What is Radon?
Radon gas is an exciting element. On the one hand, it’s relatively simple; a radioactive gas, on the other hand, what exactly that means is, well, nuclear physics… Let’s start with simple information and slowly move into the more complex parts.
Radon is a radioactive noble gas. There are two essential parts to that statement. One is that it is a noble gas. Noble gases have a neutral charge and don’t chemically interact with other atoms. Compared to all the other elements, they act aloof and distant. This means that Radon can’t be filtered, detected, or interacted with like other gasses in the atmosphere.
Radon is created when trace amounts of Uranium in the soil break down radioactively. Usually, this wouldn’t be an issue, as the material breaking down is buried underneath your floor, and you have lots of protection against it. However, Radon is a gas, meaning it can move freely through the air in the soil, known as soil gas. If there happens to be a way for that soil gas to enter your home, then the Radon gas can now enter and build up in your home, where you can be exposed to it.
When radiation is mentioned, images of hospital X-rays, the Hulk, or nuclear power generation all come to mind. These are all examples of gamma radiation, which is only one of the three types of radiation and the one that we generally worry about, as the media have popularized it. The other two types are known as alpha radiation and beta radiation.
Radon is an alpha particle emitter. Alpha radiation, or alpha particles, are very different from gamma radiation. While gamma radiation is composed of microscopic, high-energy particles that are difficult to shield from (typically hefty and dense materials such as lead and concrete are used), alpha particles are essentially helium atoms. While still very high energy, their comparatively much larger size means they don’t travel nearly as far as they continue to bump into the other atoms that make up air. While gamma particles will travel until they hit something dense or thick enough, alpha particles only travel 3-5 cm in the air. This has meant that alpha radiation wasn’t considered a significant health concern for many years. When the dead layers of skin on the outside of your body can stop it, the most protection thought to be needed was a heavy pair of nitrile gloves to handle it safely.
Unfortunately, Radon is airborne. And if it decays on the outside of your body, it is unlikely to affect you. However, when you breathe it in, and it decays inside your lungs, the alpha particles have direct access to the now vulnerable living tissue that your body uses to extract oxygen from the air.
The alpha radiation striking lung cell DNA has been described as having a similar impact to a shotgun blast, compared to the cut of a scalpel from gamma radiation. The human body has some level of ability to repair the damage caused by both forms of radiation; the clean break caused by gamma radiation is significantly more straightforward to repair correctly compared to the damage from alpha radiation, as it is much messier and more chaotic.
In the case of alpha radiation, multiple DNA fragments are floating around while the body’s repair mechanism tries to stitch it all back together. Unfortunately, this mass movement means mistakes are made, and the DNA is repaired incorrectly. This results in one of two things happening: either the cell’s secondary defenses kick in, sensing something is wrong with the DNA and killing the cell, or the cell’s repairs are okay enough for it to continue to limp on.
Depending on where in the DNA’s chain the damage happens, it can also affect the outcome of the damaged cell. It may be part of the “change” DNA that doesn’t do anything, and everything continues on as it does, or it may affect a critical part of the cell’s ability to survive, and it dies shortly after that, or it affects the cell in such a way that causes it to replicate out of control. The unfortunate consequence of a cell being damaged and replicating out of control is that this is the base description of cancer.
This would be why the risk of lung cancer scales exponentially as Radon levels increase. More exposure to Radon means more Radon particles in the lungs causing damage, and as the body does its best to detect and repair the damage from Radon, more and more mistakes happen leading to larger and larger amounts slipping by, and the wrong mistakes becoming significantly more likely to happen.
Unfortunately, Radon is impossible to eliminate. This is why the governing principle for reducing Radon is “As Low As Reasonably Achievable,” or ALARA. Sub-slab mitigation systems can effectively reduce Radon levels to meager amounts, often reducing them by 80% - 90%.