stay in the sun, even when you go to the beach, between that time.
UVC: the wavelength of UVC rays ( รังสี ยู วี ซี which is the term in Thai) is less than 280 nm. With that, we conclude that it is the one that comes closest to visible light. Despite being very harmful to the biosphere, these rays do not reach the Earth’s surface, as the ozone layer entirely absorbs them. Its reproduction is made artificially for water treatment and material sterilization processes.
Also, be very aware of the protection factor, usually issued on packaging as FPS. This number will determine how often the protector should be re-applied. Another way to prevent harm is to wear sunglasses with protection, thus avoiding problems such as cataracts and loss of vision.