10/11/2019

How People Pollute The Workplace

16:38 minutes

Group of people working around a desk
Credit: Rawpixel Ltd/Flickr/CC BY 2.0

If you live and work in an urban area, you might think about the air quality outside your home or workplace. But what about the air quality inside the office? It turns out that on average, indoor environments have higher concentrations of potentially harmful substances, such as aerosols and volatile organic compounds (VOCs). While past research has focused on chemical emissions from building materials, cleaning supplies, and even furniture, air pollution researchers are increasingly looking at another source of toxic air: us.  

New research from Purdue University to be presented at the American Association for Aerosol Research conference has found that the majority of indoor VOCs may be released by a seemingly innocuous source: human beings, their lunches and coffee breaks, and anything they may wear or bring to work. And many of these compounds, such as the terpenes released by peeling an orange, or the squalene released in human skin oil, react with ozone to form even more worrisome molecules.

Purdue University researcher Brandon Boor, an assistant professor of civil engineering, explains. 


Further Reading


Get science images that will blow your mind with our newsletter, Picture of the Week.

Segment Guests

Brandon Boor

Brandon Boor is an Assistant Professor of Civil Engineering at Purdue University.

Segment Transcript

IRA FLATOW: This is “Science Friday.” I’m Ira Flatow. If you work in an office, you know especially one of those big open plan ones, you might have some gripes about your co-workers. Maybe they’re too loud on the phone or they leave their coffee cup in the sink instead of watching it. But new research to be presented next week to the American Association of Aerosol research has another thing you can blame on your colleagues or they might blame on you– indoor air pollution.

Yep. It looks like we, just by showing up to work, are bringing with us high concentrations of volatile organic compounds and other kinds of air pollution from the oils in our skin to our deodorant to the seemingly harmless act of peeling an orange. Yeah. And unlike that tuna someone just put through the microwave, you’re not likely to smell these.

Here to explain more is Dr. Brandon Boor, assistant professor of civil engineering at Purdue University and co-author on that research. Welcome to “Science Friday.”

BRANDON BOOR: Thanks, Ira. It’s great to be here.

IRA FLATOW: Nice to have you. Explain for us what’s the big deal with volatile organic compounds. What are they? Why should we be concerned.

BRANDON BOOR: So volatile organic compounds are a class of chemicals that want to exist as a gas or vapor. And they come from many different sources in the indoor environment. We know that many furniture items, and building materials, and consumer products can off-gas VOCs to the air. This is fairly well established.

We’re also looking now at how people release VOCs into the air in an office environment. And we found that basically the human body is a big source of different types of VOCs. We call it or we refer to it as the volatilome. So we know that there’s about 2000 VOCs associated with the human body. We know that exhale breath contains many different types of VOCs, about 1,000. And these molecules are produced in our bodies as a result of metabolism through bacteria in our gut, food or medicine that we may consume, as well as smoking or vaping.

IRA FLATOW: I’m just shocked to hear about all the things our bodies are giving off. Were you surprised at that number? You said 1,000 VOCs from our breath alone.

BRANDON BOOR: Yeah. So research on exhale breath has shown that there can be about 1,000 different voices in our breath, which is quite fascinating if you think about it. And I think from my perspective, I never really thought as people as a significant source of VOCs. Most of the attention has always been on what’s off gassing from the floor, or paint on the walls, mattresses and sofas, and things like that. But recent research has shown that really people are a pretty important source of many different types of VOCs. And that’s through our breath, our skin, and our sweat and personal care products that we apply to our bodies essentially to make us smell nice.

IRA FLATOW: Let’s get into some of those. But let me first remind our audience if you want to talk about you and your skin and your air pollution in your office, our number is 844-724-8255. 844-724-8255. Or you can tweet us @scifri.

Let’s get into some of those. Let’s get into first what you just mentioned, some of the skin care products. What VOCs are being given off there?

BRANDON BOOR: So an important class of US is that really some personal care products like deodorant, or lotions, or hairspray are called siloxanes. And we found levels of many siloxanes, including one called decamethylcyclopentasiloxane, or D5, to peak in the morning after people walked into the office with freshly applied

Deodorant. And our findings are similar to a recent study at the University of California Berkeley where they also found these siloxanes to be in great abundance in a classroom and to actually be the most abundant VOC released from students in that classroom. And now along with siloxanes, we see VOCs referred to as monoterpenes. And these are added to these products to give them a pleasant scent like citrus fruit, pine trees, and lavender.

IRA FLATOW: If enough people enter an office, a closed space, with enough of this on them, could they be violating some sort of standard for VOCs?

BRANDON BOOR: That’s a good question. I’m not actually exactly sure about that. I don’t know if there’s any standards for emissions from people. But I think the concern really would be in environments where there is a high density of people. And this would include an open plan office, a classroom.

I just taught a class. We have 90 students so you have a lot of people and a small volume of air, movie theaters, and so forth. So you have a lot of people present that are all emitting these different VOCs. And if that particular space is not well ventilated, concentrations can build up quite rapidly. And as in our office, we see that concentrations of many of these VOCs can be a factor of five to factor 10 greater indoors than in the surrounding outdoor environment.

IRA FLATOW: I don’t know how to ask this next question gingerly, but I’m going to ask it anyhow. Are we talking about something different than body odor here, or is this body odor, basically, in essence those smells you’re talking about?

BRANDON BOOR: Yes. Certainly some of these are associated with body odor and sweat. In sweat particularly, we have a number of organic acids– acetic acid, lactic acid. But then there’s others that we would not necessarily detect the odor. Their concentrations are too low. But they’re still important.

IRA FLATOW: You know, I was surprised to see there’s some interesting chemistry that happens just from peeling an orange.

BRANDON BOOR: Yes. So this is very exciting. So an orange in the skin contains a lot of oils. And when you peel the orange or a Mandarin, you release VOCs into the air. And these are called monoterpenes. And an orange, the prominent monoterpene is called limonene. And limonene is very reactive of ozone. So we know ground level ozone is a big player outdoors in atmospheric chemistry. But in an office environment, it’s delivered indoors through the ventilation system. And this is because we often have some amount of outdoor air that we must provide to meet office ventilation standards.

So we have this ozone that’s entering the office space. You peel the orange, release these terpenes. The two react together. And what ends up happening is that you produce very small airborne particles which we also refer to as aerosols. And this process is called new particle formation. And we know that this is very important in influencing outdoor air quality as well as the formation of clouds. But now that we can see that it can happen in an occupied office environment.

So every time that we peeled an orange in the office, and my doctoral students did this quite many times, we generate a substantial number of particles on the order of tens of thousands of particles in each cubic centimeter of indoor air. So we’re essentially seeing that the VOCs coming out of the orange are reacting to ozone and we’re creating new particles. And these particles are as small as a single nanometer, which is one billionth of a meter.

IRA FLATOW: Wow. Let’s go to the phones, because they have lit up. After the oranges came out, the phones lit up. Let’s go to Casey in Kansas City. Hi Casey.

CASEY: Hi. Thanks for taking my call. Question about possible solutions to VOCs. We know that air purifiers, you know the machinery works. But I’d like to know both of your thoughts on moss, M-O-S-S, as in the stuff that grows on the ground, both real and preserved moss. I’d like to know your thoughts on the effectiveness of moss in absorbing VOCs.

IRA FLATOW: Mm-hmm. Good question.

BRANDON BOOR: Thanks, Casey. So there is a good amount of research on what we refer to as biofiltration using plants to effectively filter the air. And in biofiltration, you draw air through the soil at the plant. And it can be a complex array of plants that are growing through some sort of wall configuration.

And there’s a number of large scale biofiltration systems out there. And those have shown to be somewhat effective at removing VOCs. Just having potted plants in the office space itself or any indoor environment are not going to clean the air. So you have to draw air through the soil. When that happens, the bacteria in the soil can help break down some of those VOCs.

IRA FLATOW: Yeah. You talked about the problem happening when it interacts with the ozone. Ozone is everywhere in a city, from cars and things like that.

BRANDON BOOR: Yep.

IRA FLATOW: Is there any way to filter out the ozone? Or is it–

BRANDON BOOR: There are some–

IRA FLATOW: –just going to be there?

BRANDON BOOR: Yeah. It is challenging. And we do want to provide outdoor air to an office environment and really any indoor environment to help dilute concentrations of VOCs and other pollutants that are generated indoors. But when we do that, we do deliver ozone, nitrogen oxides, and ambient particulate matter indoors. With particles there’s great filtration strategies to remove them from the air. You can buy a very high efficiency filter to capture those particles. With ozone and VOCs, it can be a little bit more challenging. There’s some advance air cleaning strategies that you can deploy in a ventilation system to help scrub out those contaminants.

IRA FLATOW: Mm-hmm. Let’s go to the phones. Everybody would like to talk about it. Joe in Palo Alto. Hi, Joe.

JOE: Hi. Quick question. I keep hearing a lot about VOCs these days. And I’m curious, what are the actual demonstrated health impacts of VOCs.

IRA FLATOW: Good question.

BRANDON BOOR: Yeah. It’s a great question. So we know that indoors are exposed to a complex mixture of pollutants. And this certainly includes VOCs. And there’s many hundreds of VOCs. But we also have a diverse spectrum of particles, ozone, and nitrogen oxide. So when we talk about the health effects of indoor air pollution, I always want to emphasize that we’re exposed to a complex mixture of contaminants. And we need to look at how that complex mixture affects our health and well-being.

With VOCs, we know there’s a lot of research out there that fragrance consumer products that we use inside, such as deodorant, perfume, air fresheners, cleaning products, they can cause headaches, chest tightness, irritation of our airways and eyes, reduce pulmonary function, and worsen asthma symptoms. These siloxanes that I mentioned that are found in personal care products, we know that they can bioaccumulate and they’re persistent in the environment.

IRA FLATOW: Are the emissions that people give off in a group setting– let’s say you have a number of people together– would it be greater than the video sees that gets outgassed from the furniture or the carpeting?

BRANDON BOOR: Yes. That’s what we found in our particular office environment, which is in relatively new building that it’s really the people that are driving the emissions of VOCs. And we see this because we’re tracking occupancy. So we’re looking at how many people are in the office throughout the day. And we’re doing that by embedding temperature sensors in each chair.

So when people sit down, the temperature goes up. And we can see that they’re there. So with that information, we can compare the levels of many different VOCs when there’s a lot of people in the office and then in the evening when there’s nobody in there. And for many different VOCs, we see that the levels are much greater during these occupied periods. So they’re coming from people from our breath, skin, sweat, and the personal care products.

IRA FLATOW: And I would imagine in the morning would be the best because they’re fresh with all these things on their skin.

BRANDON BOOR: Yeah. That’s an interesting time because we often apply deodorant when we leave our house and go to work. And what we see in our office is that there is a spike in the concentration of these siloxanes in the early morning. So all the students come in. In this case, we have graduate students working there with freshly applied deodorant or other personal care products. The emissions spike in the morning and then they drop off over time. And this could present a concern if you’re trying to work at that point in time.

IRA FLATOW: No concern that this is “Science Friday” from WNYC Studios. We have a submission from Phil in Auburn through our Science Friday VoxPop app. And he’s more worried about the cleaning products that might enter the space after hours.

PHIL: For many offices, ventilation stops after hours. Then when janitors or cleaning people work, the air becomes more polluted without fresh air entering the office.

IRA FLATOW: Brandon, did you research that and look at that possible problem?

BRANDON BOOR: Yeah, that’s a great point. And I think custodial staff is perhaps people that we may not think about, and are certainly very important because they are in the buildings in the late evening. And you know, at that time, the ventilation rate often is or is reduced for energy saving purposes. So if they’re using products like Pine-Sol, we know that emits a lot of different VOCs including monoterpenes. And we did some measurements this past summer with researchers at Indiana University. And we tested different cleaning products, including Pine-Sol. And we see very elevated levels of VOCs.

And what’s also interesting is not just the VOCs. But when you have some ozone coming in the office, the two will react, as I just mentioned like with the orange. And you could end up forming these small particles. So sometimes with cleaning products and other VOC sources, you have to be concerned both about that VOC and then the reaction products that form, which may be more toxic than the VOC that was originally emitted.

IRA FLATOW: Is there any metering or something I can buy and stick in my office to know if the levels are getting too high?

BRANDON BOOR: Yes. There’s a lot of focus now on low cost air quality sensors. For VOCs, there’s nothing that’s really going to speciate and tell you the different types of VOCs that are present. We have sensors that can give you a rough indicator about the total mass of VOC in the office space or any indoor environment. But I would say that those are not terribly reliable. In our particular study, we used a very expensive instrument that is for research purposes that tells us all the different VOCs that are in the air and separates them very nicely.

IRA FLATOW: One last question. Quick question from Sonny in Pittsburgh. Hi Sonny. Sonny, are you there? I think the lights went out on that call. Sunny wanted to know what are the top three things we can do.

BRANDON BOOR: Well, that’s a great question. So I would say that the best strategies for maintaining good indoor air quality in your home or your office, the first is to minimize the sources of indoor pollutants– minimize the emissions. In an office environment, that’s challenging if people are producing a lot of VOCs. But if you’re looking at personal care products or scented products, you could try to find products that emit less quantities of VOCs.

The second thing we can do, and I think this is often very effective, is to improve the dentition of the building, basically allowing the indoor space to breathe better. And we can do this by providing greater quantities of outdoor air. And this air should be filtered. And then in an environment like an office or room, the amount of ventilation that you provide should be scaled to occupancy. So if people are a source of VOCs and there’s more people in the room, we should provide more outdoor air.

IRA FLATOW: And the last thing?

BRANDON BOOR: The last thing would be filtration and air cleaning. So you can go to your home improvement store and buy a high efficiency filter to capture particles. You can use a portable air purifier in your home or office and then perhaps some other air cleaning technologies in the ventilation system.

IRA FLATOW: Dr. Boor, you’ve been very helpful. Brandon Boor is assistant professor of civil engineering at Purdue in West Lafayette, Indiana. Thank you very much for taking the time to be with us today.

Copyright © 2019 Science Friday Initiative. All rights reserved. Science Friday transcripts are produced on a tight deadline by 3Play Media. Fidelity to the original aired/published audio or video file might vary, and text might be updated or amended in the future. For the authoritative record of Science Friday’s programming, please visit the original aired/published recording. For terms of use and more information, visit our policies pages at http://www.sciencefriday.com/about/policies/

Meet the Producers and Host

About Christie Taylor

Christie Taylor is a producer for Science Friday. Her day involves diligent research, too many phone calls for an introvert, and asking scientists if they have any audio of that narwhal heartbeat.

About Ira Flatow

Ira Flatow is the host and executive producer of Science FridayHis green thumb has revived many an office plant at death’s door.

Explore More