TOKYO -- The International Olympic Committee moved next year's Tokyo Olympic marathons and race walks out of the Japanese capital to avoid the stifling heat and humidity.
Now some swimmers and an 11,000-member coaching body are asking that something similar should be done with the distance-swimming venue in Tokyo Bay.
Known as the Odaiba Marine Park, the water temperatures there were near danger levels in test events this summer for open-water swimming and triathlon. Elevated E. coli levels have also plagued the urban venue, and athletes have complained about the odors coming from the small inlet.
"Here's the reality," Catherine Kase, who coaches open water for the United States Olympic team, said in an email to the Associated Press. "If a marathoner faints or passes out, they may get a few bumps and bruises. If the same thing happens to an open-water swimmer, the result could be lethal."
Tokyo's heat again is the main problem.
Water temperatures in the venue this summer were very warm, climbing one day to 30.5 Celsius (86.9 Fahrenheit). That's barely under the limit of 31 C (87.8 F) set by swimming's world governing body, FINA. The temperatures were consistently in the 29-30 C (84-86 F) range.
FINA rules specify that the race will be shortened or canceled if temperatures go over the limit.
"For all open-water swims, alternative plans should be made in case environmental factors make the swim unsafe, forcing it to be canceled or curtailed," Kase added. "We would like to push for a viable backup plan. The straightforward answer is that we are not comfortable with the Odaiba venue."
Kase noted that U.S. swimmers are advised against participating if temperatures exceed 29.45 C (85 F). She also said US swimmers can still choose to swim "and will likely feel pressure to do so'' at big events like the Olympics.
"Our athletes shouldn't have to worry about health concerns as they're preparing to compete in the race of their lives,'' Kase wrote.
The venue also has water-quality issues, including E. coli bacteria and problems with water transparency. Tokyo organizers say bacteria levels fall within "agreed limits" on most days, though rainfall exacerbates the problem.
John Leonard, the executive director of the American Swimming Coaches Association, was even more emphatic about a move and placed much of the blame on FINA.
"We support a change in venue," he said in an email to AP. "The ASCA position is always to err on the side of safety for the athletes. FINA talks about safety and then does the opposite and puts athletes in harm's way."
FINA and local organizers say there is no "B plan."
The IOC promised last month there would be no more venue changes. It made this pledge after angering Tokyo governor Yuriko Koike, who strongly opposed moving the marathons out of Tokyo to the northern city of Sapporo.
The IOC said the decision was made primarily to consider athletes who must run in the heat. But Koike's allies characterized it as "an IOC-first decision, not an athletes-first decision."
Cornel Marculescu, the executive director of FINA, spoke cautiously in an interview with AP.
Asked about the water temperatures at the venue, Marculescu replied: "I don't want to comment," he said, and suggested that elaborating could cause "problems."
"This is what it is," he added. "We check the quality of the water, we check the temperature all the time."
Marculescu and local organizers say race times could to be moved up to very early in the morning, hoping to beat the heat. That was also an early strategy for the marathons and race walks before they were moved.
Athletes in outdoor water events at the 2016 Rio de Janeiro Olympics faced severe pollution in venues for rowing, sailing, canoeing, open-water swimming, and triathlon. But heat was not an issue.
"We are following up with a company there [in Japan]," Marculescu said, "like we have done in Rio -- the same story -- with an official government company. We are looking at water temperatures, the quality of the water and all these kinds of things."
Water temperature was linked to the death of American swimmer Fran Crippen in 2010 at a distance swim in the United Arab Emirates. The autopsy concluded his death was from drowning and heat exhaustion, and included the possibility of a heart abnormality.
It was the first competitive death in FINA's history, and much of the blame was aimed at the swim body.
The United States and Canada both withdrew their swimmers from an open-water race in October in Doha, Qatar. The race took place in the same body of water where Crippen died. Temperatures were again reported right at the FINA limit, and some reports said they were slightly above the limit.
In an email, the Canadian Olympic Committee did not address the water issue specifically but said, "we remain confident that the organizing committee and the IOC will take every precaution to ensure that the games are held safely and successfully."
Fernando Possenti, the open-water coach for the Brazilian Olympic team, said athletes need to deal with the environment and not waste time complaining about it.
"Program yourself, adapt your athletes to this kind of condition," Possenti said in an email to AP. "This particular sport contemplates direct contact with nature and its variables. Heat and humidity are two of them."
The Odaiba venue was picked partly because it offers picturesque, 180-degree views of the skyscrapers that hug Tokyo Bay and the bridges that cross it.
Television has a powerful say in scheduling and venue location. About three-quarters of the IOC income is from broadcast rights. American network NBC has agreed to pay $7.75 billion to broadcast the Summer and Winter Olympics from 2022 through 2032.
In Tokyo, to counter E. coli levels, organizers have installed underwater screens that work as a filter. E. coli was within agreed limits on all but one day in test events this summer.
But the screens also appeared to drive up water temperatures, and organizers plan to install triple screens for the Olympics.
In a statement, Tokyo spokesman Masa Takaya said, "We will consider operating methods that can help suppress water temperatures, such as allowing the underwater screens to float, and opening them when the weather is good."