Skip to main content
Hong Kong Observatory Brand Hong Kong - Asia's world city
GovHK Traditional Chinese Simplified Chinese Search
Search Site Map Contact Us
Print Version
Print Version PDF Version

How does ionizing radiation affect our body?

The radiation affects human body in highly complicated processes. Various degrees of biological effects, from damage to death of living tissues, involve a number of pathological changes in human cells.

When exposed to ionizing radiation, large molecules such as nucleic acid and proteins in the cells will be ionized or excited. This may cause changes in the molecular structures which then affect the function and metabolism of the cells. Laboratory experiments have demonstrated that ionizing radiation can cause breakage of the DNA chain or can deter cell replications. In addition, the production of harmful free radicals (e.g. OH-1, H+ etc.) by the ionization of water molecules due to radiation may lead to changes in OH molecules that are biologically important for the functioning of cells.

Although radiation can cause damage to living tissues, human cells however can repair the damage through natural metabolic processes if the absorbed dose is not high. Recovery of cells depends on the degree of initial damage and may be different for different individuals.

Understanding the effects of radiation on human bodies provide useful information for the development of radiation protection measures. A quantitative measure of the hazards induced by radiation is the "risk factor". Press here for details.


Radiation hazards
The above information is provided by RHD of DH
Department of Health

Previous Page
Next Page
Last revision date: <01 Oct 2019>