# Cocaine contamination in Rio de Janeiro waterways > Live situation record from CLSTR: https://clstr.news/situations/cocaine-contamination-in-rio-de-janeiro-waterways > Updated: 2026-10-10T23:30:00.000Z. Sources: 4. Developments: 2. Research led by the Oswaldo Cruz Institute (Fiocruz) has identified cocaine and its primary metabolite, benzoylecgonine, in several rivers and canals within the Rio de Janeiro metropolitan area. The study analyzed water samples collected between July 2022 and June 2023 from five waterways flowing into Guanabara Bay, including the Irajá, Carioca, and Meriti rivers. Benzoylecgonine was present in every sample, and cocaine was detected in nearly all samples. Researchers noted that contamination levels in these Brazilian waters exceeded those recorded in similar studies in the United States, Spain, and Belgium. Scientists indicate that the presence of these substances reflects both drug circulation and deficiencies in sewage treatment, as untreated waste allows these substances to reach local waterways. The contamination poses significant risks to aquatic ecosystems; experiments on zebrafish embryos showed increased mortality, physical deformities, and neurological and cardiovascular alterations when exposed to the concentrations found in the rivers. ## Timeline ### 2026-10-10: Cocaine detected in Rio de Janeiro rivers amid rising trafficking in Portugal Cocaine contamination has been detected in Rio de Janeiro's rivers, while Portugal faces a rise in organized crime trafficking via narcolanchas. 2 sources. https://clstr.news/cluster/cocaine-detected-in-rio-de-janeiro-rivers-amid-rising-trafficking-in-portugal ### 2026-10-09: Fiocruz detects cocaine contamination in Rio de Janeiro waterways Fiocruz researchers found cocaine and its metabolites in rivers and canals flowing into Rio de Janeiro's Guanabara Bay, noting risks to aquatic life and issues with sewage treatment. 2 sources. https://clstr.news/cluster/fiocruz-detects-cocaine-contamination-in-rio-de-janeiro-waterways --- Cite as: Cocaine contamination in Rio de Janeiro waterways. CLSTR, https://clstr.news/situations/cocaine-contamination-in-rio-de-janeiro-waterways