New tests commissioned by the Associated Press have revealed that the waterways to be used for the 2016 Summer Olympic Games in Rio de Janeiro are as widely contaminated with pathogens further offshore as they are near to land, posing an even greater threat to athletes’ health than previously known.

Guanabara Bay, Rio.

Guanabara Bay, Rio. Image by Raoni / CC BY 2.0

Water quality test results in July revealed disease-causing viruses directly linked to human sewage at levels 1.7 million times beyond what is considered highly alarming by US or European standards. Fetid sewage flows from rivers and storm drains directly into waterways – including Guanabara Bay and Rodrigo de Freitas Lagoon, where Olympic events will take place – without any dilution factor. Experts say athletes who competed in pre-Olympic trials in the waters earlier this year did so in the viral equivalent of raw sewage, and such exposure poses almost certain dangerous risks to their health. Read more: