What Does Radon Look Like And Where Is It Found?

You can't see, smell or taste radon, whether in water or air. In outdoor air, radon is generally diluted until it is not much of a threat. Inside, radon can accumulate to unhealthy levels.

The amount of radon that accumulates depends on the amount of radon being released by materials below the building, the kind of construction materials and ventilation systems used in the building, as well as the temperature: a heated building in a cold climate may draw in more radon than a building in a warm climate.

Since most radon enters the air from soil or rock, the lower rooms in a building are usually at more risk than the rooms higher up. It is also possible for one home to be exposed to high levels of radon while the home directly next door is not.

Radon in Water: Some of the first research to measure radon in water was conducted by the Cambridge University water system in 1902. Today, research continues with groundwater in the U.S. In the granite and pegmatite (a type of rock) areas of Maine and New Hampshire, as much as 1,300,000 picocuries per liter of water has been measured, according to studies published in 1976 in the "Proceedings of the Health Physics Society". Usually, however, water contains less radon than this.

Generally speaking, certain geographic regions contain higher levels of radon than others. Based upon EPA research (National Inorganics and Radionuclides Survey), there is a correlation between radon concentrations in drinking water (above 1,000 pCi/L) and the following geologic formations: New England mountain ranges, the Adirondack mountains, the Appalachians, the Ozark Plateau, the Black Hills, the Wasatch mountains, Edwards Plateau, the Sierra Nevada mountain range, the Salmon River mountains and Blue mountains.

Geographically, the following areas are considered to be at risk (radon concentrations in drinking water above 500 pCi/L):

• all New England states
• Alabama (Northern, Alabama)
• Arizona (Southern Arizona)
• California
• Colorado (Central Colorado)
• Florida (Tampa area)
• Georgia (Northern Georgia)
• Iowa
• Idaho
• Maryland
• Minnesota
• Missouri (Southern Missouri)
• North Carolina
• North Dakota
• New Jersey (Northern New Jersey)
• New Mexico
• Nevada
• New York (except New York City and Long Island)
• Oregon (Portland & Salem areas)
• Pennsylvania (Eastern Pennsylvania)
• South Carolina
• South Dakota
• Tennessee
• Texas (Austin & Amarillo areas)
• Utah
• Virginia
• Washington (Northeast Washington)
• Wisconsin
• West Virginia (Eastern West Virginia)
• Wyoming (Eastern Wyoming)

Radon can be released from radon-contaminated water during showers, or during the operation of a dishwasher or washing machine. More radon can be released as the temperature increases, and the surface area of the water exposed to air increases. Water must contain a high level of radon, however, to increase the overall level of indoor airborne radon gas.

Generally, 10,000 picocuries per liter of radon in incoming household water is considered to be equivalent to 1 picocurie per liter of radon in air.

Radon in Air: It was once thought that the only people exposed to high levels of radon were those who lived in homes over the Reading Prong (the geological formation containing high levels of uranium under Northern NJ, South Eastern NY. and Eastern Pa.). It is now known that substantial levels may be found in homes elsewhere.