Glow in the dark tampons identify sewage pollution in rivers

Tampons may not be an obvious scientific tool, but engineers from the University of Sheffield have been using them to identify where waste water from baths, washing machines, sinks and showers is polluting our rivers and streams. The natural, untreated cotton in tampons readily absorbs chemicals commonly used in toilet paper, laundry detergents and shampoos. These chemicals - known as optical brighteners -are used to enhance whites and brighten colours, and show up under ultra-violet (UV) light, a phenomenon often seen in glowing t-shirts under certain lighting in bars and clubs. Using a mixture of laboratory tests and field trials, the team from the University of Sheffield's Faculty of Engineering have shown that when tampons are suspended in water contaminated by even very small amounts of detergents or sewage, they will pick up optical brighteners and glow under UV light. The findings are published today (31 March 2015) in the Water and Environment Journal. Professor David Lerner who led the study, explained: "More than a million homes have their waste water incorrectly connected into the surface water network, which means their sewage is being discharged into a river, rather than going to a treatment plant. Unfortunately, it's very difficult to detect where this is happening, as the discharge is intermittent, can't always be seen with the naked eye and existing tests are complex and expensive.