British scientists have found a new tool to track the source of sewage polluting our rivers: glow-in-the-dark tampons. Scientists dipped fresh tampons into the river water, and checked them out under the UV light. If they glow in UV light, it’s a clear signal that traces of organic brightening agents found in detergents, shampoos and toilet paper are present in the river.
Tampons really, really work
It is an extremely cheap and easy way to find out whether untreated sewage is being dumped into the river. The study was conducted by environmental engineers David Nicholas Lerner and Dave Mark Chandler of the University of Sheffield. Researchers said the method really works. Lerner and Chandler said over a million homes in Britain have their drains connected incorrectly. So, their sewage is discharged into the stream instead of going to treatment plants.
Existing tests to detect the sewage pollution in rivers are complex and expensive. Tampons are the cheapest way to detect them. Why do they make for such excellent detection devices? Because tampons are made with natural, untreated cotton that is an excellent carrier of optical brighteners. Other cotton materials are mostly treated with the same organic brighteners that scientists are trying to detect.
Tampons can detect even a small amount of organic brighteners
In a study published in the Water and Environment Journal, Lerner and his team said that tampons can glow for as many as 30 days after even a five-second dip in a solution with just 0.01ml of detergent per liter of water. To conduct the study, scientists suspended tampons for three days in 16 water outlets running into rivers in Sheffield.
When they tracked the tampons and checked them out under UV light, 9 of the 16 samples produced the glow associated with the optical brighteners. With the help of Yorkshire Water, a local utility, they were able to trace the path of sewage pollution backward from four outlets. While following the pipes back, researchers dipped in a cotton sample at each manhole. It helped them narrow the source down to an area where sewer lines were hooked up incorrectly.