“Do not stand next to a running microwave oven! It emits radiation”
“Don’t you know that it destroys the molecules of food?”
“We will not buy it, do you want to die?”
Probably each of us at least once in life heard such words from relatives, friends or colleagues. Around the issue of the dangers of microwave ovens there are many legends, but we decided to put an end to them and to understand this question, or rather a few: why it can be dangerous or not dangerous to humans? How does it work? What and where does it radiate? What is the effect on the structure of molecules of food?
From the standpoint of physics microwave is safe for humans. From the point of view of a nutritionist it spoils products: cells become damaged, water leaves. With regard to radiation, the microwave is shielded, and therefore it cannot affect on anything, respectively, it is not dangerous.
Do microwaves destroy food nutrients?
Principle of microwave work is based on the ability of electromagnetic waves of ultrahigh frequency (2450 MHz) to impact on the product, causing it to warm-up due to the increase of the thermal vibrations of the molecules of matter. Any food product contains a sufficiently large amount of water. Each water molecule has a characteristic molecular structure, which is due to the relative orientation of the positive hydrogen ions and negative oxygen ion looks like electric dipole – particle with two electrical poles: plus and minus.
The impact of electromagnetic waves leads to a constant shift of the dipoles, alignment of them according to the lines of force of the electromagnetic field. Since the field is alternating, and even with a high frequency, the molecules change direction periodically around with such frequency too. Molecules shift, swing, clash, collide with each other, transferring energy to neighboring molecules. This causes the release of a large amount of heat. Due to this heating the food warms-up as water is contained in any of foods.
There are no any significant changes in the product, as the microwave radiation affects only on heating of the product, so cooked food in a microwave oven is not harmful. The product can be damaged, if to overheat it above the norm. But the same occurs when cooking food on the plate.
In the oven microwaves created by a special generator – magnetron. The antenna of magnetron emits microwaves through a waveguide via a special window into the metal chamber, where the product is located.
What is radiation in cooking
Microwave radiation is non-radioactive. The radiation that is harmful to humans has a much greater frequency than that used in microwaves. To eliminate radiation outside the device different types of protection are provided. Stoves are made in such a way that when the door is closed the waves can not penetrate beyond the furnace chamber; Glass doors necessarily are shielded with metal mesh. Microwaves do not pass through metal and tend to be reflected by metal objects. For this reason, the microwaves don’t leave the area of the inner chamber when the door is closed.
Automation has several special protection circuits that prevent the microwave generator operation when the door is open. Additionally, the top of the device housing is closed by metal shell, which is also a type of protection against leakage of microwaves from the electronic oven compartment. All produced microwaves are checked for compliance with the required safety standards.