What is radon?
Radon is an odorless, tasteless, colorless gas. You cannot smell, taste, see, or feel radon in the air.
It is a radioactive gas that comes from the radioactive element uranium. You can find uranium in almost all soil around the world. Being a radioactive element means that it gives off energy.
Elements decay at varying rates from several years to a few seconds. This is called it's "half-life". During this radioactive decay the releases of energy cause varying amounts of damage to whatever surrounds the element.
Eventually, uranium decays and changes to radon. Radon has no charge. This means that it can move freely through soil. Radon decays and changes in about 4 days, which is just enough time to float through the soil, get into our homes, and decay into a series of short-lived charged particles that can get lodged in our lungs and damage the lung cells.
What is 4.0 pCi/L?
Radioactivity in the United States is measured in units of Curies, which is equal to the decay rate of a gram of radium. Curie comes from Madame Curie, the renown scientist who determined the decay rate of radium in the 1920's. One pCi/L is one trillionth of a curie of activity in a liter of air. The United States Environmental Protection Agency recommends that the level of radon in a home be reduced to below 4.0 pCi/L. The World Health Organization recommends that radon levels be reduced to less than 2.7 pCi/L.
What does radon do?
Radon gas is in the air of our homes. It decays back into a series of short-lived solid particles that are charged (reactive). These short-lived radon decay particles can be produced in our lungs from radon decay inside our lungs or they can enter our lungs from air born radon decay products that we breathe in. The decay of these solid particles is what damages our lung tissue. If there is enough exposure, it increases the chances of getting lung cancer.
Is radon’s connection to lung cancer scientific?
Every scientific group that has carefully looked at the available data has agreed that there is a connection between radon exposure and lung cancer. Radon has a Class A carcinogen rating because there is so much human data, animal studies, and sound explanation of how it takes place. See more here: Health Risk Page
Are radon levels below 4 pCi/l safe?
Other environmental exposures are regulated to reduce the lifetime risk of cancer to one in 100,000. The EPA lists radon risk exposure to 4.0 pCi/L for a lifetime (18 hours per day) to cause 7 additional lung cancers in a thousand non-smokers or 62 additional lung cancers in 1000 smokers. The risk is considered linear which means even 2 pCi/L for a lifetime would cause 3 additional cancers in a 1000 non-smokers. Fortunately, most of us are not exposed for a lifetime; however, we would get a similar risk if we were exposed to four times as much for a quarter of a lifetime or 16 pCi/L in your bedroom for 17 years.
Does radon cause other health problems or symptoms?
Exposure to elevated radon levels has been consistently shown to increase the risk of lung cancer. Scientific studies have not found any other cancers that were induced by radon exposure.
How many homes in Utah have elevated radon?
The EPA has radon maps that show what the general risk of radon is in each county of each state. Utah EPA Zone map
Air Chek, one of the largest radon test kit suppliers in the country provides a data map of how many homes in a state have elevated radon levels. Air Chek state radon levels
The Utah Department of Air Quality has data with high and average radon levels broken down by zip code. Utah DEQ Data
The Utah Geological Survey provides data for geographical areas and the radon content. Utah Geological Survey data
How do I test my home for radon gas?
You usually have two options when testing your home for radon: purchasing a do-it-yourself testing kit or paying to have an independent third party perform a test with a CRM (continuous radon monitor).
Option 1: Do-it-yourself Test Kit
You can purchase a do-it-yourself test kit from one of these three suppliers. Instructions should be strictly adhered to in order to ensure an accurate reading. These kits include shipping and the results can be obtained in 7-14 days:
If you aren't in a hurry, can follow instructions EXACTLY, and want to pay less, then a do-it-yourself test makes sense.
Option 2: Hire a Professional
If the home is being bought or sold as part of a real estate transaction or if you want quicker results then it is usually necessary to have a professional independent tester such as OnSite Home Inspections perform the test with a continuous radon monitor (CRM). These machines are calibrated yearly for accuracy and results are received in 2-4 days. These companies usually charge $100-200 to pay for set up and pick up of the machine and also to pay for the cost of the machine and yearly calibration fees.
You can, however, always test your own home. Note that a buyer may not accept test results from a measurement performed by a seller.
If you want results quickly, want someone else to set up the test, and don't mind paying a professional, then hiring a company to perform the radon test makes more sense for you.
Should I do multiple radon tests?
If only one do-it-yourself radon test was done in your home it is generally recommended to do a second measurement before deciding on mitigation. Radon tests are easy to perform and are inexpensive.
If the radon levels are greater than 10 pCi/L it is unlikely that the second test will be below the guideline. However, a second test may be wise if the first test was closer to the 4.0 pCi/L guideline. When radon levels are marginal or below the guideline it is recommended to test in an opposite season or do a long-term test to better determine the average radon levels.
It is usually best to have a second test done by a professional radon testing company that utilizes a continuous radon monitor (CRM). These machines are:
Are electronic monitors more accurate than passive tests?
Electronic radon monitors that give hour-by-hour radon results can be more accurate than passive test kits such as charcoal detectors. Most radon test kits and monitors used must pass proficiency tests. Electronic radon monitors offer the advantage of measuring the radon levels every hour, which can indicate unusual radon patterns or possible radon test tampering. The Pro-Series 3 radon monitor does not give hour by hour radon measurements but does provide a continuous long-term average. This monitor is new and has not been officially listed by the EPA or any state or national radon certification programs as an approved device.
What is a long-term radon test?
Short-term radon tests are generally 2-7 days in length. Short-term tests must be made with closed house conditions. A long-term radon test is 3-12 months in length. Long-term tests do not require closed house conditions. If radon measurements during a real estate transaction are questionable, a long-term test is sometimes performed with money left in an escrow account to pay for a radon mitigation system if the long-term test results are above the 4.0 pCi/L guideline.
Does a vacant house have higher radon levels?
The upper floors of a vacant house will likely have higher radon levels than the upper floors of a similar occupied house if a normal occupied temperature is maintained. The basement level of a vacant house, however, is not likely to be significantly different than the basement level of an occupied house and therefore is likely to have similar radon levels. Radon does not build up to higher levels the longer a home is vacant due to normal natural ventilation.
Can a home seller manipulate a radon test?
Radon levels will change when you open a window especially if the window is in the same area as the test kit. In general, however, the window or multiple windows have to be wide open in the test area to make a big change (cut radon levels in half).
Opening windows can bring marginal radon levels below the guideline. Opening windows on floors above the area being tested can cause the radon levels to go either higher or lower.
Moving the radon detector to a low radon area will obviously also change the results to the new location level, but many testing machines (CRMs) will minimize this possibility with tamper-resistant features. These machines also have temperature graphs and pressure readings that will indicate if there is a change in temperature and pressure that may affect the results of the test.
Whether you believe radon is over-hyped or not, the EPA risk table graphically illustrates that the exposure risk to radon is very serious. Lung cancer is the most deadly of all cancers. No one should ever knowingly tamper with a radon test that might end up subjecting someone to a high risk of contracting lung cancer.
Can slab or walk out basement homes have high levels?
People assume that slab-on-grade or walk-out basements will have low radon levels. Unless the windows or doors are left open, radon from the soil can just as easily enter these types of buildings. All that is needed is radon in the soil, some openings through the slab, and the air being warmer inside than outside. As warm air rises inside and then out the top of a house (stack effect) the replacement air comes from openings around windows and doors but also from soil gas containing radon.
When is the best time of year to test for radon?
Radon tests should be performed at different times of the year and at least once every 2 years. For example, a radon test done in the Spring when the house has been highly ventilated (windows open) may come back below 4.0 pCi/L, but the same house that has a test done in the Winter when the house is closed up and the heater is running (creating a stack effect) may be well above the 4.0 pCi/L guideline.
Winter testing will usually give you the worst-case scenario levels of radon in your home. We've had tests on the same house go from 3.2 pCi/L in the Spring to 16.0 pCi/L in the Winter.
The reason for radon levels being higher in the Winter time may include:
What is the stack effect?
The "stack effect" occurs when warm air inside your home rises up and escapes through the top of the home. The missing air is replaced to equalize the pressure. This is done by either sucking in outdoor air through drafts or by drawing air from the soil beneath your home through cracks and joints in the concrete or plumbing stacks. This pulls radon gas up from the ground and into the house.
How does radon get into my house?
Radon is typically drawn into the house from the soil directly under the home. The lower level of the house has negative pressure compared to the soil. This negative pressure is mostly caused by the air in the home being warmer than the outside air. Many HVAC systems in homes also induce negative pressure in the lowest level. This negative pressure draws radon gas from the soil into the house via cracks, joints, and openings in the lower level concrete slab or from a dirt floor crawlspace.