Radon and Cancer – The Most Important Cause of Lung Cancer After Smoking!

This article covers:

• What is radon?
• How is the public exposed to radon?
• How does radon cause cancer? 
• Radon exposure and lung cancer risk 
• How did scientists discover radon’s role in lung cancer development?
• What have scientists learned about the relationship between radon and lung cancer?
• How can people know whether their homes have high radon levels?

What Is Radon?

Radon is a radioactive gas released through the normal decay of uranium, thorium and radium in rock and soil. This noble gas, in group VIIIA of the periodic table, has the symbol Rn, atomic number 86 and atomic weight 222. It is invisible, odorless and tasteless, seeping from the ground and dispersing into the air. Depending on local geology, radon may enter groundwater and be released into the air when the water is used. Radon accounts for most radiation exposure from natural sources. Outdoors, it is generally present at low levels. High levels occur in poorly ventilated areas such as underground mines, which can substantially increase lung cancer risk.

According to the International Agency for Research on Cancer (IARC), radon is a group-1 carcinogen.

How Are We Exposed to Radon?

Radon is generally present in the air. Everyone inevitably breathes in at least some radon. High exposure increases lung cancer risk. Radon can enter homes through cracks in floors, walls or gaps around doors and windows. Levels are high where soil is incorporated into building materials, where well water contains radon and in areas close to the ground such as basements.

How Does Radon Cause Cancer?

Radon contains tiny radioactive particles and damages lung cells through inhalation. Long-term exposure can cause lung cancer. An association has been observed between prolonged exposure in adults and lung cancer, although the evidence is not definitive.

Radon Exposure and Lung Cancer Risk

Tobacco use is indisputably the most important cause of lung cancer. Radon is the most important cause after tobacco and tobacco products. Research estimates that in the United States alone, 15.000 to 22.000 lung cancer deaths each year are related to radon.

Although radon is one of the non-smoking causes of lung cancer, exposure to both radon gas and cigarette smoke creates an even greater lung cancer risk. Most radon-related cancer deaths occur among smokers.

How Did Scientists Discover Radon’s Role in Lung Cancer Development?

Scientists identified radon as a health concern after noticing records of high lung cancer death rates among uranium miners. Various studies confirmed this finding.

What Have Scientists Learned About the Relationship Between Radon and Lung Cancer?

Scientists agree that radon causes lung cancer. Recent research has focused on determining the effects of residential radon on lung cancer risk. In these studies, scientists compare radon levels in the homes of people with lung cancer with those in homes of people who have not developed it.

One study pooled and analyzed all radon research conducted in Canada and the United States, using data from thousands of people. Its findings showed increased lung cancer risk among people whose homes were exposed to radon. Following these studies, techniques measuring an individual’s radon exposure over time were developed in the early 2000s, and their use began spreading worldwide, particularly in Australia and the United States.

How Can People Find Out Whether Their Homes Have High Radon Levels?

Radon testing is the only way to measure residential radon levels. Indoor levels are affected by soil distribution around the house and its foundations. Rain, snow, barometric pressure and other factors may also change levels from month to month or day to day. Both short- and long-term tests are available.

Depending on the device, short-term detectors measure radon levels over 2-90 days. Long-term tests determine averages over more than 90 days and better reflect average radon levels.

The United States Environmental Protection Agency EPA recommends reducing radon in homes where airborne radon exceeds 4 picocuries per liter (pCi / L).

In our country, since 2016, the Turkish Atomic Energy Authority (TAEK) has provided radon measurement services in water and indoor spaces using a radon sensor . TAEK also conducts a nationwide study measuring radon in nature and selected locations, expected to finish and announce results in 2019. The project is called “Mapping Indoor Radon Gas Levels in Türkiye,” and installation of radon sensors in 62 thousand homes was planned.

Public Health Directorate personnel place radon sensors in homes and leave them for 2 months. According to measurements, homes with radon above the critical level require flooring to be covered with special material and cracks or water leaks in parts of the building contacting soil to be repaired. These precautions are important because radon comes particularly from the soil; ground floors should also be well ventilated. Choosing low-radioactivity construction materials is another important point.

If you would like radon measurements in the spaces where you live, you can apply by petition to the Çekmece Nuclear Research and Training Center Directorate.

It is estimated that reducing radon levels in high-radon homes could reduce lung cancer deaths by %2 to 4.