In science, the tools of the trade sometimes aren’t very glamorous. Take the recent work done by a professor and graduate student at Sheffield University in the United Kingdom. Professor David Lerner and student Dave Chandler are using tampons to help monitor wastewater pollution in waterways.

Chandler realized that the material in tampons absorbs optical brighteners, which are found in laundry detergent, toothpaste and other cleaning products. These brighteners are not found in nature, so Chandler reasoned if a tampon suspended in a waterway showed evidence of the chemicals, it was proof of wastewater contamination.

Chandler came to his conclusion while researching the impact that combined sewer overflows have on the microorganisms living in rivers and streams. That effluent “contains organic and inorganic pollution from many sources, and can potentially have a great impact on the ecosystems they are released into,” he wrote in a paper published in the Water and Environment Journal.

Lerner and Chandler placed tampons at several different points and then monitored the results. Tampons use a type of cotton without optical brighteners, so all researchers need to do is check if they glow in ultraviolet light. If they do, it’s a sign that optical brighteners are present and wastewater has gotten into the waterway.

Lerner says lab trials discovered that just five seconds of exposure to a solution containing 0.01 mL of detergent per liter of water made tampons glow for 30 days under ultraviolet light. He says the solution was diluted more than 300 times what scientists would expect to find in surface water.

Once the lab tests were done, Chandler and Lerner placed tampons in 16 surface water outlets for three days; the tampons were tied to a structure to prevent them from floating away. They were then collected and scanned under UV light for signs of pollution. Nine showed evidence of sewage pollution. From there, they worked with the local water utility – Yorkshire Water – to follow the pipe network back from four of the outlets to find the pollution source.

To do that, they dipped tampons in various manholes to identify and isolate how wastewater was entering the waterway. Eventually, Chandler and Lerner narrowed it down to a group of homes that were inspected in closer detail to find the source.

Lerner says the next step is to test the method on a larger scale to find all sewage pollution sources on Bradford Beck, the river that runs through Bradford, England. He hopes to train a group of citizen scientists to help him on the project.