Radon Information

Radon Information

NE Ohio Radon Gas Information – Re-Printed From the Ohio EPA Web Site

Found all over the U.S., radon is a naturally occurring radioactive gas without color, odor, or taste that comes from the radioactive decay of uranium in soil, rock, and groundwater. Radon tends to concentrate in enclosed spaces like underground mines or houses. Soil gas infiltration is recognized as the most important source of residential radon. Other sources, including building materials and water extracted from wells, are of less importance in most circumstances.

Radon gets into the indoor air primarily from soil under homes and other buildings. Radon is a known human lung carcinogen and is the largest source of radiation exposure and risk to the general public. Most inhaled radon is rapidly exhaled, but the inhaled decay products readily deposit in the lung, where they irradiate sensitive cells in the airways increasing the risk of lung cancer.

The EPA estimates that about 20,000 lung cancer deaths each year in the U.S. are radon-related. Exposure to radon is the second leading cause of lung cancer after smoking. Lung cancer is the only known effect on human health from exposure to radon in air. Thus far, there is no evidence that children are at greater risk of lung cancer than adults.

Smoking is the leading cause of lung cancer. Smoking causes an estimated 160,000* cancer deaths in the U.S. every year (American Cancer Society, 2004).  And the rate among women is rising. Lung cancer now surpasses breast cancer as the number one cause of death among women.  A smoker who is also exposed to radon has a much higher risk of lung cancer.

Radon is the number one cause of lung cancer among non-smokers, according to EPA estimates. Overall, radon is the second leading cause of lung cancer.  Radon is responsible for about 21,000 lung cancer deaths every year. About 2,900 of these deaths occur among people who have never smoked. 

(One) report found that even very small exposures to radon can result in lung cancer and concluded that no evidence exists that shows a threshold of exposure below which radon levels are harmless. The report also concludes that many smokers will get lung cancer due to their radon exposure who otherwise would not have gotten lung cancer. This is because of the synergistic relationship between radon and cigarette smoking in causing lung cancer.

The EPA recommends homes be fixed if the radon level is 4 pCi/L (pico Curies per Liter) or more. Because there is no known safe level of exposure to radon, EPA also recommends that Americans consider fixing their home for radon levels between 2 pCi/L and 4 pCi/L. The average radon concentration in the indoor air of America’s homes is about 1.3 pCi/L. It is upon this level that EPA based its estimate of 20,000 radon-related lung cancers a year upon. It is for this simple reason the EPA recommends that Americans consider fixing their homes when the radon level is between 2 pCi/L and 4 pCi/L. The average concentration of radon in outdoor air is .4 pCi/L or 1/10th of EPA’s 4 pCi/L action level.

Radon is a naturally occurring, gaseous element that is a by-product of the radioactive decay of another element, uranium. When an atom of uranium decays to radon it does so by transforming itself into a series of different radioactive elements, each a decay by-product of the preceding one. The series passes ultimately through radium directly to radon, which, in turn, decays to other elements. Of all the elements produced in the uranium decay series, only radon is a gas.

Because radon is a gas, it easily drifts upward through the ground to the Earth’s surface. How much of it reaches the surface depends on the uranium content of the underlying earth materials together with their depth and permeability (that is, the presence of fractures and interconnected pore spaces that act as conduits for radon). Radon will enter the lowest level of a building using whatever pathways are available. For structures with basements or slab-on-grade foundations, the entry points include (1) cracks and pores in floor slabs, walls, and floor-wall joints; and (2) openings around sump pumps, floor drains, and pipes penetrating floors and walls. Structures with a crawl space between the ground and lowest floor level may be less vulnerable to radon, which tends to escape to the outside air when appropriate vents are installed, but can still admit some of the gas through cracks in the flooring.

In Ohio, a geologic formation known as the “Ohio Shale” is enriched in uranium in amounts commonly between 10 and 40 ppm. This black, organic- and clay-rich rock originally formed 370 million years ago as a muddy sediment on the bottom of an ancient sea. The formation, which is only uraniferous west of the longitude of Cleveland, now underlies the surface of Ohio in a narrow belt running westward along the Lake Erie shore from Ashtabula County to Erie County, where it turns south and continues through the middle of the state, including Franklin County, and crosses the Ohio River in Adams and Scioto counties. This formation also underlies parts of Logan County in the west-central part of the state.

Much of the soil in Ohio contains quantities of uranium and radium. These minerals continuously break down to release radon gas. Therefore, Ohio’s geology provides an ongoing supply of radon.

In addition, a large percentage of Ohio homes have high levels of radon in the indoor air because of how they are built and how they are operated in our climate. One important factor is that many Ohio homes have basements that are used as living spaces. ODH estimates that about one in two of Ohio homes have enough radon to pose a large risk to the occupants’ health over many years of exposure. In some areas of the state, the percentage of homes that have high levels of radon is even larger.

A licensed radon tester may be used when an unbiased third party is desired. Under Ohio law, only the homeowner may test; any other tester must be an Ohio licensed radon tester. Although tests by licensed testers should be of high quality, they are still subject to the uncertainties related to the timing and duration of the test (see ODH fact sheet, Radon Testing and Use of Test Results, available by calling 1-800-523-4439).

Radon Test results by county:

Percent of actual Radon Test results for each range by county:

Radon Test Results By NE Ohio Zip Code: