UV rays or ultra violet rays are the electromagnetic radiations emitted by sun. These radiations have both positive and negative effects its positive effects include vitamin D, warmth and light whereas negative effects includes tanning, sunburns, DNA damage and skin cancer. Its effects are also divided into acute or chronic as tanning and sunburns are short lived but skin cancer and DNA damage are long term effects.
Exposure to Ultraviolet rays causes chemical changes which alters the shape of your DNA this usually happens because UV radiation is selectively absorbed by DNA, mainly in the UV-B and UV-C regions. Due to excellent photochemical properties of DNA it is damaged by only a little fraction of absorbed photons. Other words for direct DNA damage are pyrimidine dimers and thymine dimers. Absorption spectrum of DNA shows a very strong absorption for UVB radiations and low for UVB radiations. Our cells are generally very good at repairing so its takes a lot of radiations to cause permanent damage and this damage affects our body because DNA has all the instructions for the functioning of our body so if our DNA is damaged our body won’t be able to get those instructions and thus won’t be able to function properly. our cells can repair the DNA if only one strand of the DNA is messed but if a lot of damage has been done problems like cancer occurs and these can be passed down to other generations too. Thus DNA damage could be a real problem if not taken care of that is why