Bleach Basics

Everyone knows that bleach is a good weapon in the war on germs, but until recently, it wasn't clear just how the liquid did its job. Research from the University of Michigan has shown that bleach works thanks to its active ingredient, hypochlorous acid. The compound attacks proteins in bacteria, causing them to clump together and eventually die. The reaction is similar to the way in which bacteria responds to high temperatures. The hope is that this discovery will help scientists better understand how people fight off infections.

Bacteria in Your Home: Germ Geography

Think a doughnut dropped on your sparkling kitchen floor might be edible with just a quick brush off? It might be -- if you'd have no problem eating something out of the garbage. A study from the Hygiene Council (sponsored by the company that makes Lysol) found that kitchen floor just in front of the sink has more bacteria (830 per square inch) than the trash can (411 per square inch). Other surprises included the fact that the sponge held 60 times more bacteria than the pet's food bowl and that the kitchen counter was more germy than the toilet seat [source: CBS News].

In fact, toilet seats get a bad rap all around. A recent study by Gerba has shown that they're not even the dirtiest place in the bathroom. That honor goes to the toilet paper dispenser, with more than 150 times the bacterial levels of the porcelain throne. The next most contaminated spot is the paper towel dispenser, which harbors 50 times more germs than seats [source: Reuters].

To further defend the commode, your cell phone carries 25,000 germs per square inch, while toilet seats hold only 344 bacteria in the same space -- and we all know how much time we spend with our mobiles pressed close to our mouths [source: Sinovic]. Among the germs clamoring to join our conversations are staph, found on nearly half of 25 random mobile phones tested by Gerba [source: ABC News Health].

When the "germ guru" turned his attention to another everyday item -- women's purses -- the results weren't any more encouraging. Through a small random field test, the numbers of bacteria found on the bottom of ladies' bags ranged from small numbers to the nation-sized amount of 6.7 million [source: Leamy].

Fortunately, most of the germs that are crawling around our desks, on our phones and beneath our bags are of the benign kind and are kept under control with basic hygiene. But people with compromised immune systems, or those who spend time in areas likely to be contaminated with E. coli or salmonella, should definitely think for at least five seconds before putting anything in their mouths that has touched the floor.