Date of Award
Master of Science (MS)
A drinking fountain, also called a water fountain, is a facility designed to provide drinking water in public space. It consists of a basin and a spout. The users need to bend down to the stream to collect or drink water. The history of water fountains can be traced back to ancient Rome. Even before potable water was provided to individual homes, water for drinking was already made available to citizens through access to public fountains. Nowadays, drinking water fountains usually exist in public places, like schools, hospitals, and libraries. Many jurisdictions in the United States require drinking fountains to be wheelchair accessible (by sticking out horizontally from the wall) and to include an additional unit at a lower height for children and short adults .
At the start of the 20th century, it was discovered that the original design of fountains, which contain a vertical spout, were implicated in the spread of contagious diseases . Due to this reason, the vertical design of drinking water fountains was changed, and an acute angle was introduced at the flow leaving the spout. Some governments even require water spouts to be as long as four inches to meet health standards . Although the design of drinking water fountains has been improved, the risks of it spreading diseases still exist. One potential source is the water supply, as it has been found that biofilm microorganisms can proliferate on the pipe internal walls. Another source is the humans accessing the water fountain, as microbes from the skin and saliva could shed onto the fountain surfaces. Therefore, we deducted that the microorganisms on the surface of the drinking water fountains may come from the running water and human activities.
In developed countries, drinking water fountains are very common in public places. Although changes have been made in the design of drinking water fountains, the drinking water fountain is still overlooked as a source of daily exposure to opportunistic pathogens. In particular, biofilm-associated microorganisms on fountain spouts, basins and drains can be resuspended and form droplets and aerosols. Then they can be transferred to people. Despite the high usage and sanitary risk, to our best knowledge, there has not been a systematic examination of the diversity, composition, and variation of the biofilm communities that develop on water fountains. A better understanding of biofilm-associated bacteria from drinking fountains can help people understand the potential risks of using these facilities.
Inspired by our biofilm studies from other aquatic biofilms in the built environment, we first hypothesize that water fountains contain a significant number of microorganisms and some of these organisms can be harmful to people. Second, we hypothesize that there are differences in bacterial loading among different regions on the fountain surfaces. Further, there are differences in bacterial loading between lower and higher fountains in a co-located pair. To test these hypotheses, a sampling projector has been designed to precisely delineate the sampling areas and regions. Seven different buildings with consistent fountain designs were taken as sampling sites. After collecting the water fountain surface samples, we performed DNA extraction with phenol-chloroform. Then the Real Time-PCR and Miseq sequencing will be used as the main molecular experimental methods to get further biomass loading information and community compositions data.
The findings of this project are expected to build the methodological foundation to test these hypotheses. We expect to discover influences by multiple designs and human variables, such as the material and age of the water supply pipe systems, how often the fountain is used, the time at which samples were taken, the surface finish of the basin, and the ambient temperature. The final analysis can include these variables as needed. Our study is innovative because it will provide a sampling method to examine a highly overlooked facility in our daily life at a high spatial resolution. With our method, the future study can better understand the spatial variation of health-threatening microorganisms within a fountain set, which will eventually lead to better designs of drinking fountains.
Dr. Pratim Biswas
Dr. Fangqiong Ling Dr. Yinjie Tang Dr. Solanki Avni