Damaging levels of illegal drugs have been found in the river that runs through the Glastonbury Festival site in the UK.
Festival goers are now being urged to use official toilets to avoid damaging the environment.
Scientists say levels of MDMA and cocaine in the river were so high that they could be harming wildlife.
It's thought to be down to people urinating outside, rather than facing the queues for the official toilet blocks.
Fiona Regan is a Professor of Chemistry at DCU says the report is fascinating;
"It's a widely studied area and it's very interesting from a social perspective because we can actually track changes in people's activities by looking at in this case at the river water wuslity looking specifically for illicit drugs but also waste water can tell us an awful lot about what people are up to."
