The shortest UV wavelength spectral region, UVC, is negligible at the surface of the earth as it is mostly absorbed by the ozone in stratosphere. The three UV spectral regions are classified as UVA (320 - 400 nm), UVB (290 - 320 nm) and UVC (100 – 280nm). There are three spectral regions for incoming UV radiation. Ultraviolet radiation (UV) is part of the electromagnetic (light) spectrum that reaches the earth from the sun with wavelengths shorter than the visible spectrum. However, over-exposure to it may lead to short and long-term adverse effects on the skin, eyes and immune system. Small amounts of UV radiation are essential for the production of vitamin D in humans. The sun is the strongest source of UV radiation in our environment. Emissions from the sun include light, heat and UV radiation.
Everyone is exposed to ultraviolet (UV) radiation from the sun and other artificial sources used in industry, commerce and recreation.
