Jane: This is But Why: A Podcast for Curious Kids from Vermont
Public. I'm Jane Lindholm, and we're back today with a quick
bonus episode in between regular ones. It's a beautiful day here
in Vermont as I'm recording this. The sun is shining high up
in a bright blue sky, and fluffy clouds are floating by, and the
mountains in the distance are crisp and dark against the
horizon. But I have to say, that's not how it's been for a
lot of the summer here in the northeastern United States,
where But Why is based. The past few years have brought us an
atmospheric phenomenon that we didn't really have all that much
experience with, until recently. Super hazy days where the sun
looks pink and the sky is a blanket of gray and you can't
even see the mountains. The haze is caused by wildfire smoke that
has been blown into our region from forest fires hundreds or
even thousands of miles away, often in Canada. Depending on
where you live in the world, you might have experienced this
phenomenon recently, too. Back in 2020, we made a whole episode
about wildfires called "What happens to the forest after a
fire?" We'll link to that episode in the show notes. But
today's episode isn't about the forests or even the fires. We
wanted to pop in to help explain how smoke can travel so far and
why so many communities around the country and the world are
seeing these extra hazy days lately. Plus, we'll talk a
little bit about how to stay safe and healthy if air quality
levels are an issue where you live. But before we start, we do
want to say we know some of you live much closer to forest
fires, and some of you have even experienced them. That can be
really hard and sometimes scary. Our episode from 2020 includes
conversations with some kids who've told us a little bit
about what that's like. But for today's special episode, to help
us understand the way smoke travels, we called up Joel
Thornton, a professor of atmospheric and climate science
at the University of Washington.
Dr. Joel Thornton: So when forests are on fire, it's
injecting a lot of little tiny particles into the air, and
those then can travel great distances and cover large parts
of the landscape. So when it looks smoky or hazy, it's
because there are little, tiny particles in the air that are
like, like grains of sand you might find at the beach, but
even smaller, that are basically blocking the sun from getting to
our eyes.
Jane: Professor Thornton says these particles are made of
many, many thousands of different molecules and
combinations of different elements. But mostly they're
made of what scientists call carbonaceous materials, little
particles of trees and leaves and other material that have
been burned by the fire and are light enough to rise up into the
atmosphere.
Elliot: My name is Elliot, and I'm seven years old, and I live
in Camas, Washington. How far does smoke travel?
Dr. Joel Thornton: Yeah, it's kind of blows my mind every time
I think about it, how fast the air is moving. If I could hold
on to a little of pack of air for a minute and let it go, that
packet could go around the earth in about two weeks. Fires in
Canada, for example, within just a few days, can be from the
western part of Canada all the way into the eastern part of the
United States, and fires in Siberia in eastern Russia or
pollution created in Beijing in China, that can be blown across
the Pacific Ocean in the matter of a week or so and end up
impacting places in North America.
Jane: When Professor Thornton says fires can travel across the
continent in just a couple of days, he means the smoke
particles, not the fires themselves. But why do these
smoke particles travel so far when smoke from your campfire or
your wood stove doesn't travel far at all? The intense heat
from wildfires pushes smoke much higher into the atmosphere than
smoke from your campfire could get. The smoke gets so high,
maybe as much as five miles above the Earth, that it floats
into the jet stream. The jet stream is a band of strong air
current moving west to east around the world. So when soot
from wildfires gets up into the jet stream, it can get blown
across the continent in a matter of days. Plus, when wildfires
are burning, they're often very big, and there's a lot of smoke
getting into the atmosphere, so it's much more noticeable than
smoke from a smaller fire would be.
Theo: My name's Theo. I'm from Madison, Wisconsin. I'm three
years old. Why does so many smoke in the air?
Jane: There's more smoke in the air, primarily, because
wildfires are burning more forests than they used to. But
why are fires getting more intense?
Dr. Joel Thornton: This is a really important question, and
one that many scientists are trying to understand and study
right now is what is happening to the frequency of wildfires,
the intensity? So in other words, when a fire starts, how
big does it get? How long does it go on for? How are those
properties of fires changing? One of the big considerations
right now is that the Earth is warming. The Earth's sort of
average weather is changing, and it's getting warmer. And warmer
air basically causes trees and the ground to dry out faster. So
when it's warmer, the air just sort of sucks up the water from
these things. So like when we are in dry desert, our skin gets
really dry and, you know, we get thirsty because we're losing
water to the the atmosphere. The atmosphere is very hungry for
water in these conditions, and so it takes up the water, and
that causes these materials just to be more ready to burn. So
then what starts those fires can be natural. So a lightning storm
can happen, and lightning hits the tree, the tree catches on
fire, and if that forest is ready to burn, and you know, so
drier than it normally would be, it will burn more intensely and
in over a bigger area. There's also natural variations in the
weather. That's just sometimes a place gets drier for a summer
than it typically does, and that's not necessarily because
of climate change. And then there's also what we might call
management practices, and so we've, humans have really
changed our relationship with forests and with land over time,
going back to when we started clearing forests to make room
for farms and agriculture. That's been going on for really
thousands of years, but also our cities have been expanding
outwards, so then there's both changes in how we interact with
the forest, but also changes with how we've addressed
fighting wildfires and/or managing the forest to help
prevent wildfires.
Winston: Hello. My name is Winston. I'm eight years old,
and I live in Kaawa, Hawaii. Why is smoke a bad smell, but
firewood a good smell?
Dr. Joel Thornton: Smell is a very complicated science. You
know, you'd be surprised at just how one little difference in a
molecule might change the smell completely. Firewood that you're
using to sit in your fireplace at home, maybe it's a specific
type of wood. It's probably very dry, whereas wildfires, there's
lots of things burning, things like the dirt is literally
burning in a wildfire. The dead leaves on the ground, somewhat
still living branches and trees are burning. And that's not what
you would normally put in your fireplace. But I will say, if
smoke from firewood in your fireplace or smoke from a
wildfire and both not good to breathe. And you should, you
know, try to avoid breathing other kinds of smoke.
Jane: Speaking of breathing, we're going to talk a little bit
about how we can stay safe during wildfire smoke season.
Stay with us.
This is but why. I'm Jane Lindholm. Before the break, we
learned about how smoke travels in the air and can reach us,
even if we live far away from a wildfire. Now we're going to
talk about how we can stay safe and healthy when the air feels
hazy and thick.
Dr. Gregg Furie: My name is Gregg Furie. I am a primary care
doctor. I also have a job as the medical director for climate and
sustainability at Brigham and Women's Hospital in Boston.
Jane: We have some questions from kids about the health
effects of wildfire smoke.
Piper: My name is Piper. I'm nine years old, and I live in
Camas, Washington. Why is it bad to breathe in smoke in the air?
Dr. Gregg Furie: That's a great question. In general, when we
talk about smoke, we're talking about something called
particulate matter pollution.
Jane: That's those teeny, tiny particles in the air caused by
wildfires and things burning. That soot, or particulate matter
pollution, is what's going up into the atmosphere and making
the air we breathe less clean.
Dr. Gregg Furie: When people breathe in particulate matter
pollution, it can certainly affect the lungs, but in fact,
those really, really, really small particles can get into the
body and then can go on to affect essentially any part of
the body. And so that's primarily how people get exposed
to kind of the health effects from from smoke is through
breathing it in.
Jane: One of those health effects might be a tickle in
your throat.
Ava: I'm Ava. I'm seven years old. I live in San Antonio,
Texas. Why does smoke make you cough?
Dr. Gregg Furie: The main reason that people will kind of cough
when they're exposed to smoke is because they're caught, these
fine particles in the air cause inflammation in the lungs. So
that is your body appropriately responding to these foreign
particles through a process of inflammation, but that can often
trigger something like coughing. It can also trigger symptoms
like wheezing, a sense of your chest feeling tight or shortness
of breath.
Jane: Generally, hazy days aren't too much of a problem,
but there are people who are more vulnerable or more affected
by polluted air who need to pay extra special attention.
Dr. Gregg Furie: People who have lung diseases like asthma, or
some adults who have something called chronic obstructive
pulmonary disease or COPD, people who have heart conditions
or health conditions that affect their blood vessels, people who
are very old or very young, and pregnant women tend to be the
groups that are at the highest risk. And so, if someone is in
one of those groups, then they should know that they need to
take kind of extra precaution.
Jane: One way to know if air quality in your region might be
a problem is just to look at the sky. You can often see smoke in
the air because the sun looks different and the sky isn't
blue, even on a day when it's not cloudy, and the buildings or
trees look a little like they're covered in fog or haze. But
another way is to look at something online called the AQI,
the Air Quality Index. The US government monitors air quality
and lets you know what it's like in your area by putting a number
on it. The Air Quality Index ranges from zero to 500. Zero is
very clean air and 500 is very polluted air.
Dr. Gregg Furie: Once the AQI or the air quality index goes above
100 but it's less than 300, people who are in some of the
more sensitive groups, those people should be starting to
think about how they're going to take some precautions. Once the
air quality index is going to be going over 300, then everybody
needs to be considering how they're going to take some
precaution.
Jane: You probably don't need to worry about the AQI. Your adults
can help you keep an eye on air quality in your region. They
often hear about that on the radio or TV, or on a weather app
on their computer or phone or watch. And they can help let you
know if you need to slow down on your outdoor activities or maybe
wear a mask that can filter out some of that pollution. Some
people get special filters for their homes or the buildings
they work or go to school in, too. And Dr. Furie says it's
always good to check in with your doctor if you're in one of
those sensitive groups, so you can have a plan if the air
quality gets bad. Living with wildfire smoke is a new reality
for many of us, and your adults might be navigating it for the
first time, too. So maybe you can make checking the Air
Quality Index together part of your routine during wildfire
season. Thanks to Professor Joel Thornton and Dr. Gregg Furie for
helping us understand wildfire smoke, how it travels and how it
affects us. As always, if you have a question about anything,
have an adult record you asking it on a smartphone using an app
like voice memos or recorder, then have them email the file to
questions@butwykids.org. If you like our show, please have your
adults help you give us a thumbs up or a review on whatever
podcast platform you use to listen to us. It helps other
kids and families find us. But Why is produced by Melody
Bodette, Sarah Baik and me Jane Lindholm at Vermont Public. Our
video producer is Joey Palumbo. Luke Reynolds wrote our theme
music and we're distributed by PRX. We'll be back next week
with an all new episode. Until then, stay curious.