Ahhh, the microwave oven. The answer to all of a fast paced society’s fast food needs. It cooks in a jiffy and needs no preheat or maintanence. Every american home has one and uses it daily. We rely on it. We adore it. We take it for granted.
But what are the implications of this worldly device? Surely, like nuclear reactors, microwaves cannot be 100% safe and at the same time be easy, affordable, efficient, and reliable. OJO! The time is nigh for the truth to reveal itself! There’s GOT to be something wrong with it. I’ll bet scientists and doctors team up to discover that they cause some kind of cancer by route of the foods prepared in microwave ovens. Or what if an interstellar object exploded or something and cause all microwaves to explode and emit deadly radiation?
Microwave ovens create their radiation, radio waves at 2.something gigahertz, with electron tubes. The microwaves themselves do not “contain” anything that is radioactive. No electric power, no radiation.
Whether microwaved food is “safe” or not I’ll leave alone. But I personally have no qualms about it.
There are little detectors you can buy to check for that.
I also remember reading an article where a couple of engineers detailed making a a microwave emitter that could fry a car’s computer, stopping it dead. I think they used an ordinary microwave for the parts.
What happens if I find a way to make it work with the door open and use it that way? Does everything metal in the room start to spark? Do I get dain bramage? Is there a microwave/radio engineer/specialist in the house?
Fire’ll kill you, too… We’ve got to stop relying on all this fancy high-tech stuff! Eat meat the natural way, raw!
Seriously, though, the only conceivable way for microwaves to harm living tissue is by heating it, the same way that they cook food. If your microwave was made properly and isn’t falling apart, the microwaves will be completely sealed off away from you when the door is closed, and turned off when it’s open. Even if there were a leak (extremely rare), it wouldn’t cause cancer, it’d heat you. If you feel the heat, step away and get it fixed. Yes, you can be harmed by food cooked in a microwave… The exact same way that you could be harmed by food cooked in any other manner. If you try to eat it when it’s too hot, you’ll burn your mouth. Let it cool off, it’s safe again.
I recall listening to a late-night talk show host asking basically this same question when microwave ovens first hit the market – "But what’s it doin’ to the FOOD, man?
Well, it cooks the food. I’m oversimplifying here (and I’m sure someone will come along and fill in the blanks for me): microwaves are radiation in the same way that light from the sun is radiation. They are simply electromagnetic (EM) waves (light), but with lower frequencies (and longer wavelengths) than visible light or infrared light (the kind your gas oven cooks with). Microwaves are radio waves, of frequencies just above the broadcast band.
What’s special about microwaves is that water molecules (H2O) resonate at microwave frequencies, thus if you bombard a bunch of water molecules with an intense microwave beam they will vibrate faster and faster until the water boils. Since microwave light can penetrate the surface, it affects the interior of the food and speeds up cooking (conventional ovens heat up the interior air and heat up the interior of the food by thermal diffusion).
Now, some EM radiation you want to avoid, like UV, X-rays, and Gamma radiation. If you look at the EM spectrum (in any beginning physics text) you will find that harmful EM radiation all have frequencies greater than (& wavelengths shorter than) visible light. These are known as ionizing radiation, 'cuz they are energetic enough to knock electrons loose from atoms, thus they can mess with the internal equilibrium of molecules, thus if (in the unlikely event) they were to hit a DNA molecule, there is a possibility that they could cause genetic damage. The higher the frequency, the higher the energy, the greater possibility of mutation.
All forms of EM radiation with visible or lower frequencies are non-ionizing radiation, and can only hurt you in the same way that they hurt that pork roast you’ve got in the oven.
So if can jury-rig your microwave to operate with the door open, and you then turn it on and stick your head in, well, that would certainly do you no good…
As has been said, microwave ovens do not contain radiological (nuclear) sources and any adverse health effects of radiowaves are limited to heating (although there are ongoing studies of other possible effects).
Here’s what the FAA says about microwaves (pertaining to their microwave radars)…
*In contrast to the cumulative biological effects associated with exposure to ionizing radiation, the only confirmed harmful effects from exposure to RF/microwave radiation are thermal in nature.
Those organs which have a limited circulatory system are considered vulnerable to RF/microwave radiation exposure. Two structures in the human body are more susceptible to high radiation intensities than the remainder of the body:
(a) The testes are vulnerable due to their sensitivity to temperature change. Intense microwave radiation exposure to the testes of experimental animals has been shown to impart temporary and reversible sterility.
(b) The lens of the eye cannot dissipate heat as readily as the rest of the body and can suffer damage from microwave radiation. This has been demonstrated experimentally with small animals.
Nonthermal Effects - - Nonthermal effect refers to an observable or measurable biological change produced by exposure to RF/microwave radiation without a detectable temperature rise in a test system. Recent research has suggested that nonthermal effects do occur. The phenomenon of RF “hearing” has been reported and verified. Alterations in animal behavior patterns following RF/microwave radiation exposure have been observed. Effects on the immune response system and upon the central nervous system are receiving considerable attention. Efforts continue to determine if these subtle and usually reversible changes have any public health significance. *
BTW, since RF/Microwave power can’t hurt you except by heating up your tissue, and since cellular phones are just very low-power microwave transmitters, it follows that unless your head starts getting very hot, the phone causes no damage. (And don’t think that just because the side of your head feels warm after talking on the phone, that it’s due to the radiation - the phone gets warm when it operates because it dissipates power).
This is why scientists are so skeptical of claims that cell phones have caused brain cancer. It’s just not plausible.
Living and working too close to the fields can cause hair loss, problems with digestion and immune response.
The precautions involve with high power rf are pretty serious stuff.
Microwave ovens are safe enough but a blanket statement that rf power only causes damage through heating effects is not true ionisation type burns are known to be caused by rf exposure they are similar to electric arc burns *I have seen this when one colleague stupidly grabbed a whip aerial *.The magnetic fields induced in humans are not very good for you at all.The subtle alterations to chemical processes and cell division are not all that well understood.
Having had to use the various safety precautions involved with working near high powered radar emitters(nothing directly to do with the radar itself - just in the vicinity)
I am very surprised that government scientists claim the is no evidence and I would suggest that it is only because the requisite studies have not been carried out.
BTW some radars operate at nearish frequencies to microwave ovens.
Um, casdave, if your colleague actually had to grab the arial to get the effect, maybe it was an arc burn? Were it the radiation, he would have gotten the burn just from being near it.
As to the magnetic fields: Yes, EM waves consist in part of changing magnetic fields (the other part is changing electric fields, hence the name). This is true of all electromagnetic radiation, including visible light, the radio waves picked up by your TV, and the infrared radiation produced by your body. If the fields due to microwaves are harmful, then why aren’t the rest of them?
Yes, there’s a lot of warnings on radar equipment, etc. That’s because there’s lawyers, and regardless of whether or not something can harm you, someone’s going to clain that it harmed them. If someone claims to have gotten cancer from standing too close to a radar set, the lawyers can say “Well, we told you not to stand that close” a lot easier than they can explain that microwaves don’t cause cancer.
I thought there was a lot of warnings on high power rf stuff because it is high power. The dangers people have pointed out for micro waves is that it cooks things. Your micro wave oven is like 800 to 1600 watts i believe. A quick search of the fcc site. http://www.fcc.gov/mmb/asd/fmq.html#sprung4
Shows 10,000 Watts and above stations fairly frequently. I would imagine you would get cooked standing too close to those antenneas.
Didn’t microwaves being usefull for cooking get discovered by radar technitions finding that popcorn popped near the radar antenneas? Or is that just a stupid urban legend.
Popcorn was the second thing tried… The initial discovery was that a Hershey bar melted. I’d always heard it as true, and it seems perfectly plausible (something had to be first), but I don’t have any cites handy.
The power you are exposed to and the length of time of exposure.
Sunlight will cause melanomic cancer upon too much exposure and even at low levels will damage the skin over a prolonged period.
I do not wish to be smug but the mobile phone phonomenon will have its victims.There is bound to be some sales rep who has one tied to his head most of a day for years and years.It is only a matter of time.
The power output is relatively small but it is worryingly close to sensitive organs.
The article goes on to describe the rest of the history of the microwave oven all the way up to the time of printing. It’s interesting reading.
Sunlight — even after being filtered through the atmosphere — is a much broader spectrum then radiation emitted from mobile phones. The dangerous radiation in sunlight is ultraviolet radiation. UV radiation is a type of ionizing radiation. Microwaves are not. UV radiation is on the other end of electromagnetic spectrum. Here’s a link to my recent post about UV radiation.
To help explain the difference between different kinds of radiation: Which would you rather have dropped on your head, a bowling ball, or an equal weight of ping-pong balls? Even if we specify the same speed for both at impact, the bowling ball is going to do a lot of damage, wheras no amount of ping-pong balls will hurt you. Similarly, even a single far UV, X, or gamma photon can potentially cause cancer, but no number of radio photons will. It’s not the total energy that’s significant, but the energy per photon.
Since Wood Thrush actually has cites about the popcorn thing, I’ll go with that. Popcorn was definitely one of the first, though.
I don’t know if this is an urban ledgen or not, but I remember hearing somewhere that in the 50 and 60 there were big ass micro wave dishes in Alaska used for radar. The poor smucks who had to maintain them would warm themselves up during the cold months by standing in front of them for a few seconds. Ahhh all toasty and warm.
*Originally posted by jrepka *
**> What’s special about microwaves is that water molecules (H2O) resonate at microwave frequencies, thus if you bombard a bunch of water molecules with an intense microwave beam they will vibrate faster and faster until the water boils. Since microwave light can penetrate the surface, it affects the interior of the food and speeds up cooking (conventional ovens heat up the interior air and heat up the interior of the food by thermal diffusion).
But according to Louis A. Bloomfield, Professor of Physics at the University of Virginia:
It’s a common misconception that the microwaves in a microwave oven excite a natural resonance in water. The frequency of a microwave oven is well below any natural resonance in an isolated water molecule, and in liquid water those resonances are so smeared out that they’re barely noticeable anyway. It’s kind of like playing a violin under water–the strings won’t emit well-defined tones in water because the water impedes their vibrations. Similarly, water molecules don’t emit (or absorb) well-defined tones in liquid water because their clinging neighbors impede their vibrations.
Instead of trying to interact through a natural resonance in water, a microwave oven just exposes the water molecules to the intense electromagnetic fields in strong, non-resonant microwaves. The frequency used in microwave ovens (2,450,000,000 cycles per second or 2.45 GHz) is a sensible but not unique choice. Waves of that frequency penetrate well into foods of reasonable size so that the heating is relatively uniform throughout the foods. Since leakage from these ovens makes the radio spectrum near 2.45 GHz unusable for communications, the frequency was chosen in part because it would not interfere with existing communication systems.
Standard procedure after any cabinet or door repair (or anything that requires removing the door) is to run a leakage test on the machine. Out of curiosity, I ran the test on several damaged ovens–all of which still cooked, but which had been dropped so that the doors were askew (leaving gaps large enough to fit a finger through). With one cup of water in the cavity, none of the tests showed detectable leakage. With nothing in the cavity (briefly), the tests showed a small, but not dangerous, level of leakage.
As for defeating the interlocks and removing the door: You must remember that the energy density falls off very quickly with distance (good old inverse square law). I wouldn’t stand right in front of it, or stick my hand in the cavity, but a few feet away is pretty safe. Remember, you’re dealing with much lower power levels than you get from the antennas and radar dishes.