Radiation is energy that travels as a wave or particle. Some types of radiation can harm you. These types are called ionizing radiation. When this radiation is given off by substances such as uranium as they decay, it's called radioactivity.
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. These include medical tests and treatments and nuclear power plants.
There is always a risk of harm to cells or tissue when you get any amount of ionizing radiation. Over time, exposure 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:
In general, the younger you are when you are exposed to radiation, the greater the risk of cancer. For example:
Exposure to small amounts of radiation doesn't cause any symptoms. But getting large amounts all at once may cause radiation sickness and death.
Some sources give off larger amounts of radiation than others. For example, when you go through a full-body airport scanner, you get very small amounts. But if you live near the site of a nuclear accident, you're exposed to large amounts.
You may be exposed to more radiation than other people if you:
It may be 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 around you in nature. But there are some things you can do to reduce how much you get from man-made sources.
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Current as of: July 29, 2016
Adam Husney, MD - Family Medicine
& Kathleen Romito, MD - Family Medicine & R. Steven Tharratt, MD, FACP, FCCP - Pulmonology, Critical Care Medicine
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