Radiation is everywhere, so the only way to know if its harmful is if we can measure its effects over time. People who work around nuclear reactors have devices that measure not just brightness of radiation but the amount over periods of time. Bananas are radioactive. All warm objects radiate a tiny bit. The difference with microwaves is that they are the right size to be absorbed by water and can break some chemical bonds. This is not normally a big deal. Body cells are constantly dying and being replaced, anyway.
What I do with microwave ovens is I stand back a few feet while things are cooking. The oven has shielding, but adding distance decreases any radiation that escapes. Its not really necessary, but I do it anyway. Cell phones and wifi are not on microwave frequencies and are less likely to interact with water, and they are much less intense than an oven. Microwaves tend to bounce around until they hit water where they are absorbed as heat, but they can be absorbed by other things. There are youtube videos where microwave ovens are used to melt rocks. In a situation like that I would stand much further away from the oven, because more microwave energy would escape (there being no water to absorb it in the oven). An empty microwave oven must never be turned on, and if it is on turn it off. There should always be water in the oven, so that the microwaves will be absorbed and will not heat up the microwave's electronics or other objects. Most foods have at least some water in them. Never completely cover the food in metal. For example if you have a recipe that calls for use of foil, make sure some of the food is exposed. Don't use an aluminum foil covered potato. Ovens are not the most powerful microwave devices. If you are in a high powered microwave transmitter station and for some reason get a high dose of microwaves you will die pretty quickly, and the first parts of you to be cooked will be your eyes because of their watery content and testicles if you have any.
All true, except for specifics (physics).
What microwave radiation
really "wants" to do? Is interact with hydrogen atoms. Water is mostly hydrogen, so...
But. Sugar is also mostly hydrogen, or more accurately, it's a hydrocarbon with oxygen attachments.
So. Sugar will also happily absorb microwave radiation too.
As will oil. But lighter oils seem to work better--however that may simply be because they are less dense, and how quickly something heats up is a function of density (among other things).
Microwave also loves to interact with metal. Depending on the shape and composition? The interaction can be simple heat (as is the case with hydrogen atoms) or it can induce electricity.
Another thing microwaves cheerfully interact with? Phosphor compounds. One of the amusing things to do with an old microwave (that you do not mind damaging) is put a compact fluorescent bulb in there-- it'll light up as if plugged in.
But wait! It gets better! Take a
broken fluorescent bulb-- or rather, the pieces of white-coated glass (CAUTION! TOXIC! DO NOT GET CUT WITH THIS-- the wounds are very difficult to treat, and do not heal properly!) I have done this latter one: pieces into a glass bowl. A styrofoam cup of water in the corner (just for safety to the oven mechanism itself). Cook. The glass shards will light up beautifully! And they don't even get warm. It's kind of erie-- your mind knows these shards are not in any way
visibly connected to the electrical mains, yet they glow as if they were.
Microwave radiation is kinda fun, actually. If you look into the physics of how it's created? It's basically a whistle--only instead of air? Free electrons are used instead-- these hammer a piece of specially treated metal alloy (typically tungsten), which then emits radiation in the microwave frequencies.
Pretty cool.
