Radon is a naturally occurring, colorless, odorless, and tasteless radioactive gas that results from the decay of uranium found in soil and rock. It is a serious environmental health hazard in homes because it can seep inside and accumulate to unsafe concentrations.
The question of “radon poisoning symptoms” stems from a common but critical misunderstanding about how this gas affects the human body. Unlike many toxins that cause immediate, acute illness, radon’s danger is silent and cumulative.
Why Acute Symptoms Do Not Exist
Radon gas does not produce any immediate physiological symptoms like the dizziness, nausea, headaches, or fatigue associated with acute poisoning from substances such as carbon monoxide. When radon is inhaled, most of the gas is simply exhaled again without causing harm.
The danger arises because radon rapidly decays into solid, radioactive particles known as radon progeny or decay products. These solid particles are electrically charged and attach themselves to dust and aerosols in the air. When inhaled, these particles become lodged in the lining of your lungs and airways. The localized damage caused by these embedded particles is microscopic and accumulates over years, which is why there are no immediate symptoms of exposure.
The Real Health Risk: Chronic Exposure
The primary long-term health consequence of chronic radon exposure is lung cancer. The radioactive decay products lodged in the lungs emit alpha radiation, a highly energetic form of radiation. This radiation directly damages the DNA of the cells lining the lung tissue, leading to genetic mutations that can initiate cancer development over many years.
Radon is the second leading cause of lung cancer, second only to smoking, and it is the leading cause among people who have never smoked. The Environmental Protection Agency (EPA) classifies radon as a human carcinogen. Smokers exposed to radon face a significantly higher risk of developing lung cancer due to the synergistic effect between the two factors. The EPA recommends action be taken to reduce radon levels in a home if they reach or exceed 4 picocuries per liter (pCi/L).
Identifying Radon Exposure
Since exposure does not present with physical symptoms, the only way to determine the risk in a home is through testing. Radon gas typically enters a building through cracks in the foundation, construction joints, gaps around utility pipes, and open sump pits. It often accumulates in basements and first floors. Testing kits are widely available and relatively inexpensive, providing the necessary data to assess a home’s risk level.
Testing is conducted using two main types of devices: short-term and long-term kits. Short-term tests measure radon levels over two days to 90 days, offering a quick screening useful during real estate transactions. Long-term tests measure levels for 90 days or more, providing a more accurate annual average concentration because they account for seasonal and daily fluctuations. Continuous monitors, often used by professionals, can provide hour-by-hour data.
Mitigation and Remediation
If testing reveals elevated radon levels at or above the recommended action level of 4 pCi/L, remediation is necessary to protect the occupants’ health. The goal of mitigation is to reduce the concentration of radon gas inside the building. The most common and effective technique is called sub-slab depressurization, also known as active soil depressurization.
This system involves installing a vent pipe through the foundation floor connected to a continuously running fan. The fan creates a negative pressure field beneath the house slab, actively drawing the radon gas from the soil before it enters the home. The collected gas is then safely exhausted through the pipe above the roofline where it disperses. Mitigation should be performed by a certified professional to ensure the system is installed correctly for the specific structure.