UV Solar Radiation
Posted by ecostinger on 14th Aug 2014
What is UV radiation?
Emissions from the sun include light, heat and UV radiation. The UV region covers the wavelength range 100–400 nm and is divided into three bands, UVA, UVB and UVC.
All UVC and approximately 90% of UVB radiation are absorbed by ozone, water vapour, oxygen and carbon dioxide. UVA radiation is less affected by the atmosphere. Therefore, the UV radiation reaching the Earth’s surface is largely composed of UVA with a small UVB component.
UV Radiation levels are influenced by:
Sun Elevation: The higher the sun in the sky, the higher the UV radiation level.
Latitude: The closer to equatorial regions, the higher the UV radiation levels.
Cloud Cover: UV radiation levels are highest under cloudless skies but even with cloud cover, UV radiation levels can be high.
Altitude: At higher altitudes, a thinner atmosphere absorbs less UV radiation.
Ozone: Ozone absorbs some of the UV radiation that would otherwise reach the Earth’s surface.
Ground Reflection: UV radiation is reflected or scattered to varying extents by different surfaces.
Most of the known radiations that we must know about: .
- Ultraviolet A (UVA): (wavelengths between 320 and 400nm) It is the longest wavelength of the sun, this can go through your the skin's deepest layer. Sun damage can activate free radicals and promote skin aging.
- Ultraviolet B (UVB): (wavelengths between 290 and 320nm) This wavelength go into the skin's upper layer, outermost layers of cells in the skin. These rays cause sunburn, allergic reactions and skin cancers. After six times of being burned, the skin has double the risk of developing melanoma (a type of skin cancer. It can develop from abnormal moles)
- Ultraviolet C (UVC): (wavelengths between 200 and 290nm) UVC in sunlight does not reach earth's surface Generally these rays are filtered by the ozone layer so it will not reach the earths surface and they're the most damaging rays.
- Infra-Red (IR): It is the "heat" from the sun and too much can negatively impact collagen, elastic and your immune system.
The best way to protect the skin is by wearing special type of clothing which can block the sun UV radiation. Cover up as much skin as you can by wearing sun protection clothing, using tightly knitted fabrics which has been tested and verified to offer UPF50+ cover. Adding a sun hat and sunglasses will provide adequate protection and help keep you safe, also applying sunscreen on exposed skin will ensure nothing is left to chances.