What is Radon?

Radon, first discovered in 1910, is odorless, colorless, tasteless, and chemically inert. Radon is a radioactive gas. When rocks weather, these radioactive elements find their way into the soil and water. Under certain circumstances, radon can migrate through the soil and enter homes in quantities sufficient to become a health hazard. In order for this to happen, there must be a source of radon, the soil must be permeable, and there must be a conduit into the home. The most common points of entry are porous basement walls, cracks in concrete floors or slabs, and openings around utility accesses. Certain home sites exhibit reasonably predictable radon problems. These are :

  1. Homes built in areas where the rocks contain greater than normal amounts of uranium.
  2. Homes built over uranium-bearing veins and granite pegmatites.
  3. Home sites containing radium contamination.
  4. Sites in areas containing high radon concentrations in the ground water.
  5. Homes built on or constructed with radioactive materials such as uranium mill tailings.

Houses built in other areas of the Piedmont Province, particularly those built on the zone of phyllites running through central Montgomery, western Howard, eastern Frederick and central Carroll Counties can have indoor radon values far in excess of those considered safe by the Environmental Protection Agency. The sands and gravels of the Maryland Coastal Plain, in general, have been well oxidized and most of the uranium has been leached out and carried away. Certain Coastal Plain sediments, however, contain uranium-rich phosphate beds which are resistant to oxidation, and homes built on these formations may show elevated radon values. Studies indicate that often extremely localized geologic environments, coupled with the idiosyncrasies of building construction, play a major role in those Maryland homes containing abnormal concentrations of radon.

What are the Risks involved with elevated levels of Radon?

The Surgeon General has warned that radon is the second leading cause of lung cancer. If you smoke and you are exposed to elevated levels of radon, your risk of lung cancer is especially high.

How do I Know if I have a radon problem?

Testing for radon is the only way to know if you are at risk. A variety of methods can be used for detecting radon. The two most popular for the home owner are the carbon canister and the track etch. These devices are placed in either the basement or living area for a specific length of time and then returned for analysis to wherever they were purchased. It should be remembered that measurements can vary with location in the home as well as with the season. Ideally several readings should be taken at different times. Readings taken in the basement during the winter are usually the highest.

What do my test results mean?

No level of radon exposure is safe. However, the EPA recommends homes be fixed if an occupant's long-term exposure will average 4 picocurries per liter (pCi/L) or higher. pCi/L is a measure of the rate of radioactive decay of radon. One pCi/L is one trillionth of a curie, 0.037 disintegrations per second, or 2.22 disintegrations per minute. Therefore, at 4 pCi/L (EPA's recommended action level), there will be approximately 12,672 radioactive disintegrations in one liter of air during a 24 hour period.

What do I do if I have elevated levels of radon?

There are many ways to reduce the levels of radon in your home. You can contact us by E-mail, phone us toll free or click here to submit your information for an estimate directly from our website.


The following three consumer radon publications should answer most of your questions:

A Citizen's Guide to Radon

(402-K92-001, September 1994)

Home Buyer's and Seller's Guide to Radon

(402-R-93-003, March 1993)

Consumer's Guide to Radon Reduction

(402-K92-003, August 1992)


Contact Information:
Carl Pucci
(800) 773-8373

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