General Radon Information

Iowa specific radon and radon level information can be found throughout this site. You will be able to find information about certified radon inspectors in Iowa, as well as detailed radon level information for every county in Iowa.

Radon is a radioactive gas found in nature. It has no color, odor or taste and is chemically inert. Its source is natural uranium in the earth. As the uranium molecule slowly decays, it forms lead and radon gas as by-products. Being a gas, radon moves upward out of the soil and into the atmosphere. Uranium is found in most soils and in granite.

Radon gas decays into radioactive particles that can get trapped in your lungs when you breathe. As they break down further, these particles release small bursts of energy that can damage lung tissue and lead to lung cancer over time. Not everyone exposed to elevated levels of radon will develop lung cancer and the time between exposure and the onset of the disease may be many years.

Like other environmental pollutants, some uncertainty exists about the magnitude of radon health risks. However, we know more about radon risks than risks from most other cancer-causing substances. This is because estimates of radon risks are based on studies of cancer in humans (underground miners). Additional studies on more typical populations are under way.

Smoking combined with radon is an especially serious health risk. Stop smoking and lower your home's radon level to reduce your lung cancer risk.

Children are reported to have greater risk than adults for certain types of radiation-source cancers. However, current data is inconclusive as to whether children are at greater risk than adults from radon.

Your chances of getting lung cancer from radon depend mostly on:

* Your home's radon level;

* The amount of time you spend in your home; and

* Whether you are a smoker or have ever smoked.

The Indoor Radon Abatement Act of 1988 directed the U.S. Environmental Protection Agency (EPA) to identify areas of the United States that have the potential to produce elevated levels of radon. EPA along with U.S. Geological Survey (USGS) and the Association of American State Geologists produced a series of maps and documents (EPA's Map of Radon Zones, CALIFORNIA 402-R-93-025). The maps of Radon Zones identify areas of each state that have the highest potential for elevated indoor radon levels (greater than 4 pCi/L) (California map, U.S. map). The maps were designed to assist national, State and local governments and organizations to target their radon program activities and resources and should not be used to determine radon levels of a given area or house within a particular county.

All houses should be tested for radon, if not during the sale or purchase, then after you take occupancy. Even houses in areas of low radon potential can have elevated radon levels. The probability of finding radon in your home is less in low radon potential areas; however, radon levels can differ dramatically from one home to the next. The only way to know if you have radon is to test your home.

In 1993, the National Institute of Environmental Health Sciences (NIEHS) funded the Iowa Radon Lung Cancer Study, a large-scale epidemiology study that assessed the risk posed by residential radon exposure. The 5-year study was performed in Iowa. Participants were over a thousand women throughout Iowa who jad lived in their current home for at least 20 years. Four hundred and thirteen of the participants were women who had developed lung cancer, the remaining 614 participants were controls who did not have lung cancer. The study was limited to women, because they historically tend to spend more time at home and they have less occupational exposure to other lung carcinogens.

Why Iowa? Iowa has the highest average radon concentrations in the United States. In addition, women in Iowa tend to move less than most other states, which makes calculation of their past radon exposure easier. Additionally, Iowa has a quality National Cancer Institute SEER cancer registry, which helped identify women who developed lung cancer. Close to 60% of the basement measurements for both cases (participants with lung cancer) and controls (participants without lung cancer) exceeded the EPA's action level. Twenty-eight percent of the living areas for the controls and 33% of the living areas for the cases exceeded the EPA's action level of 4 pCi/L.

The major paper reporting the findings was published in volume 151 of the American Journal of Epidemiology (pages 1081-1101) in 2000. The American Journal of Epidemiology is the premier scientific journal devoted to the publication of empirical research findings and methodologic developments in the field of epidemiologic research. Findings of the study were released to the press on May 25, 2000.