Worried about radon levels in your home? Rightly so because it is the second leading cause of lung cancer to smoking and there’s no way to avoid it. It’s a natural by-product of uranium found in all types of soils.
The highest concentration is found in basements and crawlspaces closest to the soil beneath your house. It’s also high in homes with sump pump pits (especially if there’s no lid to seal it) as radon is present in water wells.
The national average for radon is 0.4 pCi/L (picocuries per liter), although that range differs from one state to the next.
If you’re moving homes, it’s a good idea to know what the air quality is like inside the house, because you are buying and moving your family into the property. Also, if you know before you buy, you can budget for the cost of any radon mitigation work that may need doing.
For information on the average radon levels in your area (U.S.) see the interactive map on the EPA website. Areas are color coded. Red represents areas where the home has levels higher than the national average, orange marking those with levels of 2 to 4 pCi/L and yellow being in the target range of under 2 pCi/L.
Understanding Measurements of Radon around the World
Measurements of radon levels in homes are expressed differently in the USA than the rest of the world. The US EPA (U.S. Environmental Protection Agency) exclusively refer to the picocurie per liter expression when referring to acceptable levels.
In countries using the metric systems, most of which use World Health Organization guidelines, measurements are referred to in becquerels.
Picocurie: The word itself refers to two aspects. A Curie (Ci) is a unit of radioactivity from 1 gram of radium. A pico means a trillionth. The expression is pCi/ means a trillionth of a Curie per liter of air.
Becquerels: These are used in the metric system and expressed using the bq abbreviation. A becquerel is one radioactive disintegration per second and measured per cubic meter instead of per liter or air.
One picocurie is equal to 0.37 becquerels, therefore 4 Picocuries are equal to 0.148 becquerels.
4 pCi/L = 0.148 bq/m3
The Environmental Health Protection Agency recommend bringing levels down to below 2 pCi/L. Dangerous levels of radon gas are above 4 pCi/L, however, in states within the European Union using the World Health Organization recommendations, homeowners cannot have levels exceeding 0.300 bq/m3. That’s 8.11 pCi/L.
Improving Air Quality by Reducing Radon Levels
There are no safe levels of radon, and there’s no way to eradicate it. In homes where there are smokers present and smoking indoors (instead of outside), the risk of developing lung cancer will be much higher.
Levels above 4 pCi/L are considered actionable, so those are in the dangerous levels of radon for indoors. Over exposure to radon increases the risk of ill health. Over years, the higher levels can lead to lung cancer.
The only way to better the air you breathe indoors is to first know what types of remediation work could be done and the various methods to reduce radon levels indoors.
The remediation work could be as simple as opening a window, or if levels are extremely high, an energy efficient heat recovery ventilator could be installed. Rarely will just opening a window be sufficient.
Knowing how much a property’s radon levels need to be reduced before you buy it can help work out how much the house will really cost and get estimates for having the radon emitting systems installed.
The Different Types of Home Radon Tests
The most common type of home test kit for radon is the cylinder canister containing charcoal. This is placed at the lowest level of your home (basement or ground floor if you have no basement), in an area where it won’t be disturbed.
The way these works is by trapping the radon in the charcoal, which is later analyzed in a laboratory to measure the amount of radon in the breathable air.
As it’s breathable air that needs to be measured, there are some things to keep in mind about the canister’s placements. Ideally, place it 20” above floor height and 3 ft away from windows, doors and exterior walls, and don’t have it near areas with excessive heat such as radiators, direct sunlight, or in rooms where there’s higher humidity levels.
The less the air is disturbed, the more accurate your readings will be.
Once the kit is in place, leave it undisturbed for 2 to 7 days, then send your samples away for laboratory testing. Results are often within the week.
Another method is to use a digital radon test meter (view on Amazon).
A digital radon test meter can be used for short and long-term testing as well as continuous radon monitoring. Most commercial radon meters are handheld, portable devices running on batteries instead of electricity so you can use them anywhere in any room any time you want to test.
How Often to Test for Radon?
Radon levels fluctuate. Even if you identify no changes to your living environment, the radon levels will change with time.
Triggers that cause changes to radon levels include:
A short-term test in the summer will produce different readings from what you get in the winter as the weather will affect the soil under your home – where the radon originates from.
Any structural work you do on your property will affect the radon levels as it can introduce new entry points for radon to get into your property.
This can happen if you turn your basement into usable space by putting in a home office, or a game room, or perhaps having an extra bedroom added to your property or an extension.
Radon gets into your home from the ground soil via drains, sump pumps, loose fitting pipes, exposed soil, cracks in floors and construction joints. Anything that can disrupt the buildings structure can create new radon intrusion points.
Other than the two changes above, the recommendation is to test your home every two years.
Symptoms of Over Exposure to Radon Gas
Inhaling radon gas will not present any symptoms in the short-term. Long-term exposure of between 5 and 25 years, radon can cause lung cancer.
In an analysis of a European health study of 21,000 participants affected by lung cancer analyzed by the NHS (UK National Health Service), only one in seven patients were affected by radon poisoning specifically. 6 out of 7 were a combination of high radon exposure and smoking.
Therefore, if you smoke and live in a home with radon levels above 4 pCi/L, there is an extremely high risk of lung cancer.
The reason: Polonium!
Polonium is another natural occurring radioactive element. Combine polonium with confined indoor air quality with existing radon gas; inhale both compounds and the risk factor of developing lung cancer is increased by a factor of 8.3.
You can’t get rid of radon. You can stop puffing on polonium.
How to Lower Radon Levels
The heavy-hitting solution to lowering radon levels is to install a mitigation system. Instead of trying to expel the radon gas, the mitigation system will actively suck the air from beneath your home, pump it through duct pipes upwards to your roof and then expel the air through an attic vent.
It looks likes this (or should):
The DIY Methods to Reduce Radon Levels include:
1 – Seal Cracks on the Ground Floor
Start on the lowest floor of your home and seal any cracks on concrete or slabbed floors with a waterproofing and radon reducing sealer. The sealer will reduce the radon levels coming through the pores of the concrete, but it won’t stop it.
2 – Seal Cracks and Crevices with a Mastic Sealant
Just as caulk is applied around bathtubs, the same technique can be used for draught proofing, stopping radon leaking into your home from the ground level.
For best results, use polyurethane sealant as it gives the highest elasticity when dried, so it can be applied to anywhere in your home with air leaks. Concrete floors, crevices, wall cracks, and any gaps in the framework around window frames, as well as to seal expansion joints without restricting movement.
3 – Seal Sump Pump Pits
This is an area not to neglect when sealing air leaks as the sump pit is where the majority of radon will collect before entering your home. To keep it in the pit, make sure it has an air-tight seal.
Linn County Homes conducted a study in 2010 discovering a sealed sump lid on a passive (no fan) system reduced radon levels by as much as 50%. On an active system (with a fan), levels reduced from 2.8 pCi/L to 0.4 pCi/L.
4 – Install Positive Pressure Ventilation
This draws air in from outside. The systems are typically installed in attics to draw air into the home, then use a fan to push the air into the hallway of the house, letting fresh air circulate the home.
A positive pressure ventilation system is a great way to increase airflow, but it’s nasty side effect is in cold winters because if there’s no heater fitted, you’re pushing cold air throughout your home, so while the fans are cheap to run, your heating won’t be.
To keep costs optimal, consider a heat recovery ventilator. This type of system has an air-to-air heat exchanger, allowing for cold air to be drawn in from outside and heated before being distributed throughout the home.
- World Health Organization: Handbook on Indoor Radon
Environmental Protection Agency:
Building Radon Out: For anyone buying land to have a new-build home constructed, this guide goes over steps to make your home as close to radon resistant as possible.