WHAT ARE ULTRAVIOLET RAYS?Sahadat Hossain
WHAT ARE ULTRAVIOLET RAYS? ARE THEY HARMFUL TO HUMANS?
Ultraviolet Rays or UV rays for short is a type of electromagnetic radiation that causes many negative health factors to the human body. Exposure to UV rays is damaging not just to the human body, but also things surrounding us. It damages living tissues and causes sunburns, sun tans, eye cataracts etc. Where does electromagnetic radiation comes from? Pretty obvious: The Sun. It is transmitted in waves at different wavelengths and frequencies. Ultraviolet rays are divided into three categories:
- UVA, or near UV (315–400 nm)
- UVB, or middle UV (280–315 nm)
- UVC, or far UV (180–280 nm)