Olympic-caliber athletes continue to be sickened by the sewage-filled waters of Rio’s Guanabara Bay, site of the aquatic events at next year’s Olympics. This time it’s South Korean windsurfer Wonwoo Cho, who was hospitalized with dehydration, vomiting, headache and dizziness following an Olympic sailing test event this week.

His coach, Danny Ok, posted photos of Cho being loaded into an ambulance and of the brownish water to his Facebook page, while also decrying the venue’s foul condition:

It seems he got infected from virus somewhere in the racing site which is supposed to be safe and clean as an Olympic venue.
I hope this wouldn’t be happened again not only for us, but for all sailors who compete on the same play ground.
Additionally, I hope IOC and ISAF must consider how the safety issue will be improved for the next year.

Speaking to the Associated Press, Ok called the water “smelly” and added, “Especially in the bay, it’s terrible. I can’t imagine how they can have racing in this area.”

Cho told the AP on Wednesday that he’s back to “50-60 percent” strength and out of the hospital.

The AP published the results of a five-month independent analysis of the water at Rio’s aquatic venues in June, finding dangerously high levels of viruses from human sewage at all of them. “Despite the scrutiny, brown sewage continues to flow into the Marina da Gloria at several points, which has drawn photos and videos from athletes that have been widely viewed on social media,” the AP’s Stephen Wade writes.

Earlier this month, the the U.S. rowing team’s doctor claimed 13 American athletes got sick after competing in the World Junior Rowing Championships, which took place at the same venue in which the Olympic rowing events will take place.

The International Olympic Committee has steadfastly refused to conduct its own viral testing of Rio’s waters, even after the AP report. Instead, the IOC will merely test for bacteria, even though a number of experts told the AP that there is little to no correlation between the amount of bacteria from sewage in waters and the number of viruses.

The AP’s testing found “astronomical viral counts up to 1.7 million times what would be considered alarming on a southern California beach, yet with bacterial levels often within legal limitations.”