It’s all about the DNA: how radon causes lung cancer

Anyone can get lung cancer. Lung cancer occurs when cells in the lung mutate or change. Various factors can cause this mutation to happen.

Most often, this happens when people breathe in dangerous, toxic substances. Smoking is the number one cause of lung cancer. Radon is the second leading cause. 

Radon is a naturally occurring gas produced in soil that contains radioactive uranium and radium, and is extremely prevalent in the BC interior, the Prairies, Southern Ontario and the Maritimes. Being a gas trapped underground, it naturally rises up towards the lower pressure at the surface – often through foundations where it accumulates in homes, schools and workplaces. Radon exposure causes lung cancer in humans; the question is, how does this happen?

Radon has a very short radioactive “half-life” of only 3.8 days. This means that in 3.8 days 50% of a given amount of radon will emit one alpha particle (a kind of radiation) and change into solid radioactive polonium. If the radon decays while within our lungs, then the alpha radiation will bombard lung tissue and the radon precipitates, becoming trapped. The trapped polonium and its decay products continue to emit alpha particles inside the lungs for the remainder of that person’s life. The longer a person stays in a high radon environment, the more alpha radiation-emitting atoms become permanently trapped in their lungs. 

More radon + more radiation + more DNA damage = a greater chance of lung cancer.

Alpha particles are highly unstable and “hungry” for electrons from other molecules to achieve stability. Basically this means that, as they pass through our bodies, alpha particles steal electrons from other molecules in a very damaging process called ionization. Human DNA is severely damaged by alpha particles, and will literally break apart causing genetic destruction almost impossible for our bodies to repair accurately. Indeed, almost all DNA damage produced by an alpha particle will introduce a genetic mutation, dramatically increasing cancer risks with each new alpha particle that pass through the lungs. The more genetic mutations that take place within a cell, the greater the overall risk becomes for that lung cell turning into cancer later in life.  

So: more radon equals more radiation equals more DNA damage equals a greater chance of lung cancer.

Dr. Aaron Goodarzi is the Canada Research Chair for Genome Damage and Instability Disease and is both the Education Lead and Microscopy Lead for the University of Calgary’s Arnie Charbonneau Cancer Institute.

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Page Last Updated: 19/08/2019