Potty Talk

Well, my friends, this is not your usual blog posting from the Meadster. Judy and I were watching the BBC America show called "How Clean Is Your House?" If you have ever watched the clean team of Kim and Aggie take on discusting, filthy homes, you know that Aggie is the scientific lady of the team who tells the owners of the house such things as the population of deadly bacteria in the sinks and types of insects living in the carpets and furniture. During this episode, Aggie mentioned that one should ALWAYS close the lide of the commode before flushing because fecal material is thrown into the air and floats around and lands feet away from the toilet. Is your toothbrush drying near the potty? I thought she was crazy! WELL!

University of Arizona environmental microbiologist Charles Gerba published a scientific article in 1975 describing bacterial and viral aerosols due to toilet flushing. He conducted tests by placing pieces of gauze in different locations around the bathroom and measuring the bacterial and viral levels on them after a toilet flush, and his results are more than just a little disturbing.

First is the confirmation of the existence of the aerosol effect, even though it is largely unrecognized. "Droplets are going all over the place—it's like the Fourth of July," said Gerba. "One way to see this is to put a dye in the toilet, flush it, and then hold a piece of paper over it". Indeed, Gerba's studies have shown that the water droplets in an invisible cloud travel six to eight feet out and up, so the areas of the bathroom not directly adjacent the toilet are still contaminated.

Walls are obviously affected, and in public or communal bathrooms, the partitions between stalls are definitely coated in the spray mist from the toilet. Also, toilet paper will be cleanest when it is enclosed in a plastic or metal casing; after all, it's subject to the same droplets splattering on it, and its proximity to the toilet bowl makes contamination potential obvious. The ceiling is also still contaminated and is in fact a potential problem site because it is often overlooked in the cleaning process. Bacteria cling to ceilings and thrive in the humid environment there; if the situation is left untreated for months or years (as is often the case), odors remain in restrooms that seem to have been to be otherwise thoroughly cleaned. The bacterial mist has also been shown to stay in the air for at least two hours after each flush, thus maximizing its chance to float around and spread.

Your toothbrush, with its traditional holder in an uncovered spot in the bathroom, it is one of the hotspots for fecal bacteria and germs spewed into the air by the aerosol effect. Understandably, the toothbrush with toilet water droplets on it is one of the most retold horror stories to emerge from Gerba's report.


"The greatest aerosol dispersal occurs not during the initial moments of the flush, but rather once most of the water has already left the bowl," according to Philip Tierno, MD, director of clinical microbiology and diagnostic immunology at New York University Medical Center and Mt. Sinai Medical Center. He therefore advises leaving immediately after flushing to not have the microscopic, airborne mist land on you. Worse still is the possibility of getting these airborne particles in the lungs by inhaling them, from which one could easily contract a cough or cold.


To limit the scope of the aerosol effect, the simplest method is to close the lid on the toilet every time before flushing . This would also provide the peace of mind that while you are washing your hands for 30 seconds, microscopic, bacteria-laden water droplet will not be descending upon your person. Unfortunately, most public toilets don't even have lids for that option. Besides, given the large number of people who have used the toilet before you, it probably wouldn't make much difference. After washing your hands, use a paper towel to turn off the faucet and to open the door to leave, in order to avoid being recontaminated. And today, get a new toothbrush and always, always keep it in the medicine cabinet or some other enclosed place after use.

Enough of this potty talk! Hope you are having a great weekend.

(Thanks to Sarah Tan for the microbiology information that was incorporated in her paper written for her Biology 103 class.)