微波炉英.ppt

Surprising Facts and Myths About Microwave Ovens Microwaves are energy efficient and convenient. But what does the radiation do to our food, and can it affect our health? Harmful effects of microwaves: Weakened immune（免疫的）systems Lowered resistance to bacterial（细菌的）and viral（病毒的）infections Cataracts （白内障） Birth defects Cancer Many other serious illnesses The dangers of microwaved foods Microwaves break chemical and molecular bonds, and can literally rip atoms apart, disrupting the basic biochemical structures of life. It’s no wonder foods cooked in such a way become so harmful to consume. Microwaved foods lose nutrition. Microwaving makes food unhealthy by forming harmful compounds Microwaved meals change blood chemistry /v_show/id_XMjY0NjM3NDIw.html Are Microwave Ovens Dangerous? Yes Microwave Ovens are Dangerous! By Olivia Microwave Cooking is Killing People! There was a lawsuit in 1991 in Oklahoma. A woman named Norma Levitt had hip surgery, but was killed by a simple blood transfusion when a nurse warmed the blood for the transfusion in a microwave oven!? Microwave Ovens Cook Food from the Inside Outside 1 Status: Myth Although many people believe this to be the case, microwaves actually work on the outer layers of food, heating it by exciting the water molecules there. The inner parts of food are warmed as heat transfers from the outer layers inward. This is why a microwave can only cook a big hunk of meat to a depth of about one inch inward. Metals Get Dangerously Hot in Microwaves 2 Status: Myth Metals reflect microwaves, whereas plastic, glass and ceramics allow them to pass through. That means metals dont appreciably heat up in a microwave oven. However, thin pieces of metal, such as foils or the tines of a fork, can act as antenna, and the waves can arc off them, forming dramatic sparks. You Cant Heat Oils in a Microwave 3 Status: Fact Oils such as olive oil do not heat well in microwaves because their molecules lack the polarity f