Radon is a radioactive gas known to cause lung cancer. The EPA explains that radon is naturally occurring and "comes from the natural decay of uranium found in nearly all soils." Furthermore, the government agency says, it doesn’t matter how new or old, drafty or sealed a home is or whether or not the home has a basement. Radon can seep into a home and become trapped, posing grave health risks.

The good news is that testing for radon is easy and affordable and will provide the information needed to remove radon if necessary. It is wise to request radon test results before buying a home or if when living in a home that has never been tested for radon. This map created by the EPA uses color coding to show radon levels in different parts of the country. Official testing by a certified radon measurement professional takes anywhere from two days to three months or a year, depending on the initial results. Professionals position a radon tracking device in the lowest lived-in level of the home to measure the home’s radon levels.

Radon is measured by its rate of decay, in units called "curies." Testing determines the levels of radon in the air. The EPA has determined a radon level of 4 picocuries per liter (4 pCi/l) or higher poses a notable health risk and means it’s time to take action. If testing reveals high levels of radon, longer tests—sometimes up to a year—may be required. Radon reduction measures, or “mitigation,” are solutions that remove the radon from homes. The first step is testing because radon is odorless, invisible, undetectable by the human eye and has no taste. If a radon test is positive, a home may also require radon mitigation services. Several factors affect the cost of radon testing.

Device and location

Radon measuring devices are generally either active or passive. Costs for testing vary, depending on the type of device, the part of the country where the testing is occurring, the testing company’s overhead and other factors. Here are some examples of cost:

• Radon testing by Master Home Inspectors in Tinley Park, Illinois: $275

  • $75 discount when purchased with a $300 home inspection for a total cost of $500

• Radon testing by Total Home Inspection Services in Wadsworth, Ohio: $125

  • 48-hour test using the AirCat constant monitoring system

  • 20 percent discount for military service members; 15 percent discount for first responders and teachers; 10 percent discount for first-time home buyers

• Radon testing by Plumb & Square Home Inspections in Boulder, Colorado: $150

  • $50 discount when purchased with a $250 home inspection for a total cost of $350

• Radon testing by Record Home Inspections in Hasbrouck Heights, New Jersey: $125

• Radon testing by Inspections Plus, Inc in Minneapolis, Minnesota: $150 when purchased with a complete home inspection

  • Solo radon testing may cost more.

Packages

Many radon measurement professionals are also certified home inspectors. Companies often offer a bundle of services at a lower cost per service than if each test or inspection is purchased individually. Here are examples of savings from Total Home Inspection Services:

• Home Inspection (for homes up to 3,500 square feet) and radon gas test: $435, which is a savings of $50

• Home Inspection (for homes up to 3,500 square feet), radon gas test and termite inspection: $490, which is a savings of $75

• Home Inspection (for homes up to 3,500 square feet), radon gas test, termite inspection, and well flow and potability investigation: $590, which is a savings of $95

Travel

Some radon testing companies charge additional travel fees if the house or building to be tested is outside of their standard service range. Inspections Plus, Inc, for example, provides service to properties within a 150-mile radius of its shop and charges 50 cents per mile outside of that radius.