Every day, hundreds of students use the hand dryers in M-A’s bathrooms after washing their hands in one of the twelve bathrooms dispersed throughout the school.
According to a Harvard Health Blog article, “Every time a lidless toilet is flushed, it aerosolizes a fine mist of microbes [that] may disperse over an area as large as six square meters (65 square feet).” Hand dryers pull air in through the vents located on their sides. Essentially, every time a student uses a hand dryer, fine mists of microbes are re-blown onto their hands. While microbes exist in abundance in your body, such as bifidobacteria, which helps regulate your GI tract, ones that are unfamiliar to your body and cause infections (such as E. coli.), can be problematic and cause illness. Luckily, only a small percentage of microbes are harmful to your body.
We tested all but one hand dryer on campus to see how hygienic they were. We were not able to test the G-wing boys’ bathroom because it was closed.
We collected samples by holding a petri dish under each dryer while it ran for five seconds. The petri dish had a layer of lurry broth agar on top. Agar plates are commonly used in experiments because they provide the necessary nutrients for bacteria to grow.
We incubated each petri dish at 37.6 degrees Celsius (human body temperature) for three days. Our results showed significant amounts of bacteria and fungi, which could lead to an increased spread of illness and bacterial infections.
E-Wing Bathrooms
In the sample from the E-wing boys’ bathroom, there was a large fungus that spread halfway around the rim of the plate and a single colony of bacteria. There is a chance that more bacterial colonies were consumed by the fungus. In the girls’ bathroom, there was one larger colony of bacteria and one small colony but no visible fungus.
D-Wing Bathrooms
In the D-wing boys’ bathroom sample, a large fungus covers a third of the plate, as well as five unique colonies of bacteria. Two out of the five colonies are likely to be Staphylococcus aureus, a bacteria that causes acne. They are very distinct in nature due to the bright yellow color and distinctly smooth appearance. In the girls’ bathroom, there is fungus, a colony of Staphylococcus aureus, and another bacterial colony whose identity is unknown.
G-Wing Bathrooms
On the G-wing girls’ petri dish, there were two competing fungi, one with a brown color and the other yellow, and four bacteria colonies, the bright yellow of which is Staphylococcus aureus.
K-Wing Bathrooms
The K-wing bathrooms had the least amount of bacteria and/or fungi on them, with each plate only having a couple of bacteria colonies present. The boys’ bathroom had a total of three small colonies, one of which was Staphylococcus aureus, while the girls bathroom had two colonies of bacteria.
I-Wing Bathrooms
In the I-wing, both bathrooms had significant amounts of bacteria. In the boys’ bathroom, there was one large fungus taking over a third of the plate, and seven bacterial colonies, two of which are the acne-causing variety of Staphylococcus aureus. In the girls’ bathroom, there is a large fungus overtaking the middle of the plate, which has likely consumed some bacterial colonies there. In total, there were sixteen bacterial colonies across the I-Wing bathrooms, making it the most infected out of all the bathrooms at M-A.
M-A’s bathrooms fared well compared to some other bathrooms. At the University of Connecticut School of Medicine, researchers averaged 18 to 60 colonies of bacteria per plate after holding it under the dryers for 30 seconds.
While seeing these results might be alarming, rest assured that most bacteria in your body is beneficial, and actually helps protect you and keep your immune system functioning so that the small percentage of bad bacteria that does exist doesn’t cause severe harm. As for washing your hands, soap and water do just fine and paper towels, while not the most environmentally efficient option, are generally considered to be safer. Even wiping your hands on your jeans is better than using the hand-dryers. In conclusion: ew, ew, ew.
