CRI听力:Study shows Rio's waterways, beaches still dangerously filthy

Just days ahead of the Olympic Games the waterways of Rio de Janeiro are as filthy as ever, contaminated with raw human sewage teeming with dangerous viruses and bacteria.

That is according to a 16-month-long study commissioned by The Associated Press.

Not only are some 1,400 athletes at risk of getting violently ill in water competitions, but the tests indicate that tourists also face potentially serious health risks on the golden beaches of Ipanema and Copacabana.

The survey shows consistent and dangerously high levels of viruses stemming from the pollution.

The first results of the study published over a year ago showed viral levels at up to 1.7 million times what would be considered worrisome in the United States or Europe.

At those concentrations, swimmers and athletes who ingest just three teaspoons-full of water are almost certain to be infected with viruses that can cause stomach and respiratory illnesses and more rarely heart and brain inflammation.

Dr. Fernando Spikli is virologist and coordinator of the molecular microbiology laboratory at Feevale University.

He says that whether or not exposed people are actually infected depends on the health of an individual's immune system.

"Basically, almost 100 percent of the people who come into contact with this water will get infected with different illnesses, but getting sick will only happen in some of those people because it all depends on the immunity level they have. For the athletes, adults, I'd say that the risk of infection is the same but the risk of illness is not as high as it is for some tourists, especially children, elderly, and people with immunity problems. Those people are at risk when they come into contact with such polluted water."

The extent of contamination is known to athletes, who have been taking elaborate precautions to prevent illnesses that could potentially knock them out of the competition, including preventatively taking antibiotics, bleaching oars and donning plastic suits and gloves in a bid to limit contact with the water.

But antibiotics only protect against bacterial infections, and not viruses. This while adenovirus readings, tested with cell cultures and verified with molecular biology protocols, turned up at nearly 90 percent of the test sites over 16 months of testing.

While athletes take precautions, what about the 300-500 thousand foreigners expected to descend on Rio for the Olympics?

Dr. Valerie Harwood is Chair of the Department of Integrative Biology at the University of South Florida. She has some advice for visitors to Rio's beaches:

"I would say, go walk on the beaches and have a nice time. I would say don't let your kids eat the sand and don't put your head underwater."

Harwood says swimmers who cannot heed that advice stand to ingest water through their mouths and noses and therefore risk getting violently ill.

Contaminated beaches and dangerously filthy water—It's not a reputation that any Olympic City wants associated with it. But with the opening ceremony just days away, it's too late for Rio to do anything to shake it.

Mario Moscatelli, a Brazilian biologist and environmental activist, calls this not only a failure, but above all, a missed opportunity.

"I don't see any change from the authorities. What I see are polluted lagoons, contaminated by sewage, which expel methane and sulphuric gas. I see Guanabara Bay, which has had three fourths of its coast transformed into a latrine, full of rubbish and, unfortunately, the opportunity for Rio to clean its waterways by the time the Summer Games started, maybe the last big opportunity, was missed."