Fight germs with gadgets?

Toilet seats get a bad rap, says Charles Gerba, an environmental microbiologist at the University of Arizona. Indeed, because of what goes on there, we tend to consider bathrooms -- even the most respectable bathrooms -- as generally less than sterile. That view, it turns out, is unfair.

In many studies, Gerba and his colleagues -- who call the longtime bacteria and virus researcher Dr. Germ -- have found that toilet seats are often one of the least germ-infested areas in your house. Much of the rest of the bathroom, too, isn't especially toxic. If you're really worried about germs, look to the kitchen.

"Cutting boards are just terrible," Gerba said, by way of example. "There's 200 times more bacteria on a cutting board than a toilet seat."

Several gadgets promise to reduce or eliminate many household pathogens. But then what?

Germs' power derives from their invisibility. How do you know if the high-tech germ destroyers are working well? Gerba said you more or less have to take it on faith. When it comes to claims of a specific product's effectiveness, firm answers are hard to get without your own lab.

Consider the VIOlight UV Cell Phone Sanitizer, a $40 device that promises to eliminate 99.9 percent of the bacteria and other nasties sitting on your phone. It purports to do so by using a beam of ultraviolet light, which is a specific wavelength of light that, when focused precisely, penetrates and damages the DNA of microorganisms.

Gerba said ultraviolet-based systems have been used in commercial and industrial sanitizing applications for many years. The technology is getting small and inexpensive enough to be found in many consumer devices, too. Most of the devices mentioned here use UV light as their primary cleaning agent.

You're on slightly firmer ground with another VIOlight device -- the $30 toothbrush sanitizer. This looks like a standard toothbrush holder, but when you press a button on the front, a UV light shines on the germs on your brush. According to a 2008 study published in the American Journal of Dentistry, toothbrushes treated with the VIOlight had 86 percent fewer "colony-forming units" -- a measure of germs -- than toothbrushes that were just rinsed in cold water. The study does note, however, that there's no proof that a cleaner toothbrush results in better oral health.

UV light also can help with your cutting board, that epicenter of household filth. The CleanWave Sanitizing Wand, a $70 device made by Verilux, looks like a shrunken light saber, and to attack your germs, you can play Luke Skywalker. Turn on the wand, hold one edge against a flat surface -- your cutting board, your countertop, your desk -- and slowly move it back and forth over the area you'd like to sanitize.

Of all the applications for UV, Gerba said studies show that it is most effective on hard, nonporous surfaces such as cutting boards. Even though you can't tell if it's working, there's a high likelihood that the wand will clean a cutting board far better than would most other home cleaning products, and it contains no harmful chemicals.

Honeywell's HEPAClean UV Antibacterial Air Purifier (about $200) uses UV lights -- in addition to several layers of filters, which are used in many air purifiers -- to kill germs passing through the air. It promises to eliminate 99 percent of such pathogens -- but, of course, you have no way to test that.

Besides UV, another high-tech sanitizing method is "super-oxygenated water," which is used in commercial agriculture.

You can fill the bowl with items to sanitize -- fruit, vegetables, meat, dishcloths, sponges, baby bottles, pacifiers -- or use the spray bottle for general cleaning. It's harmless, and effective even against stains. But how do you know the product actually harnesses the proven oxygenating process to work well? Once again: You don't.