radon in your basement
What is radon?
Radon is the subject of a lot of misinformation in terms of what radon is, how dangerous it can be, and the best course of action for mitigating or remediating radon in a home.
This guide will outline the difficulties and dangers of radon, as well as solutions.
First, studies have shown that elevated levels of radon over a period of time can contribute to the development and cause of lung cancer. The Surgeon General’s Office and the EPA estimate that radon is responsible for around 20,000 deaths in the United States per year.
At this point, this is the only known cancer that is directly linked with inhalation of radon, although some studies have suggested a connection between radon and leukemia, but this has not been fully proven.
Radon is a naturally occurring gas, formed when uranium and other radioactive metals break down in the ground or water. Once the gas is formed, it will either move through the ground until it reaches surface air or be dissolved into water.
One of the biggest problems with radon is that it is colorless, tasteless, and odorless, and thus it is often not noticed without extensive testing.
Every person inhales small amounts of natural radon each day, and this causes no long-term problems to health.
However, in some areas of high radon concentration, or areas of poor ventilation, radon can build up. This is what leads to health problems over time.
As a radioactive gas, radon has a half-life; this is only four days (meaning half of the radon particles are gone after four days), which is relatively short for a radioactive material.
The process of decay emits ionizing radiation and other radioactive byproducts. These byproducts can attach to dust and other particles and are also susceptible to being inhaled.
Where is radon in your home?
According to the EPA, roughly one in three homes contains radon above the safe level of 4pCi/L. To put this in perspective, this is 35 times the level one could expect to be exposed to immediately outside of a radioactive waste site.
The EPA standard for acceptable safety limits for carcinogens is 1 in 100,000 risk of death. Radon at 4pCi/L carries a 1 in 100 risk of resultant death.
If your home has this level in your home, you should begin radon mitigation efforts.
How does radon get into your home?
According to the EPA, the seven most common ways for radon to enter the home are as follows:
Cracks in foundation floors
Cracks in walls
Gaps in suspended floors
Cavities inside walls
Gaps around service pipes
The water supply
Radon in the Water
Radon entering your home through the water supply (dissolved in the water that enters your home) carries the risk of both inhalation and ingestion. Although ingestion seems more invasive, in fact, it is still inhalation that is the more dangerous.
Radon in water is less problematic if it comes from surface water. If, however, the radon is in groundwater (like a well or a public water supply) it can be far more dangerous, as it is likely at a higher concentration. If you test your water supply and you detect radon, there are ways to fix it.
If you take your water from a public utility, you should contact your provider immediately. If you have a private well, see the steps below on how to mitigate the problem.
You do not need to be a certified or trained expert to test for radon in your home.
However, the EPA recommends that if you are planning on buying or selling a home, you do hire a professional to test for radon.
If you are hiring a professional, you should use a licensed, certified, and/or registered professional. You can check these accreditations using the National Radon Proficiency Program or the National Radon Safety Board.
The EPA recommends that you set up your radon testing kit in the lowest lived-in level of your home, such as your basement.
Because of the way that radon enters homes, it usually is more prevalent in the lower levels, so begin your testing here.
Short-term tests last from anywhere from two to 90 days. These are best used as a means to gauge whether further testing is required. Because the amount of radon in a home fluctuates throughout the year, a short-term test is not able to tell you how much radon you may be exposed to each year. However, these tests are optimal when it comes to giving you a quick result.
These tests are extremely easy to use, and just involve setting the canister or detector in your lowest living space and returning after a predetermined period of time.
If the results on the first test are higher than 8pCi/L (i.e. twice the recommended level), the EPA advises that you take a second short-term test. However, if the results of the test have high levels, but less than 8pCi/L, take a long-term test. A long-term test is any radon detector that lasts more than 90 days.
Because of the longitudinal study, a long-term testing kit is good at determining the year-round average amount of radon in your home.
Testing the water supply
If you suspect radon in your water, you can buy an inexpensive water testing kit. Simply take a sample of water and send to the address listed on the kit.
How can you mitigate the radon level in your home?
Ultimately, an excess of radon in your home is caused by a suboptimal level of sealing: radon is able to get into your home, but not out. Almost all solutions to radon involve preventing it from entering or helping it to leave.
How you fix the problem will depend on the levels of radon, its source, and the design of your home. In all cases, it will require a professional to work on the issue, especially if you are planning on selling your home.
Radon mitigation system cost
The cost of installing a radon mitigation system in your home can run between $600-$2,000, but it varies on many factors including the size and setup of your home as well as your specific radon conditions. More details on various radon mitigation approaches below.
Here are some radon mitigation methods:
Sealing is a tactic for radon mitigation that professionals may use in conjunction with other methods. It involves plugging gaps or cracks in the exterior of your home that allows radon to enter. Because this limits the flow of radon into the home, it allows other techniques to work more effectively.
However, sealing alone is rarely a solution to an excess of radon, and therefore the EPA does not recommend that it be used exclusively.
House or room pressurization
In some cases – depending on the design of your home – it may be possible to use pressure differentials to prevent radon from entering your home. In this instance, the approach involves using a fan in your home (usually in the basement) to blow air into the home and therefore prevent radon from entering.
Heat recovery ventilator
A heat recovery ventilator is effectively an air exchange system, whereby cold air outside is drawn into the home and heated by the warm air being expelled. This mitigates the radon in a home by allowing it to exit and to be dispersed. Once set up, an HRV system can be easy to maintain and can improve overall air quality within a home.
Natural ventilation takes place in all homes and can be as simple as opening windows to let in outside and to vent inside air. This effectively vents the radon-rich air from your home, exchanging it for reduced-radon air from outside. However, the problem with relying on this system is that, once doors or windows are closed, radon levels return to the previous state, often within 12 hours.
This solution should only be seen as a short-term fix and does nothing to address the causes of radon in the home. In times of hotter or colder weather, this option is not sustainable and may lead to significant costs of heating and cooling your home.
In general, the presence of radon in your water supply is indicative of wider problems with radon, so it is rare to address only the water supply. The most common method of dealing with radon in the water is with a ‘point-of-entry’ solution, which traps the radon as it enters your home.
The two most common tools for this are a Granular Activated Carbon system or a Home Aeration Unit.
Granular Activated Carbon system
Granular Activated Carbon involves using tiny particles of carbon to trap radon in the water supply. A GAC unit is a large fiberglass tank connected to your water supply.
Because of the particles in the tank, there is a danger of clogging that cannot always be solved with regular backwash. Instead, you may need to install an additional sediment filter.
Another major drawback is that the build-up of radon in the carbon filter leads to accumulated radioactivity in your home, meaning that GAC units should be installed in isolated locations.
They also require regular removal of the radioactive material.
Home Aeration Units
Ultimately, the best course of action is to be vigilant about radon in your home. Regular testing will keep you aware of any problems and determine the best solution.
Radon only becomes problematic if left to build up over a long period of time, so staying on top of the problem mitigates any potential dangers.
Sources and Further Reading