Plastic Pollution is Chemical Pollution

How preventing and removing plastic debris mitigates chemical pollution in our oceans

Turtles tangled in fishing nets, whales washed ashore with stomachs full of plastic bags. These are images we, unfortunately, see far too often. But what about the threats you cannot see? Plastic debris is not just a physical threat to marine life, it’s a chemical threat too.

Once in the marine environment, plastics can absorb chemical pollutants from surrounding waters and transport them great distances as they move around with ocean currents. When animals eat plastic, these chemical pollutants can leach into their stomachs, causing toxic effects. Many of these chemicals have been banned from production due to concerns about human and environmental health. However, some are so persistent in the environment that they are still found today.

Plastic products also contain chemical additives such as flame retardants, UV stabilisers and colorants which are added to the plastics during manufacturing. In our ocean, these chemical additives can leach into surrounding waters—posing another potential chemical threat to marine life.

In a recently published paper, we estimated the amount of chemicals that enter the ocean within common single-use plastic items and estimated the amount of chemical pollutants that can be removed from the environment via cleanups.

2018-07-20 14.49.34We looked at some of the most common plastic items found on beaches during the International Coastal Cleanup: beverage bottles, bottle caps, styrofoam foodand drink containers, cutlery, grocery bags, straws/stirrers and food wrappers. Using International Coastal Cleanup data, the average weight of each item, and estimates of mismanaged plastic waste in 2015, we calculated the total weight of each item that entered the oceans in 2015. We then used the percent weight of chemical additives in each item to estimate the mass of chemicals that entered the ocean as a consequence of this plastic debris.

We estimate that combined, these seven plastic items contribute more than 87,000 metric tons of plastic debris to our oceans and carry with them 190 metric tons of 20 different chemical additives. If plastic pollution continues to increase, this value could almost double to 370 metric tons of additives by 2025. This might not sound like very much, but these seven items account for only about 1% of the estimated 8 million metric tons of plastic entering the oceans every year!

Furthermore, we estimated how plastic cleanups contribute to chemical cleanup by removing those absorbed chemical pollutants. For this, we compared coastal and open ocean locations using Hong Kong and Hawaii as coastal case studies and the North Pacific and South Atlantic gyres as open ocean case studies. Here, we focused on Polychlorinated biphenyls (PCBs) because they are commonly found in plastic debris, despite having been banned for decades.

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© HANNAH DE FROND

To estimate total chemical load on plastics in each location, we multiplied the mass of microplastics (g/m2) found in each area by the mass of PCBs found on microplastics (ng/g) in each area. Our results showed that chemical cleanup is more effective on shorelines compared to the open ocean, removing 85,000 times more PCBs in a stretch of coastline in Hong Kong than the same size area of the North Pacific gyre. This might come as a shock, particularly as the gyres are well known to contain large amounts of plastic debris, however, the amount of microplastic per square meter is generally much greater on the shoreline. Although the concentration of PCBs might be high in some open ocean locations, the important factor is how much plastic can be removed per unit area. The more plastic removed, the more chemical removed.

Thus, if we can prevent plastic from entering the environment and cleanup what is already there, we can also mitigate chemical pollution. This reiterates the value of reducing our plastic footprint and participating in coastal cleanups. Cleanup of plastic pollution goes beyond what the eye can see. Cleanup of plastic pollution is also cleanup of chemical pollution!

What Does Your Washing Machine Have to do with Microfibers?

New research suggests microfiber emissions from the wash can be reduced with new technology

Synthetic microfibers are just one of many types of microplastic pollution; however, microfibers are one of the most common types of microplastic pollution that we find in the environment.

Where do they come from? There are likely many sources of microfibers to the environment, and they include clothing, furniture, carpeting, and cigarette butts.

Picture1They are ubiquitous. We find these tiny fibers in samples from headwater streams, rivers, soils, lakes, sediments, ocean water, the deep-sea, wildlife, arctic sea ice, seafood, drinking water and table salt. In our own samples from the Laurentian Great Lakes, our research lab sometimes find more than 100 microfibers in an individual fish. Such widespread exposure raises concerns about effects to wildlife and human health.

But, there’s good news! There are simple solutions to help reduce the number of microfibers that enter our environment each day. Some of these include changing the way we do our laundry–YEP–our laundry.

When we wash our clothing in the washing machine, little bitty fibers come off into the wash water. This is just like when fibers come off our clothing in the dryer and collect in the lint trap. YES, microfibers are indeed a major component of laundry lint! In the washing machine these fibers exit our homes with wash water and travel to a nearby wastewater treatment plant. There, many of them will settle into the sewage sludge, but some will remain in the final treated wastewater effluent that is released directly into local watersheds, lakes and oceans. Although washing our clothes in washing machines is just one source of microfibers to the environment, we know that it’s a significant source. For example, in the city of Toronto, we estimate as many as 23 to 36 trillion microfibers may be emitted to Lake Ontario watersheds each year!

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So, coming back to the solutionswhat can we do about it? Our research group wondered the same thing and decided to test multiple mitigation strategies for washing machines to see just how well they captured fibers in the wash, diverting them away from the environment.

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What did we find? We found that technologies available on the market today work! Upon washing fleece blankets with and without a Lint LUV-R after-market filter (a, pictured above) or a Cora Ball (b, pictured above), we found a significant reduction in microfibers in washing machine effluent. The after-market filter reduced microfibers in washing machine effluent by 87% and the Cora Ball by 26%.

Picture2Our study suggests that these technologies are one effective way to reduce microfiber emissions to the environment. While more studies are needed to understand the contributions of microfibers from other sources and pathways to the environment, we know that washing machines are one pathway for microfibers to reach the environment. Why not help reduce emissions now by changing up your laundry habits today?

For more information, please read our paper published this year in Marine Pollution Bulletin.

Written by Dr. Chelsea Rochman, assistant professor at the University of Toronto and Scientific Advisor to Ocean Conservancy

No Silver Bullet Solution to Plastic Pollution

Evaluating the impact of multiple mitigation strategies to help stem the tide

Plastic pollution has become so pervasive that it is found in seafood, bottled water, beer, table salt and even the air. Hundreds of animals become entangled in discarded plastic debris and fishing gear. Ingestion of plastics by marine organisms can hurt or kill them, and may also be acting as a pathway for the transfer of harmful contaminants through food-webs, with biological implications for all life affected. The economic costs of plastic pollution affecting tourism, fisheries and shipping sectors are estimated to be at least $8 billion USD annually.

Currently, the problem of plastic pollution is being met with a suite of mitigation strategies, such as single-use bans, improving recycling capacity and waste management, substitution of products with “eco-friendly” alternatives and more. These actions are currently being implemented at the national level but the problem is so enormous that the international community has recognized that more action is needed, and urgently. Still, little work is being done to evaluate the impact of these many mitigation strategies being proposed and implemented, and how their impacts will vary in different economic and societal contexts. Without this understanding, we risk wasting vast quantities of money, time, and social and political capital in attempting to preserve the integrity of the world’s ecosystems.

We are the Plastic Pollution Emissions Group

That’s how the Plastic Pollution Emissions Group (PlasticPEG) came about. Based out of the National Socio-Environmental Synthesis Center (SESYNC), the work that we are doing will contribute to improving our understanding of the impacts of these reduction strategies, and inform governments of the most effective ways to contribute to improving the health of our oceans.

With a group of experts from across the world, including some from Ocean Conservancy, we aim to contribute to this knowledge gap by providing science-based evidence of the most effective strategies to reduce the leakage of plastic into our oceans. Our work will build on the inclusion of Plastic pollution in the Sustainable Development Goals (SDGs) and feed into an international agreement to establish a coordinated and effective strategy to drastically reduce plastic emissions into the environment.

How we will make a difference

We are conducting an evaluation of the impact of several plastic pollution management interventions. These include plastic-use reductions, broad-scale investments in waste management infrastructure, the implementation of a circular plastic economy and the cleanup of existing post-consumer plastic waste, including abandoned, lost or otherwise discarded fishing gear from the environment.

We are using ecological modelling techniques and an impact forecasting approach (sometimes referred to as ‘wedges’) to evaluate mitigation strategies at both the country and global level. This means that we can measure how much an action—such as single-use plastics bans—will have on reducing the leakage of plastic into the environment compared to if we did nothing (business as usual). Our analyses will support and inform countries to help them choose the best strategies to reduce plastic pollution, within the bounds of their resource capacity, social context and uniquely local sources of plastic debris.

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Figure 1: Illustrative example of what we aim to assess by combining and comparing different plastic emissions reduction strategies and scenarios. © STEPH BORRELLE

If we are to achieve meaningful reductions of plastics in our oceans, we need to have a toolbox of effective solutions that can be implemented at multiple geographic scales, economies and levels of governance. The aim of the Plastic Pollution Emissions Group is to help find those solutions in a meaningful way.

For further information, please visit plasticpeg.org or follow us on Twitter @PlasticPEGroup.

Written by Steph Borrelle, a Smith Postdoctoral Fellow in Conservation Biology and Dr. Chelsea Rochman, an Assistant Professor at the University of Toronto and Scientific Advisor to Ocean Conservancy

Toronto’s Don River: A Source of Plastic Pollution into our Great Lakes

Have you ever wondered just how much plastic makes its way from the Don River into Lake Ontario, and what kind?

They say 80% of all plastic in our ocean and lakes comes from land. Do you live upstream? This doesn’t mean you are immune to having your litter reach aquatic ecosystems. Our trash can hitch a ride on streams and rivers too—leading to our ocean and lakes. In fact, rivers are a major conduit for plastic pollution to reach freshwater and marine ecosystems.

In the city of Toronto, we have four major rivers that lead directly to Lake Ontario—one of the five Laurentian Great Lakes. They are Etobicoke Creek, Mimico Creek, the Humber River and the Don River. The Don River has the highest percentage of urban area than any other river in Canada. As a consequence, we might expect it to be a major source of plastic pollution to our Great Lakes, specifically Lake Ontario.

We were curious just how much plastic litter makes its way from the Don River into Lake Ontario, and what kind. To find out, we took a trip to a dock owned by PortsToronto and characterized the litter that collects on their booms.

Each year PortsToronto removes between 400-900 metric tons of debris from Toronto’s harbour, including in the Don River. At the river mouth, PortsToronto manages a boom system that captures litter before it enters the lake. Litter is removed from the water weekly and shipped to a sorting facility. The wood is recycled into animal bedding and garden mulch and the garbage is sorted into recyclables and non-recyclables.

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© CHELSEA ROCHMAN

The two piles you see were collected on the boom from June 29, 2018 through July 16, 2018. Just a little more than two-weeks. As you can see, it would take days to sort through these piles of wood and trash! Instead, we dove in for an hour and a half to see what we could collect. We picked all of the big litter off the top of both piles, and dug around in the smaller pile until very little big items remained.

What did we find? LOTS!

In 90 minutes, we collected more than 1,400 pieces of litter, plus a 133-liter bag full of Styrofoam pieces. In total, our bounty weighed 31 kg—almost 70 pounds! In our counts and weights, we did not include construction items which are quite heavy. We only included typical litter-sized items. For example, our heaviest item was a soccer ball. In fact, we found a lot of balls—53 of them to be exact! And our strangest item? A carefully wrapped package of animal fur with a beautifully crafted letter inside—in a language we could not translate.

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Overall, the majority of what we found was plastic (surprise!) trash mixed in with a lot of woody debris. You can see our list of top ten finds below. If what we found is representative, we estimate that more than 650 kg of plastic litter enter Lake Ontario from the Don River annually. This would include more than 21,000 pieces of Styrofoam, 12,500 large plastic fragments, 4,000 water bottles, 2,700 bottle caps, 1,300 food wrappers, 1,100 balls and more than 900 straws and cigarette butts each. And remember, this is an underestimate. We did not dig into that large pile.

So, what can we do? The answer is diverse, because there are many ways to prevent plastic pollution from entering our Great Lakes. First, we can make sure our waste enters the proper receptacle (i.e., our blue bin, green bin and black bin). Second, we can use less single-use plastic items, which make up the majority of what we found during our clean-up. Third, we can write letters to our local leaders asking them to consider technology that will prevent litter from entering our lakes from rivers—such as the “Mr. Trash Wheel” in Baltimore. And finally, you can join us for cleanups around the city! We would love to see you out there.

Written by Dr. Chelsea Rochman, a professor at the University of Toronto that researches the sources, fate and effects of plastic pollution in our ocean.