RIO DE JANEIRO (AP) —When Flora Duffy dives into the water in Brazil tomorrow she will be doing so in an area deemed “unfit” for swimming.

The Bermuda triathlete is competing in the Rio de Janeiro ITU World Olympic Qualification Event, and the city’s environmental agency has designated the sea unfit based on fecal coliform bacteria levels.

The most recent pollution reading at Copacabana Beach was taken from a sample this past Monday. An Olympic qualifier and Paratriathlon event begins today, and several athletes were already getting into the water yesterday.

The Rio environmental agency didn’t respond to requests for comment about whether they have carried out more recent testing this week.

Teams gathered on Copacabana Beach said the International Triathlon Union (ITU) gave them guarantees the water was safe in the areas where the parathletes trained.

Athletes said that the conditions of the water appeared better than they were expecting. However, water experts and the government’s own pollution monitoring officials all note that sewage pollution typically isn’t something that can be seen by the naked eye.

The ITU said it’s not doing its own tests on the water, but has requested specific information from local authorities about the water quality.

On Thursday, The Associated Press released the results of a five-month investigation into Rio’s waters. It showed that Olympic venues are rife with disease-causing viruses and bacteria.

The AP study showed that the spot where athletes were entering the water on Copacabana Beach yesterday had a minimal reading of more than 2 million human adenovirus per litre — that’s 2,000 times the reading that water experts in the US say would be considering highly alarming if seen on beaches in the US or Europe.

Human adenovirus multiply in the intestinal and respiratory tracts of people. These are viruses that are known to cause respiratory and digestive illnesses, including explosive diarrhea and vomiting, but can also lead to more serious heart, brain and other diseases.

The Rio de Janeiro state government and the state environmental agency in press releases blasted the AP report on Thursday as being alarmist and said it was unfair to judge Rio’s waters based on viral counts, limits of which are not designated in Brazilian legislation, nor in that of the US or the EU. The agency also questioned the qualifications of the laboratory where the AP samples were analyzed.

David Zee, an oceanography professor at Rio de Janeiro’s state university who has long researched pollution in Guanabara Bay, rejected the government’s response, saying that in Brazil “it’s natural that the authorities react saying that ‘everything is fine,’ but everything is not fine.”

He added that the AP testing “was done in a trustworthy lab.”

But the area that was ruled unfit by the Rio environmental agency for swimming earlier this week was on based levels of fecal coliforms, which are single-celled organisms that live in the intestines of humans and animals. Fecal coliforms can suggest the presence of cholera, dysentery, hepatitis A and typhoid.

The site ruled unfit for swimming has also been labeled as off limits on at least eight previous occasions this year.

Duffy is among the favourites in Rio, and is in fine form after following up her bronze-medal display at the Pan Am Games in Toronto with a victory at the Xterra Mountain Championships in Beaver Creek.

The top three women’s finishers will qualify their country for a place at next year’s Rio Olympics.

Held at the iconic Copacabana Beach, the race will be staged almost exactly a year prior to the Olympics, with Duffy expected to be well suited to the challenging bike course as she goes in pursuit of a podium finish.

Among the other contenders in tomorrow’s race will be Gwen Jorgensen, the most dominant triathlete in the world, logging her tenth straight win in the World Triathlon Series in Hyde Park, London, in May.

Her United States compatriots Sarah True and Katie Zaferes could also be in contention for success in the Olympic event.

Ranked third this season, True just missed out on a medal at the London Olympics in fourth, while Zaferes has enjoyed a breakout year.

Great Britain’s Vicky Holland and Non Stanford, who are housemates and training partners, both claimed podium places at this month’s ITU World Triathlon Series race in Hamburg, Germany, while Australia’s Emma Moffatt has shown signs of returning to form after struggling with illness and injuries for the past two years.