0:11

I'm Susan Moran. This is how an

0:13

Earth, the KG&U science show,

0:15

today is Tuesday, January 14th,

0:17

2025. Coming up, we'll discuss how

0:20

a class of synthetic chemicals

0:22

known as P-FAS, and found

0:24

in so many products,

0:26

including rain-resistant outdoor clothing, are

0:29

contained in the drinking water

0:31

of millions of Americans, and

0:34

what's been done to address

0:36

these, another... cancer-causing and

0:38

otherwise dangerous compounds. Our guests

0:41

are Dr. Bridger Rule. He's

0:43

an environmental engineer at New

0:46

York University and the lead

0:48

author of a recent study

0:51

we'll talk about, and Kate Dunlap,

0:53

the Drinking Water Quality

0:55

Manager for the City

0:58

of Boulder. We begin with a

1:00

look at some of the recent

1:02

news in science. Last year... was

1:04

the hottest year on record. That

1:06

is the news last week based

1:09

on separate analyses by

1:11

NASA, the National Oceanic

1:13

and Atmosphere Administration, NOAA, and

1:16

Copernicus, the Earth Observation

1:18

component of the European

1:20

Union's space program. Earth's

1:22

average land and ocean surface

1:24

temperatures in 2024 was 1.29

1:27

degrees Celsius above the 20th

1:29

century average. which is the

1:32

highest global temperature among all

1:34

years in Noah's climate record

1:37

since 1850. The previous record

1:39

was in 2023, and in

1:41

fact, the planet's 10 warmest

1:44

years have all occurred in

1:46

the past decade. Of particular

1:48

note, the Copernicus data

1:50

indicate that the 2024

1:52

global temperature was 1.6

1:55

degrees Celsius, that's 2.9

1:57

degrees Fahrenheit. levels, making

1:59

it the first calendar

2:01

year to exceed the

2:04

1.5 degree Celsius level

2:06

defined in the 2015

2:08

Paris Climate Agreement. Global

2:10

warming is responsible

2:13

for an increase in extreme

2:15

weather events we are experiencing,

2:18

such as heat waves, heavy

2:20

precipitation, and large hurricanes. although

2:22

the number of named hurricanes

2:25

was near the average for

2:27

1991 through 2020 and the

2:30

global accumulated cyclone energy was

2:32

about 21% below the 1991

2:35

to 2020 average. Global warming

2:37

also has been identified

2:39

as a factor in other

2:41

extreme events including large wildfires

2:44

such as those currently raging

2:46

around Los Angeles. The upper

2:49

ocean heat content also set

2:51

a record high in 2024,

2:53

and the extent of sea

2:55

ice ran near record lows,

2:57

with Antarctica averaging 4 million

2:59

square miles of sea ice,

3:01

which is the second lowest

3:03

on record. The concilience of scientific

3:06

evidence indicates that human

3:08

industrial activity is a

3:11

driving factor behind global

3:13

warming and climate change.

3:16

For how on Earth? I'm Joel Parker.

3:18

For a long time, neuroscientists

3:20

have wondered how the brain

3:23

cleaned house. Many cleaning processes

3:25

have been identified in cells

3:27

and whole animals, but the

3:29

brain was a black box.

3:31

Until about ten years ago,

3:33

when a group at the

3:35

University of Rochester discovered the

3:37

brain's plumbing system, which resembles

3:39

the body's limb system. The

3:41

lymph is a second circulatory

3:43

system that collects miscellaneous fluids

3:45

throughout the body cleans them

3:47

and returns them to the

3:49

blood. In the brain, there's a

3:51

similar network of fluid-filled channels that

3:53

drains metabolic waste and facilitates movement

3:56

of cerebral spinal fluid, the cushioning

3:58

fluid around the brain. The researchers

4:00

cleverly termed it the glimphatic

4:02

system because of the role of

4:04

glial cells in its function.

4:06

This system is most active during

4:08

non -REM sleep, a .k .a. deep

4:10

or non -dream sleep, confirming a

4:13

hypothesis that a major function

4:15

of sleep is waste clearance. Just

4:17

one night of sleep deprivation

4:19

can result in a large increase

4:21

in beta -amyloid, a causal agent

4:23

in Alzheimer's. This and other

4:25

studies not done by the Rochester

4:27

group have shown that poor

4:29

sleep is linked to the risk

4:31

and progression of Alzheimer's disease.

4:33

In a study published last week,

4:35

the Rochester team devised a

4:38

new technique that allowed them to

4:40

record brain activity in mice

4:42

without anesthesia, that is, during normal

4:44

sleep. They were able to

4:46

determine that groups of nerve cells

4:48

that act in concert during

4:50

sleep release a chemical that synchronizes

4:52

waves of contraction. These waves

4:54

then pump fluids through the brain

4:56

and out into the blood

4:58

for disposal. Ambien, perhaps the most

5:00

commonly prescribed sleep medication, was

5:02

tested for its effect on the

5:05

glimphatic system, again by the

5:07

Rochester group. Ironically, it actually suppresses

5:09

the coordination among nerve cells

5:11

that generates the fluid movement of

5:13

waste out of the brain.

5:15

This study was published last week

5:17

in the journal Cell and

5:19

emphasizes what most of us know.

5:21

We all need a good

5:23

night's sleep, and of course that

5:25

varies from person to person.

5:27

For KGNU, I'm Beth Bennett. And

5:30

on the Science Calendar, next

5:32

Tuesday, January 21st, Colorado author John

5:34

Waterman will speak at the

5:36

Boulder Bookstore about his new book.

5:38

It's called Into the Thaw,

5:40

Witnessing Wonder Amid the Arctic Climate

5:42

Crisis. Waterman is a filmmaker,

5:44

an author of 17 books including

5:46

Atlas of the National Parks

5:48

and Atlas of Wild America. The

5:50

event will start at 6 .30pm.

5:52

PM, for more info, go

5:54

to bolderbookstore .com. You're

6:01

listening to

6:04

KG and

6:06

U Science

6:09

Show. I'm

6:12

Susan Moran.

6:15

A growing environmental and public health

6:18

concern is the prevalence of so-called

6:20

forever chemicals. It's an apt moniker

6:22

because they don't break down in

6:25

the environment. You could also

6:27

call them everywhere chemicals, as in

6:29

they're so ubiquitous that it's hard

6:32

to imagine life without them. There

6:34

are non-stick frying pans, furniture, carpets,

6:36

packaging materials, and as Colorado's

6:39

can appreciate, in gortecks

6:41

another water-resistant outdoor clothing.

6:43

Research has shown that... even

6:46

at very low levels. Some

6:48

of these compounds, known collectively

6:50

as P-Fass, at short per

6:52

per and polyfluoral algal substances,

6:54

have been found, have been

6:56

linked to increased risk of

6:59

cancer and other chronic diseases.

7:01

This dangerous class of compounds

7:03

has been found in our

7:05

food, in cow's milk, in

7:08

our drinking water, and thus

7:10

in our bodies. Last year,

7:12

the U.S. Environmental Protection Agency

7:14

started regulating peafas and drinking

7:17

water. And back in 2022,

7:19

Colorado lawmakers passed legislation to

7:21

ban the sale and distribution

7:23

of certain consumer products that

7:25

contain peafas that have been

7:28

intentionally added. That law will be phased

7:30

in starting this year. We'll talk more

7:32

about that. A new study led by

7:34

one of my guests. has found that

7:36

drinking water used by more than 20

7:38

million Americans contains high levels

7:41

of certain peafas that come

7:43

from wastewater that's gone through

7:45

municipal treatment facilities. This finding

7:48

is especially noteworthy as it comes at

7:50

a time when due to the effects of

7:52

climate change, population growth, and the

7:54

resulting shrinkage of food of fresh

7:57

water supplies, more and more communities

7:59

are turning treated wastewater into drinking

8:01

water. My two guests today, both

8:03

joining us remotely, will help us

8:06

understand scientific developments, as well as

8:08

what cities and states are doing,

8:10

what we can all do as

8:12

well, to protect drinking water sources,

8:14

and what we all can do

8:16

to keep Pefas chemicals out of

8:18

the environment and out of our

8:20

bodies. First, Dr. Bridger Rule is

8:22

a research professor of environmental engineering

8:25

at New York University, and he's

8:27

the lead author of the recently

8:29

published study. Bridger, welcome to How

8:31

on Earth. Bridger, you there? Welcome

8:33

to How on Earth. Can you

8:35

hear me? Oh, great. And Kate

8:37

Dunlop, she's the Drinking Water Quality

8:39

Manager for the City of Boulder.

8:41

Kate, thank you so much for

8:44

coming on the show. Hi, thank

8:46

you for having me today, Susan.

8:48

So I want to start, Bridger,

8:50

with you. If you could just

8:52

distill, kind of in a nutshell,

8:54

what are the key findings of

8:56

this newly published study? In

8:59

this research, we were looking

9:01

at wastewater influence and effluent

9:04

from large facilities across the

9:06

United States, and we were

9:08

particularly interested in exploring what

9:11

the composition and levels of

9:13

peafasts, along with other fluorinated

9:15

chemicals, such as agrochemicals and

9:18

pharmaceuticals, in... wastewater discharge that

9:20

gets into the environment and

9:23

can potentially travel downstream and

9:25

re-enter drinking water supplies. What

9:27

we found was that the

9:30

compounds, the six compounds that

9:32

the EPA regulated in drinking

9:35

water in 2023, account for

9:37

only a small fraction of

9:39

the amount of organic flooring

9:42

that we find in the

9:44

wastewater discharges around 7 to

9:46

8%. However, even though these

9:49

are only a small fraction

9:51

of the organic flooring that

9:54

we find, there are levels

9:56

in treated wastewater being discharge

9:58

to the environment means that

10:01

they can penetrate downstream drinking

10:03

water supplies and potentially impair

10:06

the drinking water quality for

10:08

up to 23 million Americans.

10:10

And as you mentioned, this

10:13

issue is something that is

10:15

particularly challenging in the context

10:17

of climate change, which we

10:20

know causes more frequent and

10:22

severe droughts, which exacerbates. and

10:24

lowers the amount of natural

10:27

water in the environment that

10:29

we can use to dilute

10:31

wastewater, thereby further increasing potential

10:34

concentrations. Right, and of course

10:36

there are other sources for some

10:38

people, there are wells, other things,

10:40

but increasingly it seems it's really

10:43

important actually to so-called tap into

10:45

wastewater for drinking water. And we'll get

10:48

to more of that, but I wanted to

10:50

ask you to, like, what does the study

10:52

tell us more about than what... We, what

10:54

scientists haven't known before. Like

10:56

I'm thinking of a, it was

10:59

a 2023 US geological study. I

11:01

think it was the first national

11:03

study that tested P-fast but in

11:05

tap water from private and

11:07

regulated sources and found

11:09

that P-fast are contaminating drinking

11:12

water across the country, including

11:14

in small towns and large

11:16

cities and private wells and

11:19

public systems. That's different from...

11:21

or the waste water and the modeling

11:23

that you did. But so how does

11:25

this advance what's been known?

11:28

Exactly. So as you mentioned,

11:30

there are many sources of

11:32

PFS to the environment. Some

11:34

of the major sources to

11:37

drinking water include wastewater, but

11:39

also include fire, fighting and

11:41

fire training activities, airports, and

11:43

industrial manufacturing facilities. So for

11:46

the first time we were

11:48

able to estimate. the

11:50

contribution of one source, in

11:52

this case wastewater, to impact tens

11:55

of millions of Americans drinking water

11:57

supply, but that number is likely.

11:59

to be much higher on

12:01

a national level when you

12:03

add in other sources. The

12:05

other major thing that we

12:07

find here is the really

12:10

large prevalence of organic fluorine

12:12

pharmaceuticals that meet the chemical

12:14

definitions for PFAS. These are

12:16

a class of compounds that

12:18

we don't typically consider when

12:20

we think about PFAS because

12:22

they're used for much different

12:24

purposes. They're all used as

12:26

medications, but they contain the

12:28

same chemical structures that we're

12:30

familiar with and we're concerned

12:32

about in the Gore text

12:34

in nonstick coatings in the

12:36

firefighting phones. And so we're

12:38

really shining a light on

12:40

how much of these pharmaceuticals

12:42

are being discharged into the

12:44

environment and how little we

12:46

know about. what happens to

12:48

them once they exit wastewater

12:50

treatment plants. Interesting. And Kate

12:52

Dunlap, given you're the drinking

12:55

water quality manager for the

12:57

city of Boulder first, could

12:59

you just give us a

13:01

really basic primer on what

13:03

is wastewater? Since that's sort

13:05

of what we're talking about

13:07

at least in the context

13:09

of this study, the sources,

13:11

and how does it become

13:13

drinking water ultimately in some

13:15

cases? That's a

13:17

good question. I think they're

13:19

often conflated. So our drinking

13:22

water system is obviously water

13:24

that's treated directly from rivers,

13:26

lakes, or wells, depending on

13:28

where you live. And then

13:31

when you use that water

13:33

in your home, either in

13:35

your home for drinking or

13:38

through irrigation, depending on how

13:40

it gets through the piping

13:42

system, then it's piped to

13:44

your local wastewater treatment facility.

13:47

which then treats the wastewater

13:49

and that's discharged somewhere downstream

13:51

usually to a waterway. And

13:53

as Bridger mentioned, a lot

13:56

of communities, most communities are

13:58

downstream from some waste. water

14:00

treatment facility. In the city

14:02

of Boulder we're we're very

14:05

fortunate that we have three

14:07

distinct sources of drinking water

14:09

that are from headwater reservoirs

14:11

and tributaries and we do

14:14

we have not detected peafasts

14:16

or microplastics in our drinking

14:18

water and we do routinely

14:21

monitor our source water and

14:23

our treated water for a variety

14:25

of basic chemistry, but also compounds

14:27

of emerging concern. Interesting. And yes,

14:30

lucky that many of us are

14:32

in the city of Boulder, and

14:34

a little later we'll get to

14:36

some of the socio-economic and environmental

14:39

justice issues related to, you know,

14:41

who's living where, and sort of

14:43

what are the technological as well

14:46

as sort of political choices. But

14:48

see a little bit more. So that

14:50

water from... homes. I know there's the

14:52

gray, there's the black, but

14:54

it also includes wastewater, like sludge,

14:57

human sewage from toilets,

14:59

right? Yes, and I'm really not

15:01

a wastewater expert. I solely work

15:03

on the drinking water side, but,

15:05

um, Bridger actually probably tell you

15:08

more about wastewater. Okay, um, Bridger,

15:10

could you add a little more

15:12

on that front, just so we're kind

15:14

of clear of like what it is

15:16

and what's going where? So

15:19

wastewater as you

15:21

mentioned, we were

15:24

particularly focused on

15:26

municipal wastewater. So that

15:29

is wastewater that

15:31

receives water coming

15:34

from people's households

15:36

from oftentimes sewer

15:38

systems and can also

15:41

contain industrial discharges depending

15:44

on where you are.

15:46

As you mentioned, a

15:49

mix of water and

15:51

solids. We were particularly

15:54

focused in this study

15:56

on aquatic discharges so

15:59

that is the discharge

16:01

of water to downstream lakes

16:03

and rivers. I think you

16:05

had also been talking in

16:08

at some point during what

16:10

you were saying about sludge

16:13

that is formed during wastewater

16:15

treatment and becomes a solid

16:17

and is oftentimes spread on

16:20

various landscapes or on farmlands

16:22

of the type of fertilizer.

16:24

Right, in fact, a bunch

16:27

of farms, another lot of

16:29

lawsuits related to this, but

16:31

have found contamination in there,

16:34

even organic cows' milk, from

16:36

the fertilizer, which, you know,

16:39

is such a rub, right?

16:41

On the one hand, it's

16:43

like, right, there's a lot

16:46

of fertility there and richness

16:48

there, but it also can

16:50

contain pretty high or high

16:53

enough to be dangerous concentrations

16:55

of pfas and other dangerous

16:57

chemicals, right? Yes, that is

17:00

a potential concern from using

17:02

wastewater biosolids as a fertilizer

17:05

amendment to farmland soils. So

17:07

Bridgetwell, take us a little

17:09

further deeper into the study.

17:12

What was the go-to-key methodology?

17:14

How do you go about

17:16

conducting it and thus coming

17:19

to these findings? Yeah, we

17:21

were using a measurement technique

17:23

that estimates the total Pefas

17:26

present within a sample. This

17:28

technique is called extractable organofluorine.

17:31

It is different from the

17:33

standard approach for measuring Pefas

17:35

in which we measure chemical

17:38

by chemical and can assign

17:40

a concentration to a specific

17:42

chemical such as Pefos or

17:45

Pefoa. To perform those measurements,

17:47

you need chemically. commercially available

17:49

chemical standards, which isn't the

17:52

case for the many hundreds

17:54

to thousands of pfasts that

17:57

are present in used in

17:59

industry. or found in the

18:01

environment. Instead we use a

18:03

technique where we can bust the

18:05

sample at a very high temperature

18:08

releasing the fluorine from the

18:10

carbon and then measuring the

18:12

produced fluorine. So while we're

18:14

not able to ascribe a

18:16

specific chemical, a certain concentration,

18:19

we're able to say what

18:21

is the total amount there.

18:23

From that number, we can

18:25

then use advanced. mass spectrometry

18:27

techniques to further delve into

18:30

trying to figure out specific

18:32

chemicals that are present within

18:34

a sample. And you did this

18:36

at in communities across the country,

18:39

right? That's right. At large

18:41

wastewater facilities across the United

18:43

States? At the facilities themselves.

18:45

Did anything in particular surprise

18:47

you or pretty much did

18:49

the data affirm what your

18:51

team suspected was already there?

18:54

As I mentioned, we

18:56

were pretty surprised to

18:58

see how large the

19:00

fraction of fluorine coming

19:02

from pharmaceuticals was in

19:04

these samples. And we

19:06

were also surprised to

19:08

see how ineffective even

19:10

advanced wastewater treatment is

19:12

at removing fluorine prior

19:14

to discharge, which means

19:16

all of the fluorine

19:19

coming from P-Fasts, from

19:21

pharmaceuticals, from agrochemicals that

19:23

are entering the wastewater treatment

19:25

plant, are basically all exiting

19:27

and being discharged into downstream

19:29

rivers and lakes, with a

19:31

small fraction of that going

19:33

into the biosolids, which becomes

19:35

the solid problem that we

19:37

were talking about. Well, so

19:40

basically there's not even the

19:42

technology that's advanced or

19:44

granular enough. There are technologies that

19:46

do effectively treat peafas

19:48

at wastewater or at

19:51

drinking water facilities or

19:53

at experimental facilities, but

19:55

these are not currently

19:57

being used at wastewater

19:59

treatment facilities. facilities, which unlike

20:01

sort of an experimental facility, are

20:04

treating a lot of water every

20:06

single day. And right now there

20:08

aren't really technologies that are being

20:10

widely used at these facilities that

20:13

are effective. And I would imagine

20:15

there's a huge cost issue, right?

20:17

It'd be super expensive. How do

20:20

you upgrade? What communities can afford

20:22

to do the upgrades? Is that

20:24

a big issue? That is a

20:26

big issue. And I think it's

20:29

also important to note that communities

20:31

across this country will have to

20:33

install drinking water treatment, effective drinking

20:36

water treatment technologies, if they are

20:38

in exceedance of the US EPA's

20:40

federal drinking water standard. That is

20:42

a big cost in an ongoing

20:45

cost to these communities, which will

20:47

be passed on the charge in

20:49

their rates from the utility. But

20:52

it also doesn't fully solve the

20:54

problem. As you mentioned, PFS are

20:56

forever chemicals, meaning that when we're

20:58

removing them from the drinking water

21:01

or from a wastewater supply, we're

21:03

not getting rid of the chemical.

21:05

We're just transferring it from the

21:08

liquid phase. into potentially a solid

21:10

phase, which creates a solid waste

21:12

problem. So after you generate a

21:14

bunch of solid waste, then you

21:17

have to, you still have high

21:19

concentrations of PFS in that waste.

21:21

You have to figure out what

21:24

you're going to do with that

21:26

and how you're going to dispose

21:28

of that without potentially causing contamination

21:31

or other problems at the disposal

21:33

site. Interesting. I'm just going to

21:35

take a brief break. If you're

21:37

joining us late, I'm Susan Moran

21:40

and I'm discussing the sources, health

21:42

impacts and... hopefully some solutions for

21:44

these so-called forever chemicals with Bridger

21:47

Rule. He's a research professor of

21:49

environmental engineering at NYU and then

21:51

Kate Dunlap. She's the drinking water

21:53

quality manager for the city of

21:56

Boulder. Kate Dunlap, I want to

21:58

ask you actually both of you,

22:00

kind of on the solutions front

22:03

for the last few minutes we have.

22:05

You know, many people are probably

22:07

listening and have already read

22:09

about this and like, oh, all the

22:12

more reason why I've just got a

22:14

drink from water bottles, like

22:16

purchased water bottles all the time.

22:18

There's a big rub there. Can you

22:20

address that, like, why that? can be

22:23

certainly an immediate remedy, like

22:25

if you were living in

22:27

Flint, Michigan and other areas

22:29

that had their water contaminated

22:31

by lead and such. And

22:33

what's problematic about that? Yeah,

22:35

so I think it's important for,

22:37

I would recommend people reach

22:40

out to your municipality or

22:42

water provider and learn where

22:44

your water comes from and

22:46

what they're testing for and

22:48

what the results are. I think

22:51

sometimes It's very important to learn

22:53

about what's in your water. And

22:55

one concern I have is that

22:57

misinformation might lead people to

23:00

immediately go towards bottled water.

23:02

And my concern with that is,

23:04

you know, bottled water is

23:06

not regulated by the Environmental

23:08

Protection Agency. It's a food product.

23:10

It is not. held to the

23:12

same safe drinking water act standards

23:15

as a public water supplier is,

23:17

and it's causing more waste and

23:19

leading to more micro plastics in

23:21

the environment as well. So I think

23:23

it's, you know, there is a need

23:25

in some cases, of course, but I think

23:27

it's, you know, important for people

23:29

to reach out and understand where

23:31

your water comes from. And with

23:34

the city of Boulder, we have a

23:36

long standing source water protection

23:38

program. We've really prioritized that

23:40

investment in our water supply.

23:42

Like what are a couple things

23:45

that are sort of essential in

23:47

that? How how boulders going about

23:49

protecting the source water? Yeah, I think one

23:51

that's really pertinent to this

23:53

conversation here is we have

23:55

a strong partnership with an

23:57

upstream community, the town of

23:59

Netherlands. and their wastewater treatment

24:01

facility discharges into one of

24:03

our water supply reservoirs. So

24:05

we invested in and enhanced

24:08

wastewater treatment for their facility,

24:10

and we continue that agreement

24:12

where we reimburse them for

24:14

enhanced wastewater treatment. And that

24:16

helps to minimize contamination into

24:18

the drinking water supply. And

24:20

keeping those partnerships is really

24:23

critical for protecting all of

24:25

our water resources. You mean

24:27

partnerships among municipalities? Yeah, exactly.

24:29

Working together, seeing how we

24:31

can share resources, it's in

24:33

everyone's best interest to protect

24:35

the water that we do

24:38

have, especially in Colorado, where

24:40

we do go through drought

24:42

periods. And we need that

24:44

water storage, large reservoirs, to

24:46

get us through those periods.

24:48

And the more we can

24:50

protect the water at the

24:53

source, it leads to more.

24:55

water supply reliability and ultimately

24:57

reduces water treatment costs. Thank

24:59

you and Bridger Rule. I

25:01

know you're among the scientists

25:03

that are really illuminating. the

25:05

problems and the sources of

25:08

them and some of the

25:10

impacts on the policy front,

25:12

nor is Cape, but do

25:14

you want to say anything

25:16

about some things that people

25:18

can do, whether it's cities,

25:20

municipalities, individuals, all of us,

25:23

to help keep more pfas

25:25

and these other contaminations from

25:27

getting into the environment, into

25:29

our bodies for that matter?

25:31

I hope one of the

25:33

big takeaways here is that...

25:35

We start to demand more

25:38

from our leaders, from regulators,

25:40

to pay attention, that enter

25:42

the environment, that we have

25:44

very little idea about their

25:46

health risks, or even worse,

25:48

we know that they are

25:50

health risks, and that we

25:53

start to demand more from

25:55

our leaders, from regulators, to

25:57

pay attention to this issue.

25:59

and really ask for a

26:01

change and not be used

26:03

as experimental models. It's really

26:05

important putting pressure and making

26:08

behavioral choices changes. That was

26:10

Bridger Rule. He's research professor

26:13

of environmental engineering at New

26:15

York University and Kate Dunlap

26:17

for drinking water quality manager

26:19

for the City of Boulder.

26:21

First Bridger, thanks so much for

26:24

coming on the show. He

26:26

may have signed off already. Thank you.

26:28

No, I'm sorry. Welcome. And Kate

26:31

Dunlop, thank you so much. Thank you

26:33

so much. Appreciate being here. That's

26:47

all for this edition of How on

26:49

Earth. Our executive producer is Beth Bennett.

26:51

This week's show was produced by me,

26:53

Susan Moran, and engineered by Jackie Sedley.

26:55

Thanks to Beth Bennett and Joel Parker

26:58

for headline contributions. Our theme music

27:00

was written and produced by Josh

27:02

Cutler. Visit our website at How

27:04

on Earth Radio.org to find past

27:06

episodes, extended interviews, and you can

27:08

subscribe to our podcast through iTunes

27:10

and follow us on Facebook

27:12

Next and Blue Sky. Questions

27:15

or comments, call the KG&U

27:17

comment line at 3Z. for

27:19

479911. For How on Earth,

27:21

the K. Junior Science Show,

27:23

I'm Susan Moran.