Here’s an open question after the 10-kilometer open water swimming event at the Paris Olympics. With three of the four German swimmers getting sick after the event, was the Seine River still a little too polluted to hold the race?
Well, one of those swimmers, Leonie Beck, who finished ninth in the women’s swim, posted the following on Instagram following the race: “Vomited 9 times yesterday + diarrhea.” She then added, “Water quality in the Seine is approved” with a check mark sign. In the accompanying she gave the thumbs up sign, but her face seemed to be giving more the upchuck sign. Think she was being sarcastic about the water quality?
Although the German Olympic Sports Confederation hasn’t revealed specifically which of its swimmers have fallen ill, it did release the following statement: “Two female German open water swimmers were treated as outpatients (Friday) for nausea, vomiting and diarrhea. They have been feeling much better since this morning.” The statement continued with, “Another swimmer with similar symptoms is currently being treated by the German team doctors.”
Since the only other German competitor in the women’s open water race was Leonie Maertens, you can kind of guess the second female swimmer was. Maertens finished 22nd among 24 women who raced. The two German swimmers in the men’s event were Oliver Klemet, who finished with a silver medal, and Florian Wellbrock, who finished eighth among the 29 men who raced.
So continues the ongoing in-Seine saga. Since the Seine River had had a long history of being quite polluted, some had argued that the Seine-sible thing to do was to not hold Olympic swimming events in the river, But prior to the Olympics, Paris did conduct a massive extensive and expensive (costing around 1.4 billion Euro or 1.5 billion USD) clean up attempt of the Seine. Then they tried to reassure everyone that the waters were clean enough including having the Paris mayor Anne Hidalgo taking a swim in the Seine. There’s also been regular reporting of E. coli and enterococci levels measured from samples of the Seine water being within acceptable levels before and throughout most of the Games.
Keep in mind, though, the limitations of these measurements. First of all, they are from samples of the Seine and not all parts of the Seine. It would be impossible to pour the entire river into a laboratory testing facility. So it’s unclear how widely such measurements may vary throughout the river.
Secondly, these two bacteria are normally found in human poop. Therefore, such bacteria levels are indirect measures of how much poop there is in the river—with an emphasis on the word “indirect.” So, if E. coli levels are significantly above 575 colony forming units (cfu) per 100 milliliters in a single sample or 126 cfu/100mL on average over 30 days then potentially there be too much poop. The same applies enterococci levels above 151 cfu/100 mL in a in a single sample or 33 cfu/100mL for a 30 day mean.
Third of all, while drinking poop certainly ain’t good, it’s not even the worst thing to worry about in a body of water. Presumably, the more poop bacteria in the water, the more likely there is to be other even worse things like other types of dangerous bacteria, viruses, protozoans and parasites. But other types of bad pathogens can be present and do what they do even when the levels of doo-doo are seemingly not that high. Plus, other non-living things could get you sick too, such as chemicals.
Therefore, you can’t just rely on one type of measurement to determine water quality. It has to be a combination of things and accompanying judgement. For example, if you saw a toilet floating in a river but were told that the E. coli and enterococci levels were within safe limits, how comforting would that be? Again the levels of poop bacteria and thus the levels of poop in water is supposed to be just one potential marker of how polluted the water may be.
Moreover, it’s not as if the levels of E. coli and enterococci measured from Seine samples have stayed well within safe ranges at all times throughout the past two weeks. Instead, there seemed to be some fluctuations up into more concerning ranges during the Olympics. These upshifts prompted shifts in the triathlon schedule and World Aquatics to cancel last Tuesday’s test run for the marathon swimming event. That was supposed to be one of only two opportunities for the Paris Olympics competitors to better familiarize themselves with the course before the real deals Thursday and Friday. Being told that the water quality was not good the other day but fine today wouldn’t be exactly super comforting.
There were back-up plans to move the marathon swimming to the rowing and canoeing basin had E. coli and enterococci levels been above acceptable limits. But that obviously did not happen. And the German Olympic committee was reportedly OK with moving ahead with the marathon swimming being in the Seine.
The German athletes weren’t the only ones to get sick after swimming in the Seine. There have been reports of several athletes feeling ill following the triathlon event. But following the marathon swim event, the Paris Olympics organizing committee issued a statement that emphasized, “At this stage, we are not aware of any established link between the illness and the Seine’s water quality.” The statement added, “Water quality on the day of the marathon was considered ‘very good’ or ‘excellent’ across all four testing points and well within the thresholds established by World Aquatics.”
It may be difficult to ever tell whether the Seine River water is what had caused the illnesses among all the triathletes and marathon swimmers and whether it might have been better to have moved the events to another venue. When one gets ill, the bacteria, viruses or whatever pathogens causing the sickness don’t tend to say, “I am from such-and-such place.” Therefore, when epidemiologists investigate disease outbreaks, they typically will try to determine what those who got ill had in common. Did they eat the same food items, stay in the same location or share any objects for example? Of course, all of these athletes did share one gigantic object: the Seine Rover. So one does have to wonder what role the waters may have played in them getting sick.
