The Health Effects of Radon in Layman's Terms

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              HOW DOES RADON CAUSE LUNG CANCER?

There is uranium in the soil throughout the world. Uranium changes to different elements as it decays down to its final element of lead. All of the elements it changes into are solids except one, radon. Radon is a gas that does not stick to other particles. Being a free agent (noble gas), it floats freely in the soil and is easily drawn into the lower level of homes by the the natural flow of air, upward through a house. As it moves up through a house, it will change (decay) back into a solid particle (radon decay products). These solid particles easily attach to dust. Some of the inhaled radon and radon decay products attached to dust particles can decay or change in the lungs. The damage from the energy given off by the decay can genetically affect the lung cells. At some later date these damaged cells can become the beginning phase of lung cancer. Exposure to radon, no matter how much exposure, does not mean you will get lung cancer.

The EPA review of the scientific literature indicates that the risk from exposure (at the levels you might likely receive) is linear which means if you are exposed to four times more radon than someone else, you would have four times more risk.  The EPA guideline of 4.0 pCi/l is not a safe level but a recommended level at which action should be taken to reduce your exposure. In fact, the EPA was mandated by congress to have a goal of reducing indoor radon levels to outdoor levels. The average outdoor radon level is considered to be 0.4 pCi/l. You cannot eliminate exposure to radon but you can reduce your exposure.

            WHAT DO SCIENTIFIC GROUPS SAY?

In every underground mine that was studied by two scientific committee groups ( BEIR IV and BEIR VI ) there was increasing lung cancer as the radon levels increased.  Numerous residential studies have found that increased indoor radon levels were connected with increased lung cancers.     See the Iowa Radon & Lung Cancer study.

 There is no controversy about the connection between radon and lung cancer.  There is in fact world wide acceptance that radon does indeed increase the risk of lung cancer.  The question is how much increase risk is there.  The EPA in 2003 reviewed all the scientific studies and revised the risk table in there pamphlet "Citizen's Guide to Radon".  A copy of the "Citizens guide to Radon" is available as a PDF from the EPA website.

       HOW DOES RADON COMPARE TO
                   OTHER CANCER CAUSING AGENTS?


Other pollutants are regulated by the EPA to reduce the risk to only 1 additional cancer in a million people that are exposed over a lifetime to the pollutant.  Radon at 4 pCi/l for a lifetime is estimated to cause 7 additional cancers in a group of just a 1000 people.  Radon is easily classified as a "Class A" carcinogen and far and away the worst environmental risk.

           HOW MUCH RADON ARE YOU BREATHING?

The true health risk from radon is not the levels in your basement but what are the levels in the areas of the house you spend most of your time in.  Radon arrives predominately from the soil so the highest levels are almost always in the basement or lowest level of the home.  If you have a basement and there is a door between the basement and the upper floors then the upper floors will likely have significantly lower levels.  Often the basement is 3 or 4 times higher than the first floor.  In other words if you had 12.0 pCi/l in your basement it may only be 3.0 or 4.0 pCi/l in the first and second floor.  This will vary depending on the season, heating system and separation of basement and first floor.

      CALCULATING RISK USING THE EPA RISK TABLE

The scientific group under the title BEIR VI carefully looked at all the available information regarding lung cancer and published their conclusions in 1998.  In 2004 the EPA revised their “Citizens Guide to Radon” and using the BEIR VI information revised their Risk Table.  The table is presented below.

 The Epidemiology Journal in March of 2005 published a study that combined 7 North American case control studies on radon and found the risk of radon was very much in agreement with BEIR VI conclusions, which had been mostly based on world wide mining studies.

Combined North American case control study.

   THIS IS THE 2003 REVISED EPA EXPOSURE RISK TABLE

Average lifetime
radon level

If a thousand people were exposed to radon levels listed in the left column then the following additional Lung Cancers would take place

pCi/L Never Smokers Current Smokers
20 36  ( 3.6% ) 260  ( 26% )
10 18  ( 1.8% ) 150  ( 15% )
8.0 15  ( 1.5% ) 120  ( 12% )
4.0 7.3  ( 0.7% ) 62  ( 6.2%)
2.0 3.7  ( 0.4% ) 32  ( 3.2% )
1.25 2.3  ( 0.2% ) 20  ( 2.0% )
0.4 0.73  ( 0.1% ) 6.4  ( 0.6% )
Example: If you were a homemaker in a house for 18 years (1/4 lifetime) that had an average 8 pCi/l in the living areas, it would equal a lifetime risk of 2 pCi/l and a 0.4% risk of getting Lung Cancer as a non-smoker or 3.2% as a smoker.
 

       CALCULATING RISK USING THE EPA RISK TABLE

If I used the table above I could calculate my families risk to radon.  We have lived in our present home for 25 years.  Before I installed my radon mitigation system I measured 15 to 30 pCi/l in my basement.  I have an oil fired hot water heating system in the basement.  The basement has a door separating it from the first floor.  If the average radon in the basement was 22 pCi/l and the first floor was 4 times less than there would be about a 5.5 pCi/l average upstairs.  My 25 years in the same house is a third of a lifetime.  To convert my 25 years to the lifetime averages of the table above, I need to divide my 5.5 pCi/l level by 3 to make it the equivalent of an average lifetime (70 years).  This makes my equivalent lifetime average about 1.83 pCi/l or about a lifetime average of 2.0 in the table above.  I do not smoke.  Although I was not in the house 75% of the time, my wife was, as she raised our three boys.  Using the table above my wife would have had a 0.3 % chance of getting lung cancer from radon if I had not installed our radon mitigation system.  Some people would consider that an acceptable risk for themselves.  I do not think they would consider it an acceptable risk for their loved ones.

The British Medical Journal in December of 2004 published a European study that combined the data from 13 European case control studies that included 7148 cases of lung cancer.  If you factor in the use of lifetime exposure in the EPA table presented above you will find that the smokers risk from radon was very similar to the EPA numbers.  The Europeans found the non-smoking risk still significant but about 40% smaller than what the EPA table indicates for non-smokers.
                                European Radon Risk Study

The National Cancer Institute published Questions & Answers on Radon in June of 2004

The table below gives the percentage of survivors from different cancers after five years.  Unfortunately the five year survivor rate for Lung Cancer has only improved from 13% to 15% in the last 25 years we have records for. The one-year survival rate is presently about 40%.  If you smoke a pack a day for 20-years you have a 50% chance of dying from a smoke related illness.  Your chance of dying from a smoke related illness decreases to 25% after ten years of non-smoking.

               5 Year Cancer Survivor Rate

Type of Cancer  1974 to 1976 1983 to 1985 1992 to 1999
Breast 75% 78% 87%
Prostrate 67% 75% 98%
Colon 50% 58% 62%
Lung 13% 14% 15%


More people die from Lung Cancer than Breast, Prostrate and Colon combined. It is estimated that 25% of non-smoking woman who contract lung cancer it can be attributed to their exposure to radon.

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How can diet protect us from Cancers?

Obviously you need to reduce your radon levels if they are elevated.  If you are a smoker, you must make quitting a priority in your life.  Whether you are a smoker or a non-smoker there are dietary changes that can significantly reduce your risk of cancer.  Changing to a more vegetarian diet is one of the most helpful things to do.  The chart below indicates the reduction in Lung Cancer incidence as populations have a higher consumption of plant based foods versus animal based foods.  This information says at least reduce your consumption of animal based foods.  This actually includes all meats and dairy.
 

 

Here are some simple things you can do to decrease your risks:

             Eat a mixed salad and lots of vegetables

Over 125 published scientific papers have shown the exceptional protective effect of the brassica vegetables on lung cancer and other cancers.  These brassica veggies including watercress, broccoli, cauliflower, cabbage, broccoli sprouts, brussels sprouts, arugula, and kale.  All of these have been shown to fight cancer by a combination of inhibiting carcinogenesis, excreting carcinogens via liver detoxification, inducing death of cancer cells, and inhibiting tumors!  Consuming 500 grams per day (about 4 cups) can cut your risk of various cancers by up to 50%.  There is nothing more powerful you can do to protect yourself against cancer than to eat lots of lightly steamed green, yellow and red vegetables every day.

 A number of other impressive studies have also show that green tea inhibits the growth of the human lung cancer cell line.  Of all the teas, green tea is most recognized for its ability to reduce angiogenesis or blood flow to the tumor.  Now there are lots of choices of green or white in any market place.

For those of you who can’t imagine washing down brassica veggies each day with your green tea, there are nutritional supplements that contain the active ingredient in brassica veggies [Indole-3-Carbinol (I3C) ] and green tea (EGCG).  Ask for information about these products at your local health food store.  But it is ultimately better to get them fresh.

              Don’t forget  zinc, selenium, & vitamin C

Mineral tests on lung cancer patients have shown lower levels of selenium and zinc.  These two important and protective antioxidants are found in brazil nuts, almonds, and seafood.  Another powerful antioxidant is N-Acetyl Cysteine which is available from health food stores.

My Brother Peter Brodhead is a well respected nutritionist who has put together an extensive list of foods and supplements that reduce cancer risk and help cancer survivors.   Download his Cancer Nutritional Support paper which contains an amazing coverage of nutritional advice that mostly comes from Donald Yance Centre for Natural Healing.

More information about the connection between diet and cancer can be obtained at:   American Cancer Society  web page on diet.

Download a copy of this information Radon health risk

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