Q How safe are the barcode scanners that our food passes through on the supermarket checkout stand? I have heard that the radiation from these machines may be dangerous.- LB, Aberdeen
A Concern over the safety of barcode scanners is a natural offshoot of concern over food irradiation. When food is irradiated to kill bacteria, it is exposed to ionising radiation in the form of gamma rays from nuclear material, X-rays or high-speed electrons from electronic guns.
The dose of radiation varies according to the type of food, but even fruits and vegetables - which receive the least radiation - are hit by the equivalent of millions of chest X-rays. There is evidence that irradiated foods lose their vitamin content and, while irradiation can kill up to 95 per cent of bad bacteria, it can also kill any good bacteria present in foods.
Laser devices are usually non-ionising and span the energy spectrum from infrared to ultraviolet. Barcode scanners, which have very low emissions, are 'class 2A' laser devices. Although they emit some radiation, barcode scanners are generally considered to be a very low risk to food.
One factor common to all potential types of radiation poisoning is the duration of exposure. But, as food at the checkout is quickly passed by the scanner, it is unlikely to receive much radiation. It's worth asking, though, what long-term risks there may be for the cashier who sits next to a scanner (and other electronic equipment) for hours at a time every day.
Having said all this, the safety of barcode scanners is mostly theoretical. There has never been any study of their effect on food, so it is impossible to say with any authority whether all, some or no scanners are dangerous.
People who use homoeopathic and other energy medicine have concerns about barcode scanners as it may only take a small amount of radiation to lower, or antidote, a remedy. Again, however, this is theoretical and has never been tested.
The best we can say at this time is that barcodes are probably just a small part of the whole spectrum of radiation (including irradiation) that we and our foods are exposed to today.
If you still feel uncertain about this issue, there are few options. You can buy your produce from local suppliers, farms and shops who don't use lasers to keep track of stock and prices. Also, smaller grocery and healthfood shops may be willing to ring up certain items such as energy medicines independently of the scanner if you ask - a courtesy you are unlikely to find in larger supermarkets.