UV stands for ultraviolet, which refers to a type of electromagnetic radiation with a wavelength shorter than that of visible light but longer than X-rays. UV radiation is categorized into three main types based on wavelength:
- UVA (320-400 nm): This type has the longest wavelengths and accounts for about 95% of the UV radiation reaching the Earth’s surface. It can penetrate deep into the skin and is associated with skin aging and long-term skin damage.
- UVB (280-320 nm): UVB rays have shorter wavelengths and are responsible for causing sunburn. They play a key role in the development of skin cancer but are also essential for the production of vitamin D in the skin.
- UVC (100-280 nm): UVC has the shortest wavelengths and is the most harmful type of UV radiation. However, it is mostly absorbed by the Earth’s atmosphere and does not reach the surface.
UV radiation has various applications, including sterilization and disinfection, fluorescent inspection, and phototherapy. It is also a natural component of sunlight, which can have both beneficial and harmful effects on human health.