Health effects of radiation

The health effects from radiation depend on the type of radiation, the intensity of the radiation and the amount of time you are exposed.

On this page

• Ionizing radiation
• Non-ionizing radiation
• Noise (acoustical radiation)

Ionizing radiation

Low doses of ionizing radiation are not considered harmful to human health. While ionizing radiation can cause damage to human cells, these cells are very capable of repairing minor damage. In cases where damage cannot be repaired, or is repaired incorrectly, the cell may not be able to survive or reproduce. Most organs or tissues remain unaffected by the loss of a few cells.

In some cases, a damaged cell may remain viable but be modified, which may lead to abnormal cell growth, or cancer. The risk that this will happen is very low for a member of the public exposed to background levels of ionizing radiation from natural and industrial sources. A notable exception is chronic exposure to radon, where studies have shown that increased exposure to radon is associated with increased risk of lung cancer.

Higher doses of radiation can cause health effects. For example, astronauts and workers in the nuclear industry are at a higher risk for radiation-induced cataracts and take measures to protect themselves. Very high doses of ionizing radiation, especially if received over a short period of time, can cause acute health effects ranging from skin redness to acute radiation syndrome.

Non-ionizing radiation

Health effects can occur from exposure to non-ionizing radiation if the intensity of the exposure is high enough.

Extremely low frequency electromagnetic fields (EMF) can cause stimulation of peripheral nerves, which produces a tingling sensation. It can also cause stimulation of the muscles and nerves within the central nervous system.

Radiofrequency EMF can cause tissue heating at higher frequencies and stimulation of peripheral nerves at lower frequencies.

Light (optical) radiation can have different health effects depending on the frequency:

• infrared light can cause tissue heating
• visible light can cause:
  • vision loss
  • tissue heating
  • skin reddening
  • changes in melatonin levels
• ultraviolet light (UV) can cause:
  • cataracts
  • sunburns
  • skin cancer

Noise (acoustical radiation)

Noise can cause a number of health effects depending on the sound level and how long you are exposed. It can cause:

• annoyance
• disturbance of rest, sleep and concentration
• hearing damage, either temporary or permanent hearing loss

Chronic exposure to noise may also increase the risk of stress-related diseases.