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, according to a 16-month-long study.

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

The survey of the aquatic Olympic and Paralympic venues has revealed consistent and dangerously high levels of viruses from the pollution, a major black eye on Rio’s Olympic project that has set off alarm bells among sailors, rowers and open-water swimmers.

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 US or Europe. At those concentrations, swimmers and athletes who ingest just three teaspoons of water are almost certain to be infected with viruses that can cause stomach and respiratory illnesses and more rarely heart and brain inflammation — although whether they actually fall ill depends on a series of factors including the strength of the individual’s immune system

Since the release of the initial results last July, athletes 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 combat bacterial infections, not viruses. And the investigation found that infectious adenovirus readings — tested with cell cultures and verified with molecular biology protocols — turned up at nearly 90 per cent of the test sites over 16 months of testing.

“That’s a very, very, very high percentage,” said Dr Valerie Harwood, Chair of the Department of Integrative Biology at the University of South Florida. “Seeing that level of human pathogenic virus is pretty much unheard of in surface waters in the US. You would never, ever see these levels because we treat our waste water. You just would not see this.”

While athletes take precautions, what about the 300,000-500,000 foreigners expected to descend on Rio for the Olympics? Testing at several of the city’s world-famous beaches has shown that in addition to persistently high viral loads, the beaches often have levels of bacterial markers for sewage pollution that would be cause for concern abroad — and sometimes even exceed Rio state’s lax water safety standards.

In light of the survey’s findings, Harwood had one piece of advice for travellers to Rio: “Don’t put your head under water.”

Swimmers who cannot heed that advice stand to ingest water through their mouths and noses and therefore risk “getting violently ill,” she said.

Danger is lurking even in the sand. Samples from the beaches at Copacabana and Ipanema revealed high levels of viruses, which recent studies have suggested can pose a health risk — particularly to babies and small children.

“Both of them have pretty high levels of infectious adenovirus,” said Harwood, adding that the virus could be particularly hazardous to babies and toddlers who play in the sand.

“You know how quickly an infant can get dehydrated and have to go to the hospital,” she added. “That’s the scariest point to me.”

Dr Fernando Spilki, the virologist and coordinator of the molecular microbiology laboratory at Feevale University in southern Brazil whom was commissioned to conduct the water tests, says the survey revealed no appreciable improvement in Rio’s blighted waters — despite cleanup promises stretching back decades.

“Unfortunately, what we’ve seen throughout all this time is that there is a variation in the levels of contamination, but it fluctuates much more as a result of climactic conditions than due to any measures that may have been taken to try to remove this contamination,” said Spilki, one of Brazil’s most respected virologists.

The most contaminated points are the Rodrigo de Freitas Lagoon, where Olympic rowing will take place, and the Gloria Marina, the starting point for the sailing races. In March, 2015, sampling at the Lagoon revealed an “astounding 1.73 billion adenoviruses per litre” this June, adenovirus readings were lower but still hair-raising at 248 million adenoviruses per litre. By comparison, in California, viral readings in the thousands per litre are enough to set off alarm bells.

Despite a project aimed at preventing raw sewage from flowing directly into the Gloria Marina through storm drains, the waters remain just as contaminated. The first sampling there, in March, 2015, showed “over 26 million adenoviruses per litre” this June, over 37 million adenoviruses per litre were detected.

Nearby Ipanema Beach, which is not playing host to any Olympic sports but is among the city’s most popular tourist spots, exceeded California standards five times over 12 months, once spiking to nearly 50 times what would be permitted in California. One of two testing spots along the beach in the Olympic hub neighbourhood of Barra da Tijuca once hit more than 60 times that limit over the five months testing was conducted there.

“If we had exceedances that consistently were in the thousands like I’m seeing here, there would be a high likelihood that that beach would be put on our list of impaired water bodies,” said Rik Rasmussen, manager of surface water quality standards at California’s State Water Board. That would lead to water quality warnings posted on the beach, possible beach closure, and the development of a programme to root out the source of the contamination, he said

source : gulfnews