J’analyse l’eau de la Seine ! (bon…)

Merci à BoursoBank pour la collaboration sur cette vidéo sur la qualité de l’eau de la Seine, pour plus d’informations, vous pouvez consulter leur site internet ou télécharger l’application https://bit.ly/3XtSMbR

Aujourd’hui j’analyse la qualité de l’eau de la Seine, sur plusieurs paramètres : pH / Nitrates / Nitrites et pour finir E.Coli, allons-y !

Merci à “eau et rivières” pour leur aide :
https://www.eau-et-rivieres.org/home
https://labelleplage.fr/

Merci à Sophie Besnault, ingénieure chimiste à l’INRAE spécialisée en traitement de l’eau, pour son aide sur le script.

L’article dont je parle dans la vidéo https://shorturl.at/n7bXW
Le Bulletin de la Mairie https://t.ly/Lz2ed

Montage / Cadrage : https://www.youtube.com/c/jimwild3
Script : https://www.youtube.com/c/LesRecapsduMonde
Illustration : https://bit.ly/2o1bwwM
Miniature : Kasobel https://x.com/Kas0bel

Let’s go. Analysis report. Well, there are things to say. Hi, it’s Nozman, today we are going to test the quality of Paris water, more precisely the water quality of the Seine. It’s a topic which we talk a lot about at the moment. I have a small case with me which contains all the necessary chemical elements to water analysis. OK. How it works ? This case allows to test the pH, nitrates, nitrites, ammonium and phosphate in order to see where the level of cleanliness of the Seine is based on these parameters. So, for each measurement, I’m going to pour five milliliters of our sample in two samples. And the other in which I will put the reagent that will give me the measurement, the famous result. OK, quick example. Concerning the pH, for potable water, It must be between 6.5 and 9. And if we look at this test that I just did on my tap water, we see that we are between 7.5 and 8, so it’s perfect. Besides, I note this value right here, we will make the comparison with the pH of the Seine then. Later in the video, we are going to take a second sample which we will send to a laboratory which will analyze for us the level of fecal bacteria. There, we will really have the right informations. I’m sure that’s what interests you. Me too by the way. A little bet on the rate in the results? Put that in the comments, it’ll be fun. This will be in the second part of this video. For now, we are testing the pH, nitrites, nitrates, etc. Before knowing if there is a lot of dirt in the Seine, I need to introduce you the sponsor of this video, BoursoBank. You most certainly have already heard of BoursoBank. It is a 100% online bank and above all the cheapest in France for the 16th consecutive year. Including savings which can go up to €251 per year on bank charges. So it’s not nothing. In addition to having low prices, it offers lots of products, savings, loans, the stock market, insurance, good deals, etc. and by the way interesting free cards like the Welcome card or the Ultimate card which allows you to make withdrawals for free anywhere in the world. The application interface is really intuitive and it is very simple You can really manage accounts very easily and the BoursoBank app has moreover been ranked number one in stores in 2023. So personally, all financial products term account, life insurance, stock market, etc, all that is clearly a bit technical world and sometimes I’m totally lost in this. Well they launched on their site a topic to do pedagogy around that. And that, whatever your level, it’s called Bourso Campus and that allows us to learn more quietly, little by little about all these subjects, with videos, quizzes, etc. I find the approach quite cool. Thanks to them for accompanying me on this video. If you are interested, don’t hesitate to check their site in the description or to download their application. There is a link just below in the description and pinned comment. Thank you all. Come on, I’m going back to test the water of the Seine. We will start with the first step, take a sample and then we will do analyzes at the studio. Let’s go. I have to dive hand 30 cm away, that’s about where we begins to have all the elements. OK. We saw that the Brut media had released a video on the same topic. It’s not exactly the same approach, but it is very interesting. So if you want more informations on the water from the Seine, don’t hesitate to go see it. We put that in the description. There you go ! I need to save this quickly, I have to put this in a fridge afterwards. It’s very murky. Apparently, it’s normal, it’s not particularly serious. Come on, let’s go back to the studio and let’s do the analyses. There are a bunch of different criteria to judge the quality of potable water. One of the most important, there must be a good hydrogen ions concentraion. We call this the hydrogen potential. Something you probably know better by its initials, it is pH. This measurement is carried out on a scale of 0 to 7 for an acidic solution and from 7 to 14 for basic solutions. Water below 6.5 causes corrosion of metal pipes which are underwater, while water above 9 reduces the effectiveness of chlorine. More concretely, with pH values higer than eleven or less than four, well it can cause skin, eyes irritation, etc. And if you decide to drink some water with a pH unit lower than 2.4, well your organs will suffer irreversible damage. For example, lemon juice has a pH value of approximately 2.4. For quality samples, you need to keep your water cool and you can keep it maximum for 24 hours. That’s what we did. We didn’t even keep it for 5 hours, but in any case, we kept it cool. Let’s discover the pH of the Seine together. Four. For the moment, nothing too fun. We are between 8 and 8.5. pH from the Seine: 8 We are a little above, but nothing alarming. So, after our measurement, it’s good. Apparently, the pH of the Seine is OK. Does that mean I can drink it? Nah, I’m joking. OK, let’s dive directly to a big file. So the Seine has the reputation to be full of nitrates. According to the Public Health Code, in potable water, the nitrate concentration must not exceed the 50 mg/L We’re going to test this together. But before, what are nitrates? It is a chemical substance entering the nitrogen cycle, nitrogen which, I remind you, makes up 78% of our atmosphere and which can therefore be transformed in nitrates under certain conditions. Basically, it is a vital natural process for vegetation. Indeed, to develop, plants need nitrogen, that they mainly absorb in the form of nitrates. So far so good. The problem is that farming sometimes tend to abuse this system. In the Seine basin, where industrial and cereal crops are numerous, we use a lot of synthetic fertilizer boosted with nitrogen. A manipulation which, in case of misuse results in the explosion of nitrates level in the soil. But not only. When these soils a little too full of nitrates are watered by rain, before the vegetation have time to absorb them, all this nitrate fleet is streaming in the water table and watercourses like the Seine. And that’s not good. But let’s see it together. For nitrates above 50 mg/L, we won’t be good. We’ll see that. End of result for nitrates. It’s 20, 20 mg/L, it’s already interesting. However, how can nitrates, be dangerous ? The thing is, nitrates under the effect of our oral bacteria, well, they have the unfortunate tendency to transform into nitrites. Not a great development since nitrites can then attach to our red blood cells. The problem is that if they are loaded with nitrites, red blood cells will no longer be able to stock up on oxygen passing through our lungs. In fact, they will have too much stuff on them. There is no room for anything else. Basically, it causes a lot of problems. based on oxygen deprivation. But in addition to nitrates which later transform into nitrites, watercourses also directly contain nitrites naturally. They are present in small quantities, but their concentration must not exceed 0.5 mg/L for potable water. You know what ? We’re going to check all that. Bottled water nitrites: 0 Tap water nitrites: 0.02. And for the water from the Seine, we’re at 0.05, that’s fine. Overall, we have our results. All the rates we got for tap water in this video respect everything recommended and does not pose any health problems. Because we could say 40 mg/L, it’s huge and everything, but, there is no problem. Especially since we don’t measure everything, for example microplastics. And I specify that water from plastic bottles can also be contaminated by different things. It’s already happened. And they also come with a big microplastic dose, much more than in tap water by the way, and that represents the most present plastic waste in European waters. It’s really not good at all. In short, for tap water, there is no problem with these results. I will continue to drink it, and besides that, it costs way less. Now, we will move on to fecal contamination. What actually prevents you from swimming in the Seine for years is that thing that risks disgusting everyone. Poop. And swim in poop… It doesn’t make anyone want it. If apparently, the Seine is full of feces, it’s because the wastewater of Paris and its surroundings sometimes flow into it. This is due to several things, poor connections, in particular. In January 2022, for example, 23 000 habitations were still not correctly connected to the public drainage network and dumped their wastewater directly into the Seine. But it is also often due to heavy rain. When it rains too much, the old sewers of Paris are not sized to absorb the overflow. So there are valves called storm overflows which empty the surplus in the river without filter. It goes like this, a lot of shit. The thing is, obviously our droppings are full of pathogenic germs. It’s disgusting, like salmonella, campylobacter or even certain E.Coli. A good cocktail that can provoke, among others, gastro, typhoid and paratyphoid fever, or even hemorrhagic diarrhea. Yes. So, to counter this problem, work has been undertaken for several years. We modernize the processing plants, we track down bad connections or we build ponds to give more storage capacity to the network. This is particularly the case with the very recent inauguration from the Austerlitz basin, a kind of gigantic tank of 50,000 cubic meters in the heart of Paris and which will allow us to store excess water during heavy precipitation. Breakin News from today, this Thursday June 20, an article was published on huffpost saying that Austerlitz basin operated for the very first time these recent days. I think it was important to clarify that because it just came out. Now that we know all that, we’re going to measure the poop. Well, let’s go. We will therefore take the second sample and send it directly to the laboratory which will take charge to do the analysis for us. And in 48 hours, we will have our results. I’m really looking forward to seeing this. Before you see the results, you need two or three small points of understanding. It’s important, so that we understand everything. First of all, I would like to thank the laboratory which carried out the analyses, the Eurofins lab, thank you. Then, understand a water analysis is not very complicated, but to be sure and certain of our interpretation, I contacted several associations which work in water quality so that they can confirm to us what our results mean. So thank you to La Belle Plage association which helped us a lot. First, here I give you the quality thresholds for fresh waters, so the Seine is part of it. We therefore see that beyond 1800 CFU per 100 ml, we are on a bad rate, from 1800 and above. We would be on good quality if we were below 100 CFU per 100 ml. These are the thresholds of the ARS, the Regional Health Agency. And these are the thresholds of the International swimming and triathlon federation and it’s a bit stricter, with notably a bad rate from 1000 CFU per 100 ml. So these are rates not to be exceeded for swimming events in the Seine for example. The lab explained to us that the CFU value, I quote according to their email, “it is the colony forming unit per 100 ml.” So this is the number of E.Coli colonies that they will count in 100 ml of water. But there is also a second value, the MPN value, which is the most probable number per 100 ml, unit used for surface water, for example the Seine. Our results are also expressed in MPN. Now that we have that in mind, we will be able to compare them with our results and unsurprisingly, we are above all standards with 2000 MPN per 100 ml so we are above the bad threshold according to the ARS and twice the bad threshold according to the International Swimming and Triathlon Federation. Basically, on a chart it looks like this. ARS, from 0 to 100 we are good. From 100 to 1800 is average, and above 1800 is bad. We are there, so not great according to the ARS. And according to the federation, from 0 to 500 we are good, from 500 to 1000 we are average and from 1000 we are bad. And we are twice as much. Yeah. When I saw that, I wasn’t so shocked because, firstly, the Surfrider association also does samples every two weeks approximately, and they sometimes find E.Coli levels much higher than ours. Super high stuff. Well, it sucks but what scares me the most personally is that a sample could have very different results depending on the weather on the day, but also depending on the weather on the days preceding the sampling. Basically, the worse it is the days before, the crappier the rate is going to be. This is why the Surfrider association sometimes finds rates that breaks all records. Another interesting data, the town hall has published a report on the water quality from the Seine with results of their samples which date from June 1 to 9. Well, no surprises, they also find bad rates, it can go from 2000 to 6000. All that depends on the weather. I put this in the description below, It’s interesting as a complement. So what happens if we swim in it? Apparently, what we risk getting is a good gastro, headaches and potentially infections. Anyway, this kind of not so great thing. And I imagine that a gastro epidemic in the Olympic village is not what is really envisaged. It can be a bit shitty, no pun intended. So, what does that mean for the Olympics? Personally, I don’t know. We just took our samples to have scientific data. And there you have the results today. It’s not an anti Olympics video or anything at all. It’s just an interesting and important topic to talk about. I received a lot of DMs to talk about this topic. So there you have it, it’s done. I greatly thank the two associations who greatly helped me in understanding these results. La Belle Plage Association takes care, among other things, of doing participatory science. Basically, you can take samples to help them test the water quality of certain beaches. They even have a map that lists as many beaches as possible with their quality and rankings, etc. They are trying to understand where the sources of pollution come from. In short, they are doing a good job, thanks to them. Thanks to everyone on Instagram who responded and helped me with the results. I was able to have all these contacts thanks to you, thank you very much. I would like to thank Sophie Besnault, chemical engineer at INRAE, specialized in water treatment. In any case, thank you for following and watching this video. I hope you liked it. As usual, see you next time because science does not wait. Bye ! How are you ? There is another riverboat. It’s impossible to shoot here. Will they greet me? And me if I greet them, alone. Oh yes they greet me, great! There was one who recognized me. OK.