I get all sorts of interesting questions. “How do you wash microwaves out of socks?” I didn’t quite know what to make of this. Quickly, though, we established that the gentleman who posed the question was not worried about having trodden on some stray microwaves, but had heard about a device being marketed to reduce the risks of cell phone use. First of all, we need to understand that there is very little scientific evidence to suggest that the use of cell phones is dangerous, other than their use while driving. But that has not stopped the inventive marketers. They’ve come up with a sock-like device that is placed over the phone to absorb the “harmful microwaves.” Instructions that come along with this gem of an idea apparently instruct the user to launder the sock regularly to “wash out the radiation.” Total nonsense of course.
Microwaves are a form of energy, and can indeed be absorbed by materials. After all, that’s how microwave ovens work. Moisture absorbs the waves and water molecules get energized. They move around more rapidly and it is this motion we sense as heat. But microwaves cannot be “stored” in a substance for later release. It seems though, that this belief is not restricted to scam artists who want to protect us from cell phones. A listener once called up to ask how long one should allow microwaved food to stand after cooking to “allow the microwaves to escape.” Obviously, this person had been reading her microwave cookbook, which gave instructions about letting the food stand before eating. This is common practice needed to complete the cooking process. Contrary to what many think, microwaves do not penetrate deeply into food. The exterior parts are easily heated but the inside cooks through heat transfer by conduction. That’s why the food has to be allowed to stand. It has nothing to do with allowing vagrant microwaves to escape.
Microwaves are not the only form of radiation causing undue concern. A terribly agitated caller was worried because after being x-rayed she was asked to carry the films to show her physician. She had heard all about exposure to x-rays being dangerous and thought that by carrying the films she was being “exposed.” Since the infamous 9/11 date, a number of people have asked about wearing clothes that have gone through x-ray scanners at airports. They are concerned that the items may become radioactive and pose a risk to their health. Excessive exposure to x-rays can certainly be risky, but x-rayed items do not store and reemit radiation. Unfortunately, just a mention of the word “radiation” is often enough to alarm people. A gentleman wanted to know what the safest way was to dispose of a broken compact disc player. I didn’t realize what he was getting at until he asked whether a laser was a form of radiation, which of course it is. Radiation is nothing more than the propagation of energy through space. Turn on a light bulb and you are exposed to radiation. The caller knew that cd players used a laser, and since lasers produced radiation, there had to be some risk. A laser beam in a cd player is just a special type of light beam which poses no danger at all, and of course it is only emitted when the device is on. So old cd players can be safely discarded.