Archive for Monday, April 5, 2010


Microwaves scary, but safe

April 5, 2010


In 1977, as part of a unit on radiation, my eighth-grade physical science teacher, Mrs. Alderson, warned us that no good could come of microwaves. She also made us read “Hiroshima.” The screaming young girl on the cover and microwaves fused in my mind. I expressed my concern at home, but if you didn’t make peace with the microwave in my house, you didn’t eat.

I suppose I had every reason to be afraid of our Sears Kenmore Radarrange, the first microwave in our neighborhood. It was large enough to cook a small child. It had two rudimentary buttons (cook/defrost) and a large round black knob for a timer. After understanding what she could of the operating manual, my mother made sure my father and sisters and I remembered two things: 1) if you put metal in the microwave, you created an arc that would burn the house down and 2) if you opened the door before turning the thing off, you caught a face-full of microwaves, which would eventually kill you.

Aside from this, my mother fully embraced microwave cookery and encouraged us to as well. Before long, none of us could remember what we’d done before. I could think, I want a hotdog, and, without asking my mother to cook one for me, seconds later be chewing it. Never mind that unless I wrapped it properly in a wet paper towel, a hotdog came out simultaneously dry as a stick and looking like a finger that had soaked too long in the bath. Oh, the speed though.

Here’s how a microwave works: Something called a magnetron generates microwave-band, or short electromagnetic waves absorbed into the food by water molecules that rub against each other, generating heat in the process.

Just as my mother suspected, microwaves are far more energy-efficient than a conventional oven and range. Though the microwave might create a larger drag on the grid initially, it uses far less energy thanks to shorter cooking time and greater efficiency. The energy generated goes into the food rather than being wasted by heating ambient air and the cooking container.

I remember my mother triumphantly holding a baked potato, “Four minutes — I’m never going back!” Not only is it lightning-fast, the energy savings of baking a potato in the microwave is 10-fold compared to the traditional method. As my father says, it doesn’t taste quite right, but if you gobble your food, as my family is wont to do, you have nothing to worry about. (And eventually, you’ll forget what a real baked potato tastes like.) However, if you don’t gobble your food, you might want to think of the microwave as a marvel at reheating small portions and defrosting, says Peter Barham, physics professor at Bristol University and author of the “The Science of Food.” Though only some cooking tasks transfer to the microwave despite what microwave cookbooks tried to tell us — think plasticized eggs and flaccid bacon — when one can be used, it saves an average of 50 percent of the energy used in conventional cooking.

The science has caught up with microwaves. Though a few holdouts remain — my friend who leaves the room whenever she sees one, Mrs. Alderson, and people with pacemakers — microwaves are ubiquitous as cell phones and likely safer, even according to the Union of Concerned Scientists. The FDA now maintains that radiation levels are negligible, even with your face 2 inches from the glass window, watching the action. Still, Grist magazine recommends that to be safe you shouldn’t cook food in plastic containers or “sit on, straddle, or lick your microwave while it’s operating.”


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