radiation factors

Last reviewed 01/2018

Electromagnetic and particulate radiation is capable of traversing cells and causing damage to DNA. Animal experimentation and the effects of human exposure - medical, occupational and from the survivors of atomic explosions - have shown that tumours may be produced in almost every tissue.

The effect of exposure is cumulative and, for small doses, has a long latency before effects become apparent.

Different types of radiation are associated with particular neoplasms. Ionizing radiation generally causes thyroid and bone marrow cancer. The prime example of the latter is the increased incidence of acute and chronic myelocytic leukaemia in the wake of the atomic bomb dropped on Hiroshima.

Ultraviolet irradiation is associated with skin tumours, the classic example being that of the raised incidence in Caucasian Australians who have reported multiple episodes of 'sunburn'. There is also a set of autosomal recessive conditions in which ultraviolet radiation DNA damage seems to be poorly repaired due to a genetic abnormality, thus predisposing the individual to cancer. Examples include xeroderma pigmentosum, Fanconi's anaemia and Bloom's syndrome.