Fiocruz detects cocaine contamination in Rio de Janeiro waterways

Research led by the Oswaldo Cruz Institute (IOC/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 that flow into Guanabara Bay: the Irajá and Carioca rivers, the Cunha and Mangue canals, and the Meriti River.

Benzoylecgonine, a substance produced by the human body after cocaine consumption and excreted through urine, was present in every sample collected. Cocaine itself was detected in all but one sample. Researchers noted that the contamination levels found in these Brazilian waters exceeded those recorded in similar studies conducted in the United States, Spain, and Belgium.

Scientists state that the presence of these substances highlights both drug circulation and significant deficiencies in sewage treatment, which allows untreated waste to reach local waterways. The contamination poses risks to aquatic ecosystems; experiments conducted on zebrafish embryos showed increased mortality, physical deformities, and neurological and cardiovascular alterations when exposed to the concentrations found in the rivers.