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Diving Deeper: Episode 66

NOAA scientist holds an assortment of microplastics

Little debris, big problem

Plastic debris can come in all shapes and sizes, but those that are less than five millimeters in length are called “microplastics.”


Welcome to Diving Deeper! I’m your host Kate Nielsen. Today, we’ll talk about microplastics and its effects on our ocean and Great Lakes environments, especially the aquatic life that live there. Joining us today is Amy Uhrin. Amy is the Chief Scientist with NOAA’s Marine Debris Program.

Hi Amy—welcome back to our show!

AMY UHRIN: Thanks Kate, it’s nice to be back.

HOST: What are microplastics? And when we say microplastics, just how small are we talking about?

AMY UHRIN: Right, so microplastics are defined as plastic particles that are less than five millimeters in their longest dimension. There are two types of microplastics, there are primary and secondary. Primary microplastics are actually manufactured to be that small and these include things like virgin resin pellets that are used in the plastics and manufacturing process, so these are very small pellets that are actually melted down to create plastic products. Then you have microplastics that are used in abrasive blast cleaning, so if you’ve heard of things being sand-blasted, it’s the same idea except instead of sand, they would be using these tiny, tiny plastic particles. And then lastly, what folks might have heard of are microbeads. So these are the very tiny spherical plastic particles that are used in cosmetics and personal care products.

So those are your primary microplastics. And then there are secondary microplastics and folks are probably, maybe more familiar with these. So this is what happens when larger plastic items break down either through their natural life cycle, perhaps they’re a somewhat expendable plastic and they break down to their natural use, or the plastic product becomes released into the environment and it breaks down there through weathering—the sunlight hitting it, wave action on a beach, all those physical forces can break down these larger items into smaller and smaller pieces.

In addition to the primary and secondary microplastics, we also find in the environment things that are termed microfibers. These are individual synthetic filaments that are woven together to make fabrics like polyester, nylon, acrylic—those materials are actually plastic. And it’s been estimated that about 1,900 microfibers can be rinsed out into the water in the washing machine when a single clothing item made of those materials is washed. So that could be another potential source of microplastics, microfibers into the environment.

HOST: How long have we been using microbeads in our health and beauty products?

AMY UHRIN: That’s a really good question. Microbeads appeared in cosmetics and personal care products about 50 years ago and as I mentioned previously these are considered primary microplastics because they are actually manufactured to be that small and for a specific use.

HOST: Amy, how do these end up in our marine environment? Wouldn’t they be removed during wastewater treatment?

AMY UHRIN: One would think that right? So what’s happening is that the mesh size of filters that are used at wastewater treatment plants are actually too large to capture things like microbeads and microfibers and so what happens is that they end up in the effluent water from these wastewater treatment plants which has been treated thoroughly. But then what happens is it’s released into natural waterbodies—so streams, rivers—where do these streams and rivers end up? They end up in larger waterbodies like estuaries and the ocean. So they can enter the environment that way.

In addition, sometimes the microfibers in the wastewater treatment process will settle out into the sludge material and oftentimes that sludge material is used as fertilizer, so it’s applied on land. And then what can happen is, with a strong rain storm, or even just maybe natural irrigation, water running off from that process—again the same idea—can trickle into local rivers, streams and eventually on out to larger waterbodies like the ocean.

HOST: What do microplastics do to aquatic life?

AMY UHRIN: Microplastic ingestion by marine animals has actually been reported in over 600 marine species ranging from zooplankton to finfish, shellfish, sea birds, turtles on up to marine mammals. When eaten, these small particles can actually damage or perforate the digestive tract or they can possibly obstruct the digestive tract entirely, particularly if the animal has eaten a number of these particles.

When they have eaten large amounts of particles, they can then collect in the stomach, obviously, and what happens is oftentimes the animal gets a sense of feeling full because there’s a lot of material in its stomach, but the problem is that this material has no nutritional value and so the animal feels full, stops eating, it’s not deriving any nutrition from the plastic particles and there’s the potential for the animal to suffer malnutrition, starvation, death.

In addition, recent research has shown that plastic ingestion can impact some of the reproductive capacities of shellfish particularly oysters. A paper that came out earlier this year indicated that things like, in the reproductive process, the eggs were smaller, the sperm were less motile, and actually the next generation of oysters that were spawned were smaller in size. So we’re starting to see evidence that perhaps there could be population level effects and not just individual effects.

So, another issue surrounding plastic ingestion is that plastics contain a number of chemical additives and those additives are put in the plastics for a very specific reason—to make them melt easier so that they can be shaped and molded into particular forms. And so it’s possible that when the plastic particles are ingested by an animal, these chemicals can leach out into their gut fluid and then we have an issue surrounding the possibility for toxicity effects in the animal. Also, when the plastic particles are floating around in the marine environment in the ocean waters, pollutants that are already in the water can actually adhere to the surface of the plastic particles. Again then, if the plastics are ingested, those pollutants enter the animal and could then perhaps detach from the plastic particle and again create a situation where there’s exposure and potential toxicity effects.

HOST: Can plastics ever degrade on their own in the environment?

AMY UHRIN: Plastics are synthetic polymers. So they’re manmade. And what a polymer is is chains of individual monomers. And the monomers are linked together by carbon-carbon links. And the problem is that those carbon-carbon links are kind of a new thing for bacteria in the environment, they don’t have the tools or the mechanisms for breaking those particular links in the environment. And so when plastic does enter the environment, they can be broken down into smaller and smaller pieces through weathering as I talked about previously when these plastics are exposed to sunlight or water or particularly on beaches with the turbulent nature of waves, they can break down into smaller and smaller plastic pieces, but they never completely biodegrade because at the molecular level, those chains of molecules that make up the plastic polymers cannot actually be broken apart by bacteria, so the plastic still exists at that molecular level.

HOST: Amy, with everything you’ve explained to us so far, I’m sure our listeners are wondering right now what they can do to help stop or combat this problem in some way?

AMY UHRIN: It’s really important for the audience to understand, a lot of times we feel like, well I’m just one person and what can I do, but it really is important because you can teach others and you can learn from others all the time. There are some very little minor changes you can make in your daily life, your daily routine to address this flow of plastic into the environment.

Our program, the NOAA Marine Debris Program, we promote the strategy of “Reduce, Reuse, Recycle” so the three “R’s.” Reduce would mean when you’re out shopping choose products that have the least amount of plastic packaging. You can also reduce by perhaps, when you get take-out, not getting the plastic utensils that are put in your bag and not using the plastic bag that’s often provided. Make sure you have canvas totes in your car and you take them with you when you go to the grocery store. Really trying to reduce the amount of plastics that you bring into your daily living.

And then we talk about Reuse. For safety and health reasons, when it’s possible, reuse plastic containers and goods to an extent that you’re not harming yourself. Some plastics are not made to be microwaved, they’re not made to be put in the dishwasher for obvious reasons, heat can break down the plastic, things of that nature. When it’s safe, do reuse plastic containers and goods when possible.

And then we talk about Recycle. So being very cognizant of the recycling process in your community and understanding what plastics are able to be recycled in your community. Because a lot of times, there’s a lot of variation across communities, not just states, but even at the sub-state level, so just being aware of what can and cannot go into your recycle bin.

HOST: So Amy, I’ve heard about, I think this came last year, the Microbead Free Waters Act. What is that? Can you explain a little bit more to our listeners about that?

AMY UHRIN: Absolutely, that’s a really good question because probably our audience is not really sure what that entails. You’re right, the Microbead Free Waters Act was passed in 2015. This is a nationwide ban on cosmetics containing microplastics particles, microbeads. And so there are actually two parts to this act. Beginning on July 1 of 2017, what happens is that the manufacturing of these cosmetics containing the microbeads becomes banned. And then the second part to that is there are products already in the commerce system on the shelves, those kind of have to wind their way through the market system and so by January 1 of 2018, the ban that comes into effect is the sale and distribution of these rinse-off cosmetics that contain the microbead.

HOST: Thank you for clarifying that. What is NOAA’s role with microplastics?

AMY UHRIN: Our program is actually currently supporting research projects that are examining a number of issues surrounding plastics and microplastics. And when I mean support, I’m saying that these projects came from a research grant competition that we held in 2013. One project is looking at how changes in environmental conditions can affect the way these chemical additives leach out into the environment and also how environmental factors can affect how pollutants adsorb to the surface of the plastic, and so when I’m talking about environmental conditions, I mean they’re looking at how temperature, salinity, even how just the sizes or the surface area of the plastic particles affect these processes. And so, preliminary result from that work that is very interesting, has indicated that the leaching process, so the additive chemicals coming out of the plastic, that leaching process happens for a longer period of time than they anticipated. So what this tells us is that leaching from plastics can actually possibly affect a wider geographic area for a longer period of time than we previously thought because it’s taking some time for those chemicals to come out so it’s not going to be a spontaneous, localized effect.

HOST: Amy, I like to ask our guests to tell us a little bit about themselves…how did you get to NOAA and in particular how did you get to the position that you’re in today?

AMY UHRIN: I actually joined NOAA in the year 2000 and I’ve been in NOAA in a couple of different capacities for 16 years now. I joined NOAA fresh out of my Masters program in biological oceanography. I spent 15 years at an actual research field station in Beaufort, North Carolina. The majority of my research during those 15 years really focused on seagrass ecosystems, other coastal ecosystems, but mostly seagrass and different aspects of the ecology and restoration of seagrass habitats. And I also dabbled a little bit in the marine debris realm at that time. So I got involved in a couple of projects looking at derelict fishing gear particularly in south Florida and derelict gear generated from the commercial spiny lobster fishery that takes place in south Florida and so looking at distribution and abundance of that type of derelict gear and also its impacts to habitat. I was actually just looking for kind of a career change or a career shift. I just joined the Marine Debris Program last June, so its almost been a year. My background in derelict fishing gear issues really resonated with the program I think, and so here I am today!

HOST: Great, we’re glad to have you Amy!

AMY UHRIN: Thanks, I’m enjoying my time with the program.

HOST: Did you have any final, closing words to leave our listeners with today?

AMY UHRIN: Actually 2016 is a very exciting year for the NOAA Marine Debris Program, this actually marks our 10 year anniversary. Our program was actually established through an act of Congress in the year 2006, the Marine Debris Act. And so I would encourage our listeners to just check out our program’s website—marinedebris.noaa.gov—to learn more about what our program does and especially what we’ve accomplished over the past decade. For example, our program has awarded more than $12.5 million in grant funding for various removal, prevention, and research projects combined. And our removal projects over the last decade have resulted in more than 5,500 tons of debris being removed from the marine environment across the country. Our website also provides a number of educational materials that are freely downloadable. And I will stress the three R’s again—always remember Reduce, Reuse, Recycle and know that you can make a difference because all those actions add up.

HOST: Thanks Amy for joining us today on Diving Deeper. For our listeners, we have more information available for you in our show notes. Thanks for tuning in, that’s all for today’s show!

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