DIRTY BUSINESS!

This topic submitted by Katharine Fronk, Amanda Swanson, Emily Lindsay, Cat Fincun ( lindsaek@muohio.edu ) on 10/26/03 .

Natural Systems 1 Syllabus---Western Program---Miami University

Introduction:

Sitting in Alexander Dinning Hall one evening, the four of us were discussing possible ideas for our student-generated lab. We began talking about bacteria and cleanliness while eating, which then led to a conversation on hand washing. Our initial idea was to observe studentsŐ hand washing habits in the bathroom. We quickly decided, however, that this study would be difficult to objectively conduct, but we wanted to stick with the idea of cleanliness. To do this we modified our idea and came up with our present lab experiment.

Our group will be studying the amount of germs that develop in the public toilet stalls of Tappan and Peabody Halls. After doing some research we learned that there are 120 viruses in feces, so when a toilet is flushed water particles with more than 25,000 virus particles and 600,000 bacteria are ejected from the toilet bowl and can settle on any surface as far as six feet away from the toilet. These particles will last several hours and have the potential, especially in public toilets, to cause disease. These water particles can contain bacteria like salmonella or streptococcus pygoenes, which commonly causes sore throats or acute rheumatic fever. While we found this to be somewhat disturbing, we learned that the toilet seat is often not the dirtiest surface. The dirtiest places in a bathroom are as follows: exterior of the sanitary disposal bin, floor around the toilet, sink and taps, toilet seat, and then the flush handle. Perhaps what is more revolting is knowing that the toilet is usually cleaner than many kitchen surfaces because public bathrooms are more frequently disinfected and thoroughly cleaned, while kitchen counters are usually just wiped off. With all of this information we began to form our hypothesis, keeping in mind that perhaps the toilet seats would not be as germ infested as we had originally thought.

There was one other fact that helped us to form our hypothesis. It has now been established from research that the middle stalls in public restrooms are the most commonly used and thus the most contaminated. With all of our research in mind we decided that the purpose of our research would be to determine which of the toilet stalls in Peabody and Tappan Halls are most contaminated. The stall that is found to produce the most bacteria at the end of the study period will be considered the most contaminated stall. This process will be further explicated in the Materials and Methods section of this proposal.

Our lab group is expecting to find that the bathroom stalls closest to the doors (the outer stalls) will produce the least amounts of bacteria, and the inner stalls will be the most contaminated. We will be running the experiment in two halls to have more samples, which we hope will reduce the possibility for error.

Relevance of Research Question:

Our lab group feels that this experiment is relevant to college life and could have great application for the future. All of us are new to the college life, which includes our first prolonged experience using public bathrooms for our private use. We are interested in finding out how germ-infested public bathrooms really are since we have to use them every day. Germs and bacteria are also something to be concerned with when living with a large group of people because they have the potential to spread so quickly. Determining which stall is the least contaminated allows a person to attempt to reduce her exposure to disease-causing bacteria and viruses, and thus lower her chance of getting herself and those around her sick. If our results prove to be accurate, they could serve to raise awareness about personal hygiene, specifically proper hand washing to stay healthy.

Materials and Methods:

The materials we need for our experiment include:
Ą 40 Petri dishes Đ four samples per stall; 4 stalls in Peabody Hall and 6 in Tappan Hall
Ą Agar (bacteria food) to fill each Petri dish
Ą Latex gloves for sanitary purposes
Ą 40 cotton swabs to collect bacteria from seats
Ą Paper and pencils for recording data and taking notes
Ą Masking tape for labeling Petri dishes
Ą Microscope for analyzing bacterial growth
Ą Slides and cover slips for microscope evaluations
Ą Bunsen burners to heat Agar gel
Ą Cool, dark area to grow the bacteria

Procedures:
To set up our experiment, we will begin by boiling the Agar solution until it becomes clear; it will sit until it becomes thick, and then we will pour the solution into the Petri dishes. After this is ready, we can begin to collect our bacteria samples. We will take two samples from two places on the toilet in each stall; cotton swabs will be rubbed around the top of the toilet seat, while two will be rubbed underneath the toilet seat. The Petri dish will be quickly opened and the cotton swab will be swiped on the Agar solution. We will quickly close the lid so that outside elements do not taint our samples, seal the dishes, and label them for later observation. This will be repeated for each toilet stall in both bathrooms until weŐve collected 40 samples.

We will store the 40 samples in a cool, dark area in Boyd Hall, checking these samples every Tuesday and Thursday after class. When we check the samples, we will be observing mass, percentage of area covered by growth, color, and other characteristics of the colony. We will document our observations in a notebook, including drawn diagrams and perhaps digital photographs of the growth progress. One group member will be assigned to observe each one of these variables; in this way, we will have consistent documentation in each area.

Literature Cited:

Marston, Wendy. The HypochondriacŐs Handbook. Chronicle Book LLC, 1998.

Gerba, Chuck. http://www.HealthCentral.com. ŇHow Simple is Toilet Seat Sanitation?Ó September 25, 1995.

Sheff, Barbara. http://www.elibrary.com. ŇMicrobe of the Month: Streptococcus Pygoenes.Ó January 1, 2002

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