Radiation is energy that travels as a wave or particle. Some types of radiation, called ionizing radiation, can be harmful. Radioactivity is ionizing radiation that is given off by substances, such as uranium, as they decay.
About half of the ionizing radiation we're exposed to comes from nature. It's in rock, soil, and the atmosphere. The other half comes from man-made sources like medical tests and treatments and nuclear power plants.
There is always a risk of damage to cells or tissue from being exposed to any amount of ionizing radiation. Over time, exposure to radiation may cause cancer and other health problems. But in most cases, the risk of getting cancer from being exposed to small amounts of radiation is small.
The chance of getting cancer varies from person to person. It depends on the source and amount of radiation exposure, the number of exposures over time, and your age at exposure. In general, the younger you are when you are exposed to radiation, the greater the risk of cancer.
Exposure to small amounts of radiation doesn't cause any symptoms. But exposure to large amounts all at once may cause radiation sickness and death.
Some sources of radiation give off larger amounts than others. For example, when you go through a full-body airport scanner, you're exposed to very small amounts of radiation. But if you live near the site of a nuclear accident, you're exposed to large amounts of radiation.
You may be exposed to more radiation than other people if you:
To understand more about radiation exposure, you may find it helpful to compare some common sources of radiation to a standard dose from a chest X-ray. A chest X-ray gives off very small amounts of radiation.
You can't avoid radiation that occurs naturally. But there are some things you can do to reduce your exposure to man-made sources.
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ByHealthwise StaffPrimary Medical ReviewerKathleen Romito, MD - Family MedicineAdam Husney, MD - Family MedicineSpecialist Medical ReviewerR. Steven Tharratt, MD, MPVM, FACP, FCCP - Pulmonology, Critical Care Medicine, Medical Toxicology
Current as ofMay 7, 2017
Current as of:
May 7, 2017
Kathleen Romito, MD - Family Medicine & Adam Husney, MD - Family Medicine & R. Steven Tharratt, MD, MPVM, FACP, FCCP - Pulmonology, Critical Care Medicine, Medical Toxicology
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Last modified on: 8 September 2017