Researchers from the University of Sheffield have developed a cheap and effective way to test surface waters for certain pollutants: tampons. The pollutants in question are chemicals found in laundry detergents, shampoos, and toilet paper, which are general used for increased whitening. Called optical brighteners, they show up under UV light, and are the same chemicals that sometimes cause t-shirts to glow in bars and nightclubs.
When these chemicals enter surface waters, such as streams, rivers, or lakes, they can cause ecological damage. They impact the bacterial and invertebrate ecosystems, and can lead to an increase in detergent resistant organisms, such as “sewage fungus” which appears as a grey film on the bottom of streams and rivers. Waste water can also contain pathogens like norovirus, which can cause severe gastroenteritis.
These chemicals find their ways into surface water because some houses aren’t connected to the correct sewage pipes. In the UK, around a million such homes exist, and when identified, the problem is usually rectified quickly. The problem is identifying those homes. Usually, water companies would have to release dyes into the plumbing of a house, then see where that dye showed up later, but doing this for every home is prohibitive.
With the Sheffield team’s process though, figuring out which houses are incorrectly connected is much easier. Because tampons contain untreated cotton, they collect these chemicals very quickly, even at levels well below dangerous. When hit with a UV light, they glow in the dark, meaning the water is contaminated. From there, it’s a matter of testing each point at which sewage might hit the run off, and then keep working up the branches until you get back to houses that could, potentially, be the root of the problem.
The tests have worked in labs and in a minimal field test, and will next be put to work testing the waters of the Bradford Beck, a river which runs through the city of Bradford.