Our body is made of billions of cells which are arranged to form organs. Approximately one and a half metres of DNA are stored in each cell.
DNA undergoes permanent attacks and there a numerous aggressive agents. The following can be mentioned: solvents and pesticides, combustion smoke, viral aggressions, ultraviolet radiation, ionising radiation. All molecules can be affected by radiation, but it is when DNA is impacted that there are the greatest consequences for cellular operation.