Even though it comes in contact with hot water and soap multiple times daily, your kitchen sink is probably crawling with bacteria -- <a href="http://www.oprah.com/blogs/Whats-Worse-Dropping-Food-in-the-Kitchen-Sink-or-on-the-Kitchen-Floor" target="_blank">perhaps even more than you'd find on the toilets of public bathrooms</a>, which may be regularly scrubbed with powerful disinfectants. A recent study by <a href="http://www.nsf.org/" target="_blank">NSF International</a>, a nonprofit organization that develops public health standards, found that because of the frequent contact they have with food, kitchen sinks are 100,000 times more contaminated than bathroom sinks. Scrub the entire surface of yours down once or twice a week with hot water and soap, making sure to remove every trace of coffee grinds, scrambled eggs or whatever else you see.
Washing the inside of this workhorse every 40 to 80 brews won't just make your coffee taste better -- it'll also eliminate the bacteria and mold that NSF says tends to grow there because of the dark, damp environment. Fill the tank (or reservoir, as it's called on some models) with about four cups of vinegar and let it stand for 30 minutes. Run a cycle with the vinegar, followed by two or three cycles with water until the vinegar smell fades.
If we had to guess, we'd put the refrigerator door handle or microwave keypad ahead of stove dials when it comes to dirt level -- but the controls that adjust your range's heat are some of the filthiest places in your home, since you often touch them when your hands are contaminated with food, and they're harder than the fridge door handle or microwave buttons to wipe clean, according to the NSF study. Check your stove's owner's manual for cleaning instructions; you may be able to put the dials in the dishwasher (if not, wash in warm soapy water, rinse well and dry before replacing).
This benign-seeming bathroom cup is one of the germiest spots in the house: <a href="http://www.nsf.org/consumer/newsroom/pdf/fact_germs_top5_germiest_places.pdf" target="_blank">the average holder is crawling with more than 2 million cells of bacteria</a>. Bamboo and wood may look attractive, but they're difficult to clean, so go with a dishwasher-safe material like brushed stainless steel, or plastic, and clean it once or twice a week.
The average vacuum cleaner's suction and rotating-beater brush don't usually reach the bottom of the carpet, and that area is a haven for bacteria -- about 200,000 per square inch, according to research conducted by <a href="http://pathology.med.nyu.edu/people/faculty/tierno-philip-m" target="_blank">Philip Tierno, Jr., PhD</a>, a microbiologist and immunologist at New York University Langone Medical Center. In his book, <a href="http://www.amazon.com/Secret-Life-Germs-Protect-Ourselves/dp/B001PO68K6" target="_blank">The Secret Life of Germs</a>, Tierno explains that hundreds of thousands of different types of species feast on human skin cells that fall onto rugs, plus tiny pieces of food, pollen and pet dander. Most carpet manufacturers say the best way to deep clean is to use steam, aka hot-water extraction, every 18 months.
This is one of the most high-traffic surfaces in people's homes, say the experts at NSF, with everything from purses to bags of groceries to packages of raw chicken leaving behind all types of germs. After cooking or preparing food, and at the end of every day, wash the surface with hot, soapy water, then rinse. (<a href="http://www.casabella.com/index.php/kitchen-super-sponge-squeegee.html" target="_blank">Casabella's new sponge/squeegee</a> lets you easily soap up counters, rinse and swipe water off.)
Pet Food Dish
Although most dogs eat twice a day, you don't have to wash the container after every meal -- once a day is sufficient. Run it through the dishwasher or scrub it by hand with hot water and soap. <a href="http://www.vetstreet.com/" target="_blank">VetStreet.com</a> recommends stainless steel or <a href="http://www.amazon.com/Crock-Style-Dish-Cats-Dogs/dp/B002DZM37I" target="_blank">heavy plastic "crock-style" bowls</a>, since they hold up best through frequent cleanings.
We've heard these scrubbers can be a breeding ground for bacteria -- and the NSF study confirms that it's not only possible but likely that the one near your sink contains E. coli and salmonella bacteria. NSF found that after three weeks of use, 70 percent of sponges started exhibiting bacteria -- but germophobes shouldn't wait that long to clean or replace theirs. A two-minute turn in the microwave can kill most of the viruses, parasites and spores that grow on sponges, and the organization recommends changing to a new one every two weeks or less.
Bathtub And Shower
Over the course of its research in American homes, NSF found that 26 percent of bathtubs and showers harbored the bacteria known as staphylococci, <a href="http://www.ncbi.nlm.nih.gov/books/NBK8448/" target="_blank">which can cause problems from superficial skin lesions to urinary tract infections</a>. You can keep these germs at bay by using a mild shower spray daily ( just avoid abrasive cleaners).
<strong>Next: <a href="http://www.oprah.com/home/House-Cleaning-Tips-From-a-Professional" target="_blank">Cleaning secrets from a top real estate broker</a></strong>