goodhousekeeping.com http://www.goodhousekeeping.com/recipes/microwave-radiation-ovens-460709 11 Surprising Facts and Myths About Microwave Ovens A fixture in office break rooms, convenience stores and homes for decades, the microwave ovenhas been heating frozen foods, leftovers and even more elaborate meals for decades. In fact, some hip urban restaurants employ the familiar device to cook all their meals, from apps to entrees. Not only does this save energy and allow the restaurants to cope with small square footages in space-constrained districts, but it alsooffers a new retro- novelty , giving a wow factor to those who aren't familiar with the appliance's true versatility. Y et Google "are microwave ovens safe," and you'll get a barrage of hits from concerned mothers and others who are worried that the handy device might have a dark, even dangerous side. Of course, the prevailing consensus among scientists, public health experts, government agencies and the general public is that microwave ovens are overwhelmingly safe when used as directed. However, it's also true that there may be some legitimate questions about the safety of certain aspects of the technology, beyond the paranoia of the tin-foil hat crowd. Let's take a closer look at some myths, facts and misconceptions about microwave ovens, which are estimated to be used in at least 90% of American homes . 1. Microwave Ovens Were Discovered Accidentally Status: FactApparently no one thought of cook ing food with microwaves until the 1940s, when a self -taught engineer named Percy Spencer was building radar equipment in a lab for Raytheon, and noticed that a chocolate bar he had in his pocket started to melt. He had been building magnetrons, and realized that microwaves can be directed at food to heat it up rapidly. He tested his idea by popping popcorn and exploding an egg. Not long after we were all happily scarfing down TV dinners. 2. There Is Dissent Over How Microwaves Actually Heat Food Status: FactMicrowave radiation is a form of non-ionizing radiation (meaning it can't directly break up atoms or molecules) that lies between common radio and infrared frequencies. So it is not thought to damage DNA of living things, the way X and gamma rays do. Still, microwaves can obviously cause heating effects, and can harm or kill at high energies. That's why microwave ovens on the market must operate at or below strict limits set by the federal government. Most microwave ovens hit food with microwaves at a frequency of 2.45 gigahertz (GHz) (a wavelength of 12.24 centimetres (4.82 in)). The prevailing belief is that molecules in the food, particularly water , absorb energy from the waves through dielectric heating. That is, since water molecules are polar , having a positive end and negative end, they begin to rotate rapidly as the alternating electric field passes through. That rotation is thought to add heat to the food. However , there are some scientists who have dissented with this view, suggesting that other interactions between the particlesmay be responsible for the heating.
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8/12/2019 Goodhousekeeping.com-11 Surprising Facts and Myths About Microwave Ovens
11 Surprising Facts and Myths About Microwave Ovens
A fixture in office break rooms, convenience stores and homes for decades, the microwave oven has been
heating frozen foods, leftovers and even more elaborate meals for decades. In fact, some hip urban restaurants
employ the familiar device to cook all their meals, from apps to entrees. Not only does this save energy and allow
the r estaurants to cope with small square footages in space-constrained districts, but it also offers a new retro-
novelty, giving a wow factor to those who aren't familiar with the appliance's true versatility.
Yet Google "are microwave ovens safe," and you'll get a barrage of hits from concerned mothers and others who
are worried that the handy device might have a dark, even dangerous side. Of course, the prevailing consensus
among scientists, public health experts, government agencies and the general public is that microwave ovens are
overwhelmingly safe when used as directed. However, it's also true that there may be some legitimate questions
about the safety of certain aspects of the technology, beyond the paranoia of the tin-foil hat crowd.
Let's take a closer look at some myths, facts and misconceptions about microwave ovens, which are estimated to
be used in at least 90% of American homes .
1. Microwave Ovens Were Discovered Accidentally
Status: Fact
Apparently no one thought of cooking food with microwaves until the 1940s, when a self-taught engineer named
Percy Spencer was building radar equipment in a lab for Raytheon, and noticed that a chocolate bar he had in his
pocket started to melt. He had been building magnetrons, and realized that microwaves can be directed at food to
heat it up rapidly. He tested his idea by popping popcorn and exploding an egg. Not long after we were all happily
scarfing down TV dinners.
2. There Is Dissent Over How Microwaves Actually Heat Food
Status: Fact
Microwave radiation is a form of non-ionizing radiation (meaning it can't directly break up atoms or molecules) that
lies between common radio and infrared frequencies. So it is not thought to damage DNA of living things, the way
X and gamma rays do. Still, microwaves can obviously cause heating effects, and can harm or kill at high
energies. That's why microwave ovens on the market must operate at or below strict limits set by the federal
government.
Most microwave ovens hit food with microwaves at a frequency of 2.45 gigahertz (GHz) (a wavelength of 12.24
centimetres (4.82 in)). The prevailing belief is that molecules in the food, particularly water, absorb energy fromthe waves through dielectric heating. That is, since water molecules are polar, having a positive end and negative
end, they begin to rotate rapidly as the alternating electric field passes through. That rotation is thought to add
heat to the food.
However, there are some scientists who have dissented with this view, suggesting that other interactions between
No one knows, although we can take heart that the FDA limits the amount of microwaves that can leak from an
oven throughout its lifetime to 5 milliwatts (mW) of microwave radiation per square centimeter, at approximately 2
inches from the oven surface. According to the agency, "This limit is far below the level known to harm people." It's
also true that microwave energy decreases dramatically as you move away from the source of radiation. A
measurement made 20 inches from an oven would be approximately one one-hundredth of value measured at 2
inches. The federal standard also requires all ovens to have two independent interlock systems that stop the
production of microwaves the moment the latch is released or the door opened.
In an interview with TDG, mechanical engineer Mark Connelly, the deputy technical director of Consumer Reports
said that the vast majority of microwave ovens his group has tested have shown "very little leakage of radiation."
Connelly echoed the advice of the FDA, which is that if people are concerned, they can simply step away from a
microwave oven when in use.
Asked if people should avoid looking into a working microwave, since the eyes are known to be the most sensitive
to that form of radiation, and are known to develop cataracts at high field strengths, Connelly said he didn't think it
mattered, "since the window is shielded, and there shouldn't be leakage through that."
"If you are concerned, then go out and spend $20 on a testing kit to reassure yourself that there isn't any radiationleaking from your microwave," Connelly added. He said his testing of consumer-grade kits has shown them to be
reasonably reliable, despite some press accounts to the contrary. "Microwaves can wear over time, with gaskets
wearing or trouble developing in the door. So I think it's prudent to spend a little money to test them," he said.
11. Microwaves Alter Food in Undesirable, Possibly Unsafe, Ways
Status: Undetermined but Unlikely
It's a fact of life that any type of cooking changes the chemistry of food. It can reduce the levels of some nutrients,
ust as it can increase the levels of others (e.g. lycopenes), or make them more or less available to the body for
use. (Raw food anyone?) The prevailing view is that microwaves do not alter foods in ways that are any more
deleterious or harmful than other types of cooking. In fact, some have argued that the faster cooking time may
actually preserve more nutrients versus other methods.
Still, we know sufficiently little about nutrition and the cumulative effects of food science that some aren't so
convinced (of course, there is also the threat of any harmful substances present getting released upon cooking,
such as the diacetyl blamed for "popcorn lung.") In a recent article E Magazine pointed out that popular holistic
health expert Dr. Andrew Weil has written, "There may be dangers associated with microwaving food... there is a
question as to whether microwaving alters protein chemistry in ways that might be harmful." According to the
magazine, Dr. Fumio Watanabe of Japan's Kochi Women's University found that heating samples for six minutes
degenerated 30 to 40% of the milk's vitamin B12. This kind of breakdown took about 25 minutes of boiling with
conventional heat. In a 1992 Stanford Medical School study often cited by microwave opponents, researchersreported a "marked decrease" in immune-boosting factors in microwaved human breast milk. In the late 1980s
Swiss scientists reported decreases in hemoglobin and white blood cells in rats that had eaten microwaved food.
It's also much reported on the Internet that microwaving human blood renders it unsafe for transfusion -- though
medical professionals point out that rapidly heating blood via any method can have the same negative result.
The conclusion made by government agencies and mainstream organizations is that microwaved food is safe, as
well as convenient. There's a limited number of studies that may suggest otherwise, but given the lack of large-
scale or compelling evidence it's hard to feel that tossing our your microwave is a particularly smart step.
Everyone interviewed for this piece pointed to other issues as more pressing, from ubiquitous exposure to cell
phones to more serious threats from radon, or bigger energy users like heating and cooling. That doesn't meanmicrowaves aren't worth thinking about, however.