Radioactive bananas

Sometimes things get a negative reputation that distorts our understanding of them and even disrupts our ability to talk about them. Radiation is one of those things … yet, if you are still reading and haven’t locked yourself inside your lead-lined bunker, while high levels are certainly inimical to health it is actually true that radiation is omnipresent in your home and it’s not just coming from your flat screen.

In a new study, researchers used a portable gamma radiation metre to measure the gamma radiation emitted in a normal home. The basic unit of radiation absorbed in tissue is the gray (Gy) where one Gy represents the deposition of one joule of energy per one kilogram of tissue. To put this in perspective, when the researchers measured natural uranium ore it emitted 1.57 µGy/hr. In terms of worker safety, exposure to 50,000 µGy per year is considered “safe”. So, what were the levels of radiation found in an average home?

The researchers found that avocadoes give off 0.16 µGy/hr of gamma radiation. This is exceeded by bananas which give off a whopping 0.17 µGy/hr and in both cases it is due to the potassium present in the food that the radiation is emitted. Even a common house brick emitted 0.15 µGy/hr. Smoke alarms gave off 0.16 µGy/hr.

These are tiny doses and this is not intended to make you phobic about your home environment. If you wanted to harm your neighbour through radiation exposure via fruit, you would need to fire 294,000 at them in the course of a year. So don’t be alarmed: this is not information to change your behaviour it is just information to broaden your thinking.

Source: Health Physics