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Information About Radon Mitigation
Radon gas is found in homes all over the U.S.
Radon is an invisible and odorless radioactive gas. Elevated levels of radon have been found in homes all across the country. Any home in any state may have a radon problem: new and old homes, well-sealed and drafty homes, and homes with or without basements. Radon gas gets into all types of buildings, including office buildings and schools.
You and your family receive the greatest radiation dose in your home. That's where you spend most time - 70 to 75 percent, more for small children. The average person receives each year more radiation from radon than from all other natural or man-made sources combined. Over the years, the accumulated radiation exposure may exceed the exposure of uranium miners.
The never-ending supply of radon
Radon gas is produced during the natural disintegration of radioactive heavy metals uranium and thorium, which are dispersed throughout the Earth's crust. As the atoms of radioactive heavy metals disintegrate, they change into lighter and lighter radioactive heavy metals until they end up as stable, non-radioactive lead. But at each step of this radioactive decay chain the atom nuclei emit radiation - alpha and beta particles, or gamma rays (more energetic than x-rays).
We will never run out of uranium or thorium. Radon levels on Earth have not changed since the last Ice Age. The radioactive half-life of Uranium-238, when a half of its atoms disintegrates, is 4.5 billion years. The half-life of Thorium-232 is 14.1 billion years. Their decay chain continuously produces radium, which decays into radon isotopes Radon-222 (most common in homes) and Radon-220 (Thoron).
Radioactive decay makes life on Earth possible by heating its core. Japanese scientists have measured the antineutrinos produced by the decay of uranium and thorium deep inside the Earth. The decay generates about 19 million megawatts of heat, about half of all the heat generated inside the planet. The other half comes from gravitational and chemical sources. (NYT 7/28/05)
Radon is the heaviest known gas, nine times heavier than air. It is an aberration - the only gas in the long decay chain of heavy metal elements. Its disintegration begets a decay chain of radioactive heavy metals polonium, bismuth and lead. After 22 years, a half of Radon-222 atoms ends up as Lead-206, the final non-radioactive element.
Radon in the soil gas
Dig up the top 6 feet of an acre of land and you will find about 50 pounds of uranium. Uranium and its daughter products radium and radon are found in nearly all rocks and soils. Most contain only 1 to 3 parts per million (ppm) of uranium but some, like granites, dark shales, light-colored volcanic rocks, and sedimentary rocks with phosphate, may contain as much as 100 ppm. Thorium, which is even more common, also produces radium.
When radium atoms disintegrate into alpha particles and atoms of radon, 10 to 50 percent of the radon atoms escape from the mineral grain into the underground "soil gas," which also carries biological decay gases and moisture. In most areas of the United States, the soil gas contains between 200 and 2,000 pCi of radon per liter. As radon slowly diffuses from the ground into the ambient air, its flux varies widely but, typically, one square foot of soil emits 130 pCi of radon each hour (0.4 pCi/m2s). In the United States, the resulting outdoor radon level averages 0.45 pCi/L. But the stacks of radon mitigation systems emit undiluted soil gas with radon concentrations 2,000 times higher, averaging over 1,000 pCi/L.
As radon gas moves through underground fissures, it usually decays into solid particles after several feet. But it travels much farther in dry, permeable soils, like gravel or course sand. Radon is soluble in water and underground streams can carry it long distances. This unpredictable underground movement of radon gas explains why homes in low-radium areas also have high radon levels and why radon levels can vary several-fold between adjacent houses.
Sources of indoor radon
Radon gas naturally moves into the permeable disturbed soil and gravel bed surrounding foundations and then, into the buildings through openings and pores in concrete. Radon from soil is by far the main source of indoor radon.
Building materials like rocks, bricks, and concrete also give off radon by emanation. They produce Radon-222 and Thoron (Radon-220) but only 0.1 - 0.3 pCi/L each in a typical basement. The very short half-life of Thoron (96 seconds) reduces its typical concentration in homes to 0.3 pCi/L.
Radon is soluble in water and also gets indoors by "water migration." Water is drawn indoors by the capillary action of the pores in concrete or pushed by hydrostatic pressure (seepage). The higher temperature and lower pressure indoors release the dissolved gas. Water in sump pits and floor drains also releases radon. The typical basement or floor slab lets in 15 or 10 gallons of water and vapor each day.
If you have a private water well, radon from the water gets released into the air in your home during showering and when washing dishes or laundry. Inhalation of the radon gas released into air is much more dangerous than its ingestion with drinking water. As a rule of thumb, each 10,000 pCi/L of radon in water increases its level in indoor air by 1 pCi/L. In the U.S., the average radon concentration in surface water is 10 pCi/L but 750 pC/L in well water. However, levels exceeding 20,000 pCi/L are not uncommon. To check the level of dissolved radon, you can purchase our radon-in-water test kit.
Radon from outside air also settles in basements of homes because it is nine times heavier than air. Radon released by tailings from uranium mines was found to travel hundreds of miles and settle in homes. But more commonly, radon gas released from soil is drawn into basements over the top of the foundation, through bulkhead doors, or uncaulked basement windows above window wells. It can be even drawn into the attic underneath uncaulked siding and then sink into the house.
How buildings draw radon from the ground
The air pressure inside homes is slightly lower than in the ground (typically 0.7-1.4 psi vacuum), which draws in radon gas from several feet away. Combustion appliances, like furnaces, hot water heaters and fireplaces, as well as exhaust fans and vents reduce the indoor pressure indoor. The warm air inside buildings moves upwards like inside a stack and this "stack effect" reduces the air pressure on lower floors. Strong winds create a vacuum on the downwind side by the Bernoulli effect. When the ground is frozen or soaked by rain, the "bottled up" radon gas in the ground moves to the warm and permeable gravel and disturbed ground around the house.
The resulting pressure-driven flow (advection) draws in radon through openings or cracks and through the pores in concrete. This pressure-driven infiltration of radon is only a part of the radon inflow, or radon would be easy to mitigate by sealing all openings or simply pressurizing the basement.
Radon is also pulled in by the difference in radon concentration indoors and in the soil (diffusion). Radon tries to equalize the indoor concentration and its atoms easily penetrate through the pores in concrete. The diffusion flow through an intact concrete slab driven by the concentration gradient is several times higher than the pressure-driven advective flow. This explains why the method of pressurizing the basement does not work.
Porosity of concrete
Concrete cures by reacting with water - hydration. But almost half of the water added to the concrete mix for workability is surplus and has to evaporate. As the surplus water in newly poured concrete pushes to the surface, it leaves behind a network of capillaries (pores).
The pores constitute 12 to 18% of the concrete by volume. Their diameter is much smaller than a human hair but much larger than radon atoms or water molecules. They let in radon gas, water vapor, liquid water, and other gases.
Typical openings in basements
Any openings and cracks have to be sealed off or caulked to stop radon, as well as water vapor and soil gas. Examples:
- Sump pits and floor drains
- Attached crawlspaces
- Bathroom rough-ins (gravel areas)
- Gaps in floor-to wall joints (around floating slabs)
- Hollow uncapped concrete blocks (use closed-cell expansion foam the top of the cores)
- Cracks in floors or walls
- Expansion control joints in floors (straight cuts)
- Lolly (support) columns going through the floor
- Gaps around service pipes
Accumulation of radon inside homes
Modern houses tend to build up radon, because the building envelope is almost airtight while the foundation is "leaky" to soil gas. The soil gas infiltration ranges from less than 1% to over 20% of the total "fresh air" infiltration into homes. Opening basement windows to increase ventilation may help by removing the radon gas but it wastes energy and in some cases, can actually increase the radon level by increasing suction through the porous concrete. The best solution is sealing the concrete to ensure the foundation is more airtight than the building envelope.
The heavy radon gas accumulates in basements and on lower floors. Heating and air-conditioning, natural air movement, as well as diffusion of radon atoms through the floors and walls distribute radon throughout the house. This, in turn, draws in more radon from the ground by concentration-driven diffusion, until an equilibrium radon level is established on each floor in the house.
According to the Iowa Residential Radon - Lung Cancer Study (2000), the median first floor radon concentration in one-story homes is, on average, 60% of the basement level. But for two-story homes, the median radon levels at first and second floors are 51% and 62% of the basement level, respectively.
There is no Safe Radon Level!
Radon levels in U.S. homes
It is difficult for people to accept that their home, a place that one looks to for security, is hiding invisible danger. Yet, the average person receives a higher radiation dose from radon at home than from all other natural or man-made sources combined.
Outdoor radon levels in the U.S. range from 0.02 to 0.75 pCi/L (picoCuries per liter), averaging 0.4 pCi/L. But homes draw concentrated radon gas from the ground. Because radon is nine times heavier than air, elevated radon levels build up in basements and on lower floors. Although the U.S. Congress has set the natural radon concentration outdoors as the target level for homes, approximately two thirds of homes exceed it. A half of American homes have a radon level above 0.67 pCi/L (the median level). The average (mean) radon level in US homes is 1.25 pCi/L, or three times higher than the average level outdoors.
Nearly 8 million US homes, or 1 out of every 15, have radon levels above the EPA's 4 pCi/L "action" limit and nearly 1 out of 6 exceed the EPA's 2 pCi/L "consider action" limit. You should always try to reduce radon to a practical minimum - if you just settle for 4 pCi/L, your home will be more radioactive than 94% of US homes:
What are "picoCuries"?
The concentration of radon gas is not measured directly but rather by the radioactivity it produces. It is expressed in picoCuries per liter of air, or "pCi/L". A Curie is a unit of radioactivity equivalent to 1 gram of radium and the prefix "pico" means a trillionth. In the metric system, radon concentration is expressed in Becquerels per cubic meter (Bq/m3). One Becquerel means one radioactive disintegration per second, and 4 pCi/L equals to 148 Bq/m3. In an average basement, 38 million atoms will undergo radioactive decay each hour.
How about all the other radiation around us?
Background radiation levels are a combination of terrestrial (radium, thorium, radon, etc.) and cosmic radiation (photons, muons, etc.) Natural radioactivity is common in the rocks and soil that make up our planet . over 60 radionuclides (radioactive elements) can be found in nature.
Sunshine is a radiation. The visible light is in the middle of its range of wavelengths. The long-wave radiation is infrared and it warms the skin. The shortest wavelength is ultraviolet radiation which causes skin cancer.
Beyond the ultraviolet radiation is a higher-frequency radiation emitted from nuclei of unstable radioactive atoms - ionizing radiation. It has enough power to knock out electrons from atoms and convert them to electrically charged ions, which can damage the large molecules of living cells. Ionizing radiation damages DNA and just one mutant cell can cause cancer. There are several types of ionizing radiation:
- Alpha particles consist of two protons and two neutrons (like the nucleus of helium) and can pack a microscopic wallop when they collide with molecules. Because of their relatively large size, alpha particles collide readily with matter and therefore do not penetrate deep. Because they give up their energy over a relatively short distance, alpha particles can inflict more biological damage than any other radiation.
- Beta particles are fast-moving electrons (or even the anti-matter positrons) ejected from the nuclei of atoms. Being much smaller than alpha particles, they can penetrate up to 1 to 2 centimeters of water or human flesh.
- X-rays and gamma rays are pure energy transmitted in a wave without the movement of matter, just as light photons. But unlike light, they have great penetrating power and easily pass through the human body. Gamma rays emitted from nuclei are similar to x-rays but more energetic.
However, two thirds of the total effective radiation dose to the average American from all natural sources comes from radon and its progeny. Radon in homes is more concentrated and far more dangerous than outdoors - the National Academy of Sciences estimates that the outdoor radon causes only 800 out of the total of 21,000 lung cancer deaths caused radon in the US each year.
Official limits on radon levels
Although radon in homes has been declared a national health problem, there are no federal or state standards. The Radon Act 51 passed by the US Congress set the natural outdoor level which averages 0.4 pCi/L as the target radon level for homes which unfortunately most homes (two thirds) exceed.
The Environment Protection Agency was given the task of developing practical guidelines. Considering the high cost of mitigation methods available to homeowners in 1980s (averaging $1,200 but up to $2,500), EPA issued its recommendations:
- 4 pCi/L ... the "action" limit (fix your home)
- 2 pCi/L ... the "consider action" limit (consider fixing your home)
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.Unlike radon levels in homes, occupational radon limits are governed by law and regulations. The Miners Safety and Health Act (MSHA) covers underground miners. Their annual exposure is limited to less than 4 WLM (Working Level Months), equivalent to 33 pCi/L during their working hours. The Occupational Safety and Health Act (OSHA) limits cumulative radon exposure in the workplace to 30 pCi/L based on 40 working hours per week. Assuming the highest radon level in modern mines, the average person receives in his home at 4 pCi/L over 12 years the same radiation dose as if he/she worked for 5 years in a uranium mine.
Action limit is not a safety limit!
"Action limit" does not imply safety. It is merely the result of a macroeconomic cost/benefit analysis for the US population at large. Shockingly, the cancer risk from radon at the "action" limit is about 1,000-times higher than the safety limits allowed for suspected carcinogens and toxins in food or drinking water.
The societal cost of mitigating all homes to a 4 pCi/L level was estimated at $44 billion but that would rise to $101 billion if the action level was set at 2 pCi/L. Most radon-attributed deaths (70%) are caused by radon levels lower than 4 pCi/L (BEIR VI, 1998). Setting the limit at 4 pCi/L benefits (but does not necessarily save) only 30% of the 21,000 people that die each year of radon-attributed lung cancer, while a lower limit of 2 pCi/L would benefit 50%. The high "action limit" reduces the number of lives saved.
And, the societal cost of lung cancer deaths caused by radon is relatively low because it kills so quickly, often within months. Its 5-year survival rate is only 10.14 percent and thus, it costs only several billion dollars per year. Spending money, for example, on an anti-smoking campaign saves more lives, even though it is unfair to non-smokers and children who may be exposed to radon gas. (Radon causes 26% of lung cancer deaths among non-smokers.)
The "action" limit is based on the average cost of a radon mitigation system in 1980s . $1,200. If the cost of radon mitigation was only $600, the action limit recommended to homeowners would have been set at 2 pCi/L.
How safe is the 4 pCi/L radon "action limit"?
People spend most of their time at home - on average 70%, but more in case of women and particularly, children. Although the 4 pCi/L level has become a benchmark for real estate transactions, it still carries considerable risks - equivalent to getting a chest x-ray or smoking 10 cigarettes each day. (EPA)
When relaxing at home, we breathe in radon. It is soluble in blood and circulates through the body and all organs. Some tends to accumulate in fatty issues. Then, almost all is harmlessly exhaled by our lungs or skin until equilibrium is established between the ambient and internal radon concentrations.
But radon decay products, radioactive solid particles, much smaller than household dust, float in the air and get trapped in our lungs, trachea, and bronchi. At 4 pCi/L each liter of air contains 70,000 radon atoms. But less than 1% of the inhaled atoms get trapped and we thus accumulate in our airways about 600,000 radioactive particles every hour. When they shoot out alpha particles, they damage the DNA of epithelial cells, causing mutations and lung cancer.
The risk to the average person of dying of radon-caused lung cancer due to a lifetime exposure to 4 pCi/L radon level at home is 2.3 percent. If there are five people in your family, the chances that someone becomes a victim of radon over 10 percent.
The most substantial epidemiological study ever on the link between residential radon and lung cancer was published the University of Iowa in 2000. This 5-year study proves that radon even at the low levels found in homes causes lung cancer and that the risk is proportional to the radon level. The study shows that the exposure of adult women to radon over 15 years at the EPA "action" level of 4 pCi/L increases the lung cancer risk by 50 percent.
Radon Mitigation Methods for Homes
Radon levels can be reduced
According to the US EPA recommendations, you should mitigate if your radon test reads 4 pCi/L or higher, and consider radon mitigation if your radon level is above 2 pCi/L. Fortunately, radon mitigation is very effective. You will likely end up with a healthier home than your neighbors, who barely meet the EPA's action limit. There is a number of issues to consider when choosing the best radon mitigation method for your home:
Appearance of the house
The Consumer's Guide from EPA: "Minimize the effect of installing a radon reduction system in your house by assuring that it blends with its surroundings. For instance: radon vent pipes may be encased with materials that match the exterior of your house, or the pipes may be routed indoors up through closets. Suction systems require that one or more holes be drilled through the basement floor, preferably in a central location. The piping will likely constrain your ideas on finishing the basement."
Operating costs of radon mitigation systems
EPA: "Systems that use fans are more effective in reducing radon levels; however, they will increase your electric bill. Remember, the fan should never be turned off; it must run continuously for the system to work correctly. A warning device must be installed to alert you if the system stops working properly."
Covering exposed earth in basement reduces ingress of radon, as does sealing cracks and openings in ground level walls and floors.
Drain-tiles can be placed surrounding the foundation and vented away from the house (the drain-tile suction method). This method is designed to pull radon from the soil surrounding the house and vent it away from the house.
Sub-slab suction is more difficult to accomplish, as it involves placing pipes under the house (laterally through side walls or by drilling holes in the concrete slab). A fan is used to vent these pipes away from the house.
Concrete block walls can be vented by sucking air from the hollow spaces in the wall and venting it away from the house to prevent radon from re-entering.
Lastly, there are methods for decreasing negative pressures within the house by bringing air into the house in proportion to losses from chimneys, dryers, etc., or by positive pressure including basement pressurization by blowing air from upper floors into the sealed basement.
| Radon Mitigation Methods - A Comparison of Features | ||||
| Method | Typical Radon Reduction | Typical installation costs (contractor) | Typical operating costs for fan electricity and energy loss in heated/cooled air (annual) | Comments |
| Fan-based mitigation system (sub-slab depressurization) | 80%-99% | $800-2,500 | $75-175 | Works best if air can move easily under the slab - a gravel bed. Recommended by the US EPA. |
| Drain-tile suction with a fan | 90%-99% | $800-1,700 | $75-175 | Works best if drain tiles form a complete loop around the basement. |
| Block-wall suction with a fan | 50%-99% | $1,500-3,000 | $150-300 | Only in basements with hollow block walls, requires sealing of all openings. |
| Sump hole suction with a fan | 90%-99% | $800-2,500 | $100-225 | Works best if air can move easily under slab to the sump and if drain tiles form complete loop. |
| Caulking of radon entry routes | 0%-50% | $100-600 | $0 | Ignores radon infiltration through concrete. Normally used in combination with other techniques. |
| Basement pressurization | 50%-99% | $500-1,500 | $150-500 | Requires tight basements that can be isolated from outdoors and upper floors. Unpredictable results. |
| Natural ventilation through windows or vents | Variable | $200-500 if additional vents are installed | $100-700 | High loss in heated or conditioned air; operating costs depend on the ventilation and utility rates. Unpredictable results. |
| Heat recovery ventilation | 25%-50% if used for full house; 25%-75% if used for the basement | $1,200-2,500 | $75-500 for continuous operation | Reduces energy losses in heated/conditioned air. Works best in a tight house. May cause back-drafting. |
Other radon remediation ideas
There is a common belief that radon should be reduced by venting the basement. But depending on the house construction and tightness, it may actually increase the inflow of radon from the ground. The high energy losses in heated or conditioned air make this method impractical.
Some people believe that paints and surface sealers, particularly epoxy or rubber-based, stop radon. However, a layer of paint or even a polyethylene sheet has no chance of stopping radon atoms. Moreover, alkalis carried by moisture from inside the concrete attack the paint and cause its cracking and eventual peeling. EPA has tested all possible paints and surface sealers but concluded that they are not effective.
Sheetrock, wallpaper, plaster, or even polyethylene sheets do not stop radon. Covering floors with carpeting or linoleum does not work either. Remember that even several inches of concrete cannot stop radon.
Some builders believe that the plastic vapor barrier under the slab will stop radon. Although it is a part of the "radon resistant" construction, it merely retards the flow of soil gas. But it cannot stop the diffusion of radon and its accumulation underneath the floor. That's why EPA properly calls it the "soil gas retardant" membrane.
How Radon Causes Lung Cancer
Radon is the most potent carcinogen in your home
You cannot see radon gas. And you cannot smell it or taste it. But it may be a problem in your home. As the only gas in the decay chains of radioactive heavy metals, radon and its floating radioactive products can easily get into human body by inhalation. Whenever you breathe in air containing radon, it increases your risk of getting lung cancer. The National Academy of Sciences and the Environment Protection Agency (2003) estimate that in the U.S., radon in homes causes 21,100 lung cancer deaths each year.
Radiation is called the "complete carcinogen" because, unlike chemical carcinogens, it alone can initiate, promote and propagate cancer. The primary site of radioactive exposure to most people is their home. The average person receives a higher radiation dose from radon at home than from all other natural or man-made sources combined.
Radon is a proven and very potent "Class A" carcinogen. Safety limits on toxins or carcinogens in food or water are set at levels thousand times less lethal than what is the risk from radon in an average American home. "Radon in homes causes more deaths than fires, drownings and airplane crashes combined." (EPA)
The lung cancer crisis
After smoking, "radon is the second leading cause of lung cancer." (Surgeon General) Among non-smokers, radon is the No. 1 cause of lung cancer deaths.
Lung cancer is the leading cancer killer of all Americans, both men and women, claiming 160,000 lives every year - more than breast cancer, prostate cancer, and colorectal cancer combined. Over 171,000 new lung cancers are diagnosed in the U.S. each year.
The leading three causes of cancer deaths
| Men | Women | ||
| Lung cancer | 33% | Lung Cancer | 24% |
| Prostate cancer | 12% | Breast cancer | 18% |
| Colorectal cancer | 10% | Colorectal cancer | 11% |
Lung cancer is the deadliest of all cancers . its 5-year survival rate is only 10 to 14 percent. By the time people develop symptoms (shortness of breath, coughing, bloody sputum), the cancer has grown to the size of an orange or has spread to other organs. While the death rates for many types of cancer have been declining during the last 60 years, the age-adjusted incidence and mortality rates for lung cancer have been rising.
There is a lung cancer crisis, particularly among women. Lung cancer deaths have increased by 20% among men during the past two decades but by 150% among women, and in the 1990's alone, lung cancer deaths of white females have increased 60%.
Children are more susceptible to radon
Children are known to be more radiosensitive than adults. Analysis of Hiroshima victims showed a higher incidence of lung cancer among those who were exposed to the radiation blast as children. A single x-ray to the abdomen of a pregnant woman in the first six weeks of pregnancy leads to a 50 percent increase in cancer and leukemia risks to the child. The gamma rays emitted by radon progeny are far more energetic than x-rays but the emitted alpha and beta particles are even more harmful.
Radiation risk to embryos is higher than to children, which in turn is higher than to adults. Children are more susceptible to radon-induced cancer due to their rapidly dividing cells and higher breathing rates. It is compounded by their heavier exposure to radon by spending more time inside the house and/or in the basement.
(Source: Dr. Gordon Edwards - Estimating Lung Cancers)
(Source: Dr. Gordon Edwards - Estimating Lung Cancers)
Recent research in Europe confirms that radon is much more harmful to children than to adults. Lung cancer incidence as a result of radon exposure is estimated to be about ten times higher for people exposed at the age of about 15 than at about 50.
However, the onset of lung cancer takes decades. EPA has not found convincing epidemiologic evidence of increased risks to children (except to the smallest ones) and its radon guidelines for homeowners are thus based solely on the lung cancer risks to adults.
Radioactive lining of the lungs
After radon gas is inhaled, it readily dissolves in the blood and circulates through the body, organs, and tissues, until it is again exhaled through the lungs or skin. Equilibrium is established between the ambient and the internal radon concentrations. Since the radioactive half time of Radon-222 is 3.8 days, most radon atoms harmlessly leave the body before they can disintegrate.
The problem is not radon, but rather the radioactive particles it produces. As radon atoms undergo radioactive decay, they disintegrate into radiation and radon progeny ("daughters") - solid heavy metal particles of lead, polonium, and bismuth. These minute, electrically charged and chemically active particles float in the air, and when breathed in, some (less than 1%) get trapped permanently in the airways. The accumulated radioactivity in the airways is proportional to the radon level - at the 4 pCi/L level, about 600,000 radioactive particles get trapped in the lungs every hour.
The deposition in the lungs depends on whether the particles are attached to airborne dust or smoke, or unattached. Unattached daughters lodge deeper in the lung, which explains the severity and the type of radon-induced deep-lung cancers in non-smokers.
The glow of ionizing radiation
Most of the radiation dose to humans is not from radon itself but from the radon daughters, most notably Polonium-218 (radioactive half-life 3 minutes, alpha particles), and Po-214 (half-life 0.164 milliseconds, alpha), along with Bismuth-214 (half-life 19.7 minutes, beta). A half-life is the time period in which a half of the atoms decays into another element; the shorter the half-life, the more intense radiation. The radon daughter particles go through the decay chain of radioactive heavy metals until a half of the atoms finally reach the stable non-radioactive Lead-206 after more than 22 years.
At each step of the decay chain the radon progeny particles emit ionizing radiation - alpha and beta particles, and gamma rays. Ionizing radiation, which has enough power to knock out electrons from atoms and convert them to ions, kills or damages living cells, causing genetic mutations and cancer.
The inhaled radon daughter particles accumulate in the lungs and tracheobronchial tree, particularly in bifurcations. Since the bulky alpha particles cannot penetrate more than a fraction of a millimeter into the lung tissue before smashing into an atom, damage is concentrated on the epithelial cells in the immediate area. The result of such concentrated radiation is much more severe than if the radioactive dose was distributed throughout the whole body.
The radon daughters also emit beta particles and gamma rays that travel farther through the body. Beta particles travel up to 1 to 2 centimeters in human tissue. Most gamma rays, being more energetic than x-rays, pass through the body to the outside. Because the absorbed beta and gamma radiation is spread over a larger volume, it is less concentrated and less harmful. The concentrated ionizing radiation of heavy alpha particles is much more damaging and accounts for more than 85% of the damage to lungs.
The radon isotope Thoron (Rn-220) emanates from stones or building materials rich in thorium, which is as common as uranium. It undergoes similar radioactive decay and emits the same alpha, beta, and gamma radiation, but is much less common in indoor air (at most 20% of the total) because its half-life is only 56 seconds. Thoron is difficult to measure and is ignored in the NAS or EPA calculations.
A single radon atom can cause lung cancer
Carcinogens cause random damage to the chromosomes and DNA molecules contained in the nucleus of the cell. Most of these cells are either killed or sterilized. However, in a very few cases, one of these damaged cells may survive the injury and still be capable of reproducing. Such a cell may begin to proliferate in an undifferentiated or "cancerous" manner. Most cancers are of monoclonal origin, that is, they originate from damage to a single cell.
Even a single alpha particle can cause major genomic changes to the cell's DNA, including mutation and transformation. Since these effects take place in a random manner at the cellular level, there is no such thing as a "harmless" dose. Even allowing for a substantial degree of cell repair, the passage of a single alpha particle has the potential to trigger cancerous growth of cells that it does not kill outright.
Alpha particles from radon do not even have to hit the cell
The Los Alamos National Laboratory researchers discovered in 1997 that alpha particles emitted by radon do not have to hit the nucleus of a cell to damage the cell's DNA, which resides in the nucleus. Moreover, the alpha particles do not even have to hit the cell - a bombardment of the surrounding medium produces chemical radicals inside the cells, which cause DNA damage.
This negates the widely held assumption that alpha particles cause genetic changes only through direct traversals of cell nuclei. Merely the interaction of alpha particles with the fluids that line the lungs damages the DNA of nearby cells. Exposure even to the lowest doses of alpha emission produces the very reactive chemicals within cells and their production increases with the alpha-particle dose. This confirms that radon is dangerous even at very low levels - there is no "safe" threshold. The research also suggests that radon may be disproportionately more harmful at lower concentrations.
(Source: Lab researchers uncover new effects of radon emissions on human cells)
(Source: Lab researchers uncover new effects of radon emissions on human cells)
A more recent study at Columbia University (2001) provides clear evidence that a single alpha particle can induce mutations and chromosome aberrations in cells that received no direct radiation exposure to their DNA. These results indicate the need to reassess the potential genotoxic effect of low dose radiation and suggest that the assumption of direct proportionality in radiation may significantly underestimate the risk of low-dose radiation.
Does radon cause other diseases?
It is generally assumed that inhaled radon gas is quickly exhaled and has little time during its circulation through the body to deposit its radioactive products in human organs, tissues, or bones. However, the story may be more complicated. Some scientists believe that radon dissolved in the blood may cause additional diseases beside lung cancer. In addition to the gas, one-third of the inhaled radon decay particles also pass through the lungs into the blood stream and then, get trapped.
As we breathe in through the skin, the air also carries radon gas. Some studies suggest that the radiation dose to the basal layers of the skin is high with a consequent risk of skin cancer.
Radon gas is soluble in lipids and accumulates in lipid tissue throughout the body with the highest concentration in the brain, bone marrow, and nervous system. But none of its heavy metal daughters are soluble in the lipids and consequently, remain trapped in the brain and bones, where they continue to emit gamma radiation and alpha particles. Several studies indicate that radon also causes leukemia ("cancer of the blood") and other types of cancers.
Researchers at the University of North Dakota discovered that the presence of radioactive radon daughters in the brains of non-smoking persons with Alzheimer.s and Parkinson.s disease was 10 times (!) greater than it was in the brains of persons with no previous evidence of neurological disorders. Interestingly, the geographic distribution of Parkinson.s disease mortality is considerably higher in states with a greater radon potential.
Animals exposed to high concentrations of radon progeny display beside lung carcinoma emphysema, pulmonary fibrosis, and a shortened life span.
Nevertheless, the risk of other cancers or diseases is much lower than that of lung cancer. The National Academy of Sciences estimates that radon ingested with water causes about 20 stomach cancer deaths per year, which is 1,000 times fewer than from lung cancer. Since the radiation dose to other organs is much smaller than from radon decay products deposited in the bronchial epithelium, ICRP estimates the cancer risk to other organs at about 2% of the lung cancer risk.
Possible genetic damage
Ionizing radiation causes random damage to the chromosomes and DNA molecules contained in the nucleus of the cell, including genetic mutations that may affect future generations. Substances having a carcinogenic effect also have genetic and teratogenic effects. Damage to the DNA of reproductive cell, e.g. gamma irradiation of sperm, can lead to genetic deficiencies in the offspring, and if an embryonic cell is damaged, the normal development of the fetus can be disrupted.
In areas of high natural background radiation, an increased frequency of chromosome aberrations has been observed. "Any individual dose, however small, is able to produce gross malignancies and deformities if it is administered to a sufficiently large population."
(Source: Dr. Gordon Edwards - Estimating Lung Cancers)
(Source: Dr. Gordon Edwards - Estimating Lung Cancers)
Lung cancer treatments
Lung cancers start in bronchial tubes and lungs. The danger of a destructive spread of cancer is acute, because lungs are connected to other organs of the body by a complex network of blood vessels. Lung cancer often spreads to the larynx, liver, brain, bones and kidneys.
Without surgery, this condition is currently considered incurable. Surgery to remove all of the lung (pneumonectomy) or part of the lung (lobectomy) may be recommended if the cancer is at an early stage. Only 25% of tumors can be removed surgically. However, symptoms can be relieved or controlled. Radiation treatment and anticancer drugs to stop the spread of the tumor or destroy cancerous cells may be recommended.
The survival rate after 5 years is only 10 to 14 percent. Lung cancer causes more deaths than any other form of cancer and its incidence is increasing.
When can a person exposed to radon finally relax?
Never, unless already well advanced in age. The most intense radiation from radon progeny occurs during the first hours, when polonium and bismuth quickly decay into radioactive Lead-210. But then follows a much slower decay through bismuth, polonium and lead radionuclides into stable Lead-206. The total half-life of these nuclides is over 22 years. If a person has been exposed to radon, 75 percent of the radon progeny in lungs will become "harmless" lead particles after 44 years.
When an alpha particle damages a cell to make it cancerous, the onset of lung cancer takes a minimum of 5 years but most often 15 to 25 years, and even longer. The decades-long decay of radon progeny and the slow onset of cancer make it almost impossible to measure the increase in death rates caused by radon in a mobile population. Therefore, most lung cancer studies are based on the thousands of miners exposed to radon or on extensive animal, cellular and radiological research.
Only few people exposed to radon will develop lung cancer. However, once exposed to radon, the lung cancer risk lasts for one's lifetime. Children and young people naturally have a higher risk of developing lung cancer during their lifetime.
Minimize the radon level in your home!
Many of the 21,000 lung cancer deaths caused by radon in the U.S. each year are preventable. The "action" and "consider action" limits of 4 or 2 pCi/L are merely cost/benefit guidelines - EPA has left the radon mitigation decision and responsibility up to the individual homeowner. EPA has warns the public: "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."
You should always try to reduce the radon level in you home to a practical minimum. The target of the U.S. Radon Abatement Act is the natural level outdoors (average 0.4 pCi/L). Whether you current level is 30 or 3 pCi/L, or if a mitigation system is already installed, reducing radon in your home by 90 or 50 percent will reduce the risk to your family by 90 or 50 percent.
Lung Cancer Risks from Radon
The annual death toll of radon in homes
Estimates from the National Research Council, the National Academy of Sciences and the U.S. Environmental Protection Agency as published in the reports "Biological Effects of Ionizing Radiation" (BEIR VI, 1998), "Risk Assessment of Radon in Drinking Water" (1999), and "EPA Assessment of Risks from Radon in Homes" (2003):
- Radon in homes caused 21,100 lung cancer deaths in the U.S. in 1995 (14.4 percent out of the total of 146,400 lung cancer deaths)
- Radon in homes is the second leading cause of lung cancer deaths in the U.S.
- Radon causes about 1 in 8 (12%) of the lung cancers among ever-smokers (most die of smoking) but 1 in 4 (26%) among never-smokers. Radon is the No. 1 cause of lung cancer among non-smokers . about 15,000 deaths each year in people who never used cigarettes.
Health risks are proportional to the radon level
The passage of a single alpha particle can cause mutations of DNA and some damaged cells may become cancerous. Most cancers originate from damage to a single cell. The more radiation particles pass through the human body, the higher the chances of developing cancer. Therefore, the lung cancer risk is proportional to the radon concentration in the inhaled air and the length of exposure.
The radon risk drops off for very high concentrations, like for miners, because more lung cells are killed off by the radiation rather than becoming cancerous and some radiation is wasted on the already killed cells (the "inverse exposure-rate effect"). But at lower concentrations, like at home, every emitted particle counts.
Radon is dangerous at any level: 70 percent of radon-attributed deaths are caused by homes with radon below 4 pCi/L, 50 percent by levels below 2 pCi/L, and only 30 percent by radon below the mean (average) level of 1.25 pCi/L. Even the low outdoor levels not harmless - NAS estimates that out of the 21,000 lung cancer deaths caused by radon each year, 800 are caused by the natural radon levels outdoors (average 0.45 pCi/L).
The lung cancer risks at home
Smoking is by far the leading cause of lung cancer and when combined with radon, the effects are synergistic. Current smokers have about nine times the risk from radon than never-smokers or 1.5-times higher than ever-smokers.
People spend most of their time at home - on average 70%, more for children and women. The cumulative lifetime exposure to ionizing radiation from radon and the corresponding lung cancer risks to a person are dependent on the radon level:
| Radon Level (pCi/L) | Mortality risk | ||
| Never Smokers | Current Smokers | General Population | |
| 20 | 3.6% | 26.3% | 10.5% |
| 10 | 1.8% | 15.0% | 5.6% |
| 8 | 1.5% | 12.0% | 4.5% |
| 4 | 0.7% | 6.2% | 2.3% |
| 2 | 0.4% | 3.2% | 1.2% |
| 1.25 | 0.2% | 2.0% | 0.7% |
| 0.4 | 0.1% | 0.6% | 0.2% |
Note that the death risk to the average person from radon at home is 1,000-times the risk from any other carcinogen or toxin regulated by FDA or EPA. Safety limits are normally expressed in deaths per 100,000 people but radon risks in percentages (deaths per 100 people).
Calculate your own odds!
Radon progeny are the tiny radioactive metal particles floating in the air, which have not yet attached to dust and plated out. Their concentration is expressed in Working Levels. 1 WL is defined as any combination of short-lived radon daughters in 1 liter of air that results in the ultimate release of 1.3x105 million electron volts of alpha energy.
Equilibrium in a closed volume constantly supplied with radon - when the rate of decay of each daughter will equal to that of the radon itself. Each pCi/L of radon will give rise (almost exactly) to 0.001 WL. In homes, the typical equilibrium fraction is 40% - there will be 0.004 WL of progeny for each pCi/L of radon. (The radon isotopes Thoron and Actinon, which may add 5-10 percent to the radiation exposure, are ignored.)
Cumulative radon daughter exposures are measured in Working Level Months (WLM) defined as an exposure of 1 WL for 170 hours (miner's work month). We assume that 70% of our time is spent indoors. Then, the cumulative annual exposure in one year per each 1 pCi/L is:
1 pCi/L x 0.004 WL/pCi/L x 0.70 x 8,760/170 WLM/WL-y = 0.144 WLM/year
1 pCi/L x 0.004 WL/pCi/L x 0.70 x 8,760/170 WLM/WL-y = 0.144 WLM/year
Estimated risk of death from radon-attributed lung cancer per WLM for never-smokers (NS) and ever-smokers (ES), male or female, and for a population with of 53% males and 47% females:
Risk Factors per WLM
| Gender | Smoking Category | Risk per WLM (10-4) | Expected Life Span (years) |
| Male | ES | 10.6 | 71.5 |
| NS | 1.74 | 72.8 | |
| population | 6.40 | 72.1 | |
| Female | ES | 8.51 | 78.0 |
| NS | 1.61 | 79.4 | |
| population | 4.39 | 78.8 | |
| Male & Female | ES | 9.68 | 74.2 |
| NS | 1.67 | 76.4 | |
| population | 5.38 | 75.4 |
Example 1: a man, former smoker, exposed to 6 pCi/L for 40 years
6 x 0.144 WLM/y = 0.864 WLM/y annual exposure
x age 40 years = 34.56 WLM cumulative exposure
x risk factor 10.6x10-4 /WLM = 0.0366 = 3.7%
6 x 0.144 WLM/y = 0.864 WLM/y annual exposure
x age 40 years = 34.56 WLM cumulative exposure
x risk factor 10.6x10-4 /WLM = 0.0366 = 3.7%
Example 2: a never-smoker female, exposed to 4 pCi/L during her lifetime
4 x 0.144 WLM/y = 0.576 WLM/y annual exposure
x expected lifespan 79.4 years = 45.73 WLM cumulative exposure
x risk factor 1.61x10-4 /WLM = 0.0074 = 0.74%
The risk that she will die of radon-induced lung cancer during her lifetime.
4 x 0.144 WLM/y = 0.576 WLM/y annual exposure
x expected lifespan 79.4 years = 45.73 WLM cumulative exposure
x risk factor 1.61x10-4 /WLM = 0.0074 = 0.74%
The risk that she will die of radon-induced lung cancer during her lifetime.
Comparing radon to other everyday risks
"Radon in homes causes more deaths than fires, drownings and airplane crashes combined." (EPA) However, we spend incomparably more money on preventing violent deaths than on radon mitigation in our home. And media do not inform public about radon - a fire makes better TV than a lung cancer death.
Radon mitigation stacks - worse than Chernobyl?
The explosion and fire at the Chernobyl nuclear power plant in Ukraine evaporated 8 tons of nuclear fuel and ejected radioactive graphite and dust high into the atmosphere. Winds spread radioactive iodine and cesium over most of the Northern Hemisphere. The accident, kept secret by the Soviet government, was discovered when workers entering a nuclear plant in Sweden triggered radioactivity alarms. The total radioactive release out of the bounds of Chernobyl was estimated at 50 million Curies.
The US EPA estimates that 6 to 8 million homes exceed the radon "action limit" of 4 pCi/L. What if all these homeowners installed fan-based radon mitigation? Underground radon levels range from 200 to 2,000 pCi/L and average 1,000 pCi/L. With a 70 cfm fan, the typical radon stack emits 1 Curie of radioactivity per year (equivalent to 1 gram of radium). The total radioactivity released each year by all these radon stacks would amount to 6 - 8 million Curies. This is comparable to a Chernobyl-size nuclear disaster occurring in the U.S. every seven years! Moreover, the radon emissions would be concentrated in populated areas. Radon gas, being 8 times heavier than air (like steel versus water), tends to settle near the house. While the radioactive iodine from Chernobyl decayed in days, the decay of radon's radioactive daughter products into stable lead takes over 22 years.
(Comment: It is always better to mitigate - radon in homes causes many more deaths in the U.S. each year than the total death toll of Chernobyl. However, a radon mitigation method that leaves the gas in the ground would be preferable.)
Radon potions for your health!
A San Francisco company ushered in a craze in radioactive health crocks in 1912, when it was granted a patent for "Revigorator". This device saturated water with radon and people were advised to drink six or more glasses each day. "Radithor", a quack radon potion to cure sexual dysfunction and everything else, was introduced in 1925. After several years, people started dying of the effects of this potion. The manufacturer and user of Radithor died 14 years later of bladder cancer. No warnings to the public were ever issued.
Hundreds of thousands of health-conscious Americans drank bottled water laced with radium as a general elixir, known popularly as "liquid sunshine." Soon, radioactive toothpaste was marketed, then radioactive skin cream. Chocolate bars containing radium were sold as a "rejuvenator." As recently as 1952, LIFE magazine wrote about the beneficial effects of inhaling radioactive radon gas in Montana mines. Even today, people visit the radon-filled mines and report multiple benefits. However, numerous studies have concluded that the only demonstrable health effect of inhaling radon is lung cancer.
The discovery of radon in homes
In 1984, the scientific world woke up to the existence of radon in homes. A construction engineer triggered radiation alarms while entering the Limerick nuclear power plant near Philadelphia. His home in Boyertown was tested and the radon concentration was a shocking 2,700 pCi/L.
The family, including small children, was immediately evacuated. Very high radon levels were also sound in nearby houses. This region, known as the Reading Prong, has low-grade uranium deposits and encompasses parts of Pennsylvania, New Jersey, and New York.
Source: American Academy of Pediatrics - The radon record.
Avoid radioactive rain from radon clouds!
Workers entering the Super Collider at the Argonne National Laboratory near Chicago used to trigger radioactivity alarms when it rained. It was discovered that rainwater deposited on their shoes and hands carried radioactive decay products of radon. The laboratory developed special radiation monitors to detect the specific gamma rays emitted by radon progeny in rain clouds. During the first year of operation the alarm was triggered nine times. Since the radon alarms occurred simultaneously at two monitors approximately 1,000 meters apart, it proved that large radon-saturated clouds are regularly passing over populated areas. It confirmed that radon released by wastes from uranium mines in the West can travel hundreds of miles across America.
Source: Health Physics, November 1999
Source: Health Physics, November 1999
Government disputes the dangers of radioactivity
About 600,000 workers were exposed to radioactive materials in 14 nuclear weapons plants since the beginning of the Manhattan Project. Their radiation exposure was within the official "safety limits." However, increased rates of leukemia, cancers, vision difficulties, chronic fatigue syndrome and other health problems have been observed. The identified 22 types of cancers include cancer of the lung, prostate, bladder, kidney, and Hodgkin's lymphoma. Some scientists believe that radiation damages the human immune system, leaving people vulnerable to a wide range of other diseases.
Until 1999, the U.S. government disputed reports that low-level ionizing radiation is harmful. DOE and DOD waged media campaigns against "fear mongers" and spent tens of millions of dollars on lawyers. Then, after decades of denials, the government finally conceded that the radiation exposure to workers at nuclear weapons plants caused a wide range of cancers. President Clinton apologized to the "heroes of the nuclear age." But by then, many have died. The US Congress agreed to pay out $150.000 to each of the sick survivors, but denied them unlimited healthcare. Although private companies ran many of these plants for profit, the U.S. taxpayers will pick up the tab.
Source: The New York Times, January 29, 2000
(Comments: There is no plan to change the old safety limits - paying out compensation is much more cost-effective than lowering the limits throughout the whole nuclear complex. However, being a homeowner is still riskier - the radiation exposure of an average worker over several years of employment is lower than the cumulative radiation received by an average American from radon at home.)
(Comments: There is no plan to change the old safety limits - paying out compensation is much more cost-effective than lowering the limits throughout the whole nuclear complex. However, being a homeowner is still riskier - the radiation exposure of an average worker over several years of employment is lower than the cumulative radiation received by an average American from radon at home.)
The radiation craze of the last century
Within months after Wilhem Roentgen donated x-rays to the world in 1895, medical doctors used it on patients for all possible ailments. (Antibiotics had not been discovered yet.) The early x-ray machines imparted huge radiation doses. There was no reason to expect any harm from this miracle of modern science. Then, fluoroscopes ("x-ray movies") were invented, which multiplied the radiation dose. Until 1950's, radiologists tested the set-up of a x-ray machine by holding a hand in front of it to observe how soon it gets red. Many doctors developed radiation burns or even lost their fingers but they did not start dying of cancer until decades later.
When radium became widely available, radon gas expanded the radiation arsenal - it is vented off a piece of radium. Radon emits gamma rays (just like x-rays but more energetic) in addition to alpha and beta particles. Medical Life magazine claimed in 1925 that radon treatment cured at least 27 illnesses. Radiation was prescribed for heart trouble, cancer, arthritis, high blood pressure, tuberculosis, blindness, back problems, herpes, bronchial asthma, peptic ulcers, and impotence.
Embryos received x-ray doses already in the womb during abdominal exams. Newborns were routinely treated by x-rays to prevent diseases. Pediatricians used to fluoroscope babies and young children every month and during annual checkups. Many children were given massive radiation treatment for an invented disorder - enlargement of the thymus gland in the upper chest. The scalps of 10,000 New York children were irradiated to make their hair fall out as a treatment for ringworm. Depression in women was cured by irradiating the ovaries and excessive bleeding of girls during menstruation by x-rays to the uterus. Primitive mammography caused the breast cancer epidemic decades later.
Mass screenings of children for tuberculosis in the 50's sent buses with crude x-ray machines to schools throughout the country. Fluoroscopes became the fad for fitting shoes in stores. Doctors and local beauty shops used radiation for acne and unwanted hair or freckles. Dermatologists used x-ray treatments until the 70's. These deadly practices were not stopped by our pro-nuclear government but only by negative publicity in the media.
Have doctors caused our cancers and heart diseases?
Until 1920's, lung cancer was extremely rare. When a physician discovered a case, all interns were called because they would not see another case for years to come. The lung cancer epidemic in the second half of the century increased the lung cancer rate from 4 in 100,000 people to 72 in 100,000 in 1990. Coronary heart diseases also increased dramatically.
Dr. John Gofman, a prominent radiologist who helped to build the first nuclear bombs, concluded that medical irradiation has caused most of the cancers and coronary heart diseases in the twentieth century. He studied mortality rates from 1940 to 1990 of the entire U.S. population. He found that the mortality rates for cancers and coronary heart disease increase proportionally with the number of physicians per 100,000 people in each region, while all other diseases decrease. More physicians in a region means more x-rays to its population. In the case of coronary heart disease, the cause appears to be radiation-induced mutations in the coronary arteries.
Statistical analysis shows that medical irradiation has caused over a half of all cancers, two thirds of coronary heart diseases, and over 80% of breast cancers in the US. Dr. Gofman stresses that the radiation from each medical or dental x-ray can be reduced several-fold without sacrificing accuracy. All x-ray machines should be regularly calibrated and the doses measured. People should refuse unnecessary x-rays.
John W. Gofman, M.D., Ph.D. 1999: Radiation from Medical Procedures in the Pathogenesis of Cancer and Ischemic Heart Disease
See alpha particle in action!
To see a photograph of the tracks of an alpha particle (as released by radon) in lungs click here!
Dog saves people from radon
Back in the late 80's, I had a client whose dog died prematurely. They took it to the vet and x-rays showed the dog died from lung cancer. They then tested their home and found radon concentrations of 150 pCi/l! The owners stated that their dog probably saved their lives.
Source: Jay Bauder, Bauder Basement Systems, Inc
The "anti-smoking Nazis"!
Smokers who call intolerant non-smokers "Nazis" are not entirely wrong. Adolf Hitler, just like Mussolini and Franco, was a non-smoker and personally directed anti-smoking campaigns.
German scientists recognized already in 1930's, decades ahead of others, that smoking causes lung cancer. Nazis founded the "National Socialist Institute for the Study of the Dangers of Tobacco" with the mission to protect the mankind against one of its most dangerous poisons. Smoking was branded as socially undesirable and was forbidden in many public places. Tobacco advertising was strictly regulated and athletically or sexually oriented cigarette advertising was prohibited. Smokers, who frequently missed work due to sickness, were forced into nicotine withdrawal clinics. Western agents sent to Nazi Germany had to first sand off tobacco stains from their fingers to avoid detection.
Source: Robert N. Proktor - "The Nazi War on Cancer"
Radioactive fallout from uranium mines
About a ton of ore is required to extract two pounds of uranium. Huge quantities of pulverized rock (uranium tailings) are left over from the milling process. They contain thorium, radium, and all the other uranium by-products and retain 85 per cent of the ore's original radioactivity. The tailings give off at least 10,000 times as much radon gas as the undisturbed ore. Radon atoms produced inside hard rock have a low chance to escape from the grain, but when the rock is pulverized, radon gas escapes easily.
Each uranium mine is spreading radioactive poisons over vast areas of the earth, as the Chernobyl disaster or atmospheric nuclear tests have done, but at a slower rate. With only a light breeze, radon gas can travel thousand miles in a few days. Being eight times heavier than air, radon travels low to the ground and deposits its "daughters" - solid radioactive fallout - on the vegetation, soil and water below. These radioactive particles enter the food chain, ending up in fruits and berries, the flesh of fish and animals, and ultimately, in the bodies of human beings.
Radium dust is blown in the wind, washed by the rain, and leached from the tailings piles into waterways. It re-concentrates by factors of thousands in aquatic plants and by factors of hundreds in land plants. A front page article in the Wall Street Journal (February 25, 1986) described the 220 million tons of uranium tailings in the U.S. as an ecological and financial time bomb. (Canada has about 150 million tons of tailings.) Uranium tailings will remain dangerously radioactive for millions of years.
Source: Uranium: The Deadliest Metal
(Comment: Under the Uranium Mill Tailings Remedial Action Program, the Department of Energy is covering the tailings with a layer of soil to reduce the release of radon.)
(Comment: Under the Uranium Mill Tailings Remedial Action Program, the Department of Energy is covering the tailings with a layer of soil to reduce the release of radon.)
Uranium's deadly legacy
At the gateway of one of America's most popular wilderness recreation areas lies a ticking time bomb. Colorado River, winding around Moab in Utah, carries drinking water to millions of people in Utah, Nevada, Arizona and Southern California. But it also carries radioactive contaminants.
An abandoned uranium mill near Moab has left behind 10.5 million tons of uranium tailings, which are steadily leaking toxins into the groundwater and the river. Wells in the area reveal very high radioactivity in the groundwater. Fish with elevated radioactivity levels are showing up. The tailings are also releasing large quantities of radon gas into the air. The tailings pile could be compromised by floods, erosion or seismic activity.
National Parks and Conservation Association: Uranium's Legacy
Mining companies pump chemical solutions into the ground to dissolve and wash out uranium salts, polluting underground waters with chemicals and radioactivity. Over three billion cubic feet of wastes from uranium mining still await proper disposal. These waste heaps are persistent sources of water-soluble radium salts and airborne radon gas. Thousands of tons of ore were transported for processing to areas near major population centers, like Niagara Falls, Salt Lake City, Cincinnati and Chicago. Some of the radioactive mining wastes were used to make concrete for houses, buildings and roads.
Meter Conversions, Inc: Radioactivity detector
Radioactive homes
In the Southwest U.S. and in Port Hope, Ontario, many homes and schools were built using sand-like tailings from uranium mines as construction material. Some of these buildings ended up with radon levels higher than those permitted in mines. Similar (though less severe) radon problems arose in Florida and Newfoundland when phosphate tailings were used for construction.
Source: Uranium: The Deadliest Metal
The saga of radium dial painters
Shortly after its discovery radium was used to make luminous paints. During World War I, hundreds of young women in New York and Illinois were applying the highly radioactive paint to aircraft instrument dials. Radium painting expanded to "glow-in-the-dark" clocks and watches.
The young women who applied the paint frequently licked the brush to keep it pointed and their work area was saturated in radon. Suspicions arose in the late 1920's over jaw cancers among the dial painters, as their tragic saga slowly started to unfold. Initially, the plant managers accused the women of bad hygiene. Years later, most of these women died of cancer.
During World War II, young women painted radium on military instruments, so that the dials would glow in the darkness of a cockpit. Precautions were now taken to avoid the ingestion of radium, but the danger of the released radon gas was not understood. Cancer has killed many of these women during the following 20-30 years.
Since the mid 1960's, the watch manufacturers are using Tritium, a radioactive form of hydrogen with a half-life of 12 years, or Promethium, a man-made radioactive element with a half-life of 2.6 years. Both of these elements are weak beta and gamma emitters but only few of the particles penetrate the cover glass of the watch.
Radon - the killer in tobacco
Out of the nearly 4,000 chemicals found in tobacco smoke, only two definite chemical carcinogens have been found - benzopyrine and nitrosamine. However, the most potent carcinogen in tobacco is radiation from the radioactive products of radon. Polonium-210 is the only component of cigarette smoke that has produced cancers by itself in laboratory animals by inhalation - tumors appear at a level five times lower than the dose to a heavy smoker.
Lung cancer rates among men kept climbing from a rarity in 1930 (4/100,000 per year) to the No. 1 cancer killer in 1980 (72/100,000) in spite of an almost 20 percent reduction in smoking. But during the same period, the level of polonium-210 in American tobacco had tripled. This coincided with the increase in the use of phosphate fertilizers by tobacco growers - calcium phosphate ore accumulates uranium and slowly releases radon gas.
As radon decays, its electrically charged daughter products attach themselves to dust particles, which adhere to the sticky hairs on the underside of tobacco leaves. This leaves a deposit of radioactive polonium and lead on the leaves. Then, the intense localized heat in the burning tip of a cigarette volatilizes the radioactive metals. While cigarette filters can trap chemical carcinogens, they are ineffective against radioactive vapors.
The lungs of a chronic smoker end up with a radioactive lining in a concentration much higher than from residential radon. These particles emit radiation. Smoking two packs of cigarettes a day imparts a radiation dose by alpha particles of about 1,300 millirem per year. (IEM) For comparison, the annual radiation dose to the average American from inhaled radon is 200 mrem. However, the radiation dose at the radon "action level" of 4 pCi/L is roughly equivalent to smoking 10 cigarettes a day.
Philip Morris scientists wondered how come that the heavy tobacco users in the Caucasus live remarkably long lives. The local tobacco growers do not use phosphate fertilizers. But the American smoker inhales on average about 0.04 pCi of polonium-210 per cigarette, which disgorges alpha particles. It has a half life of only 138 days, making it thousand times more radioactive than the nuclear fuel used in the Hiroshima bomb.
Polunium-210 is soluble and is circulated through the body to every tissue and cell in levels much higher than from residential radon. The proof is that it can be found in the blood and urine of smokers. The circulating polonium-210 causes genetic damage and early death from diseases reminiscent of early radiological pioneers: liver and bladder cancers, stomach ulcers, leukemias, cirrhosis of liver, and cardiovascular diseases.
The Center for Disease Control concluded "Americans are exposed to far more radiation from tobacco smoke than from any other source." The Surgeon General C. Everett Koop stated that radioactivity, rather than tar, accounts for at least 90% of all smoking-related lung cancers.
Cigarette smoking accounts for 30% of all cancer deaths. Only poor diet rivals tobacco smoke as a cause of cancer in the U.S., causing a comparable number of fatalities each year. However, the National Cancer Institute, with an annual budget of $500 million, has no active funding for research of radiation from smoking or residential radon as a cause of lung cancer, presumably, to protect the public from "undue fears of radiation."
Russian Mafia uses radioactivity
Russian "Mafia" assassins allegedly planted pellets emitting gamma rays in the office of a Moscow businessman, killing him within months. At least half a dozen similar incidents have been reported in Russia.
Scientific American, January 1996
Scientific American, January 1996
A little carcinogen may be good for you?
The government and nuclear industry financed practically all the research on dangers of nuclear radiation. The scientists obligingly produced studies that the dangers of low-level radiation could not be proven, which were then widely disseminated to the public by collaborating media. Most attacked was the Linear No-Threshold (LNT) Model, which says that there is no safe threshold for exposure to radiation. This threatened the established "safety limits." According to Prof. Cohen, the apostle of pro-nuke science, low-level exposure to radioactivity or chemical carcinogens stimulates the body's defenses against cancer. For example, increasing the radon level in homes to 5 pCi/L should reduce the lung cancer risk. His comments reveal how the radon issue is connected to much larger multi-billion dollar issues:
"If Low Level Radiation was properly recognized as harmless, it would have a vast impact on many wasteful multi-billion government programs and regulations: the clean-up of the Hanford, Savannah River, Rocky Flats, and other sites; nuclear plant safety; routine emissions of radioactivity from nuclear plants; radioactive waste storage; and reduction of radon levels in homes. It would also make moot the issues of the 10,000 to 20,000 deaths projected from the Chernobyl accident, the fallout from nuclear bomb tests, and patients' fears of x-rays." "The simplistic LNT model has been also applied to chemical carcinogens, leading to severe restrictions on the use of cleaning fluids, organic chemicals, pesticides, etc. If the LNT model were abandoned for radon, it should be also abandoned for chemical carcinogens."
Stimulate your natural cancer defenses!
- Increase your radon level to 5 pCi/L - buy the pure Mountain Fresh Radon!
- Drink radon-enriched mineral water! (Proven effective since 1920's.)
- Sprinkle some asbestos, lead and arsenic around your home!
- Light up 12 cigarettes a day!
- Visit our combination tanning and x-ray health salon!
- Wear a genuine radium pendant just like Madame Curie!
EPA underestimates the radon danger
The linear hypothesis used by the EPA seriously underestimates the risk of lung cancer at low exposures to radon. In fact, the relative lung cancer risk increases for lower radon exposures. Alpha radiation is more effective in causing cancer at low dose rates. Higher doses cause overkill - cells that would have developed into cancer cells are instead killed. Studies of uranium miners clearly demonstrate the increasing effectiveness of radon exposure at low doses.
The gradual build-up of long-lived radon daughters in the lung, such as lead-210 with its 21-year half-life, makes it highly unlikely that extra cancers would stop appearing after 20 years. Lead-210 decays into polonium-210, whose potent carcinogenic properties are well documented. Long follow-up periods of 20-25 years among miners show that the incidence of cancers for nonsmokers sometimes exceeds that of smokers. Moreover, non-smokers who started mining at an early age begin to show dramatic increases in lung cancer some 40 or 50 years after the initial exposure.
Radon daughters, in addition to alpha and beta particles, also emit gamma rays. The health risk from exposure to the low level gamma radiation from radon includes not only cancers and genetic defects, but also possible increases in such diseases as diabetes milletus, cardiovascular disease, mental retardation, stroke, hypertension, and a great many infectious diseases.
Dr. Gordon Edwards: Estimating Lung Cancers
Fallout from Nevada nuclear bomb tests
During 1951-1962, nearly 100 aboveground nuclear weapons tests were conducted in Nevada. Another dozen underground tests also leaked radioactive materials into atmosphere. Rising public concern, as well as mounting litigation, led to the atmospheric test-ban treaty of 1963.
The U.S. government had assured the public that the nuclear tests were harmless. However, the Atomic Energy Commission "experts" overlooked how radioactive fallout gets into the food chain. Radioactive clouds travel hundreds of miles and after the fallout rains on grass, feeding cattle produces radioactive milk. This had exposed millions to radioactivity, particularly children. Some scientists calculated that the nuclear tests killed 400,000 American children. Government scientists rebutted that the nuclear bomb testing killed "only" 4,000 children.
The NCI report on the fallout from Nevada tests was not published until 1997, after it was kept secret for six years. It dealt only with iodine-131 and admitted that tens of thousands of Americans have received cumulative exposure of over 100 rem. ("Rem" is a measure of the ability of ionizing radiation to cause cancer or genetic defects in children of exposed people. Natural radioactivity is about 0.1 rem/year.) The highest exposures were to young children who drank milk. It has caused estimated 49,000 cases of thyroid cancer which, however, is rarely deadly.
The National Research Council: Exposure from Nevada Nuclear-Bomb Tests
DU helmets for the generals?
In 1950's, our generals marched thousands of GI's through the "ground zero" after atom bomb tests and showered our sailors with nuclear fallout to prove that radiation is harmless. Now, they insist that ammunition tipped with depleted uranium (DU) is relatively harmless. DU is 1.7 times as dense as lead and easily burns its way through steel. But most of our NATO allies want DU munitions banned.
DU is the waste left after extracting the isotope U-235 from uranium ore for nuclear weapons or reactors. While 99.3 percent of natural uranium is U-238, enrichment reduces the U-235 content in the leftover "depleted uranium" from 0.7 to 0.2 percent and makes it 40 percent less radioactive. But we are now stuck with over 1 million tons of DU waste.
The Gulf War I marked the first battlefield use of armor-piercing DU munitions and DU-reinforced armor. But the generals did not anticipate "friendly fire" accidents - U.S. tanks firing DU munitions into other U.S. combat vehicles (Bradleys). When a DU projectile hits steel, the high temperature vaporizes the uranium and exposes the survivors, as well as rescuers, to radioactive aerosol and dust. And wind can carry DU particles (less than 10 microns) for many miles. Soldiers were also exposed to DU inhalation when DU munitions burned and detonated at Camp Doha in Kuwait.
About 162 surviving soldiers had embedded DU fragments or inhaled DU particles. Most continue to excrete elevated levels of uranium, exhibit reduced problem-solving performance and have high levels of hormones harmful to reproductive health. Uranium has been found in the semen of some veterans.
When soldiers return from a modern, DU-improved war, they cannot be certain for decades whether or not they have really survived. DU exposes soldiers to low-level radiation and also produces radon, which can accumulate inside vehicles or buildings. The military has kept denying that DU has harmful radiological effects until confronted by Congress. Thus, U.S. troops were not warned that inhalation of uranium dust might cause lung cancer and birth defects in their children until 1999!
A single "hot particle" trapped in the lungs subjects the surrounding cells to radiation 800 times the dosage permitted by the Nuclear Regulatory Commission (NRC) for the entire body. The risk is equivalent to getting a chest X-ray each hour for life! Some 80,000 US Gulf War veterans now suffer from the so-called Gulf War syndrome, whose symptoms are identical to radiation sickness.
In addition to being radioactive, DU is toxic. The genetic damage to DNA from chemical toxicity or radioactivity, or both, can be inherited and passed along to successive generations. So harm may not become apparent until several generations after the DU-exposure. This puts DU munitions into the class of weapons known as "weapons of mass destruction or indiscriminate effect."
After U.S. aircraft used DU munitions in Bosnia, Kosovo, Serbia and Montenegro, the cancer deaths of 24 European peacekeepers and illnesses of many others have caused alarm in Europe. The military has pledged to Puerto Rico not to use DU munitions on Vieques, but has recently admitted mistakes.
There is a long-term devastating effect on the people we have liberated and their environment. The waste remains radioactive for thousands of years. We have dumped 350 tons of DU on Iraq, Kuwait, and Saudi Arabia and some 1 million bullets still rest in the desert. There has been an increase in lung, kidney and liver cancer, birth defects and stillbirths. Much of Kosovo's ground water has been contaminated and a cleanup would cost billions of dollars. (NYT 1/6/01)
A military contractor, making DU weapons, dumped DU into an unlined pit in the ground in downtown Concord, Mass. Now soil in Concord is contaminated with DU as far as a mile from the dump, and local wells are contaminated because DU has moved into groundwater. Shortly before this radioactive dump was added to the national Superfund list, the company directors declared bankruptcy and, so U.S. taxpayers are now paying for the difficult cleanup. (Ed Ericson, "Dumping on History: A Radioactive Nightmare in Concord, Massachusetts," E/The Environmental Magazine Mar. 5, 2004)
It was discovered only recently that DU fragments quickly disintegrate into a fine powder like cigarette ash. (NYT 9/2/02) Wind then blows this radioactive dust around for people and animals to inhale, contaminating the soil and water in a large area.
In the first Gulf War, US forces used 320 tons of DU, 80 percent of it fired by A-10 aircraft. According to Pentagon, the tonnage has been much lower in Gulf War II - about 75 tons of A-10 DU bullets. A spent tank round, just like those Iraqi children are playing with, was found to emit 260 millirads of radiation per hour. For comparison, the safety limit on exposure to the public is 100 millirems per year. (Christian Science Monitor 5/15/03)
Is there apractical alternative to DU? Yes! Tungsten-alloy weapons can kill tanks and other hardened targets as effectively as DU.
The Geneva Conventions prohibit weapons, which cause indiscriminate harm to non-combatants, and weapons, which cause widespread, long-term and severe damage to the environment. Will the U.S. taxpayers have to pay to clean up after its military in foreign countries?
Experiments on human subjects
From 1944 until 1974, the federal government funded radiation experiments on humans. In 1994, President Clinton appointed the Advisory Committee on Human Radiation Experiments. It reviewed 4,000 recorded human radiation experiments and hundreds of intentional radiation releases, which involved tens of thousands of unsuspecting subjects. A stack of copies of the "Nuremberg Code of Medical Ethics," which prohibits medical experimentation on people without their consent, was found in Defense Department files, all stamped "top secret."
Experiments were conducted on children, seriously ill and sometimes comatose patients, African-Americans, and prisoners. The poor were appropriate subjects because, as a professor at Emory University explained, "We felt we had a right to get some return from them, since it wouldn't be in professional fees and since our taxes were paying their hospital bills."
Since the very beginning of the Manhattan Project people were injected with plutonium or uranium. Total body irradiation experiments at the University of Cincinnati recorded eight deaths. Radiation doses were given to fetuses and hundreds of women at the Vanderbilt University. Prisoners' testicles were irradiated in Washington state and Oregon. Orphans at a school in Boston were fed plutonium-laced milk. Johns Hopkins University invented the radium nasal irradiation procedure given to schoolchildren nationwide and to military personnel. At a state school in Massachusetts, institutionalized mentally retarded children were lured into experiments by special treats like extra milk, occasional outings, and membership in a "Science Club."
On many occasions between 1944 and 1968, radiation was deliberately released mostly from nuclear weapons complexes to observe the impact on the population and environment. In the infamous 1949 "Green Run" release, a huge cloud of radioactive gas was secretly discharged from the Hanford site in Washington state.
Hundreds of uranium miners died unnecessarily of lung cancer. The Atomic Energy Commission deliberately did not advise them on the dangers of radon and proper mine ventilation systems were not installed, but data on their health were secretly collected.
Radon up your nose!
Irradiation of people blossomed into big business for Johns Hopkins University in Baltimore since its humble beginnings in 1912. Hopkins then decided to participate in the emerging radioactivity craze and sent one of their experts to Vienna to purchase 200 milligrams of radium. He carried it for a few hours in a lead wrapping in his pocket, but soon developed nausea and skin burns that took weeks to heal. In the 1930s, Hopkins devised an applicator with a capsule containing radon gas that could be inserted into the nose to irradiate and shrink adenoids and cure deafness.
The bid break came during World War II. Before the advent of pressurized planes, about one third of Air Force pilots was grounded by temporary deafness caused by air pressure changes during flight. Submariners and divers had similar problems. Hopkins claimed it had the cure and obtained a contract from the government to set up irradiation programs at military bases. Long-lasting radium replaced radon in the applicators and tens of thousands of servicemen were treated over the next 20 years. At least 5,000 submariners were treated in Groton, CT, and many thousands of civilians after the physician set up lucrative private practice in New London, CT.
From the '40s to the '60s, up to 2.6 million American children were treated with Nasal Radium Irradiation, a procedure promoted by Johns Hopkins, for enlarged adenoids or tonsils and mundane problems, such as head colds, stuffy noses, sore throats, and ear infections. The radioactive doses to children were 2,000-13,000 rad to nasopharynx, 100 rad to thyroid, 50-100 rad to the pituitary gland, and 15-40 rad to the brain. This "amazing" treatment reportedly helped children blossom into higher grades, improved their self-esteem, and even their looks.
Although radiation was proven harmful already in 1940s, Hopkins still claimed in 1960: "These treatments have now been given for more than a quarter of a century to hundreds of thousands of patients and no instance of damage from irradiation has yet been reported."
Decades later, tumors, thyroid and immune disorders, brittle teeth, reproductive problems and various bizarre diseases started to appear. The government appointed an Advisory Committee on Human Radiation Experiments, chaired by a professor of bioethics at Johns Hopkins. It decided to provide screening and health care to Veterans who received NRI. But, although the cancer risk to treated schoolchildren is ten times higher, it declined even to notify civilian patients. Johns Hopkins and the government have never admitted any liability.
Nazis - the health pioneers?
Decades ahead of modern Western governments, the Nazi government pursued public health policies and declared a "War on Cancer." Nazi propaganda promoted health as everybody's primary goal and responsibility.
They carried out massive campaigns for early detection of cancer. Women were shown how to examine their breasts for cancer, and men were advised to have their prostate examined as frequently as they check their car engines. The Nazis waged a large-scale anti-smoking campaign.
German scientists recognized that radon causes lung cancer and reduced the radon exposure to miners by proper ventilation. They were also the first to recognize that asbestos causes lung cancer and that asbestosis is an occupational disease. The Nazis invented occupational health and safety. They placed thousands of physicians in factories to monitor the health and safety of German workers.
The Nazis were promoting healthy nutrition: whole-grain bread (baker shops were forced to produce it by law), fruits, vegetables, and less meat. Soy beans became politically correct and earned the nickname "Nazi beans." They established the mineral water market in Europe.
Hitler was a vegetarian who called meat soup "cadaver tea." He was fond of pure olive oil and worried that consumption of whale oils would endanger the world's whale population. Himmler was strictly against the use of refined flour, sugar and white bread. Rudolf Hess preferred nutritional whole-wheat biscuits and carried his own vegetarian food even when invited for dinner, a habit which annoyed Hitler.
Hess strongly believed in homeopathy and was an advocate of natural healing. Alternative medicine and organic therapies were promoted. A government commission was established to evaluate home therapies as the cure for cancer. Large tracts of land were used for cultivation of herbs and healing plants. The Dachau concentration camp became one of the leading producers of natural herbs and spices in the world, and it also produced large quantities of organic honey.
The Nazimedizin is infamous for terrible experiments on concentration camp prisoners. But in the promotion of public health, prevention of diseases and fighting cancer the Nazis were decades ahead of their time.
Robert N. Proktor - "The Nazi War on Cancer"
Marie Curie - love of radioactivity to the end
Marie Sklodowska Curie was the first woman scientists to win worldwide fame and one of only four persons to have won two Nobel Prizes. In 1903, she shared the Nobel Prize for Physics with her husband Pierre and with Henri Becquerel for investigation of radioactivity, and in 1911 she received the Nobel Prize for Chemistry for her discovery of two new elements - polonium and radium. Later on, Curie's daughter Irene and her son-in-law Frederic Joliot-Curie also won Nobel Prizes, as did her neighbor and a close friend Perrin.
Wilhem Roentgen discovered x-rays in 1895 and frightened his wife with an image of her hand bones complete with a wedding ring. He refused to take out a patent for the benefit of mankind, and at the time of his death was nearly bankrupt. Inspired by Roentgen, Henri Becquerel discovered in 1896 that uranium emits mysterious radiation captured by photographic plates and makes surrounding air conduct electricity. Couple years later, Marie Curie persuaded her husband to abandon his research (he discovered piezoelectricity) and join her in exploring this mystery.
The Curies tested various materials for radioactivity. They found that pitchblende, then a worthless ore residue from the uranium producing plant in Joachimsthal (now in the Czech Republic), induced a current in air 300 times stronger than pure uranium. The Curies reasoned that there must be another very active element in the pitchblende. They called it polonium after Marie's native Poland, and coined the term "radio-active." Later that year, one year after their first child was born, they detected trace amounts of an element two million times more radioactive than uranium - radium. After backbreaking manual labor on chemically refining the pitchblende, the Curies managed to separate the new elements polonium and radium. During four years, they refined eight tons of ore to produce one gram of radium. The Curies presented a spec of radium, at that time more precious than diamonds, to their good friend Becquerel. He carried it in his vest pocket until he found it gave him skin burns.
Pierre Curie was killed by a horse-drawn wagon in 1906, but by that time he was already limping from bone deterioration. Marie continued the research of radioactivity. She devoted much of her life to promoting radiation as a cure for cancer. In her honor the unit of radioactivity generated by 1 gram of radium was named "Curie." As a gift for her scientific discoveries, Marie was presented with a pendant of radium. Madame Curie died in 1934 of leukemia, a cancer now known to be caused by radioactivity. Although her body was covered with lesions, she denied to the end that her beloved radium has killed her.
Years after Madame Curie's death, photographic films were placed between the sheets of her laboratory books. The photographs showed numerous fingerprints caused by the radioactivity on her hands. Her daughter Irene Joliot-Curie, who became only the second woman to win a Nobel science prize, later also died of leukemia caused by exposure to radioactivity, while her husband met the same fate a couple of years late after calling it "our occupational disease."
History of underestimating radioactivity
Source: J. Ellsworth Weaver Brief Chronology
The slow progress to safety
1784 William Morgan unknowingly produces X-rays in experiment witnessed by Ben Franklin.
1789 Martin Klaproth announces his discovery of a new element, uranium.
1895 Roentgen discovers x-rays.
1898 Marie and Pierre Curie coin the word "radioactivity" and separate Radium.
1900 Friedrich Ernst Dorn discovers radon, a radioactive product of uranium.
1904 A glass blower at Thomas Edison's Menlo Park lab is the first person known to have been killed by x-ray exposure. Severely burned in 1896, he still works with x-rays until 1898. His death causes Edison to discontinue radiation experiments.
1912 Arthritis patient dies because of Radium injections.
1921 Suggestion that radium and its emanation might cause lung cancer in miners are taken seriously but not proven.
1927 H. Muller shows genetic effects of radiation.
1929-1930 Fifty percent (!) of uranium miners are dying of lung cancer at the Joachimsthal mine.
1941 The first standard for radon levels (10-11 Ci/L) by National Bureau of Standards.
1958 (England) Alice Stewart publishes first major findings on the carcinogenic effect of diagnostic x-rays on children.
1958 Proposed that lung be regarded as a moderately radiosensitive organ.
1960's Beginning of population radiation exposure standards.
1986 Report "Lung Cancer Risk from Indoor Exposures to Radon Daughters" published.
1990 "Health Effects of Exposure to Low Levels of Ionizing Radiation - BEIR V" published.
Human guinea pigs
1943-1947 Polonium injected into incurable patients at Rochester, NY. Doses greater than occupational limits.
1945 Plutonium injected into human subjects at Los Alamos.
1945-1947 18 patients (one a five year old) injected with plutonium at Rochester, NY, Oak Ridge, TN., U. of Chicago, and UCSF. No informed consent; doses much greater than occupational limits.
1961 20 aged volunteers receive injections with radium and thorium in Boston, MA. Potential doses well above occupational limits. No follow-up done.
1963-70 64 volunteer prisoners at Washington State Prison and 67 volunteer prisoners at Oregon State Prison receive testicular irradiation; exposures from 7 to 600 roentgens.
The nuclear race
1932 "There is not the slightest indication that nuclear energy will ever be obtainable. It would mean that the atom would have to be shattered at will." - Dr. Albert Einstein
1933 "The energy produced by the atom is a very poor kind of thing. Anyone who expects a source of power from the transformation of these atoms is talking moonshine." - Lord Ernest Rutherford (after splitting the atom for the first time)
1934 Szilard applies for a patent, "Improvements in the Transmutation of Chemical Elements," stating "radio-active bodies are generated by bombarding suitable elements with neutrons. Such uncharged nuclei cause the formation of radio-active substances." He amends his patent to add "the liberation of nuclear energy for power production and other purposes through nuclear transmutation" and describes the concepts of chain reaction and critical mass. Further, "if the mass is larger than the critical value... I can produce an explosion."
1938 Nobel Prize awarded to Enrico Fermi (Italy) for his work on transuranics. The Fermi family (Enrico's wife is Jewish) escapes from Italian Nazi persecution to New York.
1939 Hitler annexes Czechoslovakia, the richest known source of uranium.
1939 Enrico Fermi patents the first nuclear reactor (conceptual plans).
1942 (June) Germany - Werner Heisenberg's fourth experimental atomic pile explodes spewing burning particles of graphite twenty feet in the air and setting the lab on fire. Heisenberg and Robert Doepel are nearly killed.
1942 (Sept) The Manhattan Project is formed to secretly build the atomic bomb before the Germans.
1942 (Dec) The first sustained and controlled chain reaction in an atomic pile at University of Chicago. The reactor is graphite moderated. Fermi oversees the design and building.
1945 USSR occupies Czechoslovakia. Soviet commanders order all German plans, parts, models, and formulas regarding the use of atomic energy, rocket weapons, and radar be turned over to them. USSR infantry and technical troops occupy Jachymov (Joachimsthal), the only European source of uranium.
1945 (July) Trinity Test - the first nuclear bomb explosion at Alamagordo, NM. 19 KT yield. Cattle receive beta-radiation burns.
1945 (Aug 6 and 9) Hiroshima and Nagasaki atomic bombed.
1949 (Aug) USSR explodes its first A-bomb in Kazakhstan.
1949 (Oct) AEC committee headed by Oppenheimer votes against hydrogen bomb. Teller, the "father" of hydrogen bomb, urges construction.
1950 (Jan) Truman orders the construction of hydrogen bomb.
1952 Great Britain explodes its first A-bomb (25 KT) in lagoon of Monte Bello Islands off Western Australia.
1952 US explodes the world's first hydrogen bomb.
1953 USSR explodes its first hydrogen bomb.
1953 (Dec) Oppenheimer loses security clearance due to contact with Communists in the 1930's and opposition to H-bomb.
1954 40,000 Soviet soldiers participate in a war game where a nuclear bomb is detonated at 1,150 feet in the air in Kazakhstan. Troops are sent immediately into the contaminated dust.
1957 First British hydrogen bomb destroys Christmas Island in South Pacific.
1960 France explodes its first A-bomb.
1961 USSR explodes a 58 megaton hydrogen bomb in the air over Novaya Zemlya. The largest weapon ever exploded in history.
1963 The limited atmospheric test-ban treaty.
1964 China explodes its first A-bomb.
Irresponsibility and accidents
1945 (June) Criticality accident at Los Alamos, 14 people exposed, some receive up to 3,000 rem gamma and neutrons.
1945 (Aug) A Los Alamos lab technician conducts an unauthorized experiment and is lethally irradiated; the first American to die of acute radiation sickness.
1949 The Green Run at Hanford reprocesses one ton of uranium too early after irradiation; releases 20,000 Curies of Xenon-133 and 7,780 Curies of Iodine-131; the plume measures 200 by 40 miles.
1949 Officials in Mayak Chemical Combine at Chelyabinsk, USSR, begin dumping wastes from plutonium production into the Techa River. From 1949 to 1956, 2.75 million Curies of radioactivity is dumped into the river without notifying the townspeople downstream. Some exposed to doses as high as 350 rem/yr.
1952 Explosion and meltdown at Chalk River reactor in Ontario, Canada, which made bomb materials for the US. Future U.S. president Jimmy Carter, a nuclear engineer by education, is one of the volunteer workers who participate in the cleanup, going on until he receives his Maximum Permissible Dose.
1953 Experimental reactor criticality accident in USSR, 2 persons exposed.
1954 US hydrogen bomb test (Castle Bravo) over Bikini results in fallout over Marshall Islands, contaminates crew of 23 on Fortunate Dragon, 28 US servicemen, and 239 Marshall Islanders.
1956 Broken Arrow 1, Lakenheath AFB, UK. US B-47 bomber catches fire on landing and crashes into nuclear bomb storage igloo. 3 nuclear bombs, each containing 8,000 lb. of TNT trigger, threaten to explode. Fire crew heroically pour foam on igloo instead of trying to save the four trapped fliers.
1957 Explosion of an underground, high-level nuclear waste storage tank at Mayak Chemical Complex near Chelyabinsk in the Urals (USSR) vents 2 million Curies over 15,000 sq. miles. Population of over 250,000 resettled due to Strontium-90 contamination. The world's worst nuclear accident until Chernobyl.
1957 British plutonium production reactor in Seascale (now Sellafield) catches fire spreading approximately 20,000 Curies of radioactive iodine across Great Britain and northern Europe. Comes within seconds of a meltdown and a large-scale nuclear accident.
1957 B-47 crashes on landing at Homestead AFB, FL, kills the four man crew, trigger explosives on nuclear weapon explode.
1958 Broken Arrow 3, B-47 drops a nuclear bomb from 14,000 ft on garden of a homeowner in Mars Bluff, SC, makes crater 35 ft deep; chemical trigger designed to set off TNT explodes spreading plutonium contamination.
1959 AEC's Sodium Reactor Experiment reactor, Santa Barbara, CA, 10 of 43 fuel assemblies damaged due to lack of heat transfer, contamination released.
1959 High levels of Strontium-90 caused by nuclear testing reported in US milk and in children's bones.
1960 Jackson, New Jersey, BOMARC nuclear missile catches fire, plutonium released to atmosphere.
1960 A 19-year old in USSR commits suicide with 10 Curies Cesium-137 source; exposure time 20 hours leads to death 18 days later.
1961 Prompt criticality accident at US Army reactor in Idaho Falls kills three. Recovery exposes 47 persons.
1961 Broken Arrow 4, Goldsboro, NC, B-52 crashes, 5 interlocks fail and the 24 MT nuclear bomb is one interlock away from detonating, crater 50 ft deep, 3 acres in area excavated to look for portion of one weapon, 4 million cu. ft. of earth removed.
1961 Loss of coolant reactor accident on the first Soviet nuclear missile submarine. Crew members die from radiation exposure while rigging a provisional cooling system using a reserve tank and pipes cut off one of the torpedoes. The welding took 90 minutes. Captain Nikolai Zateyev reported that "the ones who got radiation doses began to swell visibly. Their faces grew red. After two hours, watery discharges came from the roots of their hair. Soon it became frightening to look at their eyes and swollen lips. They were completely disfigured. Hardly able to move their tongues, they complained of pain in the entire body." Eight officers and sailors died within days, six more died within the next several years.
1963 Nuclear submarine USS Thresher sinks in North Atlantic. Government did not admit until 1990's that it was torpedoed by another US submarine.
1964 US satellite disintegrates over Madagascar and releases 17,000 Curies of plutonium into the atmosphere from its nuclear reactor.
1964-1965 In the Gulf of Abrosimov off Novaya Zemlya, USSR, eight naval reactors are dumped into the sea, including three with fuel still intact.
1979 (March) Equipment failures and human error cause an accident at the Three Mile Island nuclear reactor at Harrisburg, PA. Partial core meltdown. The worst nuclear plant accident in U.S. history.
1986 (April) Runaway reaction during a test at the Chernobyl nuclear reactor near Kiev, now Ukraine, causes explosions that rupture the containment structure and send massive amounts of radiation through the Northern Hemisphere. Soviet troops are dispatched to help fight graphite fire and contain the reactions in the melted core. The worst nuclear accident in history. Over 75 million people exposed to dangerously high levels of radiation. Soviet medical experts predict nearly 30,000 cancer-related deaths over a 50-year period due to fall-out from the accident.
1986 Nuclear powered Soviet submarine suffers explosion and fire in missile tube, kills at least three and sinks with reactor on-board.
1989 42 crewmen die when the Soviet nuclear submarine "Komsomolets" sinks in the Norwegian Sea, leaving the submarine's reactor and nuclear warheads (two nuclear torpedoes containing 28 lb. of plutonium) 310 miles off Norway.
1989 Federal agents raid Rocky Flats and allege that the plant concealed environmental contamination and improperly stored and disposed of hazardous radioactive wastes. The Energy Secretary halts all plutonium production operations.
1989 "Yellow Children" start appearing in births in Talmenka, Russia. Children have jaundice, congenital defects of nervous system and organs. In one month, 42 of 59 babies born have these symptoms. Suspected fall-out from nuclear bomb tests in Kazakhstan.
1990 After eating game and fish contaminated with Cesium-137, seven people are hospitalized in Tomsk, Siberia, Russia. Plutonium and uranium cores for weapons are manufactured in this town.
1992 "Big chunks of the republic are so poisoned they will not be suitable for human settlement for a very long time. We are talking decades," said Russia's minister for the environment. "We in Belarus lost one in four people during the Great Patriotic War (WW II), while as a result of Chernobyl, one in five citizens - approximately 2 million people, including 800,000 children - now suffer because they live in contaminated zones," said the chairman of the Belarus State Committee on Chernobyl.
1992 DOE's Office of Environmental Restoration and Waste Management (EM) and its predecessor agencies have decontaminated and dismantled over 90 contaminated facilities across the US. The organization has cleaned up 11 of 43 sites under its Formerly Utilized Sites Remedial Action Program. Under its Uranium Mill Tailings Remedial Action Program, EM has cleaned up 15 of 24 sites and 4,200 of 5,000 vicinity properties.
1992 The Hanford Site changes its mission from nuclear materials production to the clean up of its facilities.
1993 "British Medical Journal" reports an excess incidence of cancer in children aged 0 to 24 over the period 1953-1990 in Seascale, within sight of the Sellafield plant of British Nuclear Fuels.
1993 An "alarming" suicide rate among soldiers and engineers who helped clean up the Chernobyl nuclear disaster is the result of radiated nervous systems, the breakdown of immune defenses and stress. The San Francisco Examiner reports that nearly seven years after the world's most serious nuclear reactor accident exposed about 500,000 Ukraine residents, reactor workers and cleanup crews to radiation, the death toll stands at 7,000 - of whom 18 percent have taken their own lives, according to statistics provided by the Russian government. Thousands more are suffering from symptoms caused by excessive radiation, says the article. More than 40 percent of all former Chernobyl workers who ask for medical assistance suffer from severe after-effects, such as permanent memory loss and impaired thinking ability.
1993 In a new report, the Russian Federation details how the USSR broke the international rules for thirty years by dumping radioactive waste in the oceans. The amount of radioactive waste includes 2.5 million Curies and 18 nuclear reactors from submarines and an icebreaker. These were mostly dumped in the Kara Sea.
1993 Russia dumps liquid radioactive waste into the Sea of Japan.
1993 French deliberately cause a meltdown under almost identical conditions as at Three Mile Island in the Phebus reactor in the south of France. Close circuit televisions show a bright blue glow as the fuel rods melt. Environmentalists criticize the experiment as dangerous and unnecessary.
1994 Russian scientists disclose pumping 3 billion Curies of radioactive waste under layers of shale and clay for the last 30 years at sites at Dimitrovgrad (near the Volga River), Tomsk (near the Ob River), and Krasnoyarsk (on the Yenisei River).
1995 Russians drinking water from the Techa River (draining from the Mayak plutonium facility near Chelyabinsk) have more lymphatic genetic mutations (T-cell antigen receptors) than people who suffered radiation from atomic bombing of Hiroshima, according to Japanese and Russian scientists. The region's death rate is higher than its birth rate. The Japanese scientists are from the Radiation Effects Research Foundation in Hiroshima. An international symposium on radiation effects on human health is held in Chelyabinsk to discuss the hazards posed by the Mayak plant to nearby residents.
1995 Artificial reservoirs for liquid nuclear waste in Russia's Ural region may overflow if left unrepaired, destroying nearby areas around Chelyabinsk with what is called a "nuclear flash flood," Russian officials warn. The reservoirs at the Mayak chemical plant now hold a total of 400 million cubic meters of liquid nuclear waste, and there is a strong possibility the embankment will give way, inundating towns and villages along the Techa River nearby. No effective measures have been taken to prevent a 33-feet-high flood with a radioactivity as high as 200,000 Curies of Strontium-90 and Cesium-137. Suspension of an atomic power plant project in the region has added to the danger of a nuclear flash flood, since the project was designed to accelerate evaporation of water in the reservoirs by using surplus heat from the power plant.
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1-800-NO-RADON
Radon Remediation / Radon Mitigation: When a building (or house) is found to have an elevated level of radon gas (defined by the U.S. Environmental Protection Agency as a radon result of 4.0 pCi/l or higher,) methods of reducing the radon levels can be applied to cure the problem. The most common method of radon mitigation (also known as radon remediation or radon gas abatement is Active Soil Depressurization (ASD.) An ASD Radon Mitigation System utilizes PVC piping attached to an electric radon suction fan. The piping typically begins below the lowest floor of the structure's foundation (penetrating the slab of the basement or the plastic membrane of the crawl space) and extends upward to an exit point above ground level. The inline radon fan is mounted in an inconspicuous location on the exterior or within an attic above the home. In cases where the radon fan is installed in the attic, the discharge pipe extends out through the roof so the radon gas can be released outdoors. Once radon is released into the atmosphere, it is no longer hazardous. Radon is only dangerous when trapped indoors.
Active (fan assisted) radon mitigation systems can reduce the radon gas entry by as much as 99%. A qualified radon contractor (also known as a radon mitigator> or radon remediation specialist) can typically install a radon mitigation system in a home in less than a day. After the system is installed, the radon levels begin to drop almost immediately. Passive radon reduction techniques (such as sealing cracks or installing pipes without an inline radon fan) are rarely effective at reducing radon levels. The reason that these "passive" radon reduction techniques are ineffective is because radon gas is under pressure and must escape from the ground. It is a very inert, un-reactive gas that can be drawn up through the pours of concrete, around drains, utility penetrations, or expansion joints. Attempting to "seal out" radon is similar to trying to keep water out of a basement by painting the walls and floor with waterproofing paint. It may work temporarily if the problem is minor, but it wouldn't keep standing water out. The only way to fix a water problem is to redirect the water somewhere else before it enters the home. The same principles apply to radon correction. Sealing cracks and openings is part of the radon mitigation process; however this is to prevent the downward draw of conditioned air from the home and to improve the pressure field extension of the system below the slab, not to “seal out” the radon.
Radon is a colorless, odorless, naturally occurring, radioactive noble gas that is formed from the decay of radium. Radon gas is one of the heaviest substances that remains a gas under normal conditions and is considered to be a health hazard. The most stable isotope, Rn222 ( Radon Gas), has a half-life of 3.8 days and is used in radiotherapy. While having been less studied by chemists due to its radioactivity, there are a few known compounds of this generally un-reactive element.
Radon is a significant contaminant that affects indoor air quality worldwide. Radon gas from natural sources can accumulate in buildings, especially in confined areas such as the basement. Radon can be found in some spring waters and hot springs.
According to the United States Environmental Protection Agency, radon is reportedly the second most frequent cause of lung cancer, after cigarette smoking; and radon-induced lung cancer the 6th leading cause of cancer death overall. According to the same sources, radon reportedly causes 21,000 lung cancer deaths per year in the United States. Because of this, radon mitigation systems can be life-savers.
Indoor radon can be mitigated by sealing basement foundations, water drainage, or by sub-slab de-pressurization. In severe cases, radon mitigation can be achieved via air pipes and fans to exhaust sub-slab air to the outside. Indoor radon ventilation systems are less visible, but exterior radon systems can be more cost-effective in some cases. Modern construction that conserves energy by making homes air tight exacerbates the risks of radon exposure if radon is present in the home. Older homes with more porous construction are more likely to vent radon naturally. Ventilation systems can be combined with a heat exchanger to recover energy in the process of exchanging air with the outside. (This is more common with commercial and industrial radon mitigation.) radon collector installed under a radon barrier (a sheet of plastic that covers the crawl space).
The most common approaches are active soil depressurization (ASD) which utilizes a radon mitigation suction fan to pull the gas out from below the foundation of the home. The radon fan is attached in-line with a PVC pipe system running from the foundation to the roof of the home. Once the radon gas is discharged outdoors, it becomes diluted by the outdoor air to levels that are not hazardous.
1-800-NO-RADON
1-800-667-2366
How Radon Enters Your House
Radon is a naturally occurring radioactive gas produced by the breakdown of uranium in soil, rock, and water. Air pressure inside your home is usually lower than pressure in the soil around your home's foundation. Because of this difference in pressure, your house acts like a vacuum, drawing radon in through foundation cracks and other openings. Radon Mitigation works by changing the pressure difference between the soil and the home. Radon gas may also be present in well water and can be released into the air in your home when water is used for showering and other household uses. In most cases, radon entering the home through water is a small risk compared with radon entering your home from the soil. Systems are available to reduce radon entry from water sources. In a small number of homes, the building materials (e.g., granite and certain concrete products) can give off radon, although building materials rarely cause radon problems by themselves. In the United States, radon gas in soils is the principal source of elevated radon levels in homes.
Radon is a Cancer-causing, Radioactive Gas
Radon
is estimated to cause many thousands of lung cancer deaths each year. In fact,
the Surgeon General has warned that
radon is the second leading cause of lung cancer
in the United States. Only smoking causes more lung cancer deaths. If you smoke
and your home has
high radon levels,
your risk of lung cancer is especially high. If your test shows a level of 2.7
pCi/l or above, consider installing a
radon remediation system.
What Do Your Radon Test Results Mean?
Selecting a Radon Test Kit
Before you’ll know if you need a radon mitigation system, you need to conduct a test. Since you cannot see or smell radon, special equipment is needed to detect it. When you're ready to test your home, contact your state radon office (or visit our radon testing page for information on locating qualified test kits or qualified radon testers. You can also order test kits and obtain information from a radon hotline. There are two types of radon testing devices. Passive radon testing devices do not need power to function. These include charcoal canisters, alpha-track detectors, charcoal liquid scintillation devices, and electret ion chamber detectors. Both short- and long-term passive radon devices are generally inexpensive. Active radon testing devices require power to function and usually provide hourly readings and an average result for the test period. These include continuous radon monitors and continuous working level monitors, and these tests may cost more. A state or local official can explain the differences between radon devices and recommend ones which are more appropriate for your needs and expected testing conditions. Make sure to use a radon testing device from a qualified laboratory.
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. A radon mitigation system installed by a qualified (radon certified) contractor could save your life. The amount of radon in the air is measured in "picocuries of radon per liter of air," or "pCi/L." Sometimes test results are expressed in Working Levels, "WL," rather than picocuries per liter of air. A level of 0.016 WL is usually equal to about 4 pCi/L in a typical home. With this level, a radon abatement system would be recommended.
The U.S. Congress has set a long-term goal that indoor radon levels be no more than outdoor levels. About 0.4 pCi/L of radon is normally found in the outside air. EPA recommends fixing your home if the results one long-term test or the average of two short-term tests show radon levels of 4 pCi/L (or 0.016 WL) or higher. With today's technology, radon levels in most homes can be reduced to 2 pCi/L or below. You may also want to consider radon mitigation if the level is between 2 and 4 pCi/L.
A short-term radon test remains in your home for 2 days to 90 days, whereas a long-term test remains in your home for more than 90 days. All radon tests should be taken for a minimum of 48 hours. A short-term test will yield faster results, but a long-term test will give a better understanding of your home's year-round average radon level and indicate if a radon abatement or mitigation system is necessary.
The EPA recommends two categories of radon testing. One category is for concerned homeowners or occupants whose house is not for sale; refer to EPA's A Citizen's Guide to Radon for testing guidance. The second category is for radon testing and reduction in real estate transactions; refer to EPA's Home Buyer's and Seller's Guide to Radon , which provides guidance and answers to some common questions.
Why Hire a Radon Contractor?
EPA recommends that you have a qualified radon mitigation 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. However, if you decide to do the work yourself, get information on appropriate training courses and copies of EPA's technical guidance radon documents.
Will Any Radon Company Do?
EPA recommends that you use a state certified and/or qualified radon mitigation contractor trained to fix radon problems. You can determine a service provider's qualifications to perform radon measurements or to mitigate radon from your home in several ways. First, check with your state radon office. Many states require radon professionals to be licensed, certified, or registered, and to install radon mitigation systems or conduct radon testing. Most states can provide you with a list of knowledgeable radon service providers doing business in the state. In states that don't regulate radon services, ask the contractor if they hold a professional proficiency or certification credential, and if they follow industry consensus standards such as the American Society for Testing and Materials (ASTM) Standard Practice for Installing Radon Mitigation Systems in Existing Low-Rise Residential Buildings, E2121 (February 2003). You can contact private proficiency programs for lists of privately-certified professionals in your area. Such programs usually provide members with a photo-ID, which indicates their qualification(s) and the ID-card's expiration date. For more information on private proficiency programs or contact your state radon office.
How To Select A Radon Mitigator
Get Estimates
Choose a radon contractor to fix the problem just as you would choose someone to do other home repairs. It is wise to get more than one estimate, to ask for references, and to contact some of those references to ask if they are satisfied with the radon mitigation company’s work. Also, ask your state radon office or your county/state consumer protection office for information about the radon companies.
1-800-NO-RADON
1-800-667-2366
Use this check-list when evaluating and comparing radon contractors and ask the following questions:
| YES NO |
Will the contractor provide references or photographs, as well as test results of 'before' and 'after' radon levels of past radon reduction work? Can the contractor explain what the work will involve, how long it will take to complete, and exactly how the radon mitigation system will work? Does the contractor charge a fee for any diagnostic tests? Although many contractors give free estimates, they may charge for diagnostic tests. These tests help determine what type of radon reduction system should be used and in some cases are necessary, especially if the contractor is unfamiliar with the type of house structure or the anticipated degree of difficulty. See " Radon Reduction Techniques" for more on diagnostic tests. Did the contractor inspect your home's structure before giving you an estimate for radon mitigation? Did the contractor review the quality of your radon measurement results and determine if appropriate testing procedures were followed? |
Compare the contractors' proposed costs for the radon system and consider what you will get for your money, taking into account: (1) a less expensive system may cost more to operate and maintain; (2) a less expensive system may have less aesthetic appeal; (3) a more expensive system may be best for your house; and, (4) the quality of the building material will affect how long the radon mitigation system lasts.
Does the radon contractor's proposal and estimate include:
| YES NO |
Proof of state certification and/or professional proficiency or radon certification credentials? Proof of liability insurance and being bonded, and having all necessary licenses to satisfy local radon remediation requirements? Diagnostic testing prior to design and installation of a radon removal system? Installation of a warning device to caution you if the radon mitigation system is not working correctly? Testing after installation to make sure the radon reduction system works well? A guarantee to reduce radon levels to 4 pCi/L or below, and if so, for how long? |
The Radon Abatement Contract
Ask the contractor to prepare a contract before any radon remediation work starts. Carefully read the contract before you sign it. Make sure everything in the contract matches the original proposal. The contract should describe exactly what work will be done prior to and during the installation of the radon system, what the system consists of, and how the system will operate. Many radon contractors provide a guarantee that they will adjust or modify the system to reach a negotiated radon level. Carefully read the conditions of the contract describing the guarantee. Carefully consider optional additions to your contract which may add to the initial cost of the radon removal system, but may be worth the extra expense. Typical options might include an extended warranty, a service plan, and/or improved aesthetics.
Important information that should appear in the radon abatement system contract includes:
The total cost of the job, including all taxes and permit fees; how much, if any, is required for a deposit; and when payment is due in full.
The time needed to complete the radon removal work.
An agreement by the contractor to obtain necessary permits and follow required building codes for radon mitigation.
A statement that the contractor carries liability insurance and is bonded and insured to protect you in case of injury to persons, or damage to property, while the radon work is done.
A guarantee that the contractor will be responsible for damage and clean-up after the job.
Details of any guarantee to reduce radon below a negotiated level.
Details of warranties or other optional features associated with the hardware components of the mitigation system.
A declaration stating whether any warranties or guarantees for the radon remediation work are transferable if you sell your home.
A description of what the contractor expects the homeowner to do (e.g., make the work area accessible) before work begins.
What to Look for in a Radon Reduction System
In selecting a radon reduction method for your home, you and your contractor should consider several things, including: how high your initial radon level is, the costs of installation and system operation, your house size and your foundation type. An effective radon mitigation system can reduce your radon levels to less than 1 pCi/l.