HAVE TO BE A PROBLEM
Radon is a radioactive gas that is as natural as air and water, but it cannot be detected by our senses. You cannot see, smell or taste radon. Radon gas is formed by the natural decay of radium, which results from the decay of uranium. Both radium and uranium are very common elements present in Arizona soils and rock.
The only way to know how much radon is in a home is to test.
The presence of uranium in Arizona is not surprising to geologists. In fact, uranium mining was practiced in many parts of the state from the 1950s to the 1980s. Some Arizona residents mistakenly assume their home will not have a radon concern unless the home is located near the site of a uranium mine. However, the amount of uranium in soil needed to cause a concern for residential radon is far less than the amount needed to support uranium mining.
For more detailed information about radon as a geologic hazard in Arizona, plus links to other radon information sites on the Internet you can visit the Arizona Geological Survey's radon information page at: http://www.azgs.state.az.us/radon_info.htm.
Radon incidence in Arizona is similar to the national average.
Results from the state indoor radon sampling survey conducted 1987-89 by the Arizona Radiation Regulatory Agency suggest that about 1 out of 15 Arizona homes may contain radon concentrations in excess of the EPA recommended action level of 4.0 picocuries per liter of air (4.0pCi/L). That rate is similar to the national average. However, Arizona's warm temperate climate can result in a lower thermal suction on the soil beneath homes than is typically found beneath houses situated in a more northward latitude. Thus, even though radon is present, less may be drawn into a home here than in a comparable home in many other states.
Evaporative coolers can help.
Indoor radon concentrations can also be reduced by the use of evaporative coolers, sometimes called "swamp" coolers, because they push cooled outdoor air into a building. This dilutes indoor radon levels and can offset the air-pressure differences that typically bring radon into a home from the soil below.
Sub floor air ducts can allow radon entry.
Some Arizona homes have forced air conditioning systems that include a feature not often found in colder climates; return air ducts located in the soil below slab floors. If these ducts are not airtight, radon-laden air from the surrounding soil can be drawn into the house through the ducts, resulting in higher indoor radon and increased mitigation cost.
Residential usage patterns can impact average indoor radon levels.
Over time, the way residents actually use a home can strongly affect the level of indoor radon. For example, if the windows remain closed year-round, the home's average radon level will usually be higher than if occupants frequently ventilate the home when weather permits.
Arizona Radon Facts
What Makes Some Areas Higher in Radon Than Others?
The amount of radon in a building is dependent upon:
Ventilation rate of building:
usage patterns can also have an impact on average indoor radon levels: