Speaker 1: Hey, Welcome to Stuff to Blow Your Mind. My name
Speaker 1: is Robert Lamb and I'm Joe McCormick. And it is
Speaker 1: not Saturday, but it is time for a vault episode.
Speaker 1: This episode originally aired on August eleven, and it was
Speaker 1: about the life indoors. Yeah, this was a MASDA sponsored episode,
Speaker 1: and I believe that the genesis for the idea was simply, Hey,
Speaker 1: we've been spending a lot of time indoors, you know,
Speaker 1: several months into the pandemic. Uh, what is that? Like?
Speaker 1: What is the interial interior world? What is the inside
Speaker 1: environment that we have created for ourselves. I remember enjoying
Speaker 1: this one. I think I recall it made me look
Speaker 1: at the door frames inside my house in a different way. Yeah,
Speaker 1: I have not looked at my door frames the same
Speaker 1: way since. Let's jump right in Welcome to Stuff to
Speaker 1: Blow Your Mind production of My Heart Radio. Hey, welcome
Speaker 1: to Stuff to Blow your Mind. My name is Robert
Speaker 1: Lamb and I'm Joe McCormick. And today we're gonna be
Speaker 1: taking a look at interior spaces. Yeah. Year certainly brings
Speaker 1: to mind the old curse. May you live in interesting times?
Speaker 1: And one of the factors here has of course been
Speaker 1: the coronavirus COVID nineteen pandemic, and in an effort to
Speaker 1: fight the spread of the illness, save lives, and prevent
Speaker 1: overwhelming our hospitals, we've made a lot of changes to
Speaker 1: our lives, and these range from the simple such as
Speaker 1: just wearing a mask when you're out in public and
Speaker 1: you can't social distance from people, to the harder choices
Speaker 1: about employment and UH. In life choices, we've all been
Speaker 1: social distancing and stay at home orders, teleworking and quarantine
Speaker 1: have meant that we've all been spending a lot more
Speaker 1: time at home. Now. Depending on your home, this could
Speaker 1: mean a lot of things, but we wanted to explore
Speaker 1: what this means from a biological UH standpoint. For the
Speaker 1: most part here now now. Make no mistakes, spending more
Speaker 1: time at home has absolutely been the right move. But
Speaker 1: just as it's forced you to focus more on, say
Speaker 1: that weird staying on your ceiling, we wanted to focus
Speaker 1: on the other often unseen aspects of life in the
Speaker 1: home right much the same way that being, say, on
Speaker 1: a Spanish galleon out in the middle of the ocean
Speaker 1: might have made you pay much more attention to the
Speaker 1: biology and behavior of of ship rats than you ever
Speaker 1: would have otherwise. I think being at home more and
Speaker 1: more is forcing all of us to turn our eyes
Speaker 1: and maybe our microscopes and magnifying glasses to the corners
Speaker 1: and the cornices, and the shower heads and the drain
Speaker 1: traps and all of the wonderful places in our house
Speaker 1: where life dwells. Yeah, we're gonna really get into the
Speaker 1: difference really between the natural world outside of our homes
Speaker 1: and the unnatural world inside, and get into some ideas
Speaker 1: about how how we could perhaps enable our interior world
Speaker 1: to be a little more on the natural side of things.
Speaker 1: But before we get into all that, I wanted to
Speaker 1: take a moment here just to discuss the history of
Speaker 1: houses in general, you know, just to get into the
Speaker 1: concept of what a house is our our first and
Speaker 1: still most important interior artificial environment. So you can certainly
Speaker 1: look at a home as an artificial cave to a
Speaker 1: certain extent. And indeed we have lots of early evidence
Speaker 1: that early hominants sought out shelter in caves in the
Speaker 1: same way that many other animals do. Uh. These can
Speaker 1: shelter one against the elements and against predators, and as
Speaker 1: recently as a hundred and thirty thousand years ago, cave
Speaker 1: dwellers were already augmenting these natural interior environments with things
Speaker 1: like rough stone walls. They were using timbers so um.
Speaker 1: So you know, even a hundred thirty thousand years ago,
Speaker 1: we were taking naturally occurring interior spaces and making them
Speaker 1: a little less natural. Um. And of course, on top
Speaker 1: of just the shelter that caves can provide, it also
Speaker 1: seems that caves had a strong sacred meaning to many
Speaker 1: of these uh phistoric people's. Those might be important, but
Speaker 1: ultimately proximity to water is far more important. Thus, as
Speaker 1: Kate Spence and Brian and Fagan point out in UH
Speaker 1: in the a section of the seventy Grade Inventions of
Speaker 1: the Ancient World about homes, most early hominids lived out
Speaker 1: in the open, near streams and lakes. They built temporary structures,
Speaker 1: and most of this has been lost to time, but
Speaker 1: some of the earliest evidence of potential structures for homes
Speaker 1: goes back one point seven two point seven million years
Speaker 1: ago with homo erective sites in southern Africa, and these
Speaker 1: were potentially contemporary with the domestication of fire um and
Speaker 1: these would have been temporary tents, but but they still
Speaker 1: would have been artificial interior environments. Now more secure evidence
Speaker 1: comes from the Ukraine roughly forty four thousand years ago,
Speaker 1: the mammoth bone structures from Maladova, which we recently discussed
Speaker 1: on the show. Actually, yeah, we did uh talking about
Speaker 1: these uh. That would have been structures in one of
Speaker 1: the northernmost habitable regions of the Earth at the time,
Speaker 1: because this was during a time of glacial advance where
Speaker 1: the polar ice caps from the north were coming deep
Speaker 1: down into Europe and Asia and uh, and so this
Speaker 1: would have been far far north, way up among the
Speaker 1: ice and for some reason humans were building these structures
Speaker 1: out of the bones of mammoth And we don't know that.
Speaker 1: There's still things we don't know about those structures, like
Speaker 1: how how consistently they were inhabited and for how long
Speaker 1: and so forth. Right now, beyond this, the history of
Speaker 1: human homes is is largely dictated by local resources and
Speaker 1: a local climate. A long process of trial and air
Speaker 1: ends up leading to the development of regional and cultural
Speaker 1: building forms construction methods. But before nine thousand b C.
Speaker 1: We see evidence of clay houses in Palestine, what is
Speaker 1: today Palestine, and before seven thousand BC we see rectangular
Speaker 1: dwellings in Anatolia. But but home is far more than
Speaker 1: just a shelter. As the authors here point out, houses
Speaker 1: became key to social structure as well. They point out
Speaker 1: that ethnographic studies in West Africa reveal complex and layered
Speaker 1: symbolic associations and rituals in the context of dwelling. And
Speaker 1: this is a you know, it shows a clear role
Speaker 1: of physically structuring and expressing the relationship between different members
Speaker 1: of the household. And we see this of course in
Speaker 1: um and cultures, you know, throughout history and throughout the world.
Speaker 1: There's this physical shape of the place. Uh, and then
Speaker 1: that ends up defining or influencing like that, there's this
Speaker 1: this feedback between the two. It goes both ways, right,
Speaker 1: It's kind of like pouring a liquid into a container.
Speaker 1: Oh of course. And this actually got me thinking about
Speaker 1: how having permanent, constructed dwellings must have changed the way
Speaker 1: that power and hierarchy are expressed in social groups. And
Speaker 1: of course this is true with normal social status. You know,
Speaker 1: it's it's stake out through displays of wealth. There certain
Speaker 1: kinds of taste or aesthetics in your house, your apartment,
Speaker 1: you're you know, you're living space. But this also made
Speaker 1: me think about the way that for many leadership positions,
Speaker 1: there is a special house, there's a special dwelling place
Speaker 1: that comes with the job, rather than belonging to an individual.
Speaker 1: So here in Georgia we have the Governor's mansion, there
Speaker 1: is the White House there, you know, the palace that
Speaker 1: the king stays at in many cultures, and there's a
Speaker 1: there's a strange metonomy that derives from this. Often the
Speaker 1: house identified with the position of power is used as
Speaker 1: a metaphorical stand in for the person. You know, like
Speaker 1: today the White House said such that, like the permanent
Speaker 1: dwelling place is actually almost the source of the power,
Speaker 1: and there just happens to be a particular person living
Speaker 1: there right now. Yeah, it's weird. We get so used
Speaker 1: to it because it's just part of our daily, um
Speaker 1: daily you know, linguistic world. You know, you can you
Speaker 1: read the news, you read about these very as locations,
Speaker 1: these houses, and it's almost as if they have some
Speaker 1: sort of intrinsic power to them, right, I mean, if
Speaker 1: you weren't familiar with their cultures, you would read this then,
Speaker 1: and people might think, oh, well, they they clearly thought
Speaker 1: that this big white house had some sort of magical powers,
Speaker 1: and whoever was allowed to go inside it became the
Speaker 1: ruler of a country and got to do whatever they want. Yeah,
Speaker 1: and it's funny that it's so normalized for us, like
Speaker 1: we've forgotten to notice that that's weird that like the
Speaker 1: power is somehow linked to the house itself. Um. But
Speaker 1: it also makes me wonder, you know, did we think
Speaker 1: about power differently before living in artificially built environments? Yeah?
Speaker 1: To what extent did we? Um? Did we end up
Speaker 1: yet changing the way we live our lives by altering
Speaker 1: this physical environment which we live. I mean, it makes sense,
Speaker 1: right because so much of what we do, you know,
Speaker 1: it's dictated by the environments that we evolved to thrive in. Right.
Speaker 1: So anyway, I don't think we need to remind everyone
Speaker 1: about the value of a home. Housing tends to be
Speaker 1: one of, if not the most expensive parts of your life.
Speaker 1: But it's it's interesting to think about them not simply
Speaker 1: as this valuable thing in your life, for a valuable
Speaker 1: location where your life takes place. The basic idea of
Speaker 1: the house may be as old as our mastery of fire,
Speaker 1: and it forms out of and forms ideas of who
Speaker 1: and what we are, and of course it may do
Speaker 1: so in more and more powerful ways every year, as
Speaker 1: humanity slowly transitions to become a more indoors e on
Speaker 1: average species. All the time, I was reading some interesting
Speaker 1: figures about this trend in a book by the science
Speaker 1: writer Emily and thus Uh And the book is called
Speaker 1: The Great Indoors The Surprising Science of How Buildings shape
Speaker 1: our behavior, health, and happiness. This is a really interesting
Speaker 1: book and I'm going to refer to it throughout this
Speaker 1: episode because she has an early chapter that's very good
Speaker 1: about the microbial ecology of indoor spaces. But she also
Speaker 1: gets into some interesting territory about the trends in how
Speaker 1: much built environment ment and floor space we're actually creating. Obviously,
Speaker 1: this currently varies a lot by culture and climate, but
Speaker 1: in some parts of the world human kind is transitioned
Speaker 1: to an almost entirely indoor existence. And this really shows
Speaker 1: in the way we've transformed our environments to convert to
Speaker 1: this largely indoor existence. Anti writes, quote, the island of
Speaker 1: Manhattan is only twenty three square miles in size, but
Speaker 1: has three times that much indoor floor space. And furthermore,
Speaker 1: she refers to a report put together by a United
Speaker 1: Nations commission in which concluded that over the next forty years,
Speaker 1: humankind is going to roughly double the amount of indoor
Speaker 1: floor space that exists currently. And the way this works
Speaker 1: out is quote those additions are equivalent to building the
Speaker 1: current floor area of Japan every single year from now
Speaker 1: until that much floor is going to take a lot
Speaker 1: of pin sall. Yeah, I mean it is crazy to
Speaker 1: think about how certainly during pre pandemic times, you know,
Speaker 1: you would you had this home, this interior space that
Speaker 1: you live in, you sleep in, you bathe in, you
Speaker 1: spend time in, and then uh, and it is, you know,
Speaker 1: very much like the center of your life. And then
Speaker 1: you're getting into another interior space which happens to be
Speaker 1: motorized and on wheels, and use that to travel then
Speaker 1: a certain distance to another interior space that you'll go
Speaker 1: into to work either set at a desk or you know,
Speaker 1: work with some sort of machinery or what have you. Uh,
Speaker 1: and then at the end of the day back into
Speaker 1: this motorized interior space and then return to the one
Speaker 1: in which you live it's worth remembering yet again, biologically speaking,
Speaker 1: this is not normal. This is not like what our
Speaker 1: bodies are naturally adapted to. Spending this much time indoors
Speaker 1: is still fairly historically novel, and it is very weird. Yes.
Speaker 1: But the other big thing this is going to be
Speaker 1: a recurring theme throughout the rest of the episode, is
Speaker 1: that these artificial spaces that we made, they are they're
Speaker 1: not completely alien, you know, they're they're constructed all of
Speaker 1: the natural world. They're not the natural environment, but they
Speaker 1: are made out of it. And uh and and much
Speaker 1: of the natural world is still present, just in um
Speaker 1: rebalanced and unbalanced ways. Uh So that that is going
Speaker 1: to be what we're going to really get into, Like
Speaker 1: what in creating these interior spaces, what sort of environments
Speaker 1: have we created? Right? Indoor spaces are not unnatural, and
Speaker 1: that they're completely separate from the rest of the world,
Speaker 1: but they're also not just like outdoor spaces. They're kind
Speaker 1: of like a special niche environment, like a like a
Speaker 1: cliff face or an island. You know, it's a place
Speaker 1: where you have to investigate. Okay, what kinds of life
Speaker 1: from around and other places are going to colonize this space. Yeah,
Speaker 1: and and who are your roommates? Who are your inhuman
Speaker 1: roommates in this space where you've been trapped uh these
Speaker 1: past several months. Well, maybe we should take a break
Speaker 1: and then when we come back we can start talking
Speaker 1: about those in human roommates. Than alright, we're back, so U.
Speaker 1: Rob Donne, a professor of applied ecology at North Carolina
Speaker 1: State University and Raleigh, wrote an excellent book titled Never
Speaker 1: Home Alone. From Microbes to Millipedes, camel, crickets and honey bees,
Speaker 1: then natural History of where we Live. That's a nice
Speaker 1: long title. I know you'll be like those those long
Speaker 1: colond titles. I want like a whole paragraph after the colon.
Speaker 1: But it's it's as hard as I go. It's pretty
Speaker 1: good title. Anyway. It came out last October and it's
Speaker 1: currently available in all four mats. So however, you read
Speaker 1: your books. But I remember hearing an interview with the
Speaker 1: author around the time that came out, and I picked
Speaker 1: it up for this episode because it's a yeah, it's
Speaker 1: it's it's just a very well written book and it
Speaker 1: really gets into some just crazy mind bending facts about
Speaker 1: these artificial environments, most of which we won't even really
Speaker 1: be able to get into in this episode, but we
Speaker 1: wanted to touch on it. So if you look around
Speaker 1: it's science papers, you'll find Dunn's name um all over
Speaker 1: the place when it comes to this area of microbial life.
Speaker 1: For instance, he's the co author on a two thousand
Speaker 1: eighteen paper that found that chimpanzee treetop beds, which are
Speaker 1: like a daily affair, contained fewer microbes and arthropods than
Speaker 1: human beds, which is not shocking given again the the idea,
Speaker 1: there are beds that are kind of like set in place. Um,
Speaker 1: you know, we will change the sheets, but it's not
Speaker 1: every night probably, whereas the chimps are going to be
Speaker 1: refreshing things a bit more. Also, of the bacteria in
Speaker 1: human beds stem from our own bodies and includes fecal, oral,
Speaker 1: and skin bacteria. Yeah. The way I heard it put,
Speaker 1: because this is covered in anthesis book too, is that
Speaker 1: with the with the human bed basic you're just gonna
Speaker 1: find tons of human type stuff in it. But for
Speaker 1: a chimpanzees bed, you will find you know, bugs, arthur
Speaker 1: pods and microbes in in this bed, but they're almost
Speaker 1: all from the surrounding environment. Uh, The way it was
Speaker 1: put was that you might not be able to tell
Speaker 1: that a chimpanzee had ever been there. Right, very strange.
Speaker 1: But from anthesis book, there's uh So, there's a chapter
Speaker 1: that discusses a lot of the work of the same researcher,
Speaker 1: robbed On, the the ecologist at North Carolina State, but
Speaker 1: also a researcher that he's collaborated with a lot named
Speaker 1: Noah Fierre, who's a microbiologist at u C Boulder, And
Speaker 1: there's a part where it talks about a survey that
Speaker 1: they tried to conduct called the Wildlife of Our Homes Project.
Speaker 1: There was a pilot study they started in North Carolina,
Speaker 1: and so what they would do was they would get
Speaker 1: a bunch of families to take cotton swab samples of
Speaker 1: seven different surfaces from inside their homes. And this would
Speaker 1: include a countertop, a cutting board, a refrigerator or shelf,
Speaker 1: a pillow case, a toilet seat, a TV screen, and
Speaker 1: then the trim around an interior doorway. And the results
Speaker 1: were interesting. They found more than two thousand types of
Speaker 1: microbes in these samples, and there were distinct microbial habitats
Speaker 1: within the house. So perhaps on surprisingly kitchens would have
Speaker 1: a lot of bacteria that are naturally associated with food
Speaker 1: that might be you know, found on food or aid
Speaker 1: in the decomposition of food. Meanwhile, doorways would have a
Speaker 1: lot of environmental species stuff you might find outside the house,
Speaker 1: you know, things you would find on plant leaves and
Speaker 1: in the soil. But then this was the quote that
Speaker 1: really stuck with me. And this writes quote from a
Speaker 1: microbiological perspective, toilet seats and pillow cases looked strikingly similar.
Speaker 1: Both were dominated by bacteria that typically live on our
Speaker 1: skin and in our mouths. All right, So that's that's
Speaker 1: kind of a shocking sounding statement. They might make you
Speaker 1: want to instantly go and wash your pillow case and
Speaker 1: maybe your toilet seat too. But but but hold on,
Speaker 1: wait till we get through the whole episode, because I
Speaker 1: think one of the big take comes here is like,
Speaker 1: if you think that your pillow is going to be
Speaker 1: a microbial sterile um experience, you know you should think again,
Speaker 1: likewise with the toilet seat, likewise with anything in the house.
Speaker 1: So in Dunn's book, one of one of the things
Speaker 1: he drives home is that again our our house environments
Speaker 1: are again not natural environments, but they are made out
Speaker 1: of the natural environment, and they are not cut off
Speaker 1: from the natural environment. So what we end up with
Speaker 1: is an artificial environment that kind of mashes up all
Speaker 1: of these various environmental parameters, sometimes in surprising ways, especially
Speaker 1: when it comes to microbes, because if we as we've
Speaker 1: discussed on the show plenty of times before, there is
Speaker 1: no microbe free living. Our bodies, independent of anything else,
Speaker 1: are home to multitudes of microbes. To come back to
Speaker 1: a quote that we've pulled up on the show in
Speaker 1: discussion in the past, in a Life in a World
Speaker 1: without Microbes by Gilbert and Newfeld bushed in Plist biology,
Speaker 1: the authors contend that quote it would be false to
Speaker 1: claim that macroscopic life cannot exist without microbes. However, although
Speaker 1: life would persist in the absence of microbes, both the
Speaker 1: quantity and quality of life would be reduced drastically. So
Speaker 1: Done points out that even the outer layer of our
Speaker 1: skin is just this rich microbial environment. Our armpit bacteria
Speaker 1: are essentially fed by glands, nurturing what has likely been
Speaker 1: an historically important microbe passenger, and we can we can
Speaker 1: look at this as an example of the sort of
Speaker 1: microbe that then thrives in our creative environments. We tend
Speaker 1: to find the same bacteria that that that thrives in
Speaker 1: our under arms living in our homes, especially homes where
Speaker 1: males live. If there's like a predominantly male population of
Speaker 1: a household, you will find this particular bacterium. I believe
Speaker 1: it's uh corn a bacterium, just thriving Coriina bacterium, Corina bacterium. Yes. Yeah,
Speaker 1: So this thing about the sex composition of the household
Speaker 1: versus the household microbiome was also mentioned in anthesis book,
Speaker 1: and it's very interesting. So, just as you say, homes
Speaker 1: with more male residents tend to have higher counts of
Speaker 1: bacteria such as Rosa burria and this is commonly a
Speaker 1: gut bacteria, as well as Karina bacterium and Derma bacter
Speaker 1: and uh at. This points out that these are most
Speaker 1: common on the skin. Now, Coarina Bacterium is often found
Speaker 1: in the armpit. As you say, it is a contributor
Speaker 1: to body odor. But also it's been found that just
Speaker 1: on average, men tend to have more Coarina bacteria on
Speaker 1: their skin than women do, and men tend to shed
Speaker 1: more skin microbes into the environment than women do. And
Speaker 1: then on the other hand, households that have more women
Speaker 1: living in them tend to have higher counts of Lactobacillus,
Speaker 1: which is our old friend from the fermentation episode. I
Speaker 1: don't know if this translates to a workable difference, maybe not,
Speaker 1: but it makes me wonder if it's possible that houses
Speaker 1: occupied by high a numbers of women might be a
Speaker 1: better place to make sauerkraut. Interesting to some to think about,
Speaker 1: but sort of what this suggests is that humans are
Speaker 1: walking fountains of microbes. We we shed our microbial passengers
Speaker 1: everywhere we go, and it turns out this can be
Speaker 1: kind of quantified to creepy levels. So consider this. No
Speaker 1: two people's microbiomes are exactly the same. Each person is
Speaker 1: a unique ecosystem. So if everybody has their own unique
Speaker 1: profile of microbiota, and everybody is shedding microbial life all
Speaker 1: the time, are we essentially leaving identifiable microbial evidence of
Speaker 1: our presence everywhere we go, you know, kind of the
Speaker 1: slug trail of our microbiome all over the place. And
Speaker 1: the answer appears to be kind of yeah. And this
Speaker 1: reports one study led by Jack Gilbert at the University
Speaker 1: of Chicago. I think that might be the Gilbert of
Speaker 1: the Gilbert and Neufeld study that you mentioned a minute ago.
Speaker 1: But it follows three families that were in the process
Speaker 1: of moving into new homes. And what Gilbert and colleagues
Speaker 1: found was that each family began to colonize the new
Speaker 1: house with their microbes within just hours of arriving there. Uh.
Speaker 1: And that the researchers quote could even detect the individual
Speaker 1: microbial contributions of each family member. Uh. And then Gilbert says,
Speaker 1: people who spent more time in the kitchen, their microbiome
Speaker 1: dominated that space. People who spent more time in the bedroom,
Speaker 1: their microbiome dominated there. You could start to forensically identify
Speaker 1: their movement. Oh wow, So this makes one try to
Speaker 1: imagine like lawne order microbiology. Yes, surveillance biotech. But to
Speaker 1: come back to to Rob Dunn's example about Corina bacteria
Speaker 1: in homes, especially where males live. You you had an
Speaker 1: interesting thing about that. Yeah, he brings up a very
Speaker 1: curious case of an interior environment intier home that had
Speaker 1: a predominantly certainly at the time of the study, had
Speaker 1: a predominantly male um population. And that is the international
Speaker 1: Space Station. So this was basically there was a study
Speaker 1: of the micro buyouta one finds inside the I S S.
Speaker 1: This was conducted in two thousand thirteen by Jonathan I. Sen,
Speaker 1: a microbiologist at U C. Davis. So the the I
Speaker 1: S S, done rights, is very much like a house
Speaker 1: on Earth. Quote, in nearly every way, the bacteria of
Speaker 1: the I S S are the sorts of bacteria we
Speaker 1: would expect in a house on Earth if all the
Speaker 1: environmental influences were removed. I S S is what you
Speaker 1: get when you scrub and scrub and close the windows,
Speaker 1: doors and hatches. So the I S S might be
Speaker 1: kind of like a very well scrub department in a
Speaker 1: high rise in a big city. Yeah, I mean there's
Speaker 1: there's no outside to get inside, right, UM mean immediately,
Speaker 1: so obviously, um stuff can be brought up. But anyway,
Speaker 1: Done also points out that in this study of ISS microbes, quote,
Speaker 1: everything was everywhere, the interior was just coded in human
Speaker 1: bacteria and nothing from outside was getting in. Obviously. He
Speaker 1: points out that in a small traditional home made out
Speaker 1: of mud and leaves, which would have been you know,
Speaker 1: the normal for the vast uh, you know, the vast
Speaker 1: majority of human existence. Everything would be everywhere as well,
Speaker 1: but environmental microbes would be everywhere. What's outside would be inside.
Speaker 1: But for the I s s there there is no outside. Really,
Speaker 1: it is a you know, this sterile environment that is
Speaker 1: then inhabited by human beings, certainly, but then inhabited populated
Speaker 1: by human microbes. Right, So, so environmentally sterile, but heavily
Speaker 1: colonized by what the humans bring with them, right, He writes, quote,
Speaker 1: if you scrub and scrub your home, this is what
Speaker 1: you may achieve too. It is not unlike what we
Speaker 1: see in some apartment in Manhattan. And as we and
Speaker 1: others have begun to study such apartments, we have found
Speaker 1: a problem. The problem is not what is present, but
Speaker 1: instead what is absent. The problem has to do with
Speaker 1: what happens when we create homes devoid of nearly all
Speaker 1: biodiversity except that which falls from us, and then for
Speaker 1: twenty three hours of the day we don't go outside.
Speaker 1: So they're kind of getting high on our own supply here. Yeah,
Speaker 1: I mean, that's that's exactly. I mean, it's we're in
Speaker 1: these interior worlds. We're not we're actually going to great
Speaker 1: pains and many times or just by the virtue of
Speaker 1: the shape of our cities, in the shape of our lives.
Speaker 1: We're not bringing anything in or're ringing in as little
Speaker 1: as as possible, and except for everything that just sheds
Speaker 1: off of us. This kind of like constant um um,
Speaker 1: you know, fog of detritus that we're leaving in our wake. Now,
Speaker 1: this isn't to say there aren't some really interesting things
Speaker 1: living in the average human home. In his book, Done discusses,
Speaker 1: for instance, the thermophilic bacteria thermo aquaticus, which normally thrives
Speaker 1: in hot springs and geyser's uh, you know, kind of
Speaker 1: a you know, a specialist in that regard, but you
Speaker 1: can pretty much rely on the fact that you can
Speaker 1: find it in your hot water heat a part of
Speaker 1: your artificial environment that recreates environmental conditions that it finds favorable. Yeah,
Speaker 1: Anthes discusses the research on shower heads. Apparently there tends
Speaker 1: to be a lot of bacteria living in biofilms. And
Speaker 1: biofilms are you know, these mats that microbes make when
Speaker 1: they gather in big concentrations. For example, the dental plaque
Speaker 1: on your teeth is a biofilm. These tend to form
Speaker 1: on shower heads in our showers. We don't know exactly why,
Speaker 1: but maybe because you know, hey, it's the shower, doesn't
Speaker 1: it just get cleaned by itself? Like, do I really
Speaker 1: need to clean it? Uh? It is clean, it's water
Speaker 1: coming out of it, exactly. It's kind of the logic
Speaker 1: that's like, why would I ever need to wash my
Speaker 1: bath towel holes? You know, they only canter you when
Speaker 1: I'm at my cleanest um. But Anthus quotes Noah Noah Fear,
Speaker 1: explaining that when hot water suddenly starts shooting out of
Speaker 1: the shower head where these films are perched, it creates
Speaker 1: this kind of mist and spray that carries bacteria with it,
Speaker 1: and then of course, standing there under the spray in
Speaker 1: the shower, we ingest that spray, We breathe it right in.
Speaker 1: And Fierra says, quote, I think it's a really important
Speaker 1: mechanism by which we're exposed to bacteria. Which, okay, so
Speaker 1: you might be thinking again like, oh my god, my
Speaker 1: shower head. You're filled with horror, But it's not necessarily
Speaker 1: a bad thing. Again, like a lot of our exposure
Speaker 1: to microbes is either neutral or beneficial, though of course
Speaker 1: not all of it. Yeah, the biofilms in your shower
Speaker 1: head contain mostly harmless bacteria, but it but it. Interestingly enough,
Speaker 1: it includes non tuberculosis micro bacteria, which are relatives of
Speaker 1: leprosy into bercua losis um. The interesting thing here is
Speaker 1: that their chlorine tolerant. So while the chlorine in them,
Speaker 1: like a major metropolitan water system, kills a lot of
Speaker 1: the micro organisms that it might otherwise be found there,
Speaker 1: it doesn't hurt these guys and actually creates room for
Speaker 1: them to grow and to thrive. So there are otherwise
Speaker 1: quite rare and say, well water, Uh, these are I
Speaker 1: think I read that these biofilms are typically found in general,
Speaker 1: are found in swamps, totally adapted to altering between wet
Speaker 1: and dry conditions, much like your shower head. Um. But yeah,
Speaker 1: in the natural world, they're just gonna have their their
Speaker 1: niche to occupy. But we've created an artificial environment where
Speaker 1: they have room to just really grow and thrive and
Speaker 1: then of course rain down upon us. And there could
Speaker 1: be health implications about those microbacterial films. We don't know
Speaker 1: for sure, but there's a there's a possibility. Anthis talks
Speaker 1: about she writes quote. In fact, Fear and Done discovered
Speaker 1: that showerheads harboring potentially dangerous strains of micro bacteria clustered
Speaker 1: in the same regions mentioning Hawaii, southern California, Florida in
Speaker 1: the mid Atlantic that are known to be hot spots
Speaker 1: for micro bacterial related respiratory infections. So the question is,
Speaker 1: are people getting these infections from their shower heads. Fear
Speaker 1: suspects that might be the case, but that doesn't necessarily
Speaker 1: mean your shower head is making you six. Some micro bacteria,
Speaker 1: when inhaled, are are not harmful. They might even strengthen
Speaker 1: your immune system. Now Done points out that that we've
Speaker 1: been studying microbiota in our homes actually since the earliest
Speaker 1: days of microbiology. Uh. You have this individual by the
Speaker 1: name of Anthony van Lewenhoek who lived sixty two through
Speaker 1: seventeen twenty three, and he's often called just the father
Speaker 1: of microbiology and and weirdly enough, he's possibly the model
Speaker 1: for two different Vermeer paintings. I don't know if you've
Speaker 1: read about this. I haven't. Yeah, um, but courage listeners
Speaker 1: to look it up. It's pretty fascinating. Like basically he
Speaker 1: knew Vermeer and may have posed for these paintings, but
Speaker 1: he's the first individual known to have engaged in this
Speaker 1: sort of study. He charted the microbial populations of his
Speaker 1: own house, of his own body, and also some neighbors
Speaker 1: homes and bodies. Um with permission, I believe. But but
Speaker 1: after his death, no one really bothered with the sort
Speaker 1: of study again until we realized later that some of
Speaker 1: the microbes we encountered could make us sick. And so
Speaker 1: it's really it's it's really getting into modern times here
Speaker 1: where we're finally uh, taking a close look at our
Speaker 1: household microbial environment, with researchers like done playing a key role. Um.
Speaker 1: Here's another great quote where he's just talking about, you know,
Speaker 1: undertaking this this project and what they expected to find.
Speaker 1: He says, quote, we expected to find hundreds of species. Instead,
Speaker 1: we discovered, depending on just how you do the math,
Speaker 1: upward of two hundred thousand species. Many of these species
Speaker 1: are microscopic, but others are larger and yet nonetheless overlooked.
Speaker 1: Breathe in inhale deeply. With each breath, you bring in
Speaker 1: oxygen deep into the alveoli of your lungs along with
Speaker 1: hundreds or thousands of species. Sit down. Each place you sit,
Speaker 1: you are surrounded by a floating, leaping, crawling circus of
Speaker 1: thousands of species. We are never home alone WOA. And
Speaker 1: this is on top of tins and perhaps hundreds of
Speaker 1: different types of vertebrates as well as various plants. And
Speaker 1: then there are the arthropods and the fun guys. Something
Speaker 1: like forty thousand species of fungi that can be found
Speaker 1: in the home um. But the bacteria are just really
Speaker 1: the crazy Party points out that more species of bacteria
Speaker 1: have been found in human homes than there are species
Speaker 1: of birds and mammals on Earth. Yeah. This type of
Speaker 1: research is also explored in in Anthesis book, where there's
Speaker 1: a section where she talks about how Done and Fear
Speaker 1: followed up on their initial research who you know, asking
Speaker 1: people to take the swabs from the different parts of
Speaker 1: their home to find out what was there. They decided
Speaker 1: to do with like a bigger, deeper study of the
Speaker 1: microbes found specifically along the trim of interior doorways. And
Speaker 1: they picked this area because nobody ever cleans it, so dusty,
Speaker 1: you know, collects for years maybe without being sterilized. Then
Speaker 1: this would give you potentially a fuller inventory, and they
Speaker 1: just found enormous numbers of bacteria. In anthesis book, the
Speaker 1: number is over a hundred and sixteen thousand species of bacteria,
Speaker 1: more than sixty three thousand species of fungi. And the
Speaker 1: count of fungi species was especially interesting to them because
Speaker 1: they found more numbers of species of fungi in these
Speaker 1: samples around doorway trims than there are named species of
Speaker 1: fungi in all of North America, So it means that
Speaker 1: inside our houses, it's it's very likely that there are
Speaker 1: species of fungus that have not yet been discovered or
Speaker 1: cataloged by science. And they also found that that for
Speaker 1: some of these samples, there was more uh fungi diversity
Speaker 1: inside the house than outside the house, which which reminds
Speaker 1: me of the scene in Primer where they don't realize
Speaker 1: they've created a time machine yet and they think that
Speaker 1: that the box that they put together as an incubator
Speaker 1: for mold oh I forgot about that detail that a
Speaker 1: while since have seen that one and fungi in our
Speaker 1: homes are somewhat different than bacteria in our homes, so
Speaker 1: that they have a different different vectors in different ways
Speaker 1: of living Anthests discusses how the bacteria in our houses
Speaker 1: they mostly come from us and from the other creatures
Speaker 1: that live with us, like dogs, and we'll get into
Speaker 1: more on that in a bit, but the fun guy
Speaker 1: are not as populous on and in our own bodies.
Speaker 1: They tend to come more from the environment outside. And
Speaker 1: what kind of fungi are found within a home is
Speaker 1: largely determined by where the home is regionally, in the
Speaker 1: climate around the home, what kind of fungi are prevalent
Speaker 1: in the exterior environment. But there are other factors that
Speaker 1: have an effect as well. And there's one that I
Speaker 1: found very interesting. It was what the house is made of.
Speaker 1: And she quotes from Done saying it's kind of a
Speaker 1: three pigs thing. A stone house feeds different fungi from
Speaker 1: a woodhouse from a mudhouse, because unlike the bacteria, they're
Speaker 1: eating the house. So it's like, what have you put
Speaker 1: out on the buffet for them? Yeah, I mean again,
Speaker 1: it comes down to the fact that our home is
Speaker 1: not this um, this alien thing, you know, it is
Speaker 1: made out of the natural world, and therefore there are
Speaker 1: things that want to eat it, to eat those materials
Speaker 1: that made up your home. Uh, so yeah, it's it's
Speaker 1: easy to overlook that, but yeah, it makes perfect sense.
Speaker 1: So obviously, I'm sure some people, despite our our warnings
Speaker 1: early on, are like, Okay, I'm just getting the bleach.
Speaker 1: I'm gonna sterilize my entire living space. Maybe now we
Speaker 1: should explain why that that might not be a good idea. Yeah,
Speaker 1: that might be your inclination. And and really it kind
Speaker 1: of falls in line with what advertising has has been
Speaker 1: has been telling us for years. You know, the sort
Speaker 1: of world that we grew up in, where it's like
Speaker 1: we got to disinfect the house, you gotta keep the
Speaker 1: house clean, as if there is this absolute cleanliness, this
Speaker 1: nobiotic um aspect of our homes. But but this way
Speaker 1: of thinking is essentially treats our homes again like some
Speaker 1: sort of lifeless, nobiotic box, hermetically sealed from the outside,
Speaker 1: an impervious to occupation by anything but the presumably nobiotic
Speaker 1: creatures living inside it. But all of this, you know,
Speaker 1: nothing could be further from the truth, because nature of
Speaker 1: horrors of vacuum and your home will come to harbor
Speaker 1: a robust ecosystem. But our actions and our choices have
Speaker 1: an effect on that ecosystem as we saw with the
Speaker 1: shower head and the and the water heater or example above.
Speaker 1: You may keep certain things out, but that just means
Speaker 1: there's more room for other things to make themselves at home.
Speaker 1: All right, well we need to take a second break,
Speaker 1: but we will be right back with more. Alright, we're back.
Speaker 1: So raining anti microbial death down on your apartment or
Speaker 1: house is is also crazy, given that, as Done and
Speaker 1: Sebastian Tilch discussed in a two thousand nineteen study published
Speaker 1: in Nature Ecology and Evolution, only a relatively small proportion
Speaker 1: of the micro organisms in our environment actually cause disease.
Speaker 1: It's also worth noting that insects and other arthur pods,
Speaker 1: especially spiders that live in in the home, are important
Speaker 1: actors in the ecosystem, as they can exterminate mosquitoes, bedbugs, cockroaches,
Speaker 1: and house flies, all of which actually can transmit diseases.
Speaker 1: And it's not a universal thing around the world that
Speaker 1: people see a spider in their house and say, oh,
Speaker 1: we've got to kill that. Like, some cultures are much
Speaker 1: more tolerant of spiders with the knowledge that they're performing
Speaker 1: this important cleaning service. Yeah, I I personally like seeing
Speaker 1: the spider in the bathroom every day. You know it's
Speaker 1: it's a friend. You know that it's it's he or
Speaker 1: she is working to to to help make this bathroom
Speaker 1: a better environment. In that paper by Done and Tilt Uh,
Speaker 1: the authors agree that there there's simply no need to
Speaker 1: weigh devastating war against all of these organisms. But more
Speaker 1: to the point, a lot more work is needed to
Speaker 1: determine just what sorts of environments are more susceptible to
Speaker 1: the bad stuff. Another interesting wrinkle in all of this
Speaker 1: is that and and this is one Done discusses in
Speaker 1: his book, is exactly what household dogs reveal about the
Speaker 1: contrast between the exterior ecosystem and our interior worlds. Dogs
Speaker 1: are amazing at bringing you filth that I think about
Speaker 1: this with my dog every day. It's like every single
Speaker 1: day he's like, let me nourish your microbiome. Well, I
Speaker 1: think ultimately the way to look at it is the
Speaker 1: dog is not just bringing filth in. The dog is
Speaker 1: nurturing your filth. Like there's going to be filth. If
Speaker 1: you wish to categorize the microbial world as filth. Uh,
Speaker 1: there's no escaping it. Um. So the dog is ultimately
Speaker 1: just bringing something to the equation. So for a lot
Speaker 1: of us, we tend to leave our our artificial interial world,
Speaker 1: you know, again, hop into another one that happens to
Speaker 1: have wheels, travel doors, to work, come back, etcetera. A
Speaker 1: lot of us do get out into the natural world,
Speaker 1: but there are plenty of us that don't do it
Speaker 1: on a regular basis. If you have pets, indoor only
Speaker 1: varieties contribute to the microbial stew that is your home.
Speaker 1: But there's no beating a dog for a bridge between
Speaker 1: inner and outer ecosystems. There's also no beating a dog.
Speaker 1: Just I don't want to encourage anybody, but for starters,
Speaker 1: your dog is likely drawing you out into the outside environment. Uh.
Speaker 1: You know, you're gonna probably hopefully you're gonna take your
Speaker 1: dog on walks, You're gonna, you know, go out into
Speaker 1: the world with it. But at the very least, that
Speaker 1: dog is going out to get all up in the
Speaker 1: natural world and then bring some of it back home. This,
Speaker 1: this has been your experience with his a dog owner. Correct, absolutely, Now, Now,
Speaker 1: they're certainly harmful possibilities here, such as if your dog
Speaker 1: were to bring back fleas or ticks, And this has
Speaker 1: always been an issue with ancient Egyptian dog remains showing
Speaker 1: signs of brown dog ticks, which certainly do carry pathogens,
Speaker 1: but there's also a plethora of harmless effects and a
Speaker 1: seemingly beneficial um impact as well. Done points out that
Speaker 1: by looking at household microbes alone, first of all, one
Speaker 1: can tell if there's a dog in the house at
Speaker 1: all of the time. Uh. The dog just leaves a
Speaker 1: microbial footprint that's hard to miss. But be honest, it's
Speaker 1: hard to tell at this point what specific effects dogs
Speaker 1: and cats have on the inner and microbial environment, because
Speaker 1: there's a lot of complexity there. But Done says that
Speaker 1: we certainly see, especially in urban environments with dogs, that
Speaker 1: the children in those households are less prone to allergy
Speaker 1: and asthma. So the dogs might actually be a vehicle
Speaker 1: connecting the children to nature, and just the dirt on
Speaker 1: their paws, for instance, might be enough uh to essentially
Speaker 1: provide some sort of UH replacement for spending time in
Speaker 1: nature and in the natural microbial environment. Yeah. This is
Speaker 1: the connection to what used to be known as the
Speaker 1: hygiene hypothesis, though Anthes notes that some researchers have pointed
Speaker 1: out that this name can be kind of misleading because
Speaker 1: the point of the hygiene hypothesis is not that you like,
Speaker 1: shouldn't wash your hands. Uh, It's more about having an
Speaker 1: exposure to a diverse array of microbiota early in life can,
Speaker 1: if this hypothesis is correct, help help strengthen your immune
Speaker 1: system in various ways and make you less prone to say,
Speaker 1: allergies and asthma and things like that. More recently, people
Speaker 1: have tried to to recoin this thing not as the
Speaker 1: hygiene hypothesis, but as the old friends hypothesis, like the
Speaker 1: the natural microbial world is an old friend, right, that
Speaker 1: we should reacquaint ourselves with, and that it's good to
Speaker 1: get acquainted with early in life. Uh, not necessarily that
Speaker 1: you like, shouldn't wash your hands or shouldn't wipe down
Speaker 1: the counter after you've been slicing chicken or something. Yeah.
Speaker 1: Now this is primarily with dogs. With with cats there
Speaker 1: seems to be far less of a connection. Uh. And
Speaker 1: also it's noted that in rural environments, uh, we see
Speaker 1: less evidence of this, and the ideas that individuals in
Speaker 1: a rural environment are probably getting more exposure to the
Speaker 1: outside of the natural world in general. So the dog
Speaker 1: isn't going to make that much of a difference. The
Speaker 1: dog is less of a tap of hot and cold
Speaker 1: running exterior microbes. And I think all of that helps
Speaker 1: to underline, you know, our desire and our and indeed
Speaker 1: our need to get out of the house and interact
Speaker 1: with nature on a regular basis. Uh Done says that
Speaker 1: that one day we might be able to manage our
Speaker 1: interior microbiota in a way that will help ensure that
Speaker 1: we're healthy and uh and that you know, everything's in balance,
Speaker 1: But for now that's just not the case. We just
Speaker 1: we don't understand and enough if we haven't explored uh
Speaker 1: the interior world enough to know exactly what we're dealing with.
Speaker 1: And again like what kind of environments are are more
Speaker 1: prone to be occupied by the bad stuff versus the
Speaker 1: the the beneficial stuff or the stuff that is just
Speaker 1: uh there and part of the world we live in.
Speaker 1: Though I think it is clear that built environments do
Speaker 1: make a difference, that we we don't fully understand exactly
Speaker 1: what all the causal relationships are yet, but there have
Speaker 1: definitely been measured differences that show, for example, where rooms
Speaker 1: are placed and what their relationships to other rooms, where
Speaker 1: different things happen. Uh, that that does affect what kinds
Speaker 1: of microbiota we find in those rooms. Just the example
Speaker 1: of having open windows that open to the outside world
Speaker 1: as opposed to having a room that's all closed off
Speaker 1: to the outside world and just ventilated by you know,
Speaker 1: HVAC systems. That makes a difference to what the microbiome
Speaker 1: of the room looks like. Yeah, I mean, I mean
Speaker 1: even if the windows don't open. You know, we've looked
Speaker 1: at studies before, they've looked on the psychological impact of
Speaker 1: just being able to see the outside world, especially in
Speaker 1: hospital environment. Uh. And we do know a few other
Speaker 1: things too, Like one of the things that Anti mentions
Speaker 1: it seems to be a pretty straightforward finding is that
Speaker 1: one good way to encourage healthy ecosystems of microbes within
Speaker 1: the house is basically to keep the house dry. Moisture
Speaker 1: seems to activate a lot of unwanted fungal activity, but
Speaker 1: you can still have a lot of healthy microbes with
Speaker 1: the house that's that's relatively dry. Uh. You know that
Speaker 1: She says that a lot of these experts who are
Speaker 1: looking at this do not recommend using anti microbial agents
Speaker 1: in the house. As you've been talking about. So there
Speaker 1: are a few things we know, but yeah, there's still
Speaker 1: a whole lot more to learn about the interactions between
Speaker 1: our our living space architecture and our home cleaning regimes
Speaker 1: and all that stuff. With the microscopic invisible world. Yeah,
Speaker 1: and it's interesting. I mean, obviously it's going to be
Speaker 1: more of a challenge and damper environments, say like, um,
Speaker 1: you know, a rainforest environment. But I guess there, I
Speaker 1: guess one is tempted to ask the question, well, what
Speaker 1: are the traditional modes of housing? You know, what were
Speaker 1: the were the were the the trial and air developments
Speaker 1: in housing there versus the um that the modern solutions
Speaker 1: that have been brought in from other environments without perhaps
Speaker 1: without really taking full account of the local conditions. Yeah,
Speaker 1: that's an interesting question. I haven't considered that. Yeah, I mean,
Speaker 1: I don't know. You walk around any given neighborhood, right
Speaker 1: and you you you see these trends and homes and
Speaker 1: occasionally you'll see at home that is that it's clearly
Speaker 1: out of place. But it makes you wonder, like, just
Speaker 1: how out of place is it is? The design like
Speaker 1: not suited for the you know, the the energy consumption
Speaker 1: rates or the or or just the like the the
Speaker 1: the level of the amount of sun you get in
Speaker 1: a given part of the world, that sort of thing. Uh,
Speaker 1: you know, I think one of the things we can
Speaker 1: take from this episode is that homes are are far
Speaker 1: more complicated. They're not just the the space we in
Speaker 1: which we live, you know, a container for our lives.
Speaker 1: Like they they're going to shape who we are on
Speaker 1: a microbial level, on a symbolic level, Um, it's uh,
Speaker 1: you know, it's it's it's mind blowing stuff, definitely. And
Speaker 1: then sometimes you find yourself, you know, during a pandemic,
Speaker 1: spending a lot of time in your closet recording podcasts
Speaker 1: in your laundry room. Yeah, rooms that were never designed
Speaker 1: or intended for this kind of lengthy habitation. Luckily, my
Speaker 1: my closet here does have an air event in it um,
Speaker 1: which has been a lifesaver. I don't think my laundry
Speaker 1: room does sing around for it. I have. I've had
Speaker 1: a few sweaty times in here. Well, it's this good
Speaker 1: news for when the winter sets in, right for both
Speaker 1: of us, because I think this is gonna be pretty
Speaker 1: cozy in here. And if you get cold in the
Speaker 1: laundry room, you can always just turn on the dryer, right,
Speaker 1: I'm really trying to get it's set up so that
Speaker 1: I can record from a different room. I'm trying to
Speaker 1: make a different room in the house less echoy, so
Speaker 1: I can get good sound and not have to hunch
Speaker 1: over next to the washing machine. I am digging an
Speaker 1: earthen pit in my backyard, which I am told will
Speaker 1: have a really good uh sound installation. So we'll see
Speaker 1: how that goes. Mammoth Bones Studio. All right, Well, there
Speaker 1: you have it. Hopefully this provides some some food for thought. Again,
Speaker 1: we're not trying to encourage anybody to go on a
Speaker 1: h any kind of a killing spree in their house
Speaker 1: concerning microbes or Arthur pods or anything like that. Uh,
Speaker 1: just we thought that as we're spending more time looking
Speaker 1: at our homes and thinking about getting out of nature,
Speaker 1: we should really look at what the in the relationship
Speaker 1: between those two environments actually is. In the meantime, if
Speaker 1: you like to check out other episodes of Stuff to
Speaker 1: Blow your mind, well you can find us wherever you
Speaker 1: get your podcast and wherever that happens to be. Just
Speaker 1: make sure you rate, review and subscribe, and if you
Speaker 1: get in touch with us. I mean, clearly, we'd love
Speaker 1: to hear your thoughts on this episode. How do you
Speaker 1: relate to the content here, How does it change or
Speaker 1: back up your own thoughts and observations concerning your interior
Speaker 1: environment or the external world. Huge thanks as always to
Speaker 1: our excellent audio producer Seth Nicholas Johnson. If you would
Speaker 1: like to get in touch with us with feedback on
Speaker 1: this episode or any other, to suggest a topic for
Speaker 1: the future, just to say hi, you can email us
Speaker 1: at contact that Stuff to Blow your Mind dot com.
Speaker 1: Stuff to Blow Your Mind is production of I Heart Radio.
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