"The Effects of Radiation Leaking from Microwave Ovens"
About 20 people a day end up in American emergency rooms
from microwave oven related injuries.
A few from microwave popcorn steam,
overheated hair removal wax,
nearly one a day from exploding eggs,
but most are from overheated water.
See, when you boil water on the stove,
bubbles rise from the bottom,
and as they burst, the excess heat is dissipated.
Water heated with a microwave oven, though,
may not bubble, and so, can get even hotter
than normal boiling temperature.
Then, if you sprinkle in some powder,
tiny air bubbles are carried into the liquid,
and can expand into steam bubbles and erupt onto your hand.
The FDA warns to be careful
when trying to boil water in a microwave,
particularly in a shiny container,
or more than once, or for too long,
or when not letting it cool down a bit first,
or when dumping something into it.
Most microwave-related burns in young children
occur when the child reaches in to grab something hot.
Toddlers as young as 18 months can open a microwave;
so, some public health advocates have recommended
that instead of just warning people
to let stuff cool first for a few minutes,
there should be some kind of door lock
that doesn’t let you even open the thing
for 2 minutes after it stops,
which kind of undermines the whole point
of quick microwave convenience.
A better idea may be to just childproof the door;
so, you have to like turn a knob
while pressing a button to pop the door open.
When people express concerns over microwave oven safety though,
they are probably not thinking about
exploding eggs or hair wax injuries.
They’re concerned about the microwave radiation itself.
Microwave oven manufacturers caution people
not to operate the oven with the door open,
but there are interlocking safety switches
that should turn it off automatically
when you open the door, unless,
you’re stuck inside one.
God, I couldn’t even read this article.
There is some leakage of microwave radiation,
though, during operation.
There’s this famous radio telescope
scanning the cosmos for extraterrestrial civilizations.
“Fast radio bursts” were detected.
A sign of extragalactic intelligence?
Nope, turns out ET was a microwave in the staff cafeteria
that the telescope caught when it was
just at the right angle,
right when someone yanked the door open.
You don’t need a radio telescope to see it, though.
A cheap way of detecting microwave oven leakage
is to just place a computer monitor next to the oven,
and you can see disturbances on the screen.
Or, just use the microwave detector
you have in your pocket or purse right now:
cell phones.
Look, if microwaves can leak out,
they should also be able to leak in.
The wavelengths are actually quite similar in size,
though obviously different intensity
between microwaves and cell phones.
So, stick your phone in the microwave—
DO NOT TURN THE MICROWAVE ON,
but close the door and see if you can call it.
When you hear it ringing that’s confirmation
that microwave-type radiation can leak in and out.
And indeed, you can just directly measure
the leakage during operation,
though nearly all within prescribed safety limits,
and once you moved the detectors
like a foot away from the door,
the levels fall nearly to zero,
even if there’s some food particle
or something caught up in the door seal.
Now, the industry will tell you that
“there has never been any verified case
of human injury due to exposure from radiation
leakage from microwave ovens.”
This is from a guy at Raytheon, though,
where the microwave oven was invented,
after an engineer in a radar lab noticed
the chocolate bar in his pocket had melted.
There has been the rare case report
of a malfunctioning machine that didn’t turn off
when the door was open and someone burned themselves,
but this was after her hand was in there
for like a full minute.
Raytheon engineers talk about
how they inadvertently exposed themselves
lots of times to open, active microwaves.
They get a warm tummy,
they feel a little transient warmth
when they pass their arm in and out of the oven,
but no big deal they say.
In fact, the same microwaves used in microwave ovens
are the same used for medical microwave diathermy,
which physical therapists use like a hot pack
to treat like rotator cuff injuries.
Now, making the claim that,
“If the medical profession uses it, it must be safe”
isn’t exactly the strongest argument,
but does help put things in perspective.
“When the heating of people is not deliberate,
it may be desirable to limit exposure.”
Is that minor leakage during operation
anything to worry about, though?
In other words, are there nonthermal effects of microwaves.
If it doesn’t burn you, can it still hurt you?
The Soviets thought so,
irradiating everyone in the US Embassy in Moscow for decades.
In terms of microwave ovens, though,
the only report I could find was from over 40 years ago,
a case report of a women who developed cataracts
after using a leaky microwave oven, but that’s all there was,
just this kind of circumstantial evidence correlation.
Lots of people get cataracts;
lots of people use microwaves;
there has to be more that.
The only follow-up study I could find
was this Turkish study published
a few decades later, but it was on rats.
Now, they did end up finding some superficial eye abnormalities
on the rats placed next to the microwave,
but they were right up against the door,
and people don’t tend to stick their faces
right up to the glass while things are cooking.
So, even if the same thing happened to human eyes,
this study might be of limited relevance.
But, it can’t hurt to stand back
from the microwave while it’s on.
Otherwise, microwaves should be safe, unless…
you drop it on your foot.