Wastewater Analysis Reveals Alarming Rise in Ketamine and Crack Use Across Switzerland

Wastewater doesn't lie. While survey respondents might hide the truth, the sewers of Switzerland are telling a stark, unfiltered story of a nation in flux. New data released by the Eawag institute for the first half of 2025 reveals a dramatic shift in the Swiss drug landscape, characterized by an alarming surge in the consumption of ketamine and crack cocaine. These findings are not mere estimates; they are hard chemical evidence pulled from the very infrastructure of our cities.

Eawag experts have bypassed uncertain sales figures to tap directly into the source, analyzing residues that offer an unvarnished glimpse into public health. The verdict is clear: Switzerland is grappling with a rising tide of potent substances. While the country has long prided itself on stability, these chemical traces suggest a volatile undercurrent in societal behavior. The data demands immediate attention, stripping away the veneer of polite society to reveal the raw reality of consumption patterns that are intensifying beneath our feet.

Zurich is cementing its reputation as the epicenter of the party scene, but the cost is becoming chemically visible. The financial capital now records ketamine levels that significantly surpass the average of all ten surveyed Swiss locations. While ketamine serves a legitimate purpose as a medical anesthetic, the Eawag data points to a different, more recreational reality. The sewers reveal a distinct temporal rhythm: levels of the drug skyrocket on weekends, plummeting during the work week.

This "weekend effect" strongly suggests that the surge is driven by the club and rave scene, where the drug is colloquially known as "Special K." The consistency of this pattern strips away the ambiguity of medical usage. We are witnessing a recreational boom. Zurich's nightlife is leaving a chemical footprint that is impossible to ignore, signaling that for many, the weekend comedown is becoming a public health statistic. The city confronts a dual identity: industrious by day, but increasingly fueled by dissociative anesthetics by night.

The crisis is not confined to the metropolises. In a startling revelation, the data exposes a significant rise in crack cocaine consumption in Chur, the capital of Graubünden. Eawag's measurement of AEME—a specific degradation product of crack—shows values in this eastern city that sit well above the Swiss national average. This shatters the illusion that hard drug epidemics are solely the problem of Zurich or Geneva.

Like ketamine, the crack markers display a disturbing weekend spike, suggesting binge consumption patterns that differ from the chronic daily usage often associated with long-term addiction. This indicates a shift in how the drug is being marketed and consumed across the cantons. The spread to regional hubs like Chur represents a critical challenge for local health authorities, who must now contend with an issue previously associated with larger urban centers. The "crack epidemic" is no longer a distant headline; it is a local reality for eastern Switzerland.

In a landscape of rising usage, a few substances are retreating. In stark contrast to the surge in dissociatives and stimulants, the consumption of methamphetamine—crystal meth—has registered a slight decrease. Since monitoring began in 2021, the presence of this highly dangerous substance in Swiss wastewater has trended downward, offering a rare glimmer of positive news in the report. Similarly, cannabis usage appears to be tapering off.

The levels of THC-COOH, the metabolic signature of cannabis consumption, were lower in the first two quarters of 2025 compared to previous years. This suggests a substitution effect may be at play: as users gravitate toward the intensity of ketamine and crack, traditional staples like cannabis and meth are seeing reduced market share. However, this shift is hardly a victory. Trading cannabis for crack cocaine represents a dangerous escalation in public health risk. As NGOs warn that "more can be done to prevent addiction," the data underscores that the battle is not just against drugs, but against the evolving, potent nature of the market itself.