When someone tells you that too much sun is bad for you, they say that because they know that too much sunlight causes cancer. Skin cancer is caused by mutations caused by ultraviolet radiation. This Ultraviolet radiation is detrimental to the human body. Ultraviolet radiation has been established as a genotoxic agent. A genotoxic agent is a chemical agent that damages genetic information within the cell. This causes a mutation and the mutation may lead to cancer ( Bianchi, J. et al. 2013). But what exactly is ultra violet radiation?
The sunlight that reaches us is made up of two types of harmful rays: long wave ultraviolet A (UVA) and short wave ultraviolet B (UVB) There’s also a third type of ray, UVC, these are the shortest and strongest, but they are absorbed by the ozone layer and don’t typically reach the Earth ( Bianchi, J. et al. 2013). However, in many experiments UVC is used.
What We Already Know on Effects of UVB Waves on DNA Bases.
UVB radiation is the most energetic component of solar radiation that hits the earth’s surface. The main photochemical reactions within cellular DNA involve mostly the direct absorption of UVB photons by the DNA bases, mostly pyrimidine constituents, including thymine, cytosine and the minor 5-methylcytosine ( Bianchi, J. et al.).
It was also shown recently that purine bases may also be the target of UVB radiation, although to a smaller extent, as the result of the direct absorption of photons within the wavelength range 290–320 nm