Richard Arconti 
Radon, a radioactive gas that occurs naturally in the environment, is a potent health hazard that can be present in both the air and water. While the dangers of radon gas in the air are well known, many people are unaware of the potential hazards of radon in water.
This article will explore what radon in water is, its sources, and how to test it. We will also discuss the health risks of consuming radon-contaminated water and explore ways to reduce exposure.
What Exactly Is Radon In Water?
Radon in water is a radioactive gas produced by the natural decay of uranium and radium in soil and rocks. When water flows through these underground deposits, it can dissolve and pick up radon, which can then be released into the indoor air when the water is used for drinking, cooking, or showering.
Water-containing radon is particularly concerning for those who rely on private well water as their primary source of drinking water, as well water is often contaminated with higher levels of radon than municipal water supplies. It’s crucial to test your water for radon to ensure that you and your family are not exposed to potentially harmful levels of this radioactive gas.
What Is The Source of Radon In Water?
The source of radon in water is primarily the natural decay of uranium and radium in soil and rocks. It can dissolve and pick up radon gas as groundwater and surface water come into contact with these minerals. Here is where you can specifically find water containing radon:
- Uranium-rich soil: Areas with higher concentrations of uranium in the soil can lead to higher rates of radon in your water.
- Rocks: Radon gas escapes from certain types of rock, such as granite or shale, with higher levels of uranium.
- Groundwater: As radon gas is released from soil and rock formations, it can seep into groundwater and become concentrated in the well water supply.
- Surface water: Radon entering surface water sources, such as lakes and rivers, through groundwater discharges or from the atmosphere.
It’s important to note that not all soil and rock formations contain high levels of uranium, and not all drinking water sources have dangerous levels of radon.
Is Radon In Drinking Water Dangerous?
Radon is a significant health concern that can pose dangers to human health. This radioactive gas can enter the body through breathing air or ingestion and may cause serious health risks, including:
- Increased risk of lung cancer: Radon is a known carcinogen, and long-term exposure to elevated levels of radon can increase the risk of lung cancer. Breathing radon gas in indoor air (in homes or buildings) can damage lung tissue, leading to lung cancer. In fact, radon is estimated to cause approximately 21,000 lung cancer deaths per year.
- Gastrointestinal issues: Ingesting radon-contaminated water can lead to gastrointestinal problems such as stomach irritation, vomiting, and diarrhea.
- Stomach Cancer: Prolonged exposure to elevated radon levels can increase the risk of stomach cancer. Stomach cancer is caused by indoor air radon or groundwater containing radon penetrates the stomach wall and destroys sensitive cells.
Skin irritation: Contact with radon-contaminated water can cause skin irritation or rashes.
Signs Your Water Has Radon Contamination
The senses cannot detect radon contamination in drinking water since it is a colorless, odorless, and tasteless gas. The only way to determine if water is contaminated is by conducting a radon test.
However, suppose you live in an area with known uranium-rich soil, rock, and water or have a private well. In that case, it’s essential to be aware of the potential for dissolved radon contamination and take measures to ensure safe drinking water.
How to Know If Your Water Contains Radon
Radon in drinking water is a serious concern, as exposure to this radioactive gas has been linked to an increased risk of lung cancer. If you are trying to determine whether your water contains high radon levels, here are a few steps to find out.
View The Water Radon Zone Map
The U.S. Environmental Protection Agency (EPA) provides a water radon zone map, which can help you determine if your area is at a higher risk for radon contamination. The map is based on the average radon levels in public water systems across the country and can be useful in deciding whether to test your water for radon.
The radon zone map is divided into three color-coded zones indicating different levels of radon contamination potential.
- Zone 1 (red) has the highest potential for radon contamination, with levels greater than 4 pCi/L.
- Zone 2 (orange) has a moderate potential for radon contamination, with levels between 2 and 4 pCi/L.
- Zone 3 (yellow) has the lowest potential for radon contamination, with levels less than 2 pCi/L.
It is important to note that the map is only intended to be used as a guide. If you consume private well water, it is recommended that you test it for radon, regardless of whether or not your home is situated in an area with a high potential for radon indoor air contamination.
View Your EPA Water Quality Report
Water quality reports (or Consumer Confidence Reports) include information on any potential contaminants in your municipal-supplied drinking water, including radon. These reports contain information on water testing results, which detail the levels of radon and other contaminants found in the water supply.
Water supply systems are required by the EPA to test and report the water quality once per year. However, if you have private well water, you will need to test your water.
Test Your Water
The most reliable way to determine if your water contains high radon levels is to have it tested by a certified laboratory. Radon test kits can be purchased online and they include instructions for collecting a water sample and mailing it to the lab for analysis. This is especially important if you are purchasing a new home during the home inspection process.
How to Test for Radon in Drinking Water
Lab test kits are the best method to test for radon in drinking water. There are two options when choosing lab test kits. The first is to choose a test that strictly tests for radon. The second, and preferred option, is to use a comprehensive water test kit that scans for not only radon but also other common water impurities.
I recommend using the Freshnss Labs water test kit, which is one of few comprehensive kits that includes a radon scan along with dozens of other water contaminants. To perform the test, simply collect a water sample in the provided vials and send the samples to the lab. Within three business days, you will receive a detailed report with the exact radon levels and if there are any safety concerns.
Laboratory Water Test Kit
Analyzed in a certified laboratory
Includes detailed report with EPA benchmarking and safety concerns
What Is A Safe Level Of Radon In Water?
Radon is a naturally occurring gas found in outdoor and indoor air. The Environmental Protection Agency recommends taking action to reduce radon levels if the concentration is 4 pCi/L or higher, as there is no known safe level of exposure to radon. Additionally, EPA recommends that Americans consider fixing their home for radon levels between 2 pCi/L and 4 pCi/L.
Other Ways You Can Be Exposed to Radon
Radon is a radioactive gas that can cause lung cancer. Exposure to radon can occur in various ways, such as:
Radon in indoor air (airborne radon). Radon enters buildings through cracks in the floor, gaps in construction, windows, drains, or spaces around cables and pipes. It accumulates in enclosed spaces and is a significant source of public exposure to radiation.
Radon in building materials. Certain building materials, including lightweight concrete with alum shale, phosphogypsum, Italian tuff, and material from old uranium tailings, can act as significant sources of radon exposure.
Furthermore, the Centers for Disease Control and Prevention found that groundwater can also release radon, which can result in inhalation exposure when water is used for various household purposes such as washing clothes or dishes, flushing toilets, and showering, causing the radon to be released into the air.
How to Reduce Radon Exposure in Drinking Water
The most effective method is removing the radon from the water just before it enters your house, called point-of-entry treatment. There are two types of devices for this purpose that can remove radon from water:
Aeration System
Aeration devices work by bubbling air through the water to release radon gas, which is then vented out of the home through an exhaust fan. They effectively remove radon from water, other gases, and volatile organic compounds (VOCs).
Activated Carbon Filter
Activated carbon filters or Granular Activated Carbon (GAC) filters use a bed of activated carbon to remove impurities, including radon, from water. These filters work by adsorption, meaning water’s radon adheres to the carbon filter’s surface on the filter. Generally, you can get a point-of-use carbon filter, a whole-house carbon media filter, or a reverse osmosis system with carbon filters.
