Radon in my house



Topic Overview

Radon is a radioactive gas that causes cancer. Radon is found in rock, soil, water, some building materials, and natural gas. You can’t see, taste, or smell it.

How does radon exposure occur?

Any home, school, office, or other building can have high levels of radon. Radon is found in new and old buildings. It can seep in through any opening where the building contacts the soil. If a house’s water supply contains radon, radon may enter the air inside the house through pipes, drains, faucets, or appliances that use water. Then the radon may get trapped inside the house.

Studies show that nearly 1 out of 15 homes in the United States has unsafe levels of radon.footnote 1 If you live in an area that has large deposits of uranium, you may be more likely to be exposed to high levels of radon. (To see a map of the U.S. radon zones, see the website www.epa.gov/radon/zonemap.html.) But the construction features and exact location of your house may be just as likely to affect your risk. Even houses right next to each other can have very different radon levels.

What are the health effects of radon exposure?

Over time, exposure to radon can cause lung cancer. Radon causes about 21,000 lung cancer deaths each year in the U.S. It is the second leading cause of lung cancer, after tobacco smoking.footnote 1 People who smoke have an even higher risk of lung cancer from radon exposure than people who don’t smoke.

Radon exposure doesn’t cause symptoms. Unless your home or office is tested for high radon levels, you may not realize that you are being exposed to dangerous levels of radon until you or someone in your family is diagnosed with lung cancer.

How can you test your home’s radon levels?

The U.S. Surgeon General and the U.S. Environmental Protection Agency (EPA) recommend that all homes be tested for radon levels.

You can hire a qualified tester to do the test, or you can use a do-it-yourself test kit. Use only home tests that are labeled “meets EPA requirements.” You can buy radon test kits by calling the EPA at 1-800-SOS-RADON (1-800-767-7236). There are two types of tests. Both measure radon levels in the air.

  • The short-term test kit stays in your home or office for 2 to 90 days. Radon levels vary daily and from season to season. So you may want to follow up the first short-term test with a second test.
  • The long-term test kit stays in your home or office for more than 90 days. A long-term test will give more accurate results.

The EPA recommends placing the test kit in your home on the lowest level that you regularly use. If you have questions about radon in your house, you can get help from the EPA by calling 1-800-55-RADON (1-800-557-2366).

How do you reduce high levels of radon?

If tests find a high level of radon, you’ll need to reduce it. There are two parts to this:

  • Preventing radon from entering the building. The most common way to do this is through sub-slab depressurization, which vents air from beneath the foundation. This work should be done by a qualified contractor. Other control methods include sealing cracks in the foundation or walls and using air cleaners.footnote 2
  • Venting radon out of the building. Once the radon is prevented from entering the building, venting can be done to reduce the level of radon. These may include using fans, blowers, and suction devices to remove radon in the air in crawl spaces, basements, and other areas.

Use an EPA-qualified contractor with proper training in radon reduction to help with this work.

After radon reduction or prevention procedures are done, the home or building should be retested. You may need to retest more than once. It is usually safe to live in the home or building while the radon is being vented, but you may want to confirm this with your local EPA office.

For general information about removing or reducing radon in your house, you can call the Radon Fix-It Hotline at 1-800-644-6999. If you live outside the U.S., you can call your regional environmental protection office for more information.

Health Effects of Radon: Basics

What health effects are associated with radon exposure?

The Surgeon General has warned that radon is the second leading cause of lung cancer in the United States. There are currently no conclusive data on whether children are at greater risk than adults from radon. No specific subtype of lung cancer is associated with radon exposure.

Only smoking causes more cases of lung cancer. If you smoke and you are exposed to elevated radon levels, your risk of lung cancer is especially high. The U.S. Environmental Protection Agency provides radon risk comparison charts for people who smoke and those who have never smoked. Stop smoking and lower your radon level to reduce your lung cancer risk.

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. This can damage lung tissue and lead to lung cancer over the course of your lifetime. Not everyone exposed to elevated levels of radon will develop lung cancer, and the amount of time between exposure and the onset of the disease may be many years.

Breathing radon does not cause any short-term health effects such as shortness of breath, coughing, headaches, or fever.

In 1998, the National Academy of Sciences (NAS) released the Biological Effects of Ionizing Radiation (BEIR VI) Report, “The Health Effects of Exposure to Indoor Radon.” The study reviewed and evaluated data from many prior studies and drew conclusions. It fully supports estimates by the EPA that radon causes about 21,000 lung cancer deaths per year. Though some people debate the number of deaths, it is widely agreed that radon exposure is the second leading cause of lung cancer.

Research suggests that swallowing water with high radon levels may pose risks, too, although risks from drinking water containing radon are much lower than those from breathing air containing radon. A NAS report on radon in drinking water, was released in 1998. It concluded drinking radon in water causes about 19 stomach cancer deaths per year.

The EPA provides more information about health effects from radon in their publication, A Physician’s Guide to Radon, as well as their booklet Reducing the Risk From Radon: Information and Interventions (A Guide for Health Care Providers). This tri-fold brochure put together to handout in doctor’s offices also has basic information.

Radon and Cancer

What is radon?

Radon is a colorless, odorless, radioactive gas. It forms naturally from the decay (breaking down) of radioactive elements, such as uranium, which are found in different amounts in soil and rock throughout the world. Radon gas in the soil and rock can move into the air and into underground water and surface water.

Radon is present outdoors and indoors. It is normally found at very low levels in outdoor air and in drinking water from rivers and lakes. It can be found at higher levels in the air in houses and other buildings, as well as in water from underground sources, such as well water.

Radon breaks down into solid radioactive elements called radon progeny (such as polonium-218, polonium-214, and lead-214). Radon progeny can attach to dust and other particles and can be breathed into the lungs. As radon and radon progeny in the air break down, they give off radiation that can damage the DNA inside the body’s cells.

How are people exposed to radon?

At home and in other buildings

For both adults and children, most exposure to radon comes from being indoors in homes, offices, schools, and other buildings. The levels of radon in homes and other buildings depend on the characteristics of the rock and soil in the area. As a result, radon levels vary greatly in different parts of the United States, sometimes even within neighborhoods. Elevated radon levels have been found in every state.

Radon gas given off by soil or rock can enter buildings through cracks in floors or walls; construction joints; or gaps in foundations around pipes, wires, or pumps. Radon levels are usually highest in the basement or crawl space. This level is closest to the soil or rock that is the source of the radon. Therefore, people who spend much of their time in basement rooms at home or at work have a greater risk for being exposed.

Small amounts of radon can also be released from the water supply into the air. As the radon moves from the water to air, it can be inhaled. Water that comes from deep, underground wells in rock may have higher levels of radon, whereas surface water (from lakes or rivers) usually has very low radon levels. For the most part, water does not contribute much to overall exposure to radon.

Radon exposure can also occur from some building materials if they are made from radon-containing substances. Almost any building material made from natural substances, including concrete and wallboard, may give off some level of radon. In most cases these levels are very low, but in a few instances these materials may contribute significantly to radon exposure.

Some granite countertops may expose people to different levels of radon. Most health and radiation experts agree that while a small portion of granite countertops might give off increased levels of radon, most countertops give off extremely low levels. According to the US Environmental Protection Agency (EPA), it’s very unlikely that a granite countertop in a home would increase the radiation level above the normal, natural background level that comes from nearby soil and rocks. Still, people concerned about radon from countertops and from other household sources can test these levels using home detection kits or can hire a professional to do the testing (see the section “How can I avoid exposure to radon?”).

According to the EPA, the average indoor radon level is about 1.3 picocuries per liter (pCi/L). People should take action to lower radon levels in the home if the level is 4.0 pCi/L or higher. The EPA estimates that nearly 1 out of every 15 homes in the United States has elevated radon levels.

Outdoors, radon generally disperses and does not reach high levels. Average levels of radon outdoors, according to the EPA, are about 0.4 pCi/L.

At certain jobs

In the workplace, people working underground, such as some types of miners, are among the most likely to be exposed to high levels of radon. High death rates from lung problems among miners in some parts of the world were first noted hundreds of years ago, long before people knew what radon was. Studies of radon-exposed miners during the 1950s and 1960s confirmed the link between radon exposure and lung cancer.

Higher levels of radon exposure are also more likely for people who work in uranium processing factories or who come in contact with phosphate fertilizers, which may have high levels of radium (an element that can break down into radon).

Does radon cause cancer?

Being exposed to radon for a long period of time can lead to lung cancer. Radon gas in the air breaks down into tiny radioactive elements (radon progeny) that can lodge in the lining of the lungs, where they can give off radiation. This radiation can damage lung cells and eventually lead to lung cancer.

Cigarette smoking is by far the most common cause of lung cancer in the United States, but radon is the second leading cause. Scientists estimate that about 20,000 lung cancer deaths per year are related to radon.

Exposure to the combination of radon gas and cigarette smoke creates a greater risk for lung cancer than either factor alone. Most radon-related lung cancers develop in smokers. However, radon is also thought to cause a significant number of lung cancer deaths among non-smokers in the United States each year.

Some studies have suggested that radon exposure may be linked to other types of cancer as well, such as childhood leukemia. But the evidence for such links has been mixed and not nearly as strong as it is for lung cancer. Because radon and its progeny are absorbed mainly by inhaling, and because the radiation they give off travels only a short distance, it is unlikely that radon would affect other tissues in the body.

The evidence that radon causes lung cancer comes from studies in people and studies done in the lab.

Studies in people

Several types of studies in people have found that exposure to radon increases lung cancer risk:

  • Studies of people working in underground mines with high levels of radon exposure
  • Studies comparing radon levels in homes of people with lung cancer with the levels in homes of similar people without lung cancer
  • Studies comparing lung cancer cases or deaths in areas with differing levels of radon exposure

These studies also show that the overall risk of lung cancer from radon is even higher in smokers and former smokers.

Some long term studies of uranium miners have found that they had higher risks of certain other cancers. But since the people with the higher risk weren’t exposed to higher amounts of radon and radon progeny, it isn’t clear that radon is the cause of those cancers. They may instead be linked to uranium dust or other exposures in the mines.

Studies done in the lab

Studies in lab animals have also shown an increased risk of lung cancer with exposure to radon. These studies revealed that breathing in radon and its progeny increases the risk of lung tumors. The risk is higher if the animal breathes in both cigarette smoke and radon. In some animals, the risk of certain other cancers was also increased.

In lab studies using human cells, radon and its progeny have also been shown to cause damage to chromosomes (packets of DNA) and other types of cellular damage. These types of changes are often seen in cancer cells.

What expert agencies say

Several national and international agencies study different substances in the environment to determine if they can cause cancer. (A substance that causes cancer or helps cancer grow is called a carcinogen.) The American Cancer Society looks to these organizations to evaluate the risks based on evidence from laboratory, animal, and human research studies.

Based on animal and human evidence, several expert agencies have evaluated the cancer-causing potential of radon.

The International Agency for Research on Cancer (IARC) is part of the World Health Organization (WHO). One of its goals is to identify causes of cancer. Based on sufficient evidence that radon and its progeny can cause lung cancer, IARC classifies them as “carcinogenic to humans.”

The National Toxicology Program (NTP) is formed from parts of several different US government agencies, including the National Institutes of Health (NIH), the Centers for Disease Control and Prevention (CDC), and the Food and Drug Administration (FDA). The NTP has classified radon as “known to be a human carcinogen.”

The US Environmental Protection Agency (EPA) monitors the human health effects from exposure to various substances in the environment. The EPA lists radon as the second leading cause of lung cancer and the number one cause of lung cancer among non-smokers, estimating it is responsible for about 20,000 lung cancer deaths every year.

(For more information on the classification systems used by these agencies, see Known and Probable Human Carcinogens.)

Can I avoid being exposed to radon?

Radon is in the air we breathe, both indoors and out, so it isn’t possible to avoid it completely. But there may be things you can do to lower your exposure.

In the home

For most people, the largest potential source of radon exposure is in their home. You can check radon levels in your home to determine if you need to take steps to lower them. Do-it-yourself radon detection kits can be ordered through the mail or bought in hardware or home supply stores. The kits are placed in the home for a period of time and then mailed to a lab for analysis.

Short-term kits are usually left in place for several days before being mailed. Long-term kits, which may give a more accurate assessment of average radon levels over the course of a year, are usually left in place for at least 3 months. The EPA recommends testing all homes below the 3rd floor, even new homes that were built “radon-resistant.”

You can also hire a professional to test radon levels in your home. Qualified contractors can be found through state radon offices, which are listed on the EPA website at www.epa.gov/radon/whereyoulive.html.

The EPA recommends taking steps to lower radon levels if test results show levels of 4.0 pCi/L or higher. This value refers to the annual average. If you are using a do-it-yourself test, the EPA recommends using a short-term kit first. If the test result is 4.0 pCi/L or higher, do a follow-up test with either a long-term or short-term kit to be sure. If the result is still high, you should take steps to fix the problem.

A variety of methods can be used to reduce radon levels in your home, such as sealing cracks in floors and walls or increasing ventilation through “sub-slab depressurization” using pipes and fans. The EPA recommends that you have a qualified contractor fix your home because lowering high radon levels requires specific technical knowledge and special skills.

Without the proper equipment or technical knowledge, you could actually increase your radon level or create other potential hazards and additional costs. Qualified contractors can be located through state radon offices, which are listed on the EPA website at www.epa.gov/radon/whereyoulive.html. If you decide to do the work yourself, be sure you have the proper training and equipment.

Certain building materials may be more “radon tight” and may help reduce exposure in areas where radon levels are high. You can get more information from your state radon office or from qualified contractors.

In the workplace

Federal agencies, such as the Nuclear Regulatory Commission (NRC) and the Occupational Safety and Health Administration (OSHA) set limits on exposure to radon (and radon progeny) in the workplace. Because radon is known to be a health hazard, underground mines now have features to lower levels.

For people who may be exposed to radon in the workplace, it’s important to follow recommended safety procedures. If you are concerned that your exposure might be above the allowed limits, contact your workplace safety officer or these agencies.

What should I do if I’ve been exposed to radon?

There are no widely available medical tests to measure whether you have been exposed to radon.

If you smoke and have been exposed to higher levels of radon, it’s very important to try to quit smoking. The combined effects of cigarette smoking and radon exposure raise the risk of lung cancer much more than either exposure alone.

If you think you might have been exposed to high levels of radon over long periods of time, talk with your doctor about whether you should get regular health checkups and tests to look for possible signs of lung cancer. Be aware of possible symptoms of lung cancer, such as shortness of breath, a new or worsening cough, pain or tightness in the chest, hoarseness, or trouble swallowing, and tell your doctor if you start to have any of these symptoms.

For uranium miners, millers, and transporters who have certain health problems as a result of exposure to radon, the United States government has established the Radiation Exposure Compensation Program. The program offers a lump sum payment to people with lung cancer and selected non-cancerous lung diseases, if certain criteria are met. Information about the program is available at www.justice.gov/civil/common/reca.html or by calling 1-800-729-7327 (1-800-729-RECP).

Radon Risk

Its Perils Can be Prevented

If you’re buying a new home, the house may need to be tested for radon, depending on local laws. Although the tests aren’t required everywhere, you should insist on it. You might not be able to see or smell radon, but it can still harm you—slowly, and in ways that you can’t detect.

Radon is a colorless, odorless, radioactive gas. It comes from the natural decay of the radioactive chemical elements uranium or thorium. These elements are found in nearly all soils.

Radon gas typically moves up through the ground and comes into homes through cracks in floors, walls and foundations. Sometimes it enters the home through well water. Certain building materials can give off radon, too. However, building materials rarely cause radon problems by themselves. Whatever the source, your home can trap radon inside, where it can build up.

Surveys show that radon levels vary widely across the country. But high levels can occur in any area, and any home may have a radon problem. This means new and old homes, well-sealed and drafty homes, and homes with or without basements. Nearly 1 out of every 15 homes in the United States is estimated to have elevated radon levels. Elevated levels have been found in homes in every state.

Radon gas breaks down quickly, giving off tiny radioactive particles that can get trapped in your lungs when you breathe. As they break down further, these particles release small bursts of energy. This can damage lung tissue and raise your risk of developing lung cancer.

Radon exposure is thought to be the second leading cause of lung cancer after active smoking—and the leading cause among people who have never smoked. Scientists estimate that 15,000 to 22,000 lung cancer deaths nationwide each year are related to radon.

Scientists believe that there are no safe levels of radon in the home. The effects of being exposed accumulate over time so that it may take many years for disease to appear. NIH-funded scientists have been working to better understand the relationship between radon exposure and cancer risk.

The good news is that many radon-related lung cancer deaths can be prevented. But testing is the only way to know if you and your family are at risk. The Environmental Protection Agency (EPA) and the U.S. Surgeon General recommend testing all homes below the third floor for radon. Testing is inexpensive and easy. It should only take a few minutes. You can purchase radon test kits by calling the EPA-supported National Radon Hotline at 1-800-SOS-RADON (1-800-767-7236).

If you’re not comfortable doing the testing yourself, you can have a professional do it. Many states require radon professionals to be licensed, certified or registered. To find your state’s resources, go to www.epa.gov/radon/whereyoulive.html.

If it turns out you do have high radon levels in your home, you can take steps to lower those levels—a process called radon mitigation. Some radon reduction systems can reduce radon levels in your home by up to 99%. Even very high levels can be reduced to acceptable levels. Find out more about fixing radon problems at www.epa.gov/radon/pubs/consguid.html. Or call the National Radon Fix-It Line at 1-800-644-6999.

Make sure you’ve had your home tested. It’s easy, it’s inexpensive and it could save lives.

Safe Radon Levels

What is a safe and acceptable level of radon gas?

This is actually two separate questions. The first is: “What is a safe level of radon gas?” The second is: “What is an acceptable level of radon gas?”

What is a safe level of radon gas?

This is the simpler of the two questions. A safe level of radon gas is no radon gas. Radon gas is a carcinogen which causes lung cancer. The US EPA has put it plainly, stating, “Any radon exposure has some risk of causing lung cancer. The lower the radon level in your home, the lower your family’s risk of lung cancer.” The average person receives a higher dose of radiation from the radon levels in their home than from their combined exposure to all other radiation sources, natural or man-made. Radon gas is a naturally-occurring byproduct of the radioactive decay of Uranium in the soil. Depending on your geographic location, the radon levels of the air you breathe outside of your home may be as high as 0.75 pCi/L. The national average of outside radon levels is 0.4 pCi/L and it is estimated by the National Academy of Sciences that outdoor radon levels cause approximately 800 of the 21,000 radon induced lung cancer deaths in the US each year. Your risk of lung cancer increases substantially with exposure to higher radon levels. Lung cancer risk rises 16% per 2.7 pCi/L increase in radon exposure. World Health Organization, 2009 studies show that radon is the primary cause of lung cancer among people who have never smoked. However, the absolute numbers of radon-induced lung cancers are much larger in people who smoke, or who have smoked in the past, due to a strong combined effect of smoking and radon.

What is an acceptable level of radon gas?

Radon Act 51 passed by Congress set the natural outdoor level of radon gas (0.4 pCi/L) as the target radon level for indoor radon levels. Unfortunately two-thirds of all homes exceed this level. The US EPA was tasked with setting practical guidelines and recommendations for the nation. To this end, the US EPA has set an action level of 4 pCi/L. At or above this level of radon, the EPA recommends you take corrective measures to reduce your exposure to radon gas. This does not imply that a level below 4.0 pCi/L is considered acceptable, as stated in the BEIR VI study . It is estimated that a reduction of radon levels to below 2 pCi/L nationwide would likely reduce the yearly lung cancer deaths attributed to radon by 50%. However, even with an action level of 2.0 pCi/L, the cancer risk presented by radon gas is still hundreds of times greater than the risks allowed for carcinogens in our food and water.

The World Health Organization
The WHO Handbook on Indoor Radon: A Public Health Perspective indicates that radon exposure is a major and growing public health threat in homes and recommends that countries adopt reference levels of the gas of 100 Bq/m3 which is equivalent to 2.7 pCi/L.

You can download a PDF version of the WHO handbook on indoor radon here. “Radon is the second most important cause of lung cancer after smoking in many countries,” notes Dr Maria Neira, Director of WHO’s Public Health and Environment Department. “Most of radon-induced lung cancers occur from low and medium dose exposures in people’s homes. Strengthened action by policy makers, and by construction and building professionals can substantially lower the health impact by preventing and reducing radon exposure.”


While no level of radon gas is completely safe, as with most things in life we must balance the benefits and costs to find our own“acceptable” levels. We walk outside and work in the sun, exposing ourselves to ultraviolet radiation and increasing our risk of developing skin cancer. We drive in automobiles almost every day even though greater than 1 in 86 deaths is a result of automobile accidents. People smoke, eat poorly, and engage in dangerous behaviors on a daily basis. To some degree, radon gas is another daily risk that we all must take. However, you choose what you eat, whether or not you smoke, and how and when you drive. You have no choice but to breathe the air in your home. A simple and inexpensive radon test can give you the information you need to make an informed decision about what level of radon gas exposure is acceptable to you.

The agency said that another survey of radon in homes would be conducted this winter in Arizona, Indiana, Massachusetts, Minnesota, Missouri, North Dakota and Pennsylvania and on Indian reservations in Michigan, Minnesota and Wisconsin. The tests are made in winter, when windows tend to be closed and radon accumulates inside homes. New York and New Jersey Act

Agency officials also noted that a number of states, including New York and New Jersey, were conducting their own radon surveys.

A year ago the agency recommended that homeowners take action to protect themselves and their families when radon levels inside their houses are 4 picocuries per liter of air or higher. A picocurie is one-trillionth of a curie, a common measurement of radiation.

By way of comparison, the agency noted that exposure to 4 picocuries is equivalent to the radiation of more than 200 chest X-rays a year. The agency estimates that for every 1,000 people exposed to that level of radon 75 percent of the time over a 70-year lifetime, from 13 to 50 people would die of lung cancer. Highest Percentage in Colorado

The survey found that among the states surveyed, Colorado had the highest percentage of homes with radon levels over the 4 picocurie per liter level, with 39 percent of the tested homes exceeding that number. Alabama, at 6 percent, had the lowest average number of homes above that level. But the highest single reading of the survey, 180 picocuries, was in a home in Alabama.

Among the homes tested in Connecticut, 19 percent, or close to the 10-state average, recorded radon levels above the level at which homeowners are urged to take protective action. But the E.P.A. noted that the tests in Connecticut were taken on a voluntary rather than a random basis and the results therefore applied only to the houses tested.

The percentage of houses tested that exceeded the action level in the other states surveyed were 21 percent in Kansas, 17 percent in Kentucky, 9 percent in Michigan, 19 percent in Rhode Island, 16 percent in Tennessee, 27 percent in Wisconsin and 26 percent in Wyoming. Clues From Area’s Geology

Radon Gas Blog

The search is over, you finally found your dream home. The neighborhood is great, the schools are some of the best around and the price is right in your budget. You and your real estate agent make an offer and wait patiently. Soon after a few negotiations, they accept your offer! You are on your way to being the owner of this home. It’s time for the home inspection and your inspector is also a radon measurement professional. You’ve heard about the dangers of it, so you spend the extra money to have a test done. A few days pass and the results are in. The radon test failed! Suddenly your dream home doesn’t look so dreamy.

10 things you should know about buying a home with radon

  1. Know what radon is and know about its dangers.

  • Radon gas is a radioactive gas that comes naturally from the earth, not from a chemical or problem with the home itself. Radon can seep into any home that is in contact with the ground. It is undetectable unless you perform a radon test. It is the second leading cause of lung cancer and according to the EPA and CDC, it kills more than 20,000 annually. It is not something you want in the home you are buying.
  • How to test for radon in a real estate transaction.

    • Nowadays, many home inspectors measure radon gas, mold, lead, asbestos and meth as an addition to their standard services. When buying a home, it’s wise to know as much about it as possible so having these extra tests done can save you from any unexpected surprises. Radon testing in real estate typically involves a 48 hour electronic radon test. Some providers use continuous radon monitors, electret radon measurement devices or activated charcoal (passive) radon test kits. As long as these devices are calibrated and placed correctly, you can expect to get accurate results. It is very important to use a certified radon measurement provider to help make sure proper procedures are followed. In some states, these providers must be licensed by the state.
  • Understand what a “passing” and “failing” radon test is.

    • The words radon test “failed” or radon test “passed” are thrown around out there. Pass/fail should not be used to determine radon safety. No level of radon is safe. The United States EPA has established the radon level of 4.0 picocuries per liter to be the action level for radon gas in homes. Meaning, take action to reduce radon levels that are greater than four picocuries per liter. But consider taking action if radon levels are between 2-4. Remember that radon danger follows a linear curve of the amount vs the time exposed to it plus the additional factor that each individual may be more or less susceptible to radon related cancer. The World Health Organization (WHO) takes the action level a step lower by recommending that you fix radon levels greater than 2.7 pCi/L So if you hear the word radon test “passed” be cautious because the radon test result may have been 3.9 pCi/L which is barely under the EPA action level and significantly above the WHO action level.
  • Things to know about the radon test results.

    • Short term tests are good for real estate transactions and getting a quick idea but long term radon testing for more than 90 days offers a better idea of overall exposure. Radon levels can be higher in the winter or under different weather patterns from when the test was performed. If you are buying a home and the radon test comes back low, remember to re-test every so often to make sure that levels are low all of the time. We hear from many people who are selling their home and the radon test comes back high; “How is this happening? When we bought the home the inspector said we passed the radon test.” Remember that the levels can fluctuate from time-to-time.
  • How to fix high radon levels.

    • Key point: All homes can be fixed. Radon mitigation systems and the professionals who install them can fix radon problems. There is not a radon clean-up solution because radon gas continuously seeps into homes from the soil below. You have to stop the flow. Mitigation systems become permanent components of the home and have to be running all of the time to keep radon out. They do this by creating a permanent vacuum in the soil or gravel below the concrete slab or crawlspace membrane. This suction redirects the gas that’s coming from the earth, sends it through sealed ventilation pipes and the radon fan to exhaust above the eave of the home where it dissipates into the atmosphere.
  • How to choose a radon mitigation company.

    • Important bit of advice: As a buyer, try to be the one to choose who installs the radon mitigation system. Often times, the seller of the home just wants the quickest and cheapest solution to get the home sold. If you maintain the power of who does the work, you can ensure you get a high quality radon mitigation system that will work for a long time to keep levels low after you purchase the home.
    • Make sure you choose a certified or licensed radon contractor and:
    1. Make sure they can describe exactly what they are offering. Try to get an on-site quote.
    2. Check the address of the company to make sure they are local. Ask for local references because radon mitigation methods vary from area to area based upon construction styles of homes and other factors. Local knowledge rules.
    3. Read the fine print of the warranty. Make sure it truly covers radon reduction.
    4. Be leery of the price war. Get several bids. Cheap is not good when dealing with cancer causing radon gas.
    5. Make sure you get a firm price without hidden fees. Many times you will be quoted with a “basic” system and get surprised when they come to install and there are extra costs associated with system location, paint, fan model etc.
    6. Ask how it’s going to look. Some companies will install an unpainted exterior radon mitigation system that does not look nice on the home. Other companies will take the time and effort to either hide the radon system in the attic and vent above the roof or will customize the exterior system to better blend with the aesthetic of your new home.
    7. More information can be found in our Quick Guide to Selecting a Radon Mitigation Contractor
  • Who pays for it and how much do radon systems cost?

    • If you don’t negotiate it into your contract, the answer is you. Because you will either have to do it for your own health and safety after you move in or you will have to disclose to any future buyers if you go to sell. It’s very likely that your future buyer will make you fix the radon problem before they will purchase the home. It’s good to just take care of it during your real estate deal. Sometimes the seller pays for it all, sometimes they fund a credit and sometimes there is a split.
    • Most single family homes will only require one radon mitigation system. A radon system installed by a high quality radon contractor will run in the range of $1200-$1700. Different factors can impact the price of mitigation. Sometimes homes will require a system with multiple radon suction points or a higher suction radon fan. Other times the routing of the pipes may be more complex because of the construction style of the home. Every home has a unique set of circumstances to get rid of radon gas, this is why there is not just a one-size-fits-all radon system with a basic price.
  • Testing to make sure the radon system works properly.

    • One of the biggest problems in the radon industry is follow-up testing. Unfortunately, many people assume they are safe because they have a radon mitigation system but have never performed a radon test to make sure it’s actually working. Please make sure to do a radon test after a mitigation system is installed and also at least every two years after that. Radon testing is simple and cheap if you buy DIY radon test kits. We have received numerous calls over the years from people who have radon systems installed by someone they don’t remember, “when we bought the home,” and now they are going to sell and the radon test came back high. What went wrong? There is a good possibility that the radon system never worked to begin with. If you don’t perform regular follow-up testing, you may be being exposed to high level of radon under the false pretense that you are safe because you have a mitigation system. With that said, most radon mitigation systems installed by good contractors will work great to reduce radon levels.
  • Ongoing maintenance of a radon system.

    • A good maintenance plan is a good idea to keep the radon mitigation systems working well. Some companies will provide these services and some homeowners will do it themselves. Maintenance items can include: cleaning out the vent stack, re-sealing the cracks or sump pump, re-painting system parts, vacuum diagnostics and most importantly the re-test as explained earlier.
  • Does radon affect the resale value of the home?

    • This is a common question out there. Many people fear that if a radon test shows high levels in a particular home, that the home is somehow tainted and devalued. This is not accurate. Remember that all homes can be fixed. Radon mitigation systems do an excellent job of keeping radon out. More and more home buyers are seeking homes with radon solutions in place. A radon mitigation system is an improvement to the home. The systems can also keep out other soil gases like, methane, trichloroethylene, chlorine, bad odors and water vapors. Having a home with a radon mitigation system in place and keeping the levels low will help reduce lung cancer risk.

    Don’t let radon turn your dream home into a nightmare.

    Now that you know more about buying a home with radon, go out and find your dream home! Don’t let radon gas scare you away from the home you want. Most homes can be fixed for well under $2,000 with a dependable radon mitigation system. You can move into your new place and know that radon gas is not a problem as long as it’s been dealt with correctly.

    Radon in Homes

    The Minnesota Department of Health (MDH) provides information on radon and how to protect your family’s health. MDH recommends that every Minnesota home be tested for radon.

    Radon is a colorless and odorless gas that comes from the soil. The gas can accumulate in the air we breathe. Radon gas decays into fine particles that are radioactive. When inhaled these fine particles can damage the lungs. Exposure to radon over a long period of time can lead to lung cancer.

    It is estimated that 21,000 people die each year in the United States from lung cancer due to radon exposure. A radon test is the only way to know how much radon is in your home. Radon can be reduced with a mitigation system.

    Where does radon come from?

    Radon is produced from the natural decay of uranium and radium, found in rocks and soil. Uranium breaks down to radium, and radium eventually decays into the gas radon. Radon gas is in the soil and common throughout Minnesota. Because soil is porous, radon moves up from the soil and into the home. It can then accumulate in the air and become a health concern.

    Radon in Minnesota

    Radon is a serious public health concern in Minnesota. The average radon level in Minnesota is more than three times higher than the U.S. radon level. This is due to our geology and how our homes are operated. Minnesota homes are closed up or heated most of the year, which can result in higher levels of radon. In Minnesota, more than two in five homes have radon levels that pose a significant health risk.

    Is there a safe level of radon?

    Any radon level poses some health risk. While it is not possible to reduce radon to zero, the best approach is to lower the radon level as much as possible. The Environmental Protection Agency (EPA) has set the action level at 4 pCi/L (picocuries of radon per liter of air). It is highly recommended at 4 pCi/L or higher a radon mitigation system is installed to reduce the radon level.

    Radon and Lung Cancer

    Radon health risks

    It is the number one cause of lung cancer for non-smokers and the second leading cause of lung cancer in smokers. Your risk for lung cancer increases with higher levels of radon and longer periods of exposure. If you smoke, the combined risk of smoking and radon exposure is higher. Reducing smoking and radon exposure greatly reduces the lung cancer risk.

    Lifetime Risk of Lung Cancer Death from Radon Exposure (per 1,000 people)

    Average Radon Level (pCi/L) People who never smoked People who currently smoke U.S. general population
    20 36 260 110
    10 18 150 56
    4* 7 62 23
    2 4 32 12

    * EPA Action Level. For the U.S. general population who are exposed to 4 pCi/L of radon over a lifetime, it is estimated that 23 out of 1,000 people will die from lung cancer due to the radon exposure.

    How radon enters the home

    Radon levels are very low outdoors, but can accumulate to high concentrations in the home. This depends on radon levels in the soil, pathways for radon to enter the home, and the driving force. Air pressure differences between outside air and the inside air act to drive radon into the home. Some homes pull more radon into the home than others due to greater pressure differences available pathways.

    • Source – High levels of radon are naturally found in Minnesota soils.
    • Pathways – Routes the gas takes to enter the home, usually through openings between the soil and the home. These may include cracks in the concrete slab, floor-wall joints, an open sump pit or untreated crawl space, etc.
    • Air pressure – Differences in air pressure between the home’s interior and the soil can pull radon gas into the home through the pathways.

    Common radon pathways

    Air pressure

    Homes commonly operate at a lower (negative) pressure compared to the outside air. This pressure difference creates a vacuum and outside air can be pulled into the home through openings like doors and windows. Some of this replacement air comes from the soil. There are three main components contributing to air pressure changes in the home that can bring in radon gas.

    Stack effect – Warm air rises to the upper portion of the home and is lost to the outside air. Make-up air enters the lower part of the home, and some make-up air comes from the soil.
    Down Wind Draft Effect – Strong winds can blow over the top of the home, pushing and pulling air into and out of the house.
    Vacuum Effect – Appliances (water heaters, fireplaces, clothes dryers, older furnaces, etc.) and exhaust fans remove air from the home. This can drive soil gas into the home as make-up air enters the lower part of the house.


    Any home can have a radon problem, no matter the type of foundation.

    A basement provides a large surface area in contact with the soil, and radon can enter through different pathways. Taller homes add potential for a greater stack effect.
    Homes built slab-on-grade have many openings that allow radon to enter, similar to a basement.
    Homes built with crawl spaces are directly connected to the soil and create a pathway for radon to enter the home.
    Manufactured homes with solid skirting act like crawl spaces and provide a direct connection to the soil.

    Do you exercise in your basement? I do. I have been using a video workout series for the past 90 days. I have to keep in top radon technician shape. While working out in my basement every morning, I can’t help but to think of radon gas while I breathe heavily. I wonder how many people who exercise in their basements are being counterproductive to their health by exposing themselves to dangerous levels of radon?

    What is radon and why you should worry about it:

    It’s an invisible gas that comes from the soil below the home’s foundation. It causes lung cancer because it’s radioactive. It is heavier than air so lower areas of homes and buildings are usually more affected. Basements, rooms over concrete slabs and areas over crawlspaces can have high radon levels. The more of it you breathe, combined with the concentrations of it, contribute to the risk factor. According to the EPA, radon kills more than 20,000 people per year! It is the number one lung cancer killer in non-smokers. Learn more about radon gas.

    Radon, health and exercise:

    I don’t know about you, but I am interested in being healthy for my future and my family. I try to eat right, sleep well and exercise often. As much as I dread those early morning pull-ups and burpees, I know they will be good for me in the long run. While down low to the ground, doing crunches or push-ups, I think about the fact that radon typically measures higher the lower you get. I think about all the other people across the country who are doing the same exercises but they may be breathing dangerous levels of radon gas! People make all of that effort to be healthy yet the chance of lung cancer may be increased. If they only knew how easy it is to make their home (or their gym) safer.

    Radon testing is easy and inexpensive:

    There are many test kit manufacturers across the country. These radon test kits can be long-term or short-term. They are simple devices that can measure the radon levels in your home. You simply place the sampler in the room you are testing for the allotted time and send the sample back to the laboratory for analysis. The lab will send you a detailed report explaining your radon level and what to do next. If your level is greater than 4 picocuries per liter, the EPA says you should take action to reduce radon. The EPA website, states that the level of 4 in non-smokers is equal to the risk of dying in a car crash. The world health organization takes it a step further and they say you should take action if your levels are greater than 2.7 pCi/L. DIY radon test kitsare typically less than $20 and will give you an accurate understanding of the risk in your home. There are also personal use radon monitors that you can move to different rooms around the home.

    How to remove radon:

    You can’t just clean it up. It doesn’t build up over time. Because it is radioactive it is constantly decaying. When you have measurable levels in your home, it is because new gas is replacing that which is decaying. So when radon is high, the way you reduce it is by installing a permanent radon mitigation system. The systems create constant vacuum in the soil under basements, concrete slabs and crawlspaces. As the gas works its way up from the ground beneath the house, it is captured by the system and vented to a safe elevation above the roofline. From there, the radon dissipates into the atmosphere. There are nationally certified radon mitigation system installers who have been trained to properly fix the problem. Most good radon contractors will provide you with a warranty that promises a solution.


    By the way, I never finished the Stanley Watras story. He eventually started a radon testing company out of his home in Boyertown PA. Reports indicate that he considers his work “therapeutic”.

    There is a lot more information on-line…

    If I have only whetted your appetite, feel free to visit these highly informative sites. Be prepared for a lot of technical data. However, the reports are well written and should answer most of your remaining questions.

    Radon in Earth, Air, and Water is supported by the US Geological Survey at http://energy.cr.usgs.gov/radon/radonhome.html. They have links to most of the major radon sites, and also a larger version of the geological map of the US showing average radon levels throughout the United States.

    Facts Concerning Environmental Radon, from the Journal of Nuclear Medicine, Vol. 35, No. 2; Feb 1994, at http://www.physics.isu.edu/radinf/radon.htm. This is a very balanced research effort that covers all facets of radon research, with plenty of technospeak and tables!

    Radon Mitigation Strategies, reproduced in part from The Journal of Nuclear Medicine, Vol. 35, No. 2; Feb 1994 and appearing on the Idaho State University Physics Department Web site, lists various mitigation methods, with both estimated costs and effectiveness. Find it at http://www.physics.isu.edu/radinf/radon2.htm .

    Biological Effects of Ionizing Radiation (BEIR) VI Report: “The Health Effects of Exposure to Indoor Radon” Unfortunately, the full report is not available online. A good summary of the report is available at http://www.nap.edu/catalog.php?record_id=5499

    Sources of Information on Indoor Air Quality: Radon gives the official EPA position on the radon issue. Read it yourself and make up your own mind… at http://www.epa.gov/radon/.

    Radon.com, at http://www.radon.com is a commercial site that has lots of valuable radon information, especially concerning testing and mitigation. They also have a line of very reasonably priced radon test canisters for do-it-yourself testing.

    Infiltec, at http://www.infiltec.com is an online supplier of just about any radon related product you will ever need. Just visiting their site is a radon mitigation education in itself!

    Return to Sisters of Doom Articles

    FAQs: Acceptable Radon Levels

    What constitutes an acceptable or safe radon level? According to the EPA, the maximum “acceptable” level of radon is 4.0 pCi/L, but even that level is not “safe”, per se. The EPA strongly recommends you consider radon mitigation between levels 2.0 and 4.0. For perspective, the average outdoor air level of radon is 0.4 pCi/L. Professional mitigation is the only reliable way to reduce elevated radon readings.

    Frequently asked questions about radon levels:

    • Is there a “safe” level of radon gas?
    • Am I still at risk if my radon levels are below 4.0 pCi/L?
    • If I don’t go in the basement, am I safe from radon?
    • Can radon levels in our home change without intervention?
    • Do I need to test for radon if my neighbor’s house passed?
    • How do I reduce radon levels in my home?

    Is there a “safe” level of radon gas?

    Radon is radioactive and hazardous to your health. When inhaled into the lungs, it can damage DNA and cause lung cancer. The “safe” level of radon exposure is no radon at all. The EPA’s recommended level for radon mitigation is 4.0 pCi/L or above.

    It’s estimated that 1 in 15 American homes have an elevated level of radon gas. While many newer homes are built with radon-resistant features or passive radon systems, these are not always enough to sufficiently reduce radon levels in your home.

    Am I still at risk if my radon levels are below 4.0 pCi/L?

    While any amount of exposure to radon gas constitutes a health risk, your risks of contracting lung cancer decrease significantly as radon levels decrease. For example, a person living in a house with a radon level of 4.0 pCi/L or lower has an approximately 7 in 1000 chance of getting sick. On the other hand, a person living in a house with a radon level of 20 pCi/L or higher has a 36 in 1000 chance of contracting lung cancer. The World Health Organization (WHO) established an action level of 2.7 pCi/L based upon a three-year worldwide study by more than 30 prominent scientists.

    A radon level of 4.0 pCi/L is still a health risk, which is why it’s important to have professional radon mitigation. Professional mitigation can often reduce radon levels to 0.4 pCi/L. The thing to keep in mind is that the risk for lung cancer from radon is random and defies statistics. People may be exposed for a lifetime at very high levels without getting lung cancer, while others may be exposed at moderate levels for a year or two and contract lung cancer. Radon is one of the few environmental hazards we have some control over.

    If I don’t go in the basement, am I safe from radon?

    It’s a common radon myth that radon gathers in basements and you can avoid exposure by simply not going in the basement. In reality, when your furnace or air conditioning run at any time during the year, it will circulate that air — and any radon gas that comes with it — throughout the entire house, particularly if there is a return duct in the basement. You can’t avoid a radon problem by staying upstairs. The rule of thumb: radon levels are reduced by approximately 50% per floor going up through the house, except when there is a return duct in the basement.

    Can radon levels in our home change without intervention?

    Radon levels are always changing. Seasonality plays a role. Winter tends to be worse than summer when heat rising in the house creates a stronger vacuum on the soil. Radon levels spike during heavy wind, rain, or snowy weather.

    If you consistently have high levels over a period of time, or if you get a result above 4.0 pCi/L in summer, you most likely need radon mitigation.

    Do I need to test for radon if my neighbor’s house passed?

    Among the common radon myths is the idea that radon is isolated to certain neighborhoods, or that the results of a radon test in one house are accurate to the next house over. Some think that only certain types of homes are susceptible to radon.

    These are misconceptions. Radon is a geological issue. It has little to do with the age of the house, or whether there is a basement. Any structure in touch with the ground has a potential radon problem, including crawlspaces.

    As radon maps show, some areas of the country tend to have higher levels of radon than others. However, don’t be lulled into a false sense of security that your home is safe because you live in a “low radon” area. High radon levels can be found anywhere and may vary significantly from one home to the next. Because radon can’t be detected by human senses, the only way to be sure is to conduct a radon test.

    How do I reduce radon levels in my home?

    If you’ve tested your home and found higher-than-acceptable radon levels, your next step is to look at installing a radon mitigation system. Learn more about how professional radon mitigation works and what to expect from a high-quality radon repair contractor.

    Have More Questions?

    Please explore our complete Radon FAQs to educate yourself about the what’s, why’s and how’s of radon remediation. Then learn why choosing the best local radon removal company is critical.

    Ready to move forward? Give us a call or request an estimate.

    Top 10 Myths and Facts About Radon

    This article researches top 10 myths and facts about radon, from examining the claims of scientists who say radon is not dangerous to the question of whether short-term tests are enough to take action against radon.

    Myth 1: Radon isn’t dangerous

    Fact: To understand this first out of many radon myths, it’s important to first review some background. Namely, who is saying radon isn’t a problem? Many people in the lay community and even in the scientific community have claimed that radon is not an issue to worry about. For instance, a 1995 study from an American scientist named Dr. Bernard Cohen challenged the Environmental Protection Agency’s (EPA) findings about radon, claiming that the EPA’s results had a fundamental flaw based on a misunderstanding of radon dosage. He basically says that just because very high levels of radon can lead to cancer, it is erroneous to think that means low levels of radon pose a risk.

    It’s hard to know who to listen to. The scientists making claims against the EPA could be whistleblowers alerting the community to a lapse in scientific judgment, so it is worth considering what they have to say. The World Health Organization helped us do just that by analyzing the 1995 study conducted by Dr. Bernard Cohen and publishing a neutral report. They found fundamental issues with the way he formulated his study: “Cohen’s geographical correlation study has intrinsic methodological difficulties (Stidley & Samet, 1993, 1994)” (WHO).

    What is more, in addition to the EPA, the Center for Disease Control, American Lung Association, and American Medical Association all agree that radon has a harmful effect on human health. Given the number of US and international institutions claiming radon is dangerous, and the fact that Dr. Cohen’s methods were questions by the WHO, it is reasonable to conclude that radon is indeed dangerous.

    Myth 2: Radon tests are expensive and take a long time

    Fact: It is one of the common radon myths. A simple preliminary radon test is not at all expensive. You can buy short-term radon test kits for as little as $15 (National Radon Program Services). The cheaper short-term tests are going to be less accurate than others, but they will at least give you a rough idea of radon levels in your home. And they tend to take around 2–7 days, which means they are not time consuming. What’s more, once the radon test is underway you need only to wait. In this sense, they’re not overly complex to conduct.

    Myth 3: You can’t solve radon problems in all homes

    Fact: First of all it should be noted that only 6% of homes have radon levels that need to be resolved through a form of mitigation (National Radon Program Services). Secondly, homes can be fixed through a number of different means, from a homeowner caulking foundation faults in their basement to the installation of a radon mitigation system in your home. The National Radon Program Services note that “virtually any home can be fixed,” citing the above methods as the most common solutions.

    Myth 4: Only some types of home need to worry about radon

    Fact: Radon is not attracted to ranches more than victorian style homes. This might seem facetious, but it is essentially the argument people make when they say specific home types need to worry about radon and others don’t. The fact of the matter is radon comes up from the ground, and it depends on variable factors like “soil and atmospheric conditions” (University of Minnesota), among other factors such as construction materials and structural soundness. In short, no home is more or less susceptible because of its “type.”

    Myth 5: You only need to worry about radon if you live in certain areas of the country

    Fact: Some blogs claim that if you live in certain parts of the country you should be more concerned with radon than if you live in other parts of the country. While it’s true that there are regions with more and less radon, the idea that you don’t need to worry about radon just because you live in a region that tends to have low radon levels is unfounded. Radon levels are very local, and depend on soil composition, atmospheric conditions, home construction, etc. (University of Minnesota). Thus, it would be foolish not to be concerned about radon for the sole reason that the region in which you live tends to have low radon levels.

    Myth 6: Radon tests from a neighbor’s house are accurate indications of radon in your own home

    Fact: A common one in all the radon myths. Unfortunately, it’s not true. A study from the National Institute of Health showed that soil composition and ground permeability are key factors affecting radon in your home, and they are factors that are specific to your plot of land (NIH). And while the argument could be made that your neighbor’s house is built in the same soil and close enough to your own house to know that the ground permeability is relatively constant, differences in home construction between your home and theirs could alone account for different readings of radon. A resource called Radon Awareness cites cracks in a foundation as enough to allow significant levels of radon into your home. This fact renders the neighbor test idea moot.

    Myth 7: All homeowners should conduct water radon tests

    Fact: Radon testing is important, but water radon tests should be conducted after air radon tests. For one, many homes receive their water from a public water infrastructure, which should test and report radon levels. If you get your water from a personal well, a water radon test might be advisable, but a test of radon in the air would be an easier first test to conduct. This air test would tell you if radon is present, and airborne radon tends to be more dangerous than waterborne radon (New Hampshire Department of Environment Services).

    Myth 8: Selling a home that has a history of radon is difficult

    Fact: Unaddressed radon problems are obviously not attractive to homebuyers. But if measures have been taken to fix radon levels, and they have been shown to work, this can actually increase home value. Many real estate agents claim a resolved radon issue through a permanent structural fix or a radon mitigation system have a neutral effect or else a positive effect on your ability to sell a home. Radon myths like these are unfortunate as they can lead to inaction.

    Myth 9: Having lived in my house for many years it wouldn’t matter if I took action against radon now

    Fact: This is probably the least fortunate of all the radon myths. As the National Cancer Institute notes, “Long-term exposure to radon can lead to lung cancer.” It is long term exposure that matters, so it’s never really too late to check your home for radon. At the very least, you might find out you do have high radon levels, allowing you to take action to protect your home.

    Myth 10: Short-term tests aren’t enough to make a decision about taking action to fix radon in your home

    Fact: This last of of many myths is still a common one. The fact is that short-term tests can be enough, provided you use more than one. Radon.com notes that two radon tests could be enough to take action provided that at least one of the tests is above the recommended 4.0 pCi/L. This would indicate that levels at least some of the time are above recommended level, and therefore that you might want to take action. Note that if you conduct two radon tests and neither is above 4.0 pCi/L that does not mean you are safe from radon. To conclusively know if you are safe from radon you must consistently monitor radon levels. That said, short term tests can lead to radon mitigation action if they conclusively show radon levels are too high.

    We hope you’ve enjoyed this article. Now you should know all the top 10 myths and facts about radon.

    Do you have a problem? for our top five tips to reduce radon.


    Protect Yourself and Your Family from Radon

    Radon is the second leading cause of lung cancer after cigarette smoking. If you smoke and live in a home with high radon levels, you increase your risk of developing lung cancer. Having your home tested is the only effective way to determine whether you and your family are at risk of high radon exposure.

    Radon is a radioactive gas that forms naturally when uranium, thorium, or radium, which are radioactive metals break down in rocks, soil and groundwater. People can be exposed to radon primarily from breathing radon in air that comes through cracks and gaps in buildings and homes. Because radon comes naturally from the earth, people are always exposed to it.

    The U.S. Environmental Protection Agency and the Surgeon General’s office estimate radon is responsible for more than 20,000 lung cancer deaths each year in the U.S. When you breathe in radon, radioactive particles from radon gas can get trapped in your lungs. Over time, these radioactive particles increase the risk of lung cancer. It may take years before health problems appear.

    People who smoke and are exposed to radon are at a greater risk of developing lung cancer. EPA recommends taking action to reduce radon in homes that have a radon level at or above 4 picocuries per liter (pCi/L) of air (a “picocurie” is a common unit for measuring the amount of radioactivity).

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

    • How much radon is in your home–the location where you spend most of your time (e.g., the main living and sleeping areas)
    • The amount of time you spend in your home
    • Whether you are a smoker or have ever smoked
    • Whether you burn wood, coal, or other substances that add particles to the indoor air

    The chances of getting lung cancer are higher if your home has elevated radon levels and you smoke or burn fuels that increase indoor particles.

    CDC’s Radon Communication Toolkit is designed for environmental and public health professionals to use to increase awareness and understanding of radon, its health effects, and the importance of testing for radon among the communities they serve. The toolkit contains customizable fact sheets, infographics, newsletter articles, and social media posts.View large image and text description

    Test Your Home for Radon

    Having your home tested is the only effective way to determine whether you and your family are exposed to high levels of radon. Steps you can take to measure and reduce radon levels include:

    • Purchasing a radon test kit
      • Find a Radon Test Kit or Measurement and Mitigation Professionalexternal icon
    • Testing your home or office
      • Testing is inexpensive and easy — it should only take a few minutes of your time. It requires opening a package and placing a small measuring device in a room and leaving it there for the desired period. Short-term testing can take from a few days to 90 days. Long-term testing takes more than 90 days. The longer the test, the more relevant the results are to your home and lifestyle.
    • Sending the kit to appropriate sources to determine radon level
      • Follow the directions on the test kit packaging to find out where to send the device to get the results.
    • Fixing your home if radon levels are high

    More Ways to Take Action

    The U.S. Department of Housing and Urban Development pdf iconexternal icon recommends additional actions you can take to reduce high radon levels in your home and protect yourself from an increased risk of lung cancer.

    For more information on testing your home, check with your state radon officeexternal icon or call the National Radon Hotline at 1-800-SOS-RADON.

    • Stop smoking and discourage smoking in your home.
      • Smoking significantly increases the risk of lung cancer from radon.
    • Increase air flow in your house by opening windows and using fans and vents to circulate air.
      • Natural ventilation in any type of house is only a temporary strategy to reduce radon.
    • Seal cracks in floors and walls with plaster, caulk, or other mate­rials designed for this purpose.
      • Contact your state radon office for a list of qualified contractors in your area and for information on how to fix radon problems yourself. Always test again after fin­ishing to make sure you’ve fixed your radon problem.
    • Ask about radon resistant construction techniques if you are buy­ing a new home.
      • It is almost always cheaper and easier to build these features into new homes than to add them later.

    For more information on testing your home, check with your state radon officeexternal icon or call the National Radon Hotline at 1-800-SOS-RADON.

    To find out more about radon test kits, visit Radon Hotlines and Information Resourcesexternal icon or refer to the EPAexternal icon web site on how to use a test kit.

    Radon Fact Sheet

    Fact Sheet

    The U.S. Environmental Protection Agency (US EPA) and the Surgeon General’s Office have estimated that as many as 20,000 deaths are caused each year by radon. Radon is the second leading cause of lung cancer and according to the US EPA, nearly 1 in 4 homes checked in seven states, and on three Indian lands, had screening levels over 4 pCi/L, the EPA’s recommended action level for exposure.

    The alpha radiation emitted by radon is the same alpha radiation emitted by other alpha generating radiation sources such as plutonium.

    A family whose has radon levels of 4 pCi/L is exposed to approximately 35 times as much radiation as the Nuclear Regulatory Commission would allow if that family was standing next to the fence of a radioactive waste site. (25 mrem limit, 800 mrem exposure)

    An elementary student that spends 8 hours per day and 180 days per year in a classroom with 4 pCi/L of will receive nearly 10 times as much radiation as the Nuclear Regulatory Commission allows at the edge of a nuclear power plant. (25 mrem limit, 200 mrem exposure)

    Most U.S. EPA lifetime safety standards for carcinogens are established based on a 1 in 100,000 risk of death. Most scientists agree that the risk of death for radon at 4 pCi/L is approximately 1 in 100. At the 4 pCi/L EPA radon action guideline level, carries approximately 1000 times the risk of death as any other EPA carcinogen. The EPA has proposed to require community water suppliers to provide water with radon levels no higher than 4,000 pCi/L, which contributes about 0.4 pCi/L of radon to the air in your home. It is important to note that the action level is not a safe level, as there are no “safe” levels of radon gas.

    A layman’s description

    Radon is a cancer-causing radioactive gas. You cannot see, smell or taste , but it may be a problem in your . The Surgeon General has warned that is the second leading cause of in the United States today. If you smoke and your has high levels, you’re at high risk for developing . Some scientific of exposure indicate that children may be more sensitive to . This may be due to their higher respiration rate and their rapidly dividing cells, which may be more vulnerable to radiation damage.

    A scientific description: Radon is a gaseous highly radioactive element discovered by English physicist Ernest Rutherford in 1899. The discovery is also credited to German physicist Friedrich Ernst Dorn in 1900. More specifically, Rutherford discovered radon’s alpha radiation and Dorn discovered that radium was releasing a gas.

    Radon is a colorless chemically-unreactive inert gas. The atomic radius is 1.34 angstroms and it is the heaviest known gas–radon is nine times denser than . Because it is a single atom gas (unlike oxygen, O2, which is comprised of two atoms) it easily penetrates many common materials like paper, leather, low-density plastic (like plastic bags, etc.) most paints, and building materials like gypsum board (sheetrock), concrete block, mortar, sheathing paper (tar paper), wood paneling, and most insulations.

    Radon is also fairly soluble in and organic solvents. Although reaction with other compounds is comparatively rare, it is not completely inert and forms stable molecules with highly electronegative materials. is considered a noble gas that occurs in several isotopic forms. Only two are found in significant concentrations in the human environment: -222, and -220. -222 is a member of the radioactive decay chain of uranium-238. -220 is formed in the decay chain of thorium-232. -222 decays in a sequence of radionuclides called decay products, daughters, or progeny. It is -222 that most readily occurs in the environment. Atmospheric releases of -222 results in the formation of decay products that are radioisotopes of heavy metals (polonium, lead, bismuth) and rapidly attach to other airborne materials such as dust and other materials facilitating inhalation.

    PRODUCTION: is not produced as a commercial product. is a naturally occurring radioactive gas and comes from the natural breakdown (radioactive decay) of uranium. It is usually found in igneous rock and soil, but in some cases, well may also be a source of .

    EXPOSURE: The primary routes of potential human exposure to are inhalation and ingestion. in the ground, groundwater, or building materials enters working and living spaces and disintegrates into its decay products. Although high concentrations of in groundwater may contribute to exposure through ingestion, the inhalation of released from is usually more important.

    IN THE WORKPLACE: In comparison with levels in outdoor , humans in confined spaces, particularly in underground work areas such as mines and buildings, are exposed to elevated concentrations of and its decay products. Exhalation of from ordinary rock and soils and from -rich can cause significant concentrations in tunnels, power stations, caves and public baths. The average concentrations in are generally much lower than the average concentrations in underground ore mines.

    Workers are exposed to in several occupations. In countries for which data were available, concentrations of decay products in underground mines are now typically less than 1000 Bq/m3 EEC Rn (approx. 28 pCi/L). Underground uranium miners are exposed to the highest levels of and its decay products. Other underground workers and certain mineral processing workers may also be exposed to significant levels.

    What should you look for?

    Testing is the only way to know your radon level. There are no immediate symptoms that will alert you to the presence of radon. It typically takes years of exposure before any problems surface. The US EPA, Surgeon General, American Association, American Medical Association, and National Safety Council recommend testing your home for radon because testing is the only way to know your radon level.

    Radon is a national environmental problem and elevated radon levels have been discovered in every state. The US EPA estimates that as many as 8 million throughout the country have elevated levels of radon. Current state surveys show that 1 in 5 has elevated radon levels.

    Can you fix the problem?

    It’s best to rely on a professional – especially when dealing with a carcinogen. In fact, many U.S. states require radon professionals to be certified and licensed in their field. You can quickly located a RadonAway Authorized Radon Pro in your area for a free consultation.

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