The World Health Organization has asked the International Olympic Committee to run new tests on Rio’s waterways after an Associated Press investigation declared them potentially dangerous to athletes because of their high pollution levels, the AP reports. The request came in conjunction with an announcement from the governing body of world sailing that said it, too, would do its own independent testing.

At the center of the controversy is the virus load carried in the waterways in which swimmers, rowers, canoeists, sailors and triathletes will compete. According to the AP investigation, pollution from raw sewage has made those levels dangerously high and some athletes who have been training in Rio have experienced bouts of fever, vomiting and diarrhea.

Until now, water evaluations have only included testing for bacteria and not viruses, which WHO wants to change.

“WHO has … advised the IOC to widen the scientific base of indicators to include viruses,” the organization said in statement (via the AP). “The risk assessment should be revised accordingly, pending the results of further analysis. The Rio Local Organizing Committee and the IOC are requested to follow WHO recommendations on treatment of household and hospital waste.”

Potential threats from viruses that previously have not been tested for has also got the attention of the International Sailing Federation, which has promised to do its own testing.

“We’re going to find someone who can do the testing for us that can safely cover what we need to know from a virus perspective as well as the bacteria perspective,” ISAF chief Peter Sowrey told the AP. “That’s my plan.”

The fact that the waterways are polluted is a disappointment, but it’s not a surprise.

In March, Rio’s Mayor Eduardo Paes confirmed to Brazil’s SporTV that Guanabara Bay, where the sailing events are supposed to occur, would not be fully cleaned up by the time the Olympics kick off next summer. The Bay has become a receptacle for the untreated sewage for the city’s 12 million residents.

“I think it’s a shame,” Paes told SporTV on Monday. “I think it’s a lost opportunity.”

The Olympics were supposed to act as the impetus to clean Rio’s waterways, with the installation of a sewage system that would treat 80 percent of raw sewage produced in the city. As of March, however, the treatment rate was just 49 percent, according to SporTV.

Guanabara Bay isn’t the only waterway that could pose a threat to the health of athletes and even spectators, according to the AP investigation. Central Rio’s Rodrigo de Freitas lake, a separate venue for rowing and canoeing, as well as venues for triathlon and open-water swimming off Copacabana Beach also showed high virus levels.