Scientists recently discovered a "MacGyver" solution to the expensive and time-consuming problem of detecting sewer pollution from leaky pipes or illegal drains. The new technique involves deploying tampons in streams and stormwater systems instead of spending thousands of dollars in conventional but more expensive methods, such as installing fiber optic cables to monitor contamination.
"It's cheap, it's easy and it does the detective work," said study co-author David Lerner, a professor of environmental engineering at the University of Sheffield in the United Kingdom, in an interview with wired.com.
Unlike sanitary sewers which collect everything that is flushed or rinsed down the drain, storm sewers collect rain from roofs, paved roads and parking lots that is emptied into streams and rivers. It is important that the two systems are kept separate since storm sewers are not designed to receive untreated waste waters. When this does occur, it is called "grey water" contamination. It is often a result of incorrectly connected waste water pipes or dumping.
"All you need is for someone to have a cowboy builder and connect their appliances to the wrong drain and you have sewage going into the river," said the study's lead author David Lerner, a professor of environmental engineering at the University of Sheffield, in an interview with Newsweek.
In order to confirm the accuracy of the "tampon test," Lerner's team suspended tampons on rods above 16 different water outlets which ran into rivers and streams. These were then dipped in diluted detergent for five seconds. When placed under ultraviolet light, the results showed that nine of them had optical brighteners, indicating the presence of water pollution.
Since optical brighteners are a regular additive to detergents that are common in laundry water but do not occur naturally in rivers and streams, they are a useful marker for contamination from human grey water sources.
The team also found that tampons pick up even small amounts of optical brighteners. The only problem with this unconventional solution was that people sometimes removed or threw away the tampons at test sites. "We just tried to hide them better," Lerner said in an interview with livescience.com.
Unlike with most experiments, this is safe to try at home, according to Lerner. All you need is a box of tampons - make sure to save dry ones as a reference point -, an inexpensive UV light, and a completely dark room or black box.
He just had a word of caution concerning curious onlookers: "You do get people looking at you strangely, but the tampon is not that obvious."
