Radon is a naturally-occurring radioactive gas that may cause cancer, and may be found in drinking water and indoor air. Some people who are exposed to radon in drinking water may have increased risk of getting cancer over the course of their lifetime, especially lung cancer. Radon in soil under homes is the biggest source of radon in indoor air, and presents a greater risk of lung cancer than radon in drinking water. As required by the Safe Drinking Water Act, the EPA has developed a proposed regulation to reduce radon in drinking water that has a multimedia mitigation option to reduce radon in indoor air.
Here we will address:
- Radon Myths & Facts
- Provide an EPA Map of Radon Zones
- Outline the Health Risks of Radon
- Provide Information about Radon in Drinking Water
Radon Myths & Facts
Myth: Scientists are not sure that radon really is a problem.
Fact: Although some scientists dispute the precise number of deaths due to radon, all the major health organizations (like the Centers for Disease Control and Prevention, the American Lung Association, and the American Medical Association) agree with estimates that radon causes thousands of preventable lung cancer deaths every year. This is especially true among smokers, since the risk to smokers is much greater than to non-smokers.
Myth: Radon testing is difficult, time-consuming, and expensive.
Fact: Radon testing is easy. You can test your home yourself or hire a qualified radon test company. Either approach takes only a small amount of time and effort.
Myth: Homes with radon problems can’t be fixed.
Fact: There are simple solutions to radon problems in homes. Hundreds of thousands of homeowners have already fixed radon problems in their homes. Call your state radon office for help in identifying qualified mitigation contractors.
Myth: Radon affects only certain kinds of homes.
Fact: House construction can affect radon levels. However, radon can be a problem in homes of all types: old homes, new homes, drafty homes, insulated homes, homes with basements, and homes without basements. Local geology, construction materials, and how the home was build are among the factors that can affect radon levels in homes.
Myth: Radon is only a problem in certain parts of the country.
Fact: High radon levels have been found in every state. Radon problems do vary from area to area, but the only way to know your radon level is to test.
Myth: A neighbor’s test result is a good indicator of whether or not your home has a problem.
Fact: It’s not. Radon levels can vary greatly from home to home. The only way to know if your home has a radon problem is to test it.
Myth: Everyone should test their water for radon.
Fact: Although radon gets into some homes through water, it is important to first test the air in the home for radon. If your water comes from a public water supply that uses ground water, call your water supplier. If high radon levels are found and the home has a private well, call the Safe Drinking Water Hotline at 1-800-426-4791 for information on testing your water.
Myth: It’s difficult to sell homes where radon problems have been discovered.
Fact: Where radon problems have been fixed, home sales have not been blocked or frustrated. The added protection is sometimes a good selling point.
Myth: I’ve lived in my home for so long, it doesn’t make sense to take action now.
Fact: You will reduce your risk of lung cancer when you reduce radon levels, even if you’ve lived with a radon problem for a long time.
Myth: Short-term tests can’t be used for making a decision about whether or not to fix your home.
Fact: A short-term test, followed by a second short-term test* can be used to decide whether or not to fix your home. However, the closer the average of your two-short term tests is to 4 pCi/L, the less certain you can be about whether your year-round average is above or below that level. Keep in mind that radon levels below 4 pCi/L still pose some risk. Radon levels can be reduced in most homes to 2 pCi/L or below.
* If the radon test is part of a real estate transaction, the result of two short-term tests can be used in deciding whether to mitigate. For more information, see EPA’s “Home Buyer’s and Seller’s Guide to Radon.”
EPA Map of Radon Zones
The U.S. EPA and the U.S. Geological Survey have evaluated the radon potential in the U.S. and have developed this map to assist National, State, and local organizations to target their resources and to assist building code officials in deciding whether radon-resistant features are applicable in new construction. This map is not intended to be used to determine if a home in a given zone should be tested for radon. Homes with elevated levels of radon have been found in all three zones. All homes should be tested regardless of geographic location. The map assigns each of the 3,141 counties in the U.S. to one of three zones based on radon potential. Each zone designation reflects the average short-term radon measurement that can be expected to be measured in a building without the implementation of radon control methods. The radon zone designation of the highest priority is Zone 1.
Zone 1 Highest Potential (greater than 4 pCi/L)
Zone 2 Moderate Potential (from 2 to 4 pCi/L)
Zone 3 Low Potential (less than 2 pCi/L)
Massachusetts |
New Hampshire |
Important: Consult the EPA Map of Radon Zones document (EPA-402-R-93-071) before using this map. This document contains information on radon potential variations within counties. EPA also recommends that this map be supplemented with any available local data in order to further understand and predict the radon potential of a specific area. This and other indoor air quality publications can be ordered through the IAQ INFO Clearinghouse.
IAQ INFO
P.O. Box 37133
Washington, DC 20013-7133
Health Risks
Exposure to Radon Causes Lung Cancer In Non-smokers and Smokers Alike
Lung cancer kills thousands of Americans every year. Peter Jennings’ death and Dana Reeve’s death have raised public awareness about lung cancer, especially among people who have never smoked. Smoking and radon are the leading causes of lung cancer. Although lung cancer can be treated, the survival rate is one of the lowest for those with cancer. From the time of diagnosis, between 11 and 15 percent of those afflicted will live beyond five years, depending upon demographic factors. In many cases lung cancer can be prevented; this is especially true for radon.
Smoking is the leading cause of lung cancer. Smoking causes an estimated 160,000* deaths in the U.S. every year (American Cancer Society, 2004). And the rate among women is rising. On January 11, 1964, Dr. Luther L. Terry, then U.S. Surgeon General, issued the first warning on the link between smoking and lung cancer. 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.
Why is radon the public health risk that it is? 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. Radon is an odorless, tasteless and invisible gas produced by the decay of naturally occurring uranium in soil and water. Radon is a form of ionizing radiation and a proven carcinogen. 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 are adults.
For smokers the risk of lung cancer is significant due to the synergistic effects of radon and smoking. For this population about 62 people in a 1,000 will die of lung-cancer, compared to 7.3 people in a 1,000 for never smokers. Put another way, a person who never smoked (never smoker) who is exposed to 1.3 pCi/L has a 2 in 1,000 chance of lung cancer; while a smoker has a 20 in 1,000 chance of dying from lung cancer. Figure A compares the risks between smokers and never smokers; smokers are at a much higher risk than never smokers, e.g., at 8 pCi/L the risk to smokers is six times the risk to never smokers.
The radon health risk is underscored by the fact that in 1988 Congress added Title III on Indoor Radon Abatement to the Toxic Substances Control Act. It codified and funded EPA’s then fledgling radon program. Also that year, the Office of the U.S. Surgeon General issued a warning about radon urging Americans to test their homes and to reduce the radon level when necessary (U.S. Surgeon General).
Radon Risk If You Smoke
| Radon Level | If 1,000 people who smoked were exposed to this level over a lifetime*… | The risk of cancer from radon exposure compares to**… | WHAT TO DO: Stop smoking and… |
|---|---|---|---|
| 20 pCi/L | About 260 people could get lung cancer | 250 times the risk of drowning | Fix your home |
| 10 pCi/L | About 150 people could get lung cancer | 200 times the risk of dying in a home fire | Fix your home |
| 8 pCi/L | About 120 people could get lung cancer | 30 times the risk of dying in a fall | Fix your home |
| 4 pCi/L | About 62 people could get lung cancer | 5 times the risk of dying in a car crash | Fix your home |
| 2 pCi/L | About 32 people could get lung cancer | 6 times the risk of dying from poison | Consider fixing between 2 and 4 pCi/L |
| 1.3 pCi/L | About 20 people could get lung cancer | (Average indoor radon level) | (Reducing radon levels below 2 pCi/L is difficult.) |
| 0.4 pCi/L | About 3 people could get lung cancer | (Average outdoor radon level) | |
| Note: If you are a former smoker, your risk may be lower. * Lifetime risk of lung cancer deaths from EPA Assessment of Risks from Radon in Homes (EPA 402-R-03-003). ** Comparison data calculated using the Centers for Disease Control and Prevention’s 1999-2001 National Center for Injury Prevention and Control Report |
|||
Radon Risk If You’ve Never Smoked
| Radon Level | If 1,000 people who never smoked were exposed to this level over a lifetime*… | The risk of cancer from radon exposure compares to**… | WHAT TO DO: |
|---|---|---|---|
| 20 pCi/L | About 36 people could get lung cancer | 35 times the risk of drowning | Fix your home |
| 10 pCi/L | About 18 people could get lung cancer | 20 times the risk of dying in a home fire | Fix your home |
| 8 pCi/L | About 15 people could get lung cancer | 4 times the risk of dying in a fall | Fix your home |
| 4 pCi/L | About 7 people could get lung cancer | The risk of dying in a car crash | Fix your home |
| 2 pCi/L | About 4 person could get lung cancer | The risk of dying from poison | Consider fixing between 2 and 4 pCi/L |
| 1.3 pCi/L | About 2 people could get lung cancer | (Average indoor radon level) | (Reducing radon levels below 2 pCi/L is difficult.) |
| 0.4 pCi/L | (Average outdoor radon level) | ||
| Note: If you are a former smoker, your risk may be higher. * Lifetime risk of lung cancer deaths from EPA Assessment of Risks from Radon in Homes (EPA 402-R-03-003). ** Comparison data calculated using the Centers for Disease Control and Prevention’s 1999-2001 National Center for Injury Prevention and Control Reports. |
|||
Radon in Drinking Water
Public Health Standards for Radon in Drinking Water
EPA is proposing new public health standards for radon in drinking water. The proposal would provide two options to States and community water systems for reducing radon health risks in both drinking water and indoor air quality, a unique multimedia framework authorized in the 1996 Amendments to the Safewater Drinking Water Act (SDWA). Information about the proposed rule and information relating to the status of the rule can be found at: www.epa.gov/safewater/radon.html.
National Academy of Sciences (NAS) Report on Radon in Drinking Water “Risk Assessment of Radon in Drinking Water.”
A report released September 15, 1998, by the National Academy of Sciences is the most comprehensive accumulation of scientific data on the public health risks of radon in drinking water. The report was required by the Safe Drinking Water Act (SDWA). The NAS report (BEIR VI) issued earlier this year confirmed that radon is a serious public health threat. This report goes on to refine the risks of radon in drinking water and confirms that there are drinking water related cancer deaths, primarily due to lung cancer. The report, in general, confirms earlier EPA scientific conclusions and analyses for drinking water, and presents no major changes to EPA’s 1994 risk assessment.
The Office of Ground Water Drinking Water has posted the press release of “Risk Assessment of Radon in Drinking Water”. There is also a link to NAS’s Executive Summary on the report (with initial EPA perspectives) at: www.epa.gov/OGWDW/radon/nas.html.
For general information on radon in drinking water, contact the Safe Drinking Water Hotline, at (800) 426-4791. The Safe Drinking Water Hotline is open Monday through Friday, excluding Federal holidays, from 9:00 a.m. to 5:30 p.m. Eastern Time.
