Guest Host: Jen Golbeck

We can create emissions in our indoor environment by cooking, cleaning, and as Nicola Twilley writes, "simply existing."

We can create emissions in our indoor environment by cooking, cleaning, and as Nicola Twilley writes, "simply existing."

“We know barely the first thing about the atmospheres in which we spend the vast majority of our time,” Nicola Twilley writes for the New Yorker. On average, Americans spend 90% of their time indoors. And unlike outdoor air, the air we’re breathing in our homes has been largely unregulated and ignored by researchers. So, what exactly are we talking about when it comes to “indoor air pollution”? And what implications can indoor air quality have for public health?

Produced by Julie Depenbrock


  • Nicola Twilley Freelance Writer
  • Dr. Kaylan Baban Assistant Professor of Medicine and Medical Director of EMR Optimization, GW Medical Faculty Associates

Nicola's Reporting

The Hidden Air Pollution in Our Homes

Food magazines typically celebrate Thanksgiving in mid-July, bronzing turkeys and crimping piecrust four months in advance. By that time last year, Marina Vance, an environmental engineer at the University of Colorado Boulder, had already prepared two full Thanksgiving dinners for more than a dozen people.

Notes from Dr. Baban


Simple is better

Vinegar and baking soda are enough to get most surfaces clean. No need for antibacterial products. These practices limit your exposure to potential toxins and avoid contributing to antibiotic resistance. Great bonus: They’re affordable. The Environmental Working Group has great guides for safe cleaning methods, and safe personal care products.

Cooking at home

It’s one of the best things you can do for your health. Proper ventilation and putting a clean filter in your range hood helps to avoid poor air quality, and using an oil with high smoke point (such as avocado, canola, or grape seed oils) is best if you’re cooking with high heat. Avoid olive oil over high heats. The low smoke point will not only result in worse indoor air quality, but you are also likely to be creating trans fats in your food, which are inflammatory and associated with heart disease.


  • 12:32:13

    JENNIFER GOLDBECKOn average, Americans spend 90 percent of their day indoors, and, unlike outdoor air, the air we breathe has been largely unregulated and under-researched. So, what exactly are we talking about when it comes to indoor air pollution, and what implications can indoor air quality have for public health? Joining us to discuss is Dr. Kaylan Baban, assistant professor of medicine and chief wellness officer at the School of Medicine and Health Sciences at George Washington University. Did I get that right?

  • 12:32:39

    DR. KAYLAN BABANYou got it right. Thank you, Jen.

  • 12:32:39

    GOLDBECKThanks for being here. Joining us by Skype is Nicola Twilley, a freelance writer and host of the Gastropod podcast. Nikki, it's good to have you.

  • 12:32:49

    NICOLA TWILLEYThanks for having me, Jen.

  • 12:32:50

    GOLDBECKSo, Dr. Kaylan Baban, can you give us an overview of the types of indoor air pollution Washingtonians might encounter in their homes or workplace? What are we talking about?

  • 12:32:59

    BABANThere is a long list. (laugh) So, where should we start? And most of this is not going to be specific to folks in our area, but we really want to be thinking primarily about the spaces that we're living in. What are they made of? So, what are the actual building materials? Often, those are materials that we can look at and see that they are either contributing to the indoor air pollution or are going to be more supportive of our health and more inert in an indoor environment. We also want to be looking at, what are we bringing into our indoor environments? So, that's furniture, you know, that new furniture smell, new house smell. That is usually indicative of out-gassing, and it's not necessarily a positive thing. Similarly, the new car smell that a lot of people are really big fans of is the same idea.

  • 12:33:43

    BABANSo, what are we bringing in in terms of new furniture, new clothes, cleaning materials? Are we burning scented candles? Those are all things for us to be aware of. Then, just by virtue of the fact that we're living in these spaces, there are other indoor air pollutants that come with that, as well.

  • 12:33:58

    GOLDBECKSo, what are the health consequences of poor indoor air quality? Have there been any lines drawn between indoor air pollution and our health?

  • 12:34:06

    BABANYes. Although it is the case -- and I think we're going to be getting into this -- that the research is not as robust as it should be. There is a good deal of evidence that, yes, there is great health implications for poor indoor air quality. And so that may range from exacerbating asthma to putting people at risk for developing certain types of cancers.

  • 12:34:26

    GOLDBECKSo, Nicola Twilley, you wrote a story for this week's edition of the New Yorker on home smog or the hidden air pollutions in our homes, which focuses on the emissions we create in our indoor environments from cooking, cleaning and simply existing. When did you first decide this was something you wanted to investigate?

  • 12:34:42

    TWILLEYWell, I heard about it. I heard about this big experiment, which is really the first of its kind. It was called HOMEChem, and it took place in Austin last June. And it brought 20 different labs, all these different scientists together to really study, for the first time, what was actually going on inside homes. And I, uh, you know, I have a podcast about food and science. I was initially fascinated by the cooking aspect, the idea that, you know, we're told to have a home-cooked meal. That's better for us. But what are the emissions doing to us? And then I just got sucked into the science of it.

  • 12:35:19

    GOLDBECKNikki, if you've ever been at my house when I try to make something vaguely fried, you would know that I, like, negatively impact the home quality of air. (laugh) There's like smoke wafting around my kitchen when I try to do that. So, I'm not that surprised. You're obviously a better cook than me. So, in your article, you write that cooking and cleaning are the main activities by which chemicals get added to our homes in the indoor environment. But we also create emissions by existing. What does that mean?

  • 12:35:44

    TWILLEYWell, yeah. So, just by the sheer fact of sort of breathing and, yeah, like I say, existing. So, we breathe out a lot of carbon dioxide. We breathe out a bunch of other chemicals, too. Our skin oils -- this was sort of, like, an “ew” moment, (laugh) but a primary component of our skin oil is a substance called squalene that's actually very reactive with ozone in the air. So, that's something that's causing indoor air pollution. (laugh)

  • 12:36:15

    TWILLEYAnd, I mean, there are other emissions. One of the scientists on this project told me his instrument was perfectly capable of detecting the, you know, the air quality impact of a fart, had someone farted. Everyone knows scientists don't fart. But, yeah, so those kinds of things, we bring them with us. Plus, then, of course, whenever we apply product -- so, you know, body spray, shampoo, anything that's scented -- those are all, you know, VOCs that are going into the mix of chemistry inside our houses. And, you know, that makes it sounds like, oh, gosh. We're in this toxic soup. But, for the most part, we don't know that they're toxic, but they are emissions.

  • 12:37:05

    GOLDBECKSo, I’m going to follow up on that in a second. But, Dr. Kaylan Baban, I want you to define the term that Nikki just used. Since most of our listeners aren't chemists, can you explain what a VOC is?

  • 12:37:15

    BABANYes, glad to. A VOC, a volatile organic compound. So, that is essentially what it sounds like. It's something that is organic in its nature, meaning it arises naturally, but can be unstable under the circumstances under which we're usually using it, and so then goes into the air in forms that can be toxic. So, we were talking about that new car smell, for example. Anything that's out-gassing, those are usually volatile, organic compounds.

  • 12:37:41

    GOLDBECKSo, would formaldehyde be one of those?

  • 12:37:43

    BABANFormaldehyde is absolutely one of those.

  • 12:37:44

    GOLDBECKThat's the one we know to be afraid of.

  • 12:37:46

    BABANYes. Formaldehyde is on the list. We have a long list of VOCs that are known carcinogens, or are related to known carcinogens, or just haven't been adequately studied yet.

  • 12:37:57

    GOLDBECKBut some of these -- I mean, whatever it is that I'm producing from my skin oils interacting with carbon monoxide in my house hopefully isn't going to kill me. It has not killed me yet. (laugh)

  • 12:38:07

    BABANYes, right. So, that's the good news. (laugh)

  • 12:38:09


  • 12:38:10

    BABANA VOC is not necessarily going to be toxic. It's a large category of compounds, but there's a very long list of them that we do want to keep out of our homes, or minimize.

  • 12:38:20

    GOLDBECKAnd so this kind of brings me back, Nikki, to the point that you were making before, which is, it sounds like there's just not a lot of research that's been done on the quality of indoor air, and what actually is toxic and what isn't and what's in the weird space. Like, it seems really understudied.

  • 12:38:35

    TWILLEYYeah, that was a surprise to me when I started writing this, and then, of course, made absolute sense when the scientists started explaining why it was so under-studied, which is that outdoor air is federally regulated. So, there are national standards. The EPA polices those standards. States have to pay penalties if they miss those standards. And once you have something that's regulated like that, then you have funding to understand what is going on. Are we meeting those standards? What are the sources of the pollution? How can we get the levels down?

  • 12:39:11

    TWILLEYNow, the air inside your home, that's not federally regulated, as one of the scientists on HOMEChem said to me. I mean, you can light a candle in your home, as if that was the craziest thing that a person could ever do. (laugh) And I immediately was, like, (clears throat) when he said that. So, that's not regulated, and hence, there isn't and there hasn't been the funding to really study it and understand it. And also, most outdoor atmospheric chemists thought indoor air was boring. They thought when you studied indoor air, you were just looking at these single chemicals, like, you were just saying, oh, our formaldehyde level's too high. We should do something about that.

  • 12:39:54

    TWILLEYThey didn't think there was chemistry going on. And by that, I mean they didn't think that maybe the formaldehyde that's off-gassing from your paint or your particle board is also mixing with the light coming in through your windows, and the ozone coming in and the combustion effect from your gas stove, and creating new compounds. That is what goes on outside. You know, the emissions from the tailpipe of your car and the sunlight, and so on, all combine to form smog. Smog is sort of a product of all of these things. People didn't think smog forms inside your home. They thought there were individual chemicals that were problems. So, it wasn't an exciting topic.

  • 12:40:33

    GOLDBECKSo, Dr. Kaylan Baban, I want to follow up on that point that Nikki was making about regulation. How much is indoor air regulated, compared to outdoor air?

  • 12:40:41

    BABANThe answer is, not as much as it should be. (laugh) And that's particularly true in our private homes. So, there'll be some indoor spaces that are public spaces that will be more highly regulated. Schools, for example, need to have a certain level of air exchange in the classroom, or carbon dioxide levels below a certain amount. But in our own personal homes, really, the regulations are not there.

  • 12:41:03

    GOLDBECKSo, I can smoke up my kitchen whenever I...

  • 12:41:06

    BABANYou are free to do that, yes.

  • 12:41:08

    GOLDBECKSo, it's interesting, though. You say that there are some regulations on indoor air in public spaces. Does that work for, like, kitchens? An example like, you know, if I go to a restaurant, you know, hopefully, they're better than me and not smoking it up. But are there regulations about that kind of indoor air?

  • 12:41:21

    BABANYeah, so that's an interesting question. Um, there are regulations that have been set for public spaces, whereby they can say, you know, we want you to not be exceeding a certain amount. In a restaurant, I’m actually not familiar with any regulations that would pertain there. And if there were regulations, they would need to be tested regularly in order to be reinforced.

  • 12:41:42

    GOLDBECKNikki, I imagine that the headline for this story on the hidden air pollution in our homes could strike fear in a lot of people, or even in indifferent, oh, great, one more thing we have to worry about. So, what responses have you gotten to your story since it was published?

  • 12:41:56

    TWILLEYI mean, pretty much exactly that: one more thing to worry about. Oh, God. And also, people saying, well, now do I have to get rid of my toaster? Because it turns out, toasters are a big source of particulate matter that we know to be harmful. You know, I think there have been a lot of, kind of, what should I do? I try, in the article, to point out that, really, a lot of these emissions, you can tackle very simply by using the exhaust fans above your cook top. So, it's not the--you know, open a window when you're cooking something smoky. I think people have -- they know the fan above their cook top is there, but they don't necessarily switch it on.

  • 12:42:43

    TWILLEYThe scientists I spoke to who had participated in the study and seen these horrifying numbers -- and they were horrified. They all confessed, you know, they still cook at home. They just switch their exhaust fan on more. And, you know, one of them was, like, oh, I'm remodeling my kitchen next year. I think I'm going to spring for a more expensive exhaust fan. You know, it's that level. It's not like, oh, gosh, we're all, you know -- I think this problem is something we should be studying. We need to study it, but it's not, you know, let's all panic and never cook at home again.

  • 12:43:20

    GOLDBECKThat's funny. I have a very old house, and it does not have any type of exhaust fan. I can just open the window, and then let in all that pollen that we talked about in the top half of the show. Let's go to the phones. Let's take a call from Beth in Washington, DC. Beth, you're on the air. Go ahead.

  • 12:43:37

    BETHHi. Thanks for taking my call. So, over the years, I have developed very bad, severe sensitivities to all of these chemicals, fragrances you're discussing. Obviously, I can control it in my home. But do you have any suggestions, for somebody like me, what I can do when I am out of my control, in other environments? I mean, I've had to leave the theater because the person sitting next to me has on very strong perfume -- at least for my sensitivities. Do you have any suggestions what somebody can do to all of these allergens and chemicals?

  • 12:44:22

    GOLDBECKThank you, Beth. That must be very frustrating. Dr. Kaylan Baban.

  • 12:44:26

    BABANSo, Beth, I hear you. I'm sorry that you're dealing with that, and I'll be honest, that I tend to have more sensitivity than most people to a lot of these, as well. It can be very challenging. So, one of the things that you may have come across that can be helpful is planning in advance. So, for example, I took the Metro to the studio here today so I could avoid taking a Lyft or an Uber that I know is likely to have an air freshener that is another great source of indoor air pollution that can be very irritating. That's one way.

  • 12:44:56

    BABANIf you're going to be visiting the home of a friend or a family member, it may be helpful to just be able to share with them what some of your sensitivities are, so that maybe they don't have a fire going or a lit candle or something like that when you walk in. In public spaces, I agree with you, it's much more challenging. And those are circumstances under which kind of making sure that you give yourself a little bit of time to scope out a place within the theater, for example, that may be more comfortable. Perhaps bringing with you a scarf that you can breathe into or a dust mask, something of that nature, that may help to cut some of the compounds that you're sensitive to. It can be helpful, but it is difficult in public areas.

  • 12:45:32

    GOLDBECKWe got a Tweet from Carol that says, I just paid $650 to have the air inside my house cleaned. The air was so polluted, it affected my sleep. So, this was not a thing I knew you could even get done. Nikki, is that something you ran into? And if so, how do I get the air in my house cleaned?

  • 12:45:50

    TWILLEYNo, that was not, and I'm intrigued. I want to hear more. One of things the HOMEChem team did test was indoor air pollution monitors. There are a variety of sort of consumer-level ones that you can by and see what the levels in your own home are. And some of them are more reliable than others. They'll be releasing those results soon, and I think that will be really helpful for folks, to know which ones to purchase, and which ones are useless.

  • 12:46:19

    TWILLEYSimilarly, there are some indoor air filters that are great, and some you should run a mile from. Anything that release ions is a terrible, terrible idea. Get rid of it. But this service, no, I don't know. I'm intrigued.

  • 12:46:36

    BABANYou know, I wonder if the Tweet may have been referring to cleaning out the ducts.

  • 12:46:39

    GOLDBECKInteresting. We do have a call from an air duct cleaner that we may get to, but Carol, we'd love you to follow up your Tweet and let us know what you have done, so we can figure that out. So, since we're on that, all right, Yanni in Dayton, Maryland, you're going to clean our air ducts. You want to talk to us about how that helps our indoor air quality?

  • 12:46:56

    YANNIOh, hi. Good afternoon. I'm very excited. I guess I am. I am an owner of an indoor air quality company in DC for the past 15 years, and I'm just calling to give a shout-out to people who are looking for getting the air duct clean to have a responsible marketing -- I'm sorry, research, and so on. There are companies who affiliate with organizations such as NADCA, the National Air Duct Cleaner Association, and maybe some other responsible organizations who have created a guideline and a proper cleaning method of an air duct and the ventilation system in general, which is definitely a very much -- effects the indoor air quality.

  • 12:47:53

    YANNIWithin our area, we have a lot of systems that's called a heat pump, which is just a heating-cooling system that normally tends to promote more microbial growth. Microbial is a fancier name for mold, mildew, and so on. It does grow in ductwork, and it does, in fact -- the occupant of the property, the home or the building -- of course, there is a famous case of the Legionnaire disease, who was being spread through the ventilation system...

  • 12:48:21

    GOLDBECK(overlapping) Oh, geez. (laugh)

  • 12:48:23 the hotel in a Legionnaire conference, to say that.

  • 12:48:29

    GOLDBECKWell, Yanni, let me stop you there, because you're freaking me out. (laugh) I'm going to have Dr. Kaylan Baban comment on this. All right. So, I'm going to be Legionnaire's disease on the side, because obviously, that's scary. But let's just talk about, like, the normal stuff that will be in your house that air duct cleaning might be able to help with. So, mold, Yanni had mentioned. Are dust mites in there? What other stuff?

  • 12:48:49

    BABANAbsolutely, yes. So, the mold is a big one, especially in the DC area. We know that we get high humidity here, and that tends to bring with it a lot of mold. The dust mites, yes, and dust that the dust mites feed off of. That dust is partly byproducts of the fact that we're living in the home, so the dust is often a lot of skin particles. Also, you know, well, it's going to reflect whatever else we're bringing into the homes. We were speaking about furniture and cleaning solutions, etcetera.

  • 12:49:16

    BABANI think there was an article recently that I saw that was not by Nicola (laugh) that was speaking about the effects of a lot of the chemicals that we bring into our homes that end up in the dust that can be known to be endocrine disruptors, meaning they change the way our hormones function. Being able to clean out the air ducts regularly, particularly if you have an air filtration system, being able to change your filters regularly is going to be a really important step for a lot of indoor air quality. And I'll take a really quick plug, if I may.

  • 12:49:43


  • 12:49:44

    BABANFor anyone who's concerned about what they can do to determine what they can bring into their homes safely and how they can keep their home clean, the Environmental Working Group is a nonprofit organization that has some terrific resources that are meant for consumers to really empower you and to be able to use some of the products that we know are healthier. So, that's

  • 12:50:02

    GOLDBECKGreat. We will put a link up to that on the Kojo website and social media. We're running low on time, so, Nikki, I want to pitch a last question to you. You've looked into this. How do we make our indoor air healthier? So, we've talked about air duct cleaning. But what else? Do we just open the windows?

  • 12:50:17

    TWILLEYI mean, yeah. (laugh) If you live next to an incredibly busy street or freeway, then, you know, first of all, I'm sorry. And, second of all, you might want to not have your windows open all the time. One of the things that I took away from writing this article is that the spikes in indoor air from cooking and cleaning, they're really -- they're spikes. The air in your house circulates every couple hours, sometimes more or less, depending on the size of your house and your HVA system. You can get rid of those big, dangerous peaks really quickly.

  • 12:50:55

    TWILLEYSo, if you are making toast, yeah, pop open a window. You can shut it again afterwards. I don't mean for everyone to catch a chill, but that is a sort of simple method. The scientists I spoke to, some of them are working on really exciting ideas to make this sort of a more, you know, technological approach. So, clay-based paints that would be able to soak up some of these chemicals, changing the glass in windows so that less of the spectrum of light that can sort of trigger the chemistry gets in.

  • 12:51:29

    TWILLEYSo, there are some tech solutions that we could see mandated in the future, once we know more. But for now, just please switch on your vent above your oven when you cook. Consider cutting down on your personal care product application, or at least the scented ones. And, yeah, open a window.

  • 12:51:49

    GOLDBECKOkay. Thank you very much. I'd like to thank both of our guests, Dr. Kaylan Baban, assistant professor of medicine and chief wellness officer at the School of Medicine and Health Sciences at George Washington. Thanks for joining us. And Nicola Twilley, freelance writer and host of the Gastro Pod podcast. Today's shows on spring allergies and air pollution were produced by Julie Depenbrock.

  • 12:52:08

    GOLDBECKComing up tomorrow, after spending five years studying DC's artistic community, officials just released the city's first-ever cultural plan to address the needs of the local creative class. We'll explore the plan, and whether its suggestions make sense to local artists. Plus, Washington's Tidal Basin: in need of repair? What's being done to rehabilitate it? Join us tomorrow at noon. I'm Jen Goldbeck, sitting in for Kojo.

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