Tampons Detect Hidden Sewage Pollution

Engineers from the University of Sheffield devised a simple yet effective method in March 2013 to identify sewer misconnections, a problem where household wastewater enters surface-water drains. They suspended ordinary tampons in 16 surface-water sewer outlets for three days.

These tampons were then examined under ultraviolet light. Nine of them fluoresced, indicating the presence of optical brighteners from household cleaning products. These chemicals are commonly added to detergents and are not naturally found in surface water, thus acting as reliable indicators of sewage pollution.

The study, published in the Water and Environment Journal in 2015, highlighted that cotton tampons proved ideal because they did not contain interfering optical brighteners. Even brief exposure to a dilute detergent solution allowed tampons to retain detectable levels of these brighteners.

This passive sampling technique, costing approximately 20 pence per sampler, helped researchers narrow down the search for misconnections. Yorkshire Water collaborated with the engineers, who progressively tested sections of the drainage network, eventually isolating specific areas where sewage was entering surface-water systems.

In one instance, this approach led to the discovery of a house with its sink and soil stack incorrectly connected to the wrong waste pipes. The method offers an inexpensive way to identify potential pollution, complementing more expensive traditional testing methods.