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  • Radon is a radioactive gas created by the normal breakdown of uranium in rocks. Exposure causes an average of 21,000 lung cancer deaths each year
  • Hazardous levels of radon can be found in nearly 1 out of every 15 American homes. Levels in heavily contaminated homes can in some cases exceed the established standards permitted for underground miners
  • Common sources include building materials; contaminated air seeping into your home through cracks in the foundation, walls and floors; deep wells; ionization-type smoke detectors; and watches with luminescent dials
 

One in 15 American Homes Is Affected by Major Lung Cancer Hazard

February 17, 2016 | 205,869 views
| Available in EspañolDisponible en Español

By Dr. Mercola

Did you know that radon — a major cause of lung cancer,1 second only to cigarette smoking — may be lurking in your home, school, or office? According to the Environmental Protection Agency2 (EPA), hazardous levels of radon can be found in nearly 1 out of every 15 American homes.

As noted by the National Safety Council:3

“In Utah, the ratio is 1 in every 3 homes that have been tested. Dr. Wallace Akerley of the Huntsman Cancer Institute ... likened living under such conditions to smoking one or two packs of cigarettes a day.”

In the U.S., Iowa and the Appalachian Mountain areas in Pennsylvania are known to have some of the highest environmental radon levels, although the presence of radon indoors can vary widely from one home or building to the next, even if they’re right next to each other.

To get an idea of what the natural radon levels in your area are, check out the EPA’s radon map.4 Worldwide, the town of Mallow in Ireland has the highest natural levels of radon ever registered.5

Radon kills 7 times more people each year than home fires, yet most people are completely unaware of this threat, and neglect to test their home for this pervasive carcinogen. 

I strongly encourage you to investigate how much of this gas you and your family are exposed to, and take the necessary steps to remediate the problem if it turns out you have elevated levels in your home.

Radon — A Major Source of Carcinogenic Radiation

Radon is a radioactive gas created by the normal breakdown of uranium in rocks (including shale, phosphate rock, granite, and limestone). As a result, radon is to some extent or another present in most soils, water, and air.

It’s odorless, tasteless, and invisible, so the only way to determine whether radon is present is to measure it using a special test kit.

Estimates6,7 suggest radon exposure causes an average of 21,000 lung cancer deaths each year, and 10 to 25 percent of them are non-smokers.8,9 Typically, cancer tends to develop anywhere from 5 to 25 years after exposure.10

The combination of smoking and radon exposure can significantly increase your risk of lung cancer. According to the EPA,11 if 1,000 smokers were exposed to the "action" radon level of 4 pCi/L over a lifetime, about 62 of them would get lung cancer from the radiation, compared to about 7 out of 1,000 non-smokers.

Interestingly, it’s been suggested that radioactive phosphate fertilizer may actually be a major contributor to the carcinogenicity of cigarettes. Uranium and radium are also two known carcinogens found in fluorosilicic acid used for water fluoridation.

While the evidence is limited, radon may be linked to other cancers besides lung cancer. One study conducted in Denmark from 1968 to 1994 suggests a statistically significant link between radon exposure and acute childhood lymphoblastic leukemia.12

Another study by the University of Texas Medical Branch concluded radon exposure may be a significant risk factor for pancreatic cancer in African-Americans, American-Indians, and Asian-Americans.13

Common Sources of Radon Exposure

As for radon in your home, it can originate from a number of sources, including:

  • Building materials, including silicone-rich magmatic rocks (particularly granite, and especially the more exotic granites like the red, pink and purple varieties), gypsum waste products, cement, concrete, pumice, and basaltic rock.
  • Contaminated air seeping into your home through cracks in the foundation, walls and floors. Radon levels are highest in rooms closest to the ground, so if you spend a lot of time in basement rooms at home, work or school, your risk for exposure could be greater.
  • Well water. While the risk of exposure from water is generally minimal, deep wells sunk into rock with a high radium concentration may contain high levels of radon. I would encourage you to test for this poison if you get your water from an underground well.
  • Smoke detectors. Residential smoke detectors fall into three different categories: the ionization type, the photoelectric type, and detectors that contain both types of sensing devices.
  • Ionization smoke detectors are less expensive and more commonly used, but they emit small amounts of radon, and also have a higher rate of false alarms than the photoelectric variety.

  • Certain clocks and watches. Certain clocks and watches can also add to the overall radon levels of your surroundings. If you own one with a luminous dial, it probably contains either Tritium, a radioactive form of hydrogen, or Promethium, a man-made radioactive element.14
  • Both elements emit small amounts of radon, and while most of it is contained in the cover of the watch, there is still a minimal risk associated with having luminous watches around.

    If you happen to own a World War I vintage “glow in the dark” clock or watch, be aware that highly radioactive radium was used to make the luminous paint for the dials. Wearing such watches, and certainly repairing them, poses a significant risk of radon exposure.

Heavily Contaminated Homes May Exceed Safety Standards for Miners

Radon in air is ubiquitous, meaning it’s everywhere, and while radon gas disperses before reaching high levels of concentration outdoors, in tightly sealed or poorly ventilated indoor spaces even low levels of radon can accumulate over time and pose a significant health hazard.

The levels of radon found in heavily contaminated homes can be the equivalent to levels found in underground mines, and may actually exceed the established standards permitted for miners.

Radon has a half-life of 3.5 to 4 days. In other words, half of a given amount of radon takes over 3 days, but less than 4, to decay. Your overall radon exposure risk therefore depends on a number of factors, including:

  1. The levels of radon in your indoor environments
  2. The amount of time you spend in those environments
  3. Whether or not you are a smoker (if you smoke and live in a home with elevated radon levels, your risk of lung cancer is particularly high)
  4. Exposure to phosphate fertilizers and other sources of radon exposure, either at home or at work

At What Point Does Radon Become a Health Threat?

Radon is measured in picocuries per liter of air, or "pCi/L." Outdoor air generally has background radon levels of about 0.4 pCi/L, whereas the average radon level indoors is estimated to be about 1.3 pCi/L. The EPA recommends taking immediate action if your home's levels exceed 4 pCi/L. This does not mean that levels below 4 pCi/L are "safe," however, as there really is NO safe level for radiation.

Even the EPA admits that lower levels can still pose a health risk, and suggests taking action to further reduce the amount of radon in your indoor space if it’s between 2 to 4 pCi/L. I would recommend addressing the issue even if your level is lower than that, because 1.3 pCi/L is the level associated with causing 21,000 deaths each year. Clearly, even that is too high for safety!

How to Test Your Home or Office for Radon

The EPA and the Surgeon General recommend that ALL homes and buildings should be tested for radon. Since radon concentrations can vary from day to day or week to week depending on a number of variables,15 such as weather, time of day, and the usage of ventilation systems, the EPA recommends performing long-term rather than short-term measurements. This will give you the most accurate assessment of your radon exposure.

Be sure not to air out your house prior to testing, as this may lead to a deceptively low measurement. Testing during winter months is ideal, as this will give you a good idea of your maximum levels, since windows and doors remain consistently closed. Place the test kit in the lowest area of your home — in the basement if you have one. It would be a good idea to also test the ground level living areas.

Keep in mind that while a Geiger counter measures alpha, beta and gamma radiation, it will NOT detect the presence of radon gas in your indoor air. It can however be useful for locating other sources of harmful radiation inside your home or other building. Here are a few resources for radon testing:

  • To hire a certified technician to measure the radon levels in your home or other indoor environment, contact the American Association of Radon Scientists and Technologists (AARST)16
  • Do-it-yourself test kits for radon are your least expensive option. While the median cost for homeowners to test for radon is around $600,17 you can purchase a DIY kit for about $30 or less. They can be purchased on Amazon for $10.50 and at your local hardware store. The test kit is typically placed in your home for several days, up to as long as three months, after which you mail it to a laboratory for analysis.
  • The National Radon Program Services at Kansas State University offers discounted test kits available to purchase online.18 To buy a radon test kit by phone, call 1-800-SOS-RADON (767-7236).
  • You can find more information on certified technicians and do-it-yourself testing from the EPA.19 State and regional information can be found on the EPA’s Indoor Air Quality Contact page.20

Radon Remediation


If your home or office is found to have elevated levels of radon, it’s important to find a qualified radon service professional to address the problem. Some U.S. states maintain lists of contractors that have met certain qualifications for radon mitigation; your state radon coordinator21 will have this information.

The following organizations can help you find a qualified radon service professional that meets and follows the American national standards and best practices for radon measurement and mitigation:

  • The American Association of Radon Scientists and Technologists22 (AARST)
  • The National Radon Safety Board (NRSB)23
  • The National Environmental Health Association (NEHA)24

There are a variety of ways to remediate indoor radon levels, including the following. (As for cost, it all depends on the size and design of your home and the specific remediation needed. That said, the average cost of a radon remediation system25 ranges from $800 to $1,200.)

  • Sealing cracks in floors and walls
  • Increasing ventilation through sub-slab depressurization with pipes and fans
  • Removing granite countertops if they are emitting high levels of radon
  • Replacing ionization smoke detectors with the photoelectric type

Insist on Radon-Resistant New Construction


If you’re building a home or other structure, insist on building materials that are more resistant to the naturally occurring radon in the outdoor environment. You can find information about Radon-Resistant New Construction (RRNC) on the EPA’s website.26 The five basic features of a radon-resistant home suggested by the EPA are:27

  1. Gravel laid below the foundation which allows radon in the soil to circulate freely underneath your house
  2. Plastic sheeting or other vapor retarder laid over the gravel to stop soil gases from entering the structure
  3. Vent pipe run vertically from the gravel layer up to the roof to safely vent radon from the soil outside the house
  4. Sealing and caulking of all cracks, crevices and other openings in the concrete foundation and the walls of the structure
  5. Electrical junction box installed in the attic for use with a vent fan, should one be needed

U.S. and Canadian Helplines for Radon Questions

Kansas State University maintains two national radon helplines you can peruse if you need to talk to someone about your radon concerns:

  • National Radon Helpline: Get live help for your radon questions. 1-800-55RADON (557-2366)
  • National Radon Fix-It Line: For general information on fixing or reducing the radon level in your home. 1-800-644-6999
  • Canadians can find more information by visiting healthcanada.gr.ca/radon, or by calling 1-800-O-Canada.

As a general rule, once you have addressed the radon level in your home, it’s recommended that you re-test your home every two years. If your home initially tested low, it’s also a good idea to re-test every couple of years to make sure the levels remain low.

Considering the prevalence of radon in American households (and in other areas of the world as well), and the significant health risks associated with elevated levels, testing your home and other areas where you spend significant amounts of time is well-worth the investment — which can be as low as $10 if you go with a simple DIY kit.

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