Radon testing and home inspectors
As a home inspector I can’t tell you how many times I have heard it said that radon is not a problem, that it is a way for people to make money, and even that it is a conspiracy from the government. Also, it is common for test results to come back high for a home with a recommendation to have a system installed to lower the level and it is ignored. The following information has been compiled from a portion of the radon measurement course from INTERNACHI, KDHE (Kansas Department of Health and Environment) and some of my own observations.
As you read through the following information you will notice that it has taken some very intelligent people to compile the data that backs up the danger of radon. If you start reading about uranium, radium, radon, atoms, and how they all connect I would bet your eyes will glaze over a time or two before it starts to sink in, and you understand it thoroughly. If this is a conspiracy, the amount of work that has gone into it compared to the return would rank it somewhere not far below the trips to the moon that never happened. It is my desire that this article will convince you to test for radon and if the number comes back high do something about it.
As far as the money that is made from the radon business, I don’t believe anyone is getting rich. I do not install any mitigation systems, but I do know what the material costs and the going rate for a typical system and I can do basic math. I can tell you first hand from an inspector’s point of view radon testing is more a cost of doing business than a supplemental income. There is the cost of the equipment, along with material, calibrations, and repairs. The licensing requires a quality assurance plan and the paper work to back it up, continuing education classes, one or two days per year, that not only require missing a day’s wages but cost anywhere from $150 - $250 per day for the class. And then there is the trip to the property two times, the miles and driving time, and the times that the realtor or home owner forgot you were coming and the time sitting in the vehicle waiting or rescheduling another trip with no extra charge. All for a very reasonable price.
(check the website: www.laselleck.com/services-and-pricing.html)
A good home inspector should be concerned about giving you a thorough inspection and that should include the home’s environment. He or she would never tell you, you don’t need a radon test but instead would kindly try to educate you as to why you should have it tested and if it comes back high why you should follow up and get it fixed.
Exposure to Radon Causes Lung Cancer in Non-Smokers and Smokers Alike
Lung cancer kills thousands of Americans every year. Smoking, radon, and second-hand smoke are the leading causes of lung cancer. Although lung cancer can be treated, the survival rate is one of the lowest for those with cancer. From the time of diagnosis, between 11 and 15% of those afflicted will live beyond five years. In many cases, lung cancer can be prevented -- this is especially true for radon.
Smoking is the leading cause of lung cancer. Smoking causes an estimated 160,000 cancer deaths in the U.S. every year, according to 2008 statistics from the American Cancer Society. And the rate among women is rising. In 1964, Dr. Luther L. Terry, then U.S. Surgeon General, issued the first warning regarding the link between smoking and lung cancer. Lung cancer now surpasses breast cancer as the Number One cause of cancer deaths among women. A smoker who is also exposed to radon has a much higher risk of lung cancer.
Radon is the Number One cause of lung cancer among non-smokers, according to EPA estimates. Overall, radon is the second leading cause of lung cancer. Radon is responsible for about 21,000 lung cancer deaths every year. About 2,900 of these deaths occur among people who have never smoked.
Second-hand smoke is the third leading cause of lung cancer and is responsible for an estimated 3,000 lung cancer deaths every year. Smoking affects non-smokers by exposing them to second-hand smoke. Exposure to second-hand smoke can have serious consequences for children’s health, including asthma attacks. It can also affect the respiratory tract and make them vulnerable to bronchitis and pneumonia, etc. It may lead also to ear infections.
The following Web sites provide a wide range of comprehensive information about lung cancer, prevention and treatment:
Why is radon the public health risk that it is?
The EPA estimates that radon is responsible for about 20,000 lung cancer deaths each year in the United States. Exposure to radon is the second leading cause of lung cancer after smoking. Radon is an odorless, tasteless and invisible gas produced by the decay of naturally occurring uranium in soil and groundwater. Radon is a form of ionizing radiation and a proven carcinogen. Lung cancer is the only known effect on human health from exposure to airborne radon. Thus far, there is no conclusive evidence that children are at greater risk of lung cancer than adults.
Radon in air is ubiquitous. It is found in outdoor air and in the indoor air of buildings of all kinds. The EPA recommends that the problem be addressed if a home's radon level is 4 pCi/L (picocuries per liter) or more. Because there is no known safe level of exposure to radon, the EPA also recommends that the problem be addressed for homes with radon levels between 2 pCi/L and 4 pCi/L. The average radon concentration in the indoor air of the average American home is about 1.3 pCi/L. The EPA bases its estimate of 20,000 radon-related lung cancers a year on this number. The average concentration of radon in outdoor air is 0.4 pCi/L, or one-tenth of the EPA’s recommended 4 pCi/L action level.
For smokers, the risk of lung cancer is significant due to the synergistic effects of radon and smoking. For this at-risk population, about 62 people in a 1,000 will die of lung cancer, compared to about seven people in a 1,000 who have never smoked. Put another way, a person who has never smoked and is exposed to 1.3 pCi/L has a 2-in-1,000 chance of dying from lung cancer, while a smoker has a 20-in-1,000 chance. The risk to smokers compared to those who have never smoked is six times greater.
The radon health risk is underscored by the fact that, in 1988, the United States Congress added Title III on Indoor Radon Abatement to the Toxic Substances Control Act. It codified and funded the EPA’s then-fledgling radon program. That same year, the Surgeon General issued a warning about radon, urging Americans to test their homes and to reduce the radon level, when necessary.
Unfortunately, many Americans presume that because the action level is 4 pCi/L, a radon level of less than that is considered safe. This perception is all too common in the residential real estate market. In managing any risk, we should be concerned with the greatest risk. For most Americans, their greatest exposure to radon is inside their homes, especially in rooms that are below grade (such as basements), as well as rooms that are in contact with the ground, and the rooms directly above them.
RADON RISK for PEOPLE WHO HAVE NEVER SMOKED
If 1,000 people who have never smoked were exposed to this level over a lifetime. The risk of cancer from radon exposure compares to the following:
20 pCi/L about 36 of them would get lung cancer. 35 times the risk of drowning.
10 pCi/L about 18 of them would get lung cancer. 20 times the risk of dying in a fall.
8 pCi/L about 15 of them would get lung cancer. 4 times the risk of dying in a fall.
4 pCi/L about 7 of them would get lung cancer. the same risk as dying in a car crash.
2 pCi/L about 4 of them would get lung cancer. the same risk as dying from poison.
1.3 pCi/L about 2 of them would get lung cancer.
Radon in water
Property owners with wells who have confirmed elevated indoor radon levels should also test their well water for radon. Radon in the water supply can increase the indoor radon level, although, in most cases, radon entering the home through water will be a small source of risk compared to the levels of radon entering through the soil. The EPA estimates that indoor radon levels will increase by about 1 pCi/L for every 10,000 pCi/L of radon in water. (The EPA's Office of Ground Water and Drinking Water has developed publications relating to radon in drinking water which can be found at http://www.epa.gov/safewater/radon.html.)
How is radon tested in water?
Before testing for radon in the residential water supply, test the air. If the indoor radon level is high and the home uses groundwater, test the water. If the radon level in the air is low, there is no need to test the water. Test results are expressed in picocuries of radon per liter of water (pCi/L). In general, 10,000 pCi/L of radon in water contributes roughly 1 pCi/L of airborne radon throughout the house. The EPA currently advises consumers to act if the total household air level is above 4 pCi/L.
For waterborne radon, a simple step is to make sure that the bathroom, laundry room and kitchen are well ventilated. If the well water has only moderate levels of radon, this may adequately reduce exposure to waterborne radon. However, if the well has high levels of radon, consider using water-treatment devices, such as granular activated-carbon (GAC) units and home aerators.
What do the results of a water test mean?
It is possible to estimate how much the radon in the water supply is affecting the indoor radon level. The formula to gauge whether indoor air levels are elevated is to subtract 1 pCi/L from the indoor air radon level for every 10,000 pCi/L of radon that was found in the water. For example: If there are 30,000 pCi/L of radon in the water, then 3 pCi/L of the indoor measurement may have come from radon in the water.
If most of the radon is not coming from the water, mitigate the indoor levels and then re-test the indoor air to make sure that the source of elevated radon was not coming from the property's well. If a large contribution of the radon in the house is coming from the water supply, homeowners want to consider installing a special water treatment system to remove radon. The EPA recommends installing a water treatment system only when there is a radon problem found in the water supply.
How is radon removed from water?
Radon can be removed from water by using one of two methods: aeration treatment, or granular activated-carbon (GAC) treatment.
Aeration treatment involves spraying water or mixing it with air, and then venting the air from the water before use.
GAC treatment filters water through carbon. Radon attaches to the carbon and leaves the water free of radon. The carbon may need special handling for its disposal if it is used at a high radon level, or if it has been used for a long time.
In either treatment, it is important to treat the water where it enters the home (at the point-of-entry) so that all the water will be treated. Point-of-use devices, such as those installed on a tap or under the sink, will treat only a small portion of the water and are not effective in reducing radon in the water. It is important to maintain home water treatment units properly. Failure to do so can lead to other water contamination problems. Some homeowners opt for a service contract from the installer to provide for carbon replacement and general system maintenance.
Why does radon in water affect me?
While most radon-related deaths are due to radon gas accumulated in houses from seepage through cracks in the foundation, up to 1,800 deaths per year are attributed to radon from the household's water supply. Showering, washing dishes and laundering can disturb the water and release radon gas into the air.
Radon's Movement into your home
Because radon is a gas, it has much greater mobility than uranium and radium, which are fixed in the solid matter of rocks and soils. Radon can more easily leave the rocks and soils by escaping into fractures and openings in rocks and into the pore spaces between grains of soil.
The ease and efficiency with which radon moves in the pore space or fracture affect just how much radon enters a house. If radon is able to move easily in the pore space, then it can travel a great distance before it decays, and it is more likely to collect in high concentrations inside a building.
The method and speed of radon's movement through soils are controlled by the amount of water present in the pore space (the soil's moisture content), the percentage of pore space in the soil (the porosity of the soil), and the "interconnectedness" of the pore spaces that determines the soil's ability to transmit water and air (called soil permeability).
Radon moves more rapidly through permeable soils, such as coarse sand and gravel, than through impermeable soils, such as clays. Fractures in any soil or rock allow radon to move more quickly.
Radon in water moves slower than radon in air. The distance that radon moves before most of its decays is less than 1 inch in water-saturated rocks and soils, but it can move more than 6 feet, and sometimes tens of feet, through dry rocks and soils. Because water also tends to flow more slowly through soil pores and rock fractures than does air, radon travels shorter distances through wet soils than through dry soils before it decays.
For these reasons, homes in areas with drier, highly permeable soils and bedrock, such as hill slopes, mouths and bottoms of canyons, coarse glacial deposits, and fractured or cavernous bedrock, may have high levels of indoor radon. Even if the radon content of the air in the soil or fracture is within the "normal" range (200 to 2,000 pCi/L), the permeability of these areas permits radon-bearing air to move greater distances before it decays, and thus contributes to high indoor radon.
Radon Entry into Buildings
Radon moving through soil pore spaces and rock fractures near the surface of the earth usually escapes into the atmosphere. Where a house is present, however, soil air often flows toward its foundation for three reasons:
1) differences in air pressure between the soil and the house;
2) the presence of openings in the house's foundation; and
3) increases in permeability around the basement (if one is present).
In constructing a house with a basement, a hole is dug, footings are set, and coarse gravel is usually laid down as a base for the basement slab. Then, once the basement walls have been built, the gap between the basement walls and the ground outside is filled with material that often is more permeable than the original ground. This filled gap is called a "disturbed zone."
Radon moves from the surrounding soil into the disturbed zone and the gravel bed underneath. The backfill material in the disturbed zone is commonly made up of rocks and soil from the foundation site. These also generate and release radon. The amount of radon in the disturbed zone and gravel bed depends on the amount of uranium present in the rock at the site, the type and permeability of soil surrounding the disturbed zone and underneath the gravel bed, and the soil's moisture content.
The air pressure in the ground around most houses is often greater than the air pressure inside the house. Thus, air tends to move from the disturbed zone and gravel bed into the house through openings in the house's foundation. All house foundations have openings, such as cracks, utility entries, seams between foundation materials, and uncovered soil in crawlspaces and basements.
Most houses draw less than 1% of their indoor air from the soil; the remainder comes from outdoor air, which is generally quite low in radon. Houses with low indoor air pressures, poorly sealed foundations, and several entry points for soil air, however, may draw as much as 20% of their indoor air from the soil. Even if the soil air has only moderate levels of radon, levels inside the house may be very high.
Radon in Water
Radon can also enter the home through its water system. Water from rivers and reservoirs usually contains very little radon because it escapes into the air, so homes that rely on surface water usually do not have a radon problem from the water. In big cities, water processing in large municipal systems aerates the water, which allows radon to escape, and delays the use of water until most of the remaining radon has decayed.
In many areas of the country, however, groundwater is used as the main water supply for homes and communities. These small public water works, and private domestic wells often have closed systems and short transit times that do not remove radon from the water or permit it to decay. This radon escapes from the water to the indoor air as people take showers, wash clothes, do the dishes, and use water in general. A rule of thumb for estimating the contribution of radon from domestic water to the indoor level of airborne radon is that water with 10,000 pCi/L of radon contributes about 1 pCi/L to the level of radon in the indoor air.
The area’s most likely to have problems with radon in groundwater are areas that have high levels of uranium in the underlying rocks. For example, granite in various parts of the United States are sources of high levels of radon in groundwater that is supplied to private water supplies.
Also check the bottom of the page, “myths and facts” about radon at:
My goal is to have a series of articles that deal with items that may be found on the home inspection report. There will also be articles on choosing a home inspector and a realtor. This information will be based on my experience in the construction industry as well as information I research. I welcome your comments. If you have a question or would like to see an article on a particular subject please ask.