A 2016 Rio Olympics venue is full of human waste and teeming with viruses - here's what it looks like

Days after the head of the International Olympic Committee identified Rio de Janeiro's polluted waterways as the No. 1 challenge facing the 2016 Olympics, an Associated Press investigation revealed just how dangerously filthy these waters really are.

The AP tested the water and found that Guanabara Bay, Copacabana beach, and Rodrigo de Freitas Lake - all of which will host watersports events next summer - aren't safe for swimming or boating, and contain concentrations of viruses that are "roughly equivalent to raw sewage."

"As a result, Olympic athletes are almost certain to come into contact with disease-causing viruses that in some tests measured up to 1.7 million times the level of what would be considered hazardous on a Southern California beach," the AP reports.

The pollution is the result of untreated human waste pouring into the waterways. It has been a public health issue in Rio for decades, but with the world's biggest sporting event 12 months away, Rio's waters are literally being put under the microscope.

Looking at recent photos from these polluted venues, it's alarming that they'll be hosting the Olympics in 12 months.