Skip Navigation

Tox Town - Environmental health concerns and toxic chemicals where you live, work, and play
Radonen español
Radon is a radioactive gas found in some homes. You can test for radon in your home.

What is radon?

Radon is a radioactive gas that is formed naturally from the radioactive decay of uranium in rocks and soil. The chemical symbol for radon is Rn. It can remain in the soil, move to the soil surface and enter the air, or enter groundwater. It is more common in some areas of the country than others. 

Radon is colorless, odorless, and tasteless, but extremely toxic. When cooled below the freezing point, radon becomes phosphorescent, in yellow and orange-red tones. 

Radon was previously used to treat cancer, arthritis, diabetes, and ulcers. It is currently used to predict earthquakes, study atmospheric transport, and explore for petroleum and uranium. It is also used to initiate and influence chemical reactions, in the study of surface reactions, and as a tracer in leak detection.

How might I be exposed to radon?

You can be exposed to radon through breathing or swallowing it, either as a gas or as particles of radon that attach to dust. You can be exposed to very low levels of radon in outdoor air. 

If you live in an area where the amount of uranium and radium in rocks is high, you can be exposed to higher levels of radon indoors and in underground work areas such as mines. If radon is in the rocks and soil around a building, cracks in the building's basement or foundation can allow radon to move into the building. You can also be exposed to radon by drinking water obtained from wells that contain radon. 

You can be exposed to higher levels of radon at work if you are a uranium miner, a hard rock miner, or work in tunnels, power stations, public baths, or spas.

How can radon affect my health?

Radon is listed as a human carcinogen in the Thirteenth Report on Carcinogens published by the National Toxicology Program because it causes lung cancer. Exposure to high levels of radon can cause other lung diseases such as emphysema and thickening of lung tissues. Simultaneous exposure to radon and cigarette smoking can increase the incidence of lung cancer and lung disease.

For poisoning emergencies or questions about possible poisons, please contact your local poison control center at 1-800-222-1222.

This description is based on the information found in the Web links listed with this topic.


Web Links from MedlinePlus (National Library of Medicine)
Radon

More Links
Map of Superfund Hazardous Waste Sites with Radon in the United States. TOXMAP (National Library of Medicine)
Radon home page (Environmental Protection Agency)
Radon, Radioactive. Hazardous Substances Data Bank (National Library of Medicine)
Radon. Haz-Map (National Library of Medicine)
Radon. ToxFAQs (Agency for Toxic Substances and Disease Registry)
What Is Radon? (Navy and Marine Corps Public Health Center) (PDF — 203.07 KB)

Locations where Radon may be found: more neighborhoods >>
City
City
Farm
Farm
Town
Town
Drinking Water
Factory
Homes
Hospital
Indoor Air
Offices and Stores
School
Drinking Water
Homes
Hydraulic Fracturing
Indoor Air
Drinking Water
Factory
Homes
Indoor Air
Mining
Offices and Stores
School
<< previous neighborhoods
US Border Regions
US Border Regions
Port
Port
US Southwest
US Southwest
Drinking Water
Homes
Indoor Air
Maquiladora
Tienda
Drinking Water
Homes
Indoor Air
Offices and Stores
Abandoned Mines
Drinking Water
Homes
Hydraulic Fracturing
Indoor Air
Mining
Oil and Gas Fields
Uranium Tailings
Water Wells

Last Updated: October 7, 2014

Interactive Graphic Neighborhoods City Farm Town US Border Regions Port US Southwest