A study of the water in Italy’s Po river has revealed some rather embarrassing news about the recreational habits of residents living near the country’s longest waterway: The inhabitants snort some 200,000 lines of cocaine daily.

The discovery came after researchers from the Mario Negri Institute for Pharmacological Research in Milan measured the amount of bezoylecgonine, the compound produced when the body breaks down cocaine, in sewage water samples.

The findings were reported in the science journal Nature, based on a study published in Environmental Health.

An estimated 5 million people are responsible for sewage that runs into the Po, which flows across northern Italy, spilling out to the Adriatic, near Venice.

Ettore Zuccato, who led the team of scientists, said the amount of blow in the water flow suggested drug use was higher than expected.

The same researchers used the technique in the past to measure pharmaceutical levels. But this is the first time it’s been used to measure a community’s illegal drug abuse, Nature reported.

Cocaine is a stimulant that comes from the coca plant. It is addictive, creates a sense of euphoria, increases energy, and decreases appetite. It is illegal in most parts of the world.

The Italian researchers plan to look for other illegal drugs in sewage water. However, the waste-water technique cannot detect marijuana usage. Heroine also poses challenges.

Most cocaine comes from Colombia, Bolivia, and Peru, according to Interpol, a global police organization. An estimated 60 percent of all cocaine that leaves Latin America winds up in Europe and North America.

It was unclear whether the information would be used by authorities.