Health Impacts from Radon
Video on Radon by the Centers for Disease Control and Prevention
Radon is the leading cause of lung cancer among nonsmokers.
- Radon is responsible for approximately 21,000 deaths each year in the United States.
- Radon is responsible for approximately 450 deaths each years in North Carolina.
- Everyone is exposed to radon, but some populations described in the literature are at higher risk of exposure to increased radon levels. In addition, some populations are more at risk of adverse health effects from radon exposure.
- The risk of lung cancer from radon exposure is estimated at between 10 to 20 times greater for persons who smoke cigarettes as compared with those who have never smoked.
Radon gas decays into radioactive particles that can get trapped in your lungs when you breathe. As they break down further, these particles release small bursts of energy. This can damage lung tissue and lead to lung cancer over the course of your lifetime. Not everyone exposed to elevated levels of radon will develop lung cancer, and the amount of time between exposure and the onset of the disease may be many years.
Many factors influence the risk of radon-related lung cancer due to exposure, such as
- Age during exposure,
- Duration of exposure,
- Concentration of radon as a function of age and duration,
- Cigarette smoking,
- Time spent and concentrations in different portions of the home, in transportation routes, and in the office, (e.g., where and how long persons sleep, work, and recreate).
- Source of water – if well water is the major radon source, upper floors can be affected more than lower floors (e.g., showers),
- Climate and time of year—in colder climates, radon levels are often higher in the winter and lower in the summer,
- Static-prone times of year—degree to which radon progeny attach to dust particles can increase during static-prone times (e.g., in April and October) and,
- Time elapsed since initiation of exposure.
Breathing radon does not cause any short-term health effects such as shortness of breath, coughing, headaches, or fever.
Research suggests that swallowing water with high radon levels may pose risks, too, although risks from drinking water containing radon are much lower than those from breathing air containing radon. A National Institute of Health report on radon in drinking water was released in 1999. It concluded drinking radon in water causes about 20 stomach cancer deaths per year.
Radon-Induced Lung Cancer Risks
Radon and tobacco smoking are synergistic. The following table is for those who have smoked 100 cigarettes or more.
| Radon Level | If 1,000 people who smoked were exposed to this level over a lifetime*... |
|---|---|
| 0.4 pCi/L | About 3 people could get lung cancer |
| 1.3 pCi/L | About 20 people could get lung cancer |
| 2.0 pCi/L | About 32 people could get lung cancer |
| 4.0 pCi/L | About 62 people could get lung cancer |
| 8.0 pCi/L | About 120 people could get lung cancer |
| 10 pCi/L | About 150 people could get lung cancer |
| 20 pCi/L | About 260 people could get lung cancer |
Note: If you are a former smoker, your risk may be lower.
* Lifetime risk of lung cancer deaths from EPA Assessment of Risks from Radon in Homes (EPA 402-R-03-003).
| Radon Level | If 1,000 people who never smoked were exposed to this level over a lifetime*... |
|---|---|
| 0.4 pCi/L | |
| 1.3 pCi/L | About 2 people could get lung cancer |
| 2.0 pCi/L | About 4 person could get lung cancer |
| 4.0 pCi/L | About 7 people could get lung cancer |
| 8.0 pCi/L | About 15 people could get lung cancer |
| 10 pCi/L | About 18 people could get lung cancer |
| 20 pCi/L | About 36 people could get lung cancer |
Note: If you are a former smoker, your risk may be higher.
* Lifetime risk of lung cancer deaths from EPA Assessment of Risks from Radon in Homes (EPA 402-R-03-003).
Data collected by the North Carolina Behavioral Risk Factor Surveillance System reports that in 2015 and in 2019 only 20.1 percent of current smokers surveyed have tested their homes for radon.
https://schs.dph.ncdhhs.gov/data/brfss/2015/nc/risk/radontst.html
https://schs.dph.ncdhhs.gov/data/brfss/2019/nc/risk/radontst.html
The following table reflects the numbers reported in both 2015 and 2019.
Studies Find Direct Evidence Linking Radon in Homes to Lung Cancer
Two studies show definitive evidence of an association between residential radon exposure and lung cancer. Two studies, a North American study and a European study, both combined data from several previous residential studies. These two studies go a step beyond earlier findings. They confirm the radon health risks predicted by occupational studies of underground miners who breathed radon for a period of years.
Early in the debate about radon-related risks, some researchers questioned whether occupational studies could be used to calculate risks from exposure to radon in the home environment. “These findings effectively end any doubts about the risks to Americans of having radon in their homes,” said Tom Kelly, Former Director of EPA’s Indoor Environments Division. “We know that radon is a carcinogen. This research confirms that breathing low levels of radon can lead to lung cancer.”
- Read the "Iowa Radon Lung Cancer Study" by Dr. William Field on radon-related lung cancer in women.
- Read the "Radon in Homes and Risk of Lung Cancer: Collaborative Analysis of Individual Data from 13 European case-control studies" by Dr. David Hill.