Microplastics, the Ocean, and the Atmosphere with Hosein Foroutan

Music

Travis

It's probably not news to you to hear that a lot of plastic waste ends up in the ocean. What if I told you that some of it may not actually stay there?

If you're like me, you'd probably start to ask, where is it going? How is it getting there? And will it pose a new threat to the environment or me? Will that Dr. Thunder bottle that I didn't dispose of properly as a child come back to haunt me? Maybe that last one's just me, but regardless, there are a lot of questions around this topic. And thankfully, Virginia Tech's Hosein Frohatan was willing to share his expertise on this very subject.

Hosein is an associate professor of civil and environmental engineering, as well as an affiliate faculty member of the Global Change Center in the Fralin Life Sciences Institute. His research interests include atmospheric science aerosols, air quality environmental flows, and microplastics. So, Hosen and I chatted a little about the emerging evidence that these plastics are actually getting out of the ocean and into the atmosphere, some of the theories he has as to how that's actually happening, and what risk that actually poses to us humans. We also talked a little about how he got into this field of research and what about it gives him hope for the future.

I'm Travis Williams and this is Virginia Tech's Curious Conversations.

Travis

That might be a really good place to start. What is a microplastic? What's a nanoplastic? Are they the same? Are they different? What should I have in my head when talking about those? That's a great question.

Hosein

The historical definition of microplastics is that anything below five millimeter. So you can just picture a little piece of plastic below five millimeter used to be called microplastics. And that was a definition mostly used by people interested in the water pollution. But as people are getting more interested into other environmental compartments, including atmosphere or soil, the definition started to become...more relevant for different environments. And believe it or not, we still don't have a very standard definition of micro and nanoplastics. In fact, I recently saw a paper called, the title of the paper was that micro and nanoplastics are talking about the same language. So it shows that there is still a non -standard way of defining. But what most people now use is that below one millimeter or 1 ,000 micron is called microplastics. And then below one micron, which is 1 ,000 times smaller than a millimeter, is called nanoplastics. OK. So we're talking about just extremely small, I guess, pieces of plastic. Yeah. So if we want to just picture it, the size of a grain of sand is 100 micro.

So now it helps with picturing that, like what size I'm talking about. So nanoplastic would be a hundred times maybe smaller than a grain of salt or a grain of sand.

Travis

And so I guess your area of study is figuring out where these little tiny grains of sand of plastic are and how they get there, right?

Hosein

Yes, exactly. So we have something known as the plastic paradox. And the plastic paradox is that the amount of ocean plastic that we can detect is only 1 % of the amount of estimated plastics that getting into the ocean. Basically, the fate of 99 % of the plastic is not known. So we all know about the garbage, big garbage patch, right? Like a piece of plastics in there. And we have the picture of...a plastic bag or straw in the ocean and how we interfere with the turtle or with that little bird. All of this is less than 10 % of all the plastic pollution. 90 % of it is all this small plastic that we don't see, which is really fascinating because essentially we don't know where they are. I mean, obviously there are hypotheses.

They basically accumulated at the bottom of the ocean. They may spray from the ocean to the atmosphere. And now we talk about the plastic cycle. Before, ocean was thought as a dead end of plastic. So basically, plastic started an urban environment in the cities, basically washed out through the rivers and accumulated in the ocean. That was the picture maybe 10, 20 years ago.

But now we're talking about the plastic cycle, meaning that it goes to the ocean, get to the atmosphere, and it comebacks to the environment. And basically move from one environmental compartment to the other.

Travis

Wow. So it sounds like we used to believe all this plastic was just somewhere in the ocean. We didn't know where, but we thought it was in the ocean. And now we think or we know that it's getting into the air.

Hosein

Yeah, we are pretty sure. We're certain that it's in the air. A few years ago, there are some pioneering studies that they measured plastic in the air in some very remote regions. So imagine kilometers, hundreds of kilometers from the closest city. So really there is no nearby effect. And they basically saw pieces of plastic collected in the air. And then after that, I would study after study that they found it anywhere from North Pole all the way to South Pole, on top of the Mount Everest, at top of Alps, all the places that are really away from all the human activities, which really tells that the atmosphere is a conveyor for these pieces of plastic.

Travis

And do we know how, or do we know what we think? Do we have theories as to how plastic is getting out of the ocean and back up into the air?

Hosein

So that's really my focus. So really, I started into this research by answering that question that based on our evidence, we know that it's in the air. So now let's take a look at, see what are the potential sources that can contribute to the atmospheric microplastics and nanoplastics. And more important than that, identify them, they're basically quantified see what's the relative contribution of these different sources, right? So the two, there are many, obviously, but the two that I've been actively looking into is the ocean to the atmosphere transfer, basically via the sea spray, which we see as we've always been to the beach and see that how this spray basically generates small droplets. And if plastics in the ocean, these droplets, may contain small pieces of plastic. So that's one potential source of atmospheric microplastics. Now the very important one is from tire. So tire wear particles contains plastics, tire contains plastics, and as the tire goes on the road, it's well known that there's what we know as road dust basically. But road dust is not just dust that has a lot of pieces of plastics that are getting into the air and can transport the longest distance. Okay. Well, the ocean spray always looked a lot of fun. Road dust never sounded fun. And now they both don't seem quite as fun.

Travis

So when when stuff like that gets into the air, I assume because I breathe the air, there's the possibility that it gets into me. I'm assuming that's why we're so concerned about this.

Hosein

That's exactly true. And we try to really push into that and really change our point of view of air pollution. Because traditionally, we think about air pollution maybe as a smokestack or tailpipe pollution or something that comes from the exhaust of the vehicle. And now thinking about tires can contribute to the air pollution, the air that we can breathe.

That's really true. So we really try to bring in the component of plastic as a species of interest for the air pollution, if that makes sense. Yeah. What do you hope that the average person, when they learn about this and they start to think about it, what are some things that you hope that they maybe start to do as a result of learning about this issue? Yeah, it's a lot of changing in behavior because you think about the effort that went, I give you an example, the effort that went in this country to reduce the exhaust emission from vehicles. And that's something that all these studies shows that reducing knocks for instance, or particulate matter from the vehicles. And we are getting to the point that vehicles are...relatively clean compared to 20 years ago. But this shift now, just understanding that the type of air pollution is changing. And we are interested in different types that we haven't thought about before as air pollutants. That's interesting. And then how day -to -day life can contribute to that. Really the amount of pollution as little piece of plastic that we generate or type of the car that you're traveling with, you are contributing to this type of pollution. Small pieces, but we add together, it becomes important.

Travis

If we're able to better identify how this plastic gets into the air, will that help us prevent more of it from getting into the air, you think?

Hosein

Yes, I think so, because obviously as an environmental engineer, I really believe that looking to the source, and cutting the source is the best way to reduce the pollution. That's the history. It shows us that that's the best way that it works. So looking into the source, understanding the source, quantifying the source, not only helps to develop better policy around, but also for people to know where the sources are, what they can do to contribute to reduction of that source. Rather than identifying, I mean, it's as important to look into the thing and see that plastic in the environment. But I think I like to change this perspective of instead of looking into the environment and show and being and basically developing another study that say, hey, we saw it also here. We look into the source and say, okay, let's just cut it really at the source. Because, again, as I said, whenever we were as a community, we were successful in cutting the source. I give you an example of ozone hole. I give you an example of the cars. I give you an example of power plants and coal. We always look into the source, understanding the pollution at the source, and we basically manage that. And my goal would be looking into this, basically. Taking the same approach, which we saw that worked a few times in the past.

Travis

How did you get into this field of research?

Hosein

Yeah, that's an interesting question. So I was really fascinated with the water and air interface. So my study started when I was interested to look into bacteria going from the water to the air and looking into this, specifically the harmful algal bloom, which you probably heard of a lot also. And these harmful algal blooms, they sign the bacteria can also transport it from water to air.

In Florida, they call them red tide. There's this event that basically transfer this toxin from surface of the water into the air and people can breathe that. I actually been to Florida and you can see that effect immediately. So you start to cough and feel in your throat because you basically inhale the toxin. Then at the same time, I came across those studies that asking the exact same question that we just discussed that how does it get into the air? And immediately I've been thinking about if that's in the ocean and they're small enough, the size of bacteria, which we know, but the bacteria is one or two micron. And I just tell you that nano plastics in the same size. So even they are in the same size and interestingly, a lot of them are hydrophobic, meaning that they don't like water. Meaning that they prefer to leave the water environment or they basically accumulated at the surface then they should be getting into the air. That's really a natural way of thinking. So we build a setup in the lab and we actually test that. And we try different types of plastic, different sizes, and we saw that, wow, a lot of them can actually get out.

Travis

Yeah, it sounds like just a natural curiosity, wanting to know more about where this stuff is coming from and maybe how you can help make stuff better. Can you go to the ocean now and enjoy it? Are you constantly like trying to figure out how it's working?

Hosein

Definitely can still enjoy it for sure. I maybe, I mean that's the fact that I go to the ocean and including enjoying the beach, I take a look a lot in the wave breaking and the process of spraying and thinking about everything that getting out there. I think in terms of enjoyment, I think we still can really enjoy that the beach, the air. The risk assessment is a whole process, I think. And it requires a lot of thinking because it means the concentration but also exposure and everything. So yeah, I think the amount of, if I want to give you an example, the amount of bacteria and virus that can get airborne from the ocean is...tens and hundreds or maybe thousands more than plastics. So again, it's all risk. So what type of virus get airborne, you don't know. But yeah, the concentration is not to the level that a personal exposure for that period of time causing any concern.

Travis

Well, that's really good to know as a person that enjoys going to the ocean. And I also can relate, sometimes it's hard to leave your work at home. Even when you're going somewhere to relax.

Hosein

Yeah, so that's one thing that I have to kind of keep myself from staring too much at the wave breaking because every time just take a look and you can get droplets that get up and think about, okay, what can get airborne from this?

Travis

 Well, you know, I talked to a lot of folks about environmental issues and a lot of stuff that we're discovering and we're trying to learn more about. And sometimes those conversations can be a little bit scary, I guess, or a little bit gloomy. But when we're talking about these types of issues, I'm curious what in this space gives you hope.

Hosein

Yes, I think the hope is in the fact that what you're seeing of adding, I mean, at the same time, it's an interesting point because what makes it scary, I think the microplastic scary at the same time would be the hope. And I let me explain why. Because I just tell you that all these Smaller piece are basically forming 90 % of plastic pollution But you think about the fact that really this 90 % comes from these little tiny pieces that just all add together Right. So let's think about it as a positive one and I hope it means that if every one of us really make their own share Little share and then all add up together there is a way to go around this because You think about the fact that how much comparison can influence compared to this huge problem of plastic. And it's scary. Hopeless. But when you add them up and integrate over all the effort, I think then there's hope.

Travis

So maybe by breaking it down and thinking about all these little tiny pieces, the big piece of plastic that I can maybe recycle and take better care of makes a bigger difference.

Hosein

Absolutely. Just imagine that big macro plastic that you have and then you basically don't waste. It's thousands and thousands of pieces of small plastics that you prevent to go to the inbox.

Travis

Thanks to Hosen for sharing his expertise related to microplastics, the ocean, and the atmosphere. If you or someone you know would make for a great curious conversation, email me at traviskw at dt .edu. I'm Travis Williams and this has been Virginia Tech's Curious Conversations.