0:00

Science Friday is supported by Progressive

0:02

Insurance. Whether you love true crime

0:04

or comedy, celebrity interviews or news,

0:07

you call the shots of what's

0:09

in your podcast queue, right? And

0:11

guess what? Now you can call them

0:14

on your auto insurance too, with

0:16

the name your price tool from

0:19

Progressive. It works just the

0:21

way it sounds. You tell Progressive how

0:23

much you want to pay for car

0:25

insurance, and they'll show you coverage options

0:27

that fit your budget. Get your

0:30

quote today at progressive.com to

0:32

join the over 28 million

0:34

drivers who trust Progressive. Progressive,

0:37

Casualty Insurance Company and affiliates.

0:39

Price and coverage match limited

0:41

by state law. WNYC

0:45

Studios is supported by MathWorks,

0:47

creators of MATLAB and Simulink,

0:49

software for technical computing and

0:52

model-based design. MathWorks, accelerating

0:54

the pace of discovery in engineering and

0:56

science. Learn more at mathworks.com. Learn more at

0:58

mathworks.com. WNYC Studios is brought to you

1:00

by Zbiotics. Seize the day

1:03

after night of drinks with Zbiotics

1:05

pre-alcohol probiotic drink. Zbiotics

1:07

was invented by PhD scientists to break

1:09

down the byproduct of alcohol, which is

1:11

most responsible for making you feel crummy

1:13

the next day. Drink Zbiotics

1:15

before your first drink, drink responsibly, and

1:17

you'll wake up refreshed and ready to

1:20

take on the day. Try

1:22

it for yourself at zbiotics.com/WNYC

1:24

and get 15% off your

1:26

first order when you use

1:28

WNYC at checkout. That's

1:31

zbiotics.com/WNYC and

1:34

use the code WNYC at checkout for 15%

1:36

off. Listener

1:42

supported, WNYC Studios.

1:50

France invested over a billion dollars to

1:52

clean up the river Seine before the

1:54

Paris Summer Olympics. And it's

1:56

still polluted with, well, poop. is

2:00

not necessarily a sign that the

2:02

infrastructure projects are not working. They

2:04

might be working and the river

2:06

is also polluted from upstream. It's

2:09

Friday, June 27th, or as we call

2:11

it around here, it's Science Friday. I'm

2:14

sci-fi producer Shoshana Bucksfound. With the Paris Games

2:16

less than a month out, will the sun

2:18

clear up in time for swimmers to take

2:21

a dip? For the first

2:23

time in over a century, we'll dive

2:25

into the science of urban river pollution.

2:27

But first, here's guest host Anna Rothschild

2:29

with some of the other top science

2:31

news of the week. This

2:34

week, China's Chang'e 6 robot lander

2:36

returned to Earth, bringing samples of

2:39

rock and dust from the far

2:41

side of the moon. Here

2:43

to tell us more and other stories from this

2:45

week's news is Rachel Feltman,

2:48

host of the Weirdest Thing I

2:50

Learned This Week and Scientific American

2:52

Science Quickly podcasts. Welcome back, Rachel.

2:55

Thanks for having me. So we talked

2:57

about this moon mission when it

3:00

was just about to land. What's

3:02

it been up to since then?

3:04

So it has successfully landed back

3:06

in Inner Mongolia, and scientists

3:08

are now going to be able to start

3:10

studying the rocks that it brought home from

3:12

the far side of the moon, which is

3:15

super cool. Yeah, that's so exciting. So what

3:17

could these samples tell us about the moon

3:19

that we don't already know? These

3:21

will be our first samples from the far side

3:23

of the moon. China is the

3:26

first space agency to successfully get

3:28

landers over there at all. And

3:30

the thing to keep in mind is

3:33

that before the Apollo 11 mission

3:36

brought back any moon rocks,

3:38

we were totally wrong about how we thought

3:41

the moon formed. And we

3:43

still don't have like the mountains

3:45

of evidence we would like to prove

3:48

our current idea of how the moon formed.

3:50

So getting rocks from

3:52

the far side will help sort of

3:55

like corroborate some evidence and could like

3:57

help us finally be really sure we

3:59

know how that's thing got up there.

4:02

So cool. Yeah. Yeah. I mean, it

4:04

would basically be like studying Earth, but

4:06

you only studied Europe or something. Exactly.

4:09

Yeah, exactly. Okay. Moving on. In other

4:11

news, the CDC issued a warning about

4:13

dengue fever. Tell us what's going on there.

4:16

Dengue is really spiking all over

4:19

the world this year, even in

4:21

the U.S. So there have been

4:23

2,200 cases so far this year,

4:26

including around 1,500 in Puerto Rico.

4:28

And most of the cases in

4:30

the lower 48 have been travel

4:33

related, meaning folks have gotten sick

4:35

traveling either abroad or in

4:37

territories like the U.S. Virgin Islands or

4:40

Puerto Rico. But there have been a

4:42

handful of cases in Florida where people

4:44

have caught dengue locally. So the CDC

4:47

is on notice. And

4:49

this is something that's passed by mosquitoes,

4:51

right? Yeah, that's correct. It's

4:54

passed by mosquitoes. But what

4:56

is concerning is that when

4:59

a mosquito bites someone

5:01

who is infected with dengue, several

5:03

days later, the mosquitoes can then

5:06

transmit that dengue to other people.

5:08

So the more folks we have

5:10

coming home with travel

5:12

related dengue, the more likely

5:14

we are to start seeing more

5:16

widespread local transmission. Yeah, that makes

5:19

sense. This has spread

5:21

by mosquitoes. Is there a climate connection here?

5:23

Why might we be seeing more cases? Yeah,

5:26

you know, to my knowledge,

5:28

no one has looked specifically

5:30

at the numbers of mosquitoes

5:32

this year. But we know

5:34

that mosquitoes thrive in warm

5:36

weather, specifically warm, wet weather.

5:38

And it's been a pretty

5:40

warm, wet season. So it's

5:43

not hard to connect those

5:45

dots. Gotcha. All right, so

5:47

turning from warm temperatures to

5:49

icy and cold temperatures, researchers

5:51

are saying that we need to give more

5:53

respect to the role of slush. Why is

5:56

that? Yeah, so, of

5:58

course, folks

6:00

are familiar with ice shelves in

6:02

Antarctica. They know that it's

6:05

not good that they're melting, that they hold a

6:07

lot of the world's water and that they can

6:09

release that water into the ocean, raising

6:12

sea levels. It's not great.

6:14

But this new study used

6:17

satellites along with machine learning to

6:19

figure out how much sort

6:22

of like half melted water is

6:24

kind of pooling on top of

6:26

ice sheets, as opposed to

6:28

just, you know, running out into the

6:31

surrounding water, and also how much

6:33

slush is staying on there. This

6:35

pooling water and slush that sits

6:37

on top of the ice sheets

6:39

is basically not being sufficiently accounted

6:42

for in the climate models. And

6:44

the reason that's a problem is

6:46

because slush and

6:48

this like pooling meltwater, it's

6:51

less reflective than the ice itself.

6:53

So that means it's absorbing more

6:56

heat. And so these places

6:58

where instead of ice or snow, we

7:01

have these little pools of meltwater or

7:03

piles of slush, that

7:05

they're actually potentially going to be

7:07

experiencing faster melt overall than the

7:09

climate models are predicting. Right. So

7:11

it's sort of like a vicious

7:13

cycle. Slush makes more slush because

7:15

it all stays kind of warmer. Going

7:18

back in time now, we have

7:20

some interesting findings from some ancient

7:22

Neanderthal remains. Tell me about that.

7:25

Yeah, so about

7:27

146,000 years ago, these Neanderthals

7:30

in a cave in what's now Spain,

7:33

had a member of their community, a

7:35

child of about six years old when

7:37

they passed away, who has these very

7:40

particular anomalies in their

7:42

inner ear bones. And

7:44

researchers are saying that these are

7:46

extremely similar to the formation

7:49

of the ear bone you would

7:51

see in a child with Down

7:53

syndrome, trisomy 21. And while

7:56

they haven't done DNA testing, they're hoping to,

7:58

but ancient DNA is, you know, fenicky

8:00

and often degraded. So they haven't done that

8:02

yet. So they don't know for sure that

8:04

this child actually had

8:06

Trisomy 21. However,

8:08

they do feel confident that this

8:10

child would have had hearing

8:13

impairment and probably issues with

8:16

balance because of

8:18

the the earbud alone. And so

8:20

they're pointing out that this is

8:22

a great example of how

8:24

wrong we were for so long

8:26

about Neanderthals and their culture that

8:28

they clearly cared for this

8:31

child and provided them with the

8:33

support they needed. And again, you

8:35

know, just more and more evidence

8:38

points to Neanderthals and other earlier

8:40

species of human having these really

8:43

rich, caring communities. All right. Let's

8:45

move to another story about ancient

8:47

remains. But this one has a

8:49

bit of a modern twist. It's

8:52

in ancient Egypt. Yes.

8:54

So researchers looked

8:57

at the remains of scribes from around

8:59

like 2700 B.C. And

9:03

being a scribe was like a pretty sought

9:05

after position. It meant you could write, you

9:07

could do ab and work, which, you know,

9:09

at the time was was pretty clutch. And

9:12

the scribes that they looked at

9:14

compared to other dudes buried around

9:16

them had more degeneration

9:20

around their jaws, collarbones,

9:22

shoulders, thumbs, knees and

9:24

spines, which the

9:26

researchers think is from all of

9:28

the work they did, like hunched

9:30

over their tablets, writing stuff. So

9:33

basically, they like kind of had their own versions

9:35

of like tech neck and texting thumb, which is

9:37

just kind of great to me, thinking about whether

9:39

people complained about how technology was like destroying the

9:42

human body, you know, 4000 years ago. It

9:46

sounds just like me hunched

9:48

over my computer. Love it.

9:50

OK, moving on. I

9:52

really love this next story. So you think

9:54

of butterflies as being really fragile and delicate,

9:56

but there's no evidence that at least some

9:58

of them have flown. all

10:00

the way across an ocean? Yeah,

10:03

it's true. You really think of butterflies as

10:05

being so fragile, but

10:08

these painted ladies, they're

10:10

already pretty impressive. They're known to regularly

10:13

take a 9,000 mile trip from

10:17

Europe to Sub-Saharan Africa when they

10:19

migrate. But they like

10:21

have stops. They like have rest stops

10:23

along the way. You know, they like grab some snacks, they have

10:25

a nap. So we

10:28

understand how they manage that, but

10:30

then a decade ago, a

10:33

researcher was walking

10:35

on a beach in French Guiana and

10:38

saw a painted lady and was like, how

10:40

did you get here? This is across the

10:42

Atlantic. And basically

10:44

they've just been like spending the last

10:46

decade looking for various clues because insects

10:48

are really hard to track with the

10:50

same methods we use to track larger

10:53

animals. Like they're tiny, it's hard to

10:55

put a band or a

10:57

sensor on them. So they

10:59

kind of just had to like find a

11:01

bunch of puzzle pieces to put together. They

11:04

tested their genomes and then also they

11:08

sequenced the pollen that they had on

11:10

them to like prove, yes, these butterflies

11:12

had recently been in West Europe and

11:14

West Africa. There wasn't just like some

11:16

random person decided to have a bunch

11:18

of pet painted lady butterflies over

11:21

on the other side of the planet. And

11:23

then they started looking

11:25

at wind patterns that might've helped

11:27

them. And they think that the Saharan air

11:29

layer, this air current that we already know

11:32

does really amazing stuff. It blows dust from

11:34

the Sahara over to South America where

11:36

it helps fertilize the Amazon river basin. It

11:38

can even make it all the way to

11:40

Florida. So we think that using

11:43

the power of this current, they

11:46

probably were able to make the trip in

11:48

just like five days, which explains how they

11:50

did it without a place to stop

11:54

because they were just over the Atlantic. It's

11:57

great. Incredible. Finally,

12:00

we got a Star Watcher alert.

12:03

There may be a reason to keep your eye on

12:05

the skies in the coming weeks. Why is that? Yeah,

12:08

so we have a like

12:10

once in a lifetime Nova

12:12

explosion to look forward to.

12:15

It's not the same as a supernova, which is

12:17

like, you know, kind of the dying, the

12:21

very beautiful death knell of

12:23

an exploding star. This

12:26

is a Nova, which happens

12:28

in a binary system. In

12:31

this case, it's a white dwarf, which is

12:33

like a dead star remnant

12:36

about the size of

12:38

our planet. It's got a mass about the same

12:40

as our sun. And then a big

12:43

red giant. And

12:46

basically the hydrogen from

12:48

the red giant like builds up

12:51

on the surface of the white

12:53

dwarf. And all of

12:55

that pressure and heat eventually triggers

12:57

a thermonuclear explosion that like bursts,

12:59

it like blows all of that

13:01

built up material away. So it

13:03

like reaches critical mass and it

13:05

just, and

13:08

that seems to happen every 80 years for

13:10

this particular object, T.

13:13

corone Borealis, also called the

13:15

blaze star. And

13:18

we're like due for one very soon. That

13:23

being said, scientists have called it kind of

13:25

contrarian. So

13:28

it's, you know, the actual

13:30

burst itself will be brief. And

13:34

we don't know exactly what's going to happen. It

13:36

will make this star visible

13:39

to our eyes for

13:41

about a week, which will be cool. Cause you

13:43

know, it's usually not visible. So it kind of

13:45

seems like a new star appears in the sky.

13:49

That being said, we don't actually

13:51

know if it's happening this summer

13:53

because yeah, one NASA

13:56

researcher said they're unpredictable and

13:58

contrarian. And as

14:00

soon as you start to rely on them repeating

14:02

the same pattern, they deviate from it completely. So

14:06

I would say don't hold your breath. Don't

14:09

hold your breath, but do keep looking up. Yes.

14:12

Yes. Always. All

14:14

right. Well, Rachel, that's all the time we have for

14:16

today. Thank you so much for being with me. Thanks so much for having me. Rachel

14:19

Feltman is the host of The

14:21

Weirdest Thing I Learned This Week

14:23

and Scientific American's Science Quickly podcasts.

14:26

Support for Science Friday comes from the Rita

14:28

Allen Foundation. More at ritaallen.org.

14:34

The Paris Summer Olympics are fast

14:36

approaching. Opening ceremonies for the

14:39

games kick off in less than a month,

14:41

and all eyes are on the River Seine.

14:44

It's a notoriously polluted river. Due

14:47

to aging infrastructure, sewage has sometimes

14:49

flowed directly into it. For the

14:51

past hundred years, swimming in the

14:53

river was banned, but the French

14:55

government has spent roughly $1.5 billion

14:58

to upgrade sewage treatment in

15:00

Paris in time for athletes to

15:03

be able to swim in the Seine. Earlier

15:05

this week, Paris mayor Ani Talgo was set

15:08

to take a dip in the river to

15:10

prove its cleanliness. In protest,

15:12

some Parisians threatened to poop in the

15:15

Seine to show their dislike of the

15:17

disruptions and high price tag of the

15:19

games. The dip was postponed

15:21

until after upcoming elections, but recent

15:23

water quality tests indicate that the

15:25

river is not yet safe to

15:28

swim in. Joining me

15:30

now to talk about the current state

15:32

of the river is my guest, Dan

15:34

Angelescu, the founder and CEO of Fluidian,

15:37

a water testing company based in

15:39

Paris, France. Dan, thank you so much

15:41

for being here. Thank you very much, Emma.

15:43

It's a pleasure. Let's dive right

15:45

in. What pollutants are

15:48

you screening for in the Seine? Well,

15:51

we're particularly looking at

15:53

any kind of fecal

15:55

indicator bacteria. These are

15:57

bacteria such as E.

15:59

coli. it

18:00

means that the E. coli is like a

18:02

proxy for how much poo is in the

18:04

water and the fecal matter will contain other

18:07

pathogens that might be bad for you. Exactly.

18:10

And E. coli also comes from

18:12

poo that's not necessarily human. It

18:14

can come from dogs, from birds,

18:17

it can come from cow

18:19

manure and other sources.

18:21

So in order to understand that,

18:23

we also trace other human markers

18:26

as we call, which are certain

18:28

organisms that are only found in

18:30

the human intestinal tract. So that

18:33

allows us to also have

18:35

confidence that the E. coli we measure

18:37

actually come from human poop and that

18:39

is associated with the highest risk. That's

18:42

really interesting. So I've read that the

18:44

high levels of E. coli from your

18:46

recent tests may be related to heavy

18:48

rainfall. How does that happen? Yes.

18:51

So indeed, high rain has

18:54

been traditionally associated with important

18:56

pollution from sewage. And

18:59

the way that works is that in

19:01

Paris we have a combined sewer system,

19:03

which means that rainwater and sewage, they

19:06

go through the same pipes. And normally

19:08

in dry weather or with very little

19:10

rain, it all goes to a wastewater

19:13

plant, it's treated and then released back

19:15

in the river. But when

19:17

you get a lot of water, a lot of

19:19

rain, well, the sewage system is

19:21

unable to transport all that, right? So whatever

19:23

is over the capacity of the sewage system

19:26

and of the treatment plants is

19:28

released back in the river. And

19:30

when it is released in the river,

19:32

that's essentially raw sewage that's released and

19:34

that is really dangerous. What

19:37

the city has been trying to do

19:39

is to stop the overflow from happening.

19:41

And the way they tried to do

19:44

that is by retaining

19:46

it before it goes into the

19:48

river. So they built underground storage

19:50

tanks, which can store a few

19:52

Olympic size pools of water and

19:55

mixed with sewage. And

19:57

if the rain event is relatively small,

19:59

then that's... should not overflow. And

20:02

we're not sure exactly if and

20:05

when these will be operational. So this is one

20:07

of the things we've been monitoring for, to try

20:09

to see in the data what

20:11

are the results of that. Oh, interesting.

20:13

So I know that the city built

20:16

this giant water basin,

20:18

the Austerlitz water basin, and it

20:20

holds 20 Olympic pools full of

20:22

water, something like that. Is

20:25

that not operational yet? We

20:27

don't know. It was inaugurated officially.

20:29

But by looking at the data,

20:31

we cannot tell that it's operational.

20:33

We still see levels of

20:36

pollution that are similar to what we saw earlier

20:38

in the season. Now,

20:40

to be clear, you don't have a contract with

20:42

the city, right? How did you decide to start

20:44

collecting water samples in the Seine? Well,

20:47

first, we are on the borders of

20:49

the Seine River, and

20:51

we are developing water quality instrumentation. So

20:53

the Seine River has been our playground

20:56

for many years, in a way.

20:58

That's where we do all our research.

21:00

So we sample for our own research.

21:02

That's how we develop our instruments, and

21:05

we use samples

21:07

every single day. This is a pretty

21:09

big event, so we decided to start

21:11

an independent sampling campaign. But

21:14

then, in previous years, we

21:16

have worked with the city, and the

21:18

city decided for the Olympic Games to

21:20

only stay with laboratory data, which is,

21:22

you know, it's a decision on their

21:24

side. And we continued

21:27

monitoring on our own and developing the

21:29

densest independent data set of water quality

21:31

in the Seine River. Has

21:33

there been an improvement in the water

21:36

quality since you began sampling? Well,

21:39

a little bit. We

21:41

can see that water quality has

21:43

slightly improved. We had a dry

21:46

period at about the beginning of

21:48

the month of June until the

21:50

15th of June, and we

21:52

saw that water quality has improved during

21:54

that period. Then we had rain events

21:56

again, and then water quality has degraded

21:59

again. And so, you know, it goes up

22:01

and down. Just yesterday,

22:03

we measured some of

22:06

the best water quality we've

22:08

recorded since beginning of April when we

22:10

started monitoring, but you know, it's one

22:12

data point so far. We'll

22:14

see if that trend continues and

22:17

if the water quality will improve significantly

22:19

after that. The Olympic Committee

22:21

remains committed to doing the triathlon

22:23

and marathon swimming in the Seine.

22:26

Do you think it will be clean enough to swim in

22:28

by then? Well, that

22:30

is the million dollar question and it

22:32

is a little bit difficult for me

22:35

to respond to that. I

22:37

don't know. I don't know.

22:39

The data will tell. This is where

22:41

having systems that can provide

22:43

you with water quality results very

22:45

quickly is essential because we see

22:48

the water quality results changing

22:50

significantly from day to day.

22:53

And if you don't have timely

22:55

data, it's going to be very

22:57

difficult to say whether the river

22:59

is safe or not. So

23:03

the data will tell. That's all I can say.

23:06

Great. You know, the ultimate

23:08

plan is for people to swim in

23:10

the river again recreationally next summer. So

23:12

2025, is that realistic? Well,

23:16

if this infrastructure project is effective

23:18

and it does reduce the combined

23:20

shore overflows in Paris, then there

23:23

could be portions of the river

23:25

where water quality might be for

23:27

certain weeks of the year acceptable

23:30

for swimming. And past monitoring, we

23:32

have seen several weeks on

23:35

end where water quality was acceptable for

23:37

swimming day after day. This is usually,

23:39

it happens during the driest part of

23:41

the summer when there is a lot

23:44

of sunlight and there is, you know,

23:46

little river flow. So, you know, the

23:48

water is not very perturbed. There is

23:50

a lot of UV light that can

23:52

kill the bacteria in the water so

23:55

the water flow is slow. So there is

23:58

no sedimentary suspended and there are no water

24:00

flow. no rain events which would create combined

24:02

through overflows. This is generally

24:04

when we see the water quality

24:07

improving significantly. So far this

24:09

year, we haven't been so

24:12

lucky with the weather. It's been raining a

24:14

lot during the month of May and now

24:16

it's raining again beginning of June, so, you

24:19

know, till the mid of June. Is

24:22

the fact that there's E. coli in

24:24

the water a sign that the improvements

24:26

haven't worked or is water contamination just

24:28

bound to happen sometimes in a big

24:30

old city like this? Well,

24:34

no. I mean, what we see is

24:36

not necessarily a sign that the infrastructure

24:38

projects are not working. They

24:41

might be working and the river

24:43

is also polluted from upstream of

24:45

where this capture project is. This

24:47

one captures really the sewage releases

24:50

within Paris. But you

24:52

have plenty of cities upstream which have

24:54

combined sewers and then you have other

24:56

sources of pollution. You have

24:58

wastewater plants that release their effluent

25:00

in the river. Now

25:03

the city now is implementing disinfection of

25:05

the effluent, so that shouldn't be a

25:07

big contribution. But you

25:10

have many houses that have illicit

25:12

connections to the storm drainage

25:14

rather than to the sewage.

25:16

So they release their poop, if you'd like,

25:18

directly in the river. And,

25:21

you know, historically there have been errors

25:23

done by plumbers maybe 100 years ago,

25:26

which now result in this having a

25:28

big effect on water quality. But

25:30

looking for all of these sources of

25:32

pollution house after house, and it

25:35

does require a lot of expertise. It

25:37

does require time and it's not an

25:39

easy project. So the city has done

25:41

a very decent and honest effort to

25:44

try to look for

25:46

all those sources of pollution. But I

25:48

think the river comes already polluted at

25:50

the entrance of Paris. And if that

25:52

is the case, you cannot clean it,

25:55

right? But all that this big

25:57

infrastructure project does is that it

25:59

stops. new pollution to be

26:01

added to whatever comes in into Paris. So

26:03

if it's polluted when it comes in, you

26:06

won't clean it by the time it gets

26:08

to the Olympic side. Yeah, it's a huge

26:10

infrastructure project. Dan, thank you so

26:13

much for taking the time to speak

26:15

with me. I really appreciate it. Thank

26:17

you so much as well. And I

26:19

hope that this will raise interest about

26:21

water quality, which is a global issue.

26:23

It's not only in Paris. It happens

26:25

everywhere. Dan Angelescu is founder

26:27

and CEO of Fluidion, a

26:29

water testing company based in

26:31

Paris, France. That's all

26:33

the time we have for today. Lots of

26:35

folks help make the show happen, including John

26:38

Dankoski, Kathleen Davis, D. Peter

26:40

Smith, Robin Kasmer. Next

26:42

week on the show, you've

26:45

probably heard about publication bias.

26:47

Scientific journals prioritize results that

26:49

support a researcher's hypothesis. We'll

26:52

talk with the editor of a journal

26:54

that only publishes, quote unquote, negative results.

26:57

Thanks for listening. Catch you next time.

26:59

I'm sci-fi producer Shoshana Buxbaum.

27:21

Sandals, sneakers, denim, luxury

27:23

bags and sunglasses. Rack

27:26

up the deals today and save up to 60

27:28

percent on summer at your Nordstrom Rack

27:30

store. With

27:33

the five dollar meal deal at McDonald's, you

27:35

pick a McDouble or a McChicken, then get

27:37

a small fry, a small drink and a

27:39

four piece McNuggets. That's a lot of McDonald's

27:41

for not a lot of money. Price and

27:44

participation may vary for a limited time only.