万花筒 2013-02-14&02-17 如何洗手最干净?洗手液-肥皂杀菌效果大对决(在线收听

 In this season of flu and so many other germs, we’re told again and again that hand sanitizers and soap are the best defense. Last year, American spent more than 170 million dollars on hand sanitizers alone. So we wandered what works best and how do the sanitizers compare in the showdown with soap? Well tonight our key medical editor doctor Richard Besser puts them to the test and gets some real answers. 

Clean? As many as 400,000 germs per hand, that’s how many bacteria travel with us every day. So here at the
University of Maryland food safety lab, 6 brave grad students and I voluntarily
dust our hands in a toxic brew, thousands of E. coil bacteria. Yeah, E. Coil.
“Good? Something a little odd about rubbing e-coil.” 
To see what would take it off. 
First up, hand sanitizers. We tested two kinds you’ll find at the store: one with 60% alcohol, and one so-called natural formula containing no alcohol. The key with hand sanitizers is to use enough of it. Your hands should take a full 15 seconds or longer to dry.
“Now let that air dry, ok?”
Then we pressed our hands onto special incubation plates to grow any remaining bacteria. The result? Dramatic. Here, those green spots are the e-coil that grew from unwashed hands. After, using hand sanitizer with 60% alcohol. But the formula without alcohol? Just look how many germs are left behind.
Alcohol-based sanitizers work so much better because alcohol breaks up the bacteria’s proteins and kills them. But if you really want to get clean, what’s your best of all? Guess what? It’s your old friend soap. Soap not only does as well on bacteria as the sanitizer, it gets more viruses too. Surprisingly, studies show regular and antibacterial soap are about equally effective. But how you use it is crucial. 
“Go!”
Most of us only spend five seconds at the sink.
“Stop!”
Just look how many germs remain. Yuk!
“Go!”
You have to wash your hands for a full twenty seconds to really get the bugs off. And yeah, that’s singing Happy Birthday twice. 
So let’s review it again. Hand sanitizers if you can get to a sink. Look for one with at least 60% alcohol, but washing with soap, any kind, is better, as long as you wash for long enough.
Dr. Richard Besser, ABC News, College Park, Maryland.
  原文地址:http://www.tingroom.com/lesson/wanhuatong/2013/229344.html