Recently, we’ve had more than a few patients ask us if the benefits of getting dental x-rays (bitewings and PAs) outweigh their risks. These patients are of course worried about the perceived amount of radiation that x-ray machines give off. Why are they suddenly so worried? It’s simple: the media. Similar to the fluoride debate, everyone from Instagram influencers to politicians has been dismissing dental x-rays (and x-rays in general) as dangerous and unnecessary. The second anyone who has a platform speaks, millions listen — even if what they say doesn’t have a shred of truth. Does getting an x-ray expose you to a very small level of radiation? Yes. But you know what else does? Living.
As scary as it sounds, radiation isn’t hiding in just x-ray machines and nuclear power plants. It’s all around us, all of the time. This kind of radiation is called background radiation. Wikipedia defines it as: “a measure of the level of ionizing radiation present in the environment at a particular location which is not due to the deliberate introduction of radiation sources.” Background radiation comes from a variety of sources but scientists have broken them down into four main categories: terrestrial, airborne, cosmic, and ingested.
Uranium naturally occurs in the earth’s crust and can be found in varying quantities around the globe. When uranium decays, it becomes radon, which is a radioactive gas. The largest amount of background radiation comes from radon that has been released into the atmosphere.
Your daily exposure to radon depends heavily on where you live. The rock and soil in certain areas of the world contain higher levels of uranium — and thus higher levels of radon. Houses built in areas with high radon levels need to meet certain safety requirements, including proper basement sealing and suction ventilation to help reduce radon exposure. If you’re concerned about radon levels in your home, have the soil and air tested to make sure it’s at a safe level.
Space is full of radiation — and that radiation eventually finds its way down to earth. Like airborne radiation, exposure to cosmic radiation also depends on where you live. The closure you are to space, the higher your level of cosmic radiation exposure. For example, people who live in cities that are well above sea-level, like El Alto in Bolivia or Juliaca in Peru, will have a higher daily dose of cosmic radiation than people who live in lower cities.
Cosmic radiation is much stronger and more intense in the upper troposphere which is why it can be a concern for airline crews and people who frequently fly. Two hours in a jet plane equals out to about 1 mrem which isn’t much but, if you’re flying every week or even every day, it can certainly add up.
Two of the main “ingredients” that make up the human body — potassium and carbon — have radioactive isotopes. This means that although we need them to survive, they’re actively decaying and emitting small levels of radiation. Scientists call this “internal radiation exposure.”
Other Sources of Radiation
The list of everyday items that contain radiation is close to endless. Cigarettes contribute the most radiation exposure, with people who smoke a pack a day experiencing 1,500 mrem a year. Other items include granite countertops, brazil nuts, bananas, and smoke detectors. These account for a very small percentage of the average person’s background radiation.
The Bottom Line
You’re probably wondering where medical x-rays land on this list. CT scans of the chest and back can expose you to about 1000 mrem but dental x-rays, which are much smaller and less intensive, expose you to .5 mrem. Compare that to the 7 mrem people get from living in a stone house every year and you can understand why worrying about dental x-rays isn’t warranted. Bitewings and PAs allow dentists to see dental decay before it becomes a problem. A dental x-ray can easily be the difference between you needing a cavity filled and you needing an extraction.
Low-level radiation exposure happens on a daily basis and it isn’t something you should worry about. Taking care of your body by eating well, getting plenty of sleep, and regularly visiting your healthcare providers is how you can prolong your life. Skipping essential x-rays (both at the dentist and your regular doctor) is much more dangerous than opting to get them.