Science Friday - The Sample From The Far Side Of The Moon | Will The Seine Be Clean Enough For The Olympics?

Episode Date: June 28, 2024

China’s Chang’e 6 return capsule landed in Mongolia, carrying samples from the far side of the moon. Also, Paris has invested $1.5B in cleaning up the Seine for open-water swimming events, but recent tests indicate it’s not yet safe.A Sample From The Far Side Of The Moon Lands On EarthThis week, the return capsule from China’s Chang’e 6 lunar mission returned to Earth, touching down in a remote part of Inner Mongolia. Inside were dust and rock samples collected from the far side of the moon. Researchers hope that the samples could shed light on both the moon’s formation, and conditions in the ancient solar system.Rachel Feltman, host of the podcast “The Weirdest Thing I Learned This Week,” joins guest host Anna Rothschild to talk about the mission and other stories form the week in science, including a CDC warning about dengue fever, a trans-oceanic butterfly flight, and the possibility of seeing a stellar nova in the coming weeks.Will The Seine Be Clean Enough For Olympic Swimmers?The Paris Summer Olympics are fast approaching. Opening ceremonies for the games kick off on July 26. And all eyes are on the notoriously polluted River Seine. Due to aging infrastructure, sewage has sometimes flowed directly into it. For the past 100 years swimming in the river was banned. Now, the French government has spent roughly $1.5 billion to upgrade sewage treatment in Paris in order for athletes to be able to swim in the Seine.Earlier this week, Paris mayor Anne Hidalgo was set to take a dip in the river to prove its cleanliness. In protest some Parisians threatened to poop in the Seine to show their dislike of the disruptions and high price tag of the Games.The dip was postponed until after upcoming elections, but recent water quality tests indicate that the river is not yet safe to swim in.Guest host Anna Rothschild talks about the current state of the river with Dr. Dan Angelescu, founder and CEO of Fluidion, a water testing company based in Paris, France.Transcripts for each segment will be available after the show airs on sciencefriday.com. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

France invested over a billion dollars to clean up the river Sen before the Paris Summer Olympics, and it's still polluted with, well, poop. What we see is not necessarily a sign that the infrastructure project are not working. They might be working, and the river is also polluted from upstream. It's Friday, June 27th, or as we call it around here, it's Science Friday. I'm SciFri producer Shoshana Bucksbaum. With the Paris Games less than a month out, will the Sen clear up? in time for swimmers to take a dip for the first time in over a century, we'll dive into

the science of urban river pollution. But first, here's guest host Anna Rothschild with some of the other top science news of the week. This week, China's Chang'e-6 robot lander returned to Earth, bringing samples of rock and dust from the far side of the moon. Here to tell us more, and other stories from this week's news, is Rachel Feldman, host of the weirdest thing I learned this week and Scientific American Science Quickly Podcasts. Welcome back, Rachel. Thanks for having me. So we talked about this moon mission when it was just about to land. What's it been up to since then? So it has successfully landed back in Inner Mongolia and scientists are now going to be able to start studying the rocks that it brought home from the far side of the moon, which is super cool.

Yeah, that's so exciting. So what could these samples tell us about the moon, that we don't already know. These will be our first samples from the far side of the moon. China is the first space agency to successfully get landers over there at all. And the thing to keep in mind is that before the Apollo 11 mission brought back any moon rocks, we were totally wrong about how we thought the moon formed. And we still don't have like the mountains of evidence we would like to prove our current idea of how the moon formed. So getting rocks from the far side will help sort of like corroborate some

evidence and could like help us finally be really sure we know how that thing got up there. So cool. Yeah. Yeah. I mean, it would basically be like studying Earth, but you only studied Europe or something. Exactly. Yeah. Exactly. Okay. Moving on. In other news, the CDC issued a warning about Dengue fever. Tell us what's going on there. Dengue is really spiking all over the world this year, even in the U.S. So there have been 2,200 cases so far this year, including around 1,500 in Puerto Rico. And most of the cases in the lower 48 have been travel related, meaning folks have gotten sick traveling either abroad or, you know, in territories like the U.S. Virgin Islands or Puerto Rico. But there have been a handful of cases in Florida where people have

caught dengue locally. So the CDC is on notice. And this is something that's passed by mosquitoes, right? Yeah, that's correct. It's passed by mosquitoes. But, you know, what is concerning is that when a mosquito bites someone who is infected with dengue, several days later, the mosquitoes can then transmit that dengue to other people. So the more folks we have coming home with travel-related dengue, the more likely we are to start seeing more widespread local transmission. Yeah, that makes sense. You know, since this is spread by mosquitoes, is there a climate connection here?

Why might we be seeing more cases? Yeah, you know, to my knowledge, no one has looked specifically at the numbers of mosquitoes this year. But we know that mosquitoes thrive in warm weather, specifically warm, wet weather. And it's been a pretty warm, wet season. So it's not hard to connect those dots. Gotcha. All right. So turning from warm temperatures to icy and cold.

cold temperatures. Researchers are saying that we need to give more respect to the role of slush. Why is that? Yeah. So, of course, most folks are familiar with ice shelves in Antarctica. They know that it's not good that they're melting, that they hold a lot of the world's water and that they can release that water into the ocean, raising sea levels. It's not great. But this new study used satellites along with machine learning to figure out how much sort of like half melted water is kind of pooling on top of ice sheets as opposed to just, you know, running out into the surrounding water. And also how much slush is staying on there. This pooling water and slush that sits on top of the ice sheets is basically not being sufficiently accounted for in the climate models. And the reason that's a problem is because slush and this like pooling melt water, it's less reflective than the ice itself.

So that means it's absorbing more heat. And so these places where instead of ice or snow, we have these little pools of meltwater or piles of slush, they're actually potentially going to be experiencing faster melt overall than the climate models are predicting. Right. So it's sort of like a vicious cycle. Slush makes more slush because it all stays kind of warmer. Going back in time now, we have some interesting findings from some ancient Neanderthal remains. Tell me about that. Yeah, so about 146,000 years ago, these Neanderthals in a cave in what's now Spain, had a member of their community, a child of about six years old when they passed away, who has these very particular anomalies in their inner earbones.

And researchers are saying that these are extremely similar to the formation of the earbone you would see in a child with Down syndrome, trisomy 21. And while they haven't done DNA testing, they're hoping to, but ancient DNA is, you know, finicky and often degraded. So they haven't done that yet. So they don't know for sure that this child actually had trisomy 21. However, they do feel confident that this child would have had hearing. impairment and probably issues with balance because of the earboat alone. And so they're pointing out

that this is a great example of how wrong we were for so long about Neanderthals in their culture that they clearly cared for this child and provided them with the support they needed. And again, you know, just more and more evidence points to Neanderthals and other earlier species of human, having these really rich, caring communities. All right. Let's move to another story about ancient remains. But this one has a bit of a modern twist. It's in ancient Egypt.

Yes. So researchers looked at the remains of scribes from around like 2,700 BC. And being a scribe was like a pretty sought-after position. It meant you could write so you could do aben work, which at the time was pretty clutch. And the scribes that they looked at compared to other dudes buried around them had more degeneration around their jaws, collarbones, shoulders, thumbs, knees, and spines, which the researchers think is from all of the work they did, like hunched over their tablets writing stuff.

So basically they like kind of had their own versions of like tech neck and texting thumb, which is just kind of great to me. Thinking about whether people complained about how technology was like destroying the human body, you know, 4,000 years ago. Yeah, it sounds just like me hunched over my computer. Love it. Okay, moving on. I really love this next story.

So you think of butterflies as being really fragile and delicate, but there's now evidence that at least some of them have flown all the way across an ocean? Yeah, it's true. You really think of butterflies as being so fragile, but these painted ladies, they're already pretty impressive. They're known to regularly take a 9,000 mile trip from Europe to sub-Saharan Africa when they migrate. But they like have stops. They like have rest stops along the way. You know, they like grab some snacks. They have a nap. So we understand how they manage that. But then a decade ago, a researcher was walking on a beach in French Guiana and saw a painted lady and was like,

how did you get here? This is across the Atlantic. And basically they've just been like spending the last decade looking for various clues because insects are really hard to track with the same methods we used to track larger animals. Like they're tiny. It's hard to put a band or a sensor on them. So they kind of just had to like find a bunch of puzzle pieces to put together. They tested their genomes and then also the they sequenced the pollen that they had on them to like prove yes these butterflies had recently been in West Europe and West Africa there's there wasn't just like some random person decided to have a bunch of pet painted lady butterflies over on the other side of the planet and then they started looking at wind patterns that might have helped them and they think

that the Saharan air layer this air current that we already know does really amazing stuff it it blows dust from the Sahara over to South America, where it helps fertilize the Amazon River basin. It can even make it all the way to Florida. So we think that using the power of this current, they probably were able to make the trip in just like five days, which explains how they did it without a place to stop because they were just over the Atlantic. It's great. Incredible. Okay. Finally, we got a Starwatcher alert. There are maybe a reason to keep your eye on the skies in the coming weeks. Why is that? Yeah. So we have a like once in a lifetime Nova explosion to look forward to. It's not the same as a supernova, which is like,

you know, kind of the dying, the very beautiful death knell of an exploding star. This is a Nova, which happens in a binary system. In this case, it's a white dwarf, which is a white dwarf, which is like a dead star remnant about the size of our planet. It's got a mass about the same as our sun. And then a big red giant. And basically the hydrogen from the red giant like builds up on the surface of the white dwarf. And all of that pressure and heat eventually triggers a thermonuclear explosion that like bursts. It like blows all of the, that built-up material way. So it like reaches critical mass and it just, p. And that seems to happen every 80 years for this particular object, T. Corona Borealis, also called the Blaze Star.

And we're like due for one very soon. That being said, scientists have called it kind of contrarian. So it's, you know, the actual burst itself will be brief and we don't know exactly what's going to happen. It will make this star visible to our eyes for about a week, which will be cool because, you know, it's usually not visible. So it kind of seems like a new star appears in the sky. That being said, we don't actually know if it's happening this summer because, yeah, one now. NASA researchers said they're unpredictable and contrarian. And as soon as you start to rely on them repeating the same pattern, they deviate from it completely. So I would say don't hold your breath. Don't hold your breath, but do keep looking up. Yes. Yes. Perfect. All right. Well, Rachel,

that's all the time we have for today. Thank you so much for being with me. Thanks so much for having me. Rachel Feltman is the host of the weirdest thing I learned this week and Scientific Americans Science Quickly Podcasts. The Paris Summer Olympics are fast approaching. Opening ceremonies for the Games kick off in less than a month, and all eyes are on the River Sen. It's a notoriously polluted river. Due to aging infrastructure, sewage has sometimes flowed directly into it. For the past hundred years, swimming in the river was banned, but the French government has spent roughly $1.5 billion to upgrade sewage treatment in Paris,

in time for athletes to be able to swim in the river. Sen. Earlier this week, Paris mayor, Anitalgo, was set to take a dip in the river to prove its cleanliness. In protest, some Parisians threatened to poop in the Sen to show their dislike of the disruptions and high price tag of the games. The dip was postponed till after upcoming elections, but recent water quality tests indicate that the river is not yet safe to swim in. Joining me now to talk about the current state of the river is my guest Dan Angelescu. the founder and CEO of Fluidian, a water testing company based in Paris, France. Dan, thank you so much for being here.

Thank you very much, Anna. It's a pleasure. Let's dive right in. What pollutants are you screening for in the Sen? Well, we're particularly looking at any kind of fecal indicator bacteria. These are bacteria such as e-coli, e-coli, e-churitia coli, and enterococci, which are found whenever there is sewage contamination to a waterway. So we look for those. And generally, when there are large concentrations of these fecal indicators, it mean that there are a lot of other pathogens associated with it. So you're testing the sun every day. What's the latest testing of the river showing? If we look at the results from the past few days here, we had better results in the

in the past couple of days than we had previously, we have levels between 1,300, 1,700, ecoli per 100 ML. But this is still above the threshold that the European regulations and also the World Triathlon regulations allow for in terms of swimming. Yeah, can you put that into context for us? Just how dangerous would it be to swim in the seine in its current state with that much E. coli? You can swim in it and nothing may happen. It's not given that you may get sick. It's just that, you know, based on epidemiological studies that have been done decades ago, the risk goes above a certain threshold that you might get sick. And, you know, it really depends on you a lot. If you have a very strong immune system, you know, you're in really good shape, nothing may happen to you. But, you know, if you have a weaker immune system or if you're a kid and you get a very strong immune system, you know, you're in really good shape, you know, you're in a diarrhea and you can dehydrate, that can be really dangerous. So you can, you know, you can even die from exposure to some of the pathogens in the water. It's not the E. coli or the endurochokai, generally that will get you, but everything else. Most often it's norovirus. But we screen for

E. coli and enterococcus because these are relatively standard to measure and can provide a pretty good indication of the risk. Just to make sure I'm understanding, basically it means that the acoly is like a proxy for how much poo is in the water, and the fecal matter will contain other pathogens that might be bad for you. Exactly. And the coli also comes from poo that's not necessarily human. It can come from, you know, from dogs, from birds. It can come from cow manure and other sources. So, you know, in order to understand that, we also trace other human markers, as we call, which are certain organisms that are only found in the human intestinal tract. So that allows us to also have confidence that the E. coli will measure actually come from

human poop, and that is associated with the highest risk. That's really interesting. So I've read that the high levels of E. coli from your recent tests may be related to heavy rainfall. How does that happen? Yes, so indeed, high rain has been traditionally associated with important pollution from sewage. And the way that works is that in Paris we have a combined sewer system, which means that rainwater and sewage, they go through the same pipes. And normally in dry weather or with very little rain, it all goes to a wastewater plant. It's treated and then released back in the river. But when you get a lot of water, a lot of rain, well, the sewage system is unable to transport all that, right? So whatever is over the capacity of the sewage system and of the treatment plants is released back in the river.

And when it is released in the river, that's essentially raw sewage that's released, and that is really dangerous. What the city has been trying to do is to stop the overflow from happening. And the way they tried to do that is, you know, by retaining. before it goes into the river. So they built underground storage tanks, which can store, you know, a few Olympic-sized pools of water and mix with sewage. And if the rain event is relatively small, then that should not overflow. And we're not sure exactly if and when these will be operational. So this is one of the things we've been monitoring for to try to see in the data. What are the results of that? Oh, interesting. So I know that the city built.

this giant water basin, the Australas water basin, and it holds 20 Olympic pools full of water, something like that. Is that not operational yet? We don't know. It was inaugurated officially, but by looking at the data, we cannot tell that it's operational. We still see levels of pollution that are similar to what we saw earlier in the season. Now, to be clear, you don't have a contract with the city, right? How did you decide to start collecting water samples in the Sen? Well, first, we are on the borders of the Sand River and we are developing water quality instrumentation. So the Sand River has been our playground for many years, in a way. That's where we do all our research. So we sample for our own research. That's how we develop our instruments and

we use samples every single day. This is a pretty big event. So we decided to start an independent sampling campaign. But then in previous years, we have to be a very simple. worked with the city and the city decided for the Olympic Games to only stay with laboratory data, which is, you know, it's a decision on their side. And we continued monitoring on our own and developing the densest independent data set of water quality in the sand river. Has there been an improvement in the water quality since you began sampling? Well, a little bit, we can see that water quality has slightly improved. We had a dry period at about the beginning of the month of June until the 15th of June and we saw that water

quality has improved during that period. Then we had rain events again and then water quality has degraded again. So, you know, it goes up and down. Just yesterday, we measured some of the best water quality we've recorded since beginning of April when we started monitoring, but, you know, it's one data point so far. We'll see if that trend. and continues, and if the water quality will improve significantly after that. The Olympic Committee remains committed to doing the triathlon and marathon swimming in the CEN. Do you think it will be clean enough to swim in by then? Well, that is the million-dollar question, and it is a little bit difficult for me to respond to that.

I don't know. I don't know. The data will tell this is where having systems that can provide you with water quality results, quickly is essential because we see the water quality results changing significantly from day to day. And if you don't have timely data, it's going to be very difficult to say whether the river is safe or not. So the data will tell. That's all I can say. Great. You know, the ultimate plan is for people to swim in the river again recreationally next summer. So 2025. Is that realistic? Well, if this infrastructure project is effective and it does reduce the combined-shoulders in Paris, then there could be portions of the river where water quality might be for certain weeks of the year

acceptable for swimming. In past monitoring, we have seen several weeks on end where water quality was acceptable for swimming day after day. This is usually it happens during the driest part of the summer, when there is a lot of sunlight and there is little river flow. So, you know, the water is not very perturbed. There is a lot of UV light that can kill the bacteria in the water. So the water flow is slow.

So there is no sedimentary suspended. And there are no rain events which would create combined through overflows. This is generally when we see the water quality improving significantly. So far this year, we haven't been so lucky with the weather. It's been raining a lot during the month of May, and now it's raining again beginning of June, so, you know, till the mid of June. Is the fact that there's Ecoli and the water a sign that the improvements haven't worked, or is water contamination just bound to happen sometimes in a big old city like this? Well, no. I mean, what we see is not necessarily a sign that the infrastructure project are not working. They might be working, and the river is also polluted from upstream of where this capture project is.

This one captures really the sewage releases within Paris. But you have plenty of cities upstream, which have combined sewers, and then you have other sources of pollution. You have wastewater plants that release their effluent in the river. Now, the city now is implementing disinfection of the affluent, so that shouldn't be a big contribution. But you have many houses that have illicit connections to the storm drainage rather than to the sewage. So they release their poop, if you'd like, directly in the river. And historically, that have been errors done by plumbers maybe 100 years ago, which now result in this having a big effect on water quality. But looking for all of these sources of pollution, house after house, and it does require a lot of expertise.

It does require time, and it's not an easy project. So the city has done a very decent and honest effort to try to look for all those sources of pollution. But I think the river comes already polluted at the entrance of Paris. And if that is the case, you cannot clean it, right? All that this big infrastructure project does is that it stops new pollution to be added to whatever comes in into Paris. right? So if it's polluted when it comes in, you won't clean it by the time it gets to the Olympic side. Yeah, it's a huge infrastructure project. Dan, thank you so much for taking the time to speak with me. I really appreciate it.

Thank you so much as well. And I hope that this will raise interest about water quality, which is a global issue. It's not only in Paris. It happens everywhere. Dan Angelescu is founder and CEO of Fluidian, a water testing company based in Paris, France. That's all the time we have for today. Lots of folks help make the show happen, including John Dancosky, Kathleen Davis, Dee Petersmith, Robin Casmer. Next week on the show, you've probably heard about publication bias.

Scientific journals prioritize results that support a researcher's hypothesis. We'll talk with the editor of a journal that only publishes quote-unquote negative results. Thanks for listening. Catch you next time. I'm sci-fi producer Shishana Bucksbaum.