How does Radiation attacks the human body?
As highly charged ionizing radioactive particles or waves enters your body, it enters your body by going through your skin, the amount of energy that radiation contains can start stripping off electrons from an atom, causing the stable to become an ion, or a charged atom, which is why it is called ion-izing radiation. If the energy contained in the radiation particles or wave is high enough, it is able to destroy the nucleus of the atom, which will destroy the atom. When this happens the base pair of your DNA, which contains important genetic information about the cell functions can be damaged in an instant. This will causes mutation in the DNA strands, it can make a cell produce the wrong amino acids, or even replace the stop codon with something else, causing problems in the cells and mitosis.
With mutations in DNA, the cell can't carry out its normal function, but just takes up space. These cells are called cancer cells. They will start multiplying and soon multiply out of control, causing tumors. They can spread to important areas of the body, possibly clogging up or destroying important organs, causing what we know as cancer.
Melanoma is a common cancer in the U.S, caused by overexposure to Ultraviolet rays, which is a part of radiation.