THC-COOH (Cannabis Metabolite)
Cities measured
87
Detected in
84 / 87
Highest
0.035 μg/L — Casablanca
Overview
THC-COOH (11-nor-9-carboxy-THC) is the primary urine metabolite of THC (delta-9-tetrahydrocannabinol). It is detected ubiquitously in European wastewater and rivers. Cannabis is partially or fully decriminalised in many EU jurisdictions.
Health Relevance
THC-COOH is not pharmacologically active. At environmental concentrations, no known effect on humans via drinking water. Ecotoxicological data limited.
Regulatory Limits
Drinking Water Directive 2020/2184
No regulatory limit.
Controversy & Contested Science
EMCDDA WBE data show cannabis use is the most geographically widespread substance use in Europe — THC-COOH detected in virtually every monitored EU city. Germany's 2024 legalisation is expected to increase THC-COOH loads in wastewater by 30–40%, requiring additional treatment. The environmental cost of cannabis legalisation — increased pharmaceutical-style monitoring, potential agricultural pesticide runoff from cultivation — is rarely discussed in policy debates focused on criminal justice and public health.