In a microwave oven contains a magnetron, in which the impact is precisely the harm. This device converts electrical energy into a conventional high-frequency electric field with a frequency 2450 MHz (megahertz). This electric field interacts with the water molecules, which is in the food. Therefore utensils barely heats itself, but only from the heated food already.
The microwaves act on water molecules, so that they begin to rotate at great speed - millions of times per second. This gives rise to molecular friction, and which heats the food. This friction is capable of causing damage to the fibers of food and molecules, they are broken and deformed. To put it simply, the microwave radiation at the time of killing in the products of all living things, causing the collapse of food.
In terms of biology, the most harmful to the human body is a high-frequency radiation in the centimeter range, which gives the electromagnetic radiation of high intensity. Such radiation is impossible to hear, see or feel, but they adversely affect the human body. The mechanism of action of the microwaves does not appear immediately, but gradually accumulates, leading to serious diseases.
Microwave radiation leads gradually to the weakening of human cells. And because the cells have significantly broken and destroyed, the cell membranes are not able to protect them against the ingress of fungi, viruses and other microorganisms. In addition, the natural self-repair mechanisms are suppressed.