· X rays are a form of electromagnetic radiation that penetrates body tissue.
· The body absorbs some of the X rays while the rest emerges on the other side to expose the film creating an image.
· Belonging to the high end of the electromagnetic spectrum, they carry high frequency and a lot of energy.
· An X-ray track passing through a cell may directly disrupt the molecular bonds of cellular material such as DNA leading to abnormal cell replication and initial event of carcinogenesis
· The high energy of x-rays causes water molecules to be ionised into HO, HO2 free radicals or hydrogen peroxide H2O2 that have the ability to disrupt molecular bonds.
· These free radicals cause breakage in DNA double bonds leading further to induction of mutations, chromosome aberrations and cell death.
· Rapidly multiplying cells like those of gastrointestinal, skin or gonads are more affected.