The whole idea of cooking food via some kind of invisible death ray has always made people a bit nervous, so rumors of health risks have circulated since the microwave oven was invented. There are two main rumors, the first one has to do with stray radiation giving you cancer, but the second and more recent has to do with carcinogens (cancer-causers) that are somehow created in food when heated by microwaves.
It all started in the late 1980s, when a scientist named Hans Hertel locked himself and seven of his vegetarian buddies in a hotel, eating little more than microwave-prepared vegetables and milk for two whole months (we argue by that point, their farts alone would be cancerous).
Hertel popped out after the two months and stated his findings: "[The men's blood] appears to indicate the initial stage of a pathological process such as occurs at the start of a cancerous condition." Since then, numerous studies have been done on the effects of microwave heating as well as the radiation given off every time you reheat your P.F. Chang's.
Why It's Bullshit
"Who wants pot roastOH MY GOD, MY OVARIES ARE BURNING!"
Hans Hertel dropped out of the public view shortly thereafter, but what he said scared the shit out of the public. After all, most people had been using a microwave for years. However, if you carefully examine his statement above, he never offers any evidence that food prepared in a microwave will cause cancer, just that it kind of looks like there might be some kind of cancer shindig about to go down, maybe.
Not only that, but his findings were not based on any scientific proof, were not published in any kind of scientific journal, and were never peer-reviewed. At the end of the day it was just a bunch of dudes doing this off the cuff in a hotel, so they might as well have published their findings on the back of a box of Crunch Berries.
What we now know about microwaves is that the radiation used to heat the food is absolutely not powerful enough to either damage someone's DNA or alter the foods in way that may cause cancer (sadly, this also means that tossing a spider into the microwave and then getting it to bite you will not, in fact, give you super powers).
The actual micro-waves that are used to heat our food are non-ionizing, which means that they do not contain cancer-causing agents like UV rays, X-rays, and other kinds of rays that do act as carcinogens. This is one of those things that should probably fall into the "no shit" category, since we didn't see an explosion of cancer among people around microwaves all day (that is, people who work in restaurants) and who are bombarded by their supposed dangerous radiation for hours at a time.
Though that doesn't mean you should get drunk and start sticking random shit from your house in one.
2Power Lines, Computer Monitors... Pretty Much Anything With Electricity
The whole "power lines give you cancer" scare can probably be traced back to 1979, when two researchers named Nancy Wertheimer and Ed Leeper did a study that showed that there was a link between child leukemia and the close proximity of power lines in some Denver neighborhoods. The cause for this, they said, were the electro-magnetic fields given off from the lines... the same electro-magnetic fields that are given off by TV and computer monitors, microwaves, and half of the stuff around your house.
I will fucking murder you with cancer.
Naturally, this generated a whole shit-storm of other studies on electrical currents and whether or not they were really safe to use. Ironically, these studies were more than likely analyzed using at least once electronic device, so cancer had an inside man like Matt Damon in The Departed.Why It's Bullshit
There were quite a few things wrong with Nancy and Ed's Denver study, first and foremost being that they never actually measured the magnetic fields from the power lines (sort of like that time in 11th grade when you wrote a paper on The Scarlet Letter without ever reading the book). To date, any study that measured the fields has shown no consistent relationship between how powerful the fields were and much cancer people got.
Tesla Bowie would be pissed.
Secondly, they didn't consider the fact that those who live close to power lines are generally low-income families who can't always afford proper health care or a place to live where their children aren't constantly loomed over by the threat of electric death. In fact, there are studies that single out poverty-stricken individuals as having a higher risk of cancer than anyone, because their lives aren't shitty enough already.
The Cracked staff are at an especially high risk.
Meanwhile there have been literally hundreds of studies on things like electric blankets, computer screens and power lines, most with the same results: there is not enough evidence out there to suggest that electromagnetic fields pose a real cancer risk.
See? (Thanks, xkcd!)
As for the community in the Denver study, over the past few decades the use of electrical appliances in their homes has actually increased while Leukemia rates have dropped. However, deaths from child neglect, gunshots, and stabbings have also increased in low income communities, so really cancer just passed the buck on this one.