The Municipality of Public Cleaning, an agency of the Manaus City Hall, says that an average of 30 tons of garbage is removed daily from the Amazon waterways — but that doesn’t seem to have made more than a dent in the problem. “Half of this waste is dumped by the residents themselves, unfortunately,” says da Conceição. “But the other part is thrown out by people from other neighborhoods — we see everything from plastic bottles to refrigerators to dead animals.”

It’s also the primary source of waterborne diseases that afflict residents, according to infectious disease specialist Antônio Magela of the Fundação de Medicina Tropical do Amazonas. The most common diseases, says Magela, are hepatitis A and E, acute diarrhea, intestinal parasites like amoebiasis and giardiasis, and also leptospirosis, an infectious bacterial disease.