
What could be lurking in your showerhead?
It’s a wild life, when you’re a Virginia Master Naturalist. Headwaters chapter members Adrie Voors and Stephanie Gardner recently proved just that with our participation in The Showerhead Microbiome Project. Our showerhead scanning was part of the larger Your Wild Life initiative, a series of experiments that are hosted, analyzed and interpreted by the Your Wild Life team of biologists, professional science writers, and science students.
The Your Wild Life team works with citizen scientists to collect bodily and household microbes in the human-made environment and to explore the little noticed everyday worlds of creatures around us. The projects often have a high “yuck” factor. The group’s early belly button and armpit swabbing projects got the attention of the citizen science and biological communities. Your Wild Life scientists are also looking at the microbes in sourdough bread starters, on the doorframes of houses, and on historic and modern clothing. Still other Your Wild Life projects examine mites living in facial pores, household camel crickets, cicadas, and the movements of housecats.
Much of the projects’ analytical work is done in the laboratory of Dr. Robert Dunn, Professor of Applied Ecology at North Carolina State University. Dunn has published, The Wild Life of Our Bodies, among other articles and books about microscopic wildlife and the unnoticed wildlife of the world. The Showerhead Microbiome Project involves a team of international scientists, including Dr. Dunn, with Dr. Noah Fierer at the University of Colorado as the project leader.
The Showerhead Microbiome Project had American and European citizen scientists completing questionnaires about our homes, testing for hard water, carefully swabbing the biofilm on the inside of our showerheads, and mailing the samples to scientists to culture for examination.
Your Wild Life projects move slowly, and there is often a wait of a year or more for initial results. Preliminary results of the showerhead project were released to citizen scientist participants last week. Adrie and Stephanie eagerly logged on to see what microorganisms are growing in the biofilms of our showerheads and falling on us while we bathe. The results were prefaced with an email from Dr. Dunn warning participants not to be afraid when we learn about the bacteria growing inside our bathrooms. The email reminded us that the data sets show bacteria by genera and are not yet broken down into helpful and harmful bacteria. The scientists currently believe that what was cultured in the showerheads is mostly helpful.

Stephanie’s and Adrie’s showerhead results are featured on this map. Click on the image then on the two dots around Harrisonburg to see their lists. “The results displayed by clicking on each point on the map include the presence and relative abundance of each of the top 25 most common genera over all.”
Adrie and Stephanie each yielded seven to ten of the bacterial genera tested. Oddly enough, our showerheads yielded a high percentage of bacteria other than those genera measured in the test. In initial analysis, we both noticed that our results of “Other” seem higher than those of other study participants. Could it be based on our local agricultural environment? Could it be due to our immaculate housecleaning? Is it the Shenandoah Valley water? This is still a mystery.
Future tests will continue to study the bacteria, offering more results and conclusions about household microbes growing in showerheads and what the results could mean about differing environments and water sources.
Read more about the project here: http://yourwildlife.org/2017/10/the-leopard-in-your-showerhead/
Adrie and Stephanie previously participated in the Wild Life of Our Homes project in which we swabbed doorframes in our houses for bacteria. You can read about that project here: http://robdunnlab.com/projects/wild-life-of-our-homes/
Headwater Master Naturalists may gain (citizen science) volunteer hours by participation in Your Wild Life Projects. We recommend them to people with a sense of adventure and a strong stomach.
– Stephanie Gardner, October 2017
Your showerhead is personal. It is the conduit through which water falls on you to keep you clean. It is also full of life. Showerheads can, in other words, clean you and dirty you at the same time.
We are interested in the life in showerheads, particularly the life that accumulates in biofilms (tiny microbial cities) inside the showerheads. There are many reasons to be interested in these biofilms. For ecologists, these biofilms are relatively simple (they tend to contain few species) and discreet enough to be understood. They are an opportunity to test the newest theories. For medical researchers, these biofilms can contain pathogens. For those who study cooperation, biofilms offer a model of how bacteria work together. All of these things are interesting, but among the very most interesting things about biofilms is that lurking in them we often encounter species with the potential to perform useful services for humanity. Biofilms are a font of innovation, new possibilities spraying down upon you each time you bathe.
– Dr. Rob Dunn