While it may not be the most glamorous of scientific instruments, engineers believe that tampons could actually help clean up polluted rivers and streams.
Engineers believe the super absorbent properties of tampons could be used to detect pipes that are leaking sewage into streams instead of treatment plants. They found that the cotton products absorb chemicals commonly used in toilet paper, detergents and shampoos, which glow under UV light, meaning they could actually shed light on previously undetectable leaks and misplumbed pathways.
Professor David Lerner, who led the study at the University of Sheffield's Faculty of Engineering, 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."
Now, however, his team have shown that tampons can glow in ultra-violet light because they absorb chemicals found in products containing "optical brighteners" that are used to brighten colors.
"The main difficulty with detecting sewage pollution by searching for optical brighteners is finding cotton that does not already contain these chemicals," Professor Lerner said.
"That's why tampons, being explicitly untreated, provide such a neat solution. Our new method may be unconventional - but it's cheap and it works."
Lab trials determined that exposure to a solution of just .01ml of detergent per liter of water allowed the tampon to glow for 30 days. Scientists with the help of Yorkshire Water followed a pipe network back from a polluted outlet they identified, dipping a tampon in at each manhole to see where the sewage entered the system. This enabled them to successfully isolate the section where the leak originated thus narrowing down the households which would need to be inspected.
Professor Lerner said, "Often the only way to be sure a house is misconnected is through a dye test - putting dye down a sink or toilet and seeing where the coloured water appears in the sewer."
"It's clearly impractical for water companies to do this for all the households they supply, but by working back from where pollution is identified and narrowing it down to a particular section of the network, the final step of identifying the source then becomes feasible."
Most households don't even realize they are connected to the wrong discharge system and, once notified, immediately repair the problem.
