Protection against UV Rays
What is UV radiation?
UV (ultraviolet) radiation is light with wavelengths shorter than visible light. The human eye can perceive light with wavelengths between 430 nanometers (violet) and 790 nanometers ? (red). UV radiation is energy that moves very quickly. The human body cannot withstand exposure to large amounts of UV radiation.
Scientists divide UV radiation into three categories according to their wavelength: UV-A (315-400 nm), UV-B (290-315 nm) and UV-C (220-290 nm). UV-A radiation makes up the largest part of the UV radiation that reaches the earth. Its wavelengths are longer than UVB's and can penetrate deeper into our skin layers. UV-A is considered the main cause of skin aging. UV-A radiation also causes photochemical smog, discoloration and damage to wood, plastic, paint and fabrics.
Exposure to UV rays in general can cause skin cancer, premature aging of the skin, wrinkles, cataracts and other damage to the eyes. Only 1% of solar radiation is UV-B radiation and most of this is absorbed by the ozone layer. Yet UVB rays can do the most damage to human skin. UV-C radiation is completely absorbed by the ozone layer and other gases and does not reach the earth. Even small doses of radiation can cause significant damage over time. In addition, small changes in the ozone layer can cause significantly more UV-B rays to reach the earth.
According to The Skin Cancer Foundation, excessive exposure to UV rays not only causes sunburn, but also accelerates skin aging and increases the risk of skin cancer.