GIMME SHELTER- Got radon? January's the month to find out

Wolfgang Hermann
NRSB certified Radon Mitigation Specialist

Q: I recently read that January is National Radon Action month. Unfortunately, as a home owner, I don't know much about radon. What exactly is it, and how should I deal with it? 

A: Radon is an odorless radioactive gas that is a product of the breakdown of uranium in the soil. It's a natural disintegration and release of gas that takes place over millions of years. Uranium is present in most of the soil and rock locally and in other countries around the world. It's typically concentrated in areas with lots of granite, shale, phosphate, and limestone. 

The Environmental Protection Agency estimates that approximately 1 in 16 homes has an elevated radon level. Although radon in the outside air is essentially harmless, in a house the gas can't move freely and can accumulate in concrete basement floors or crawl spaces. The thermal flow inside the house (warm air rising upward) creates a vacuum that draws the gas through cracks in the floor and into living spaces. 

Exposure to radon can increase one's chances of lung cancer. In fact, scientists are more certain about radon risks than risks from most other cancer-causing substances. Smoking combined with radon exposure is an especially dangerous health hazard.

Radon gas in the air decays into radioactive particles that can be drawn into the lungs when people breathe. Scientists believe this form of radiation is approximately 20 times more damaging than x-rays. On average, radon causes around 20,000 lung cancer deaths in the U.S. each year.

The only way to detect radon is to have the house tested. Technicians use a radon monitor that measures and analyzes radon in the air every hour during a 48-hour period. 

Homeowners can also check radon levels by using an alpha track detector or carbon detector. An alpha track detector takes one to six months to determine radon levels. These detectors cost about $30, which includes postage and test data reports. Because tests like this monitor radon for a longer period, they are considered more accurate than the short-term carbon detector tests. Those can be conducted in two to seven days and cost $20 per kit. Such kits are available at local hardware stores or online.

Radon levels above 4 piCu/l must be mitigated to a safe level– below 2 piCu/l. There are several areas in and around Charlottesville with higher levels ranging from 4.1 to 16 piCu/l– or in rare cases, up to 100. Unfortunately, people don't find out about this until they're trying to sell their house. It's now mandatory in Virginia that radon tests be carried out as part of a home inspection.

There are several approaches to reducing radon levels. The most common system is called active soil de-pressurization, where a PVC pipe system with a fan draws air from underneath the concrete floor and discharges it safely above the roof. These typically cost between $900 and $1,300, including a follow-up test.

For more information, readers can visit the EPA's website at or the National Radon Safety Board at

Wolfgang Hermann