The general public has next to no understanding of radiation and how dangerous it is – or is not. I know this because I work as a radiographer and have encountered many panicked parents questioning whether scanning their child is going to result in the premature death of their child.
I’ve met many a nurse who literally leaves the entire ward when I go to take a chest x-ray, suspecting that my powerful beams are going to rebound off the patient, turn a corner and chase them out the door. I’ve had people ask for lead shielding to protect their ovaries from a wrist x-ray and another threaten to sue me if they go blind (OK, that last one was a psych patient). But rather than inflict my judgement on these uneducated folk, I’ve decided to give a quick lesson in the dangers of radiation, specifically, the kind of radiation used in CT and x-ray scans.
I don’t blame people for asking the questions they ask (although I do get annoyed when they don’t believe me). The media as a whole has done a terrible job of scare mongering people into wrapping their microwaves in lead just in case it causes cancer down the way. I know you don’t want a science lesson, so here’s some quick and easy examples of how dangerous that x-ray of your teeth actually is.
Radiation is present in many, ordinary things. Like bananas. Bananas are a natural source of radioactive isotope, which means that you receive a radiation dose from eating a banana. This dose has even been converted into a measurement called the Banana Equivalent Dose (BED) so that the public can understand how much radiation they are receiving in terms of bananas instead of complicated units like Sieverts and Grays. The BED is controversial, but without going into it too much, a chest x-ray is said to be the equivalent of eating 200 bananas. A dental x-ray is 50, and a chest CT scan is 70,000. To put that into perspective, 20 million bananas are required for severe radiation poisoning.
My favourite way of putting radiation into perspective is through aeroplane rides. No one thinks twice about hopping on an aeroplane (even those in the early stages of pregnancy – the time when the foetus is most sensitive to radiation) but many get pretty scared when they turn up for a chest x-ray. Good news – a return flight from New York to LA will give you approximately the same dose as a chest x-ray. That’s roughly a 12 hour flight.
Radiation is literally everywhere. You’d accumulate the same amount of radiation from a chest x-ray in two and a half days from natural background radiation – even quicker if you live in a city at high-altitude, so for the 80% of hospital patients that do require a chest x-ray, there’s really no need to worry. The dose jumps up for a CT abdomen – it would take you 182 days to acquire that dose through background radiation, but significantly less people are referred for a CT than an x-ray.
In short, radiation can be a deadly, terrifying thing… but it’s usually not. Feel free to question your doctor over any imaging they refer you to (especially if they refer you for imaging regularly), but please understand that the utmost care is taken by us technicians to give you and your child the lowest dose possible. And that dose is pretty damn low.
Kait has been working as a CT and general radiographer for seven years and hopes this article helps you feel more comfortable next time you or your child needs imaging.
