Plastics

A team of researchers at the ��߲ݴ�ý have designed a solution to reduce the amount of microplastic fibres shed when washing synthetic fabrics.

In a world swamped by fast fashion – an industry that produces a high-volume of cheaply made clothing at an immense cost to the environment – more than two thirds of clothes are now made of synthetic fabrics, such as nylon, polyester, acrylic and rayon.

When clothes made from synthetic fabrics go in the washing machine, the friction caused by cleaning cycles produces tiny tears that cause microplastic fibres – measuring less than 500 micrometres in length – to break off and make their way down laundry drains to enter waterways, where the particles can be difficult to remove and take decades or more to fully break down.

But U of T researchers say the slippery solution to this problem could already be in your cabinet: a silicon-based organic polymer coating found in many household products.

Kevin Golovin, an assistant professor of mechanical and industrial engineering in the Faculty of Applied Science & Engineering, and his team have created a two-layer coating made of polydimethylsiloxane (PDMS) brushes, which are linear, single polymer chains grown from a substrate to form a nanoscale surface layer.

Experiments conducted by the team showed that this coating can significantly reduce microfibre shedding of nylon clothing after repeated laundering, according to findings published in Nature Sustainability.

“My lab has been working with this coating on other surfaces, including glass and metals, for a few years now,” says Golovin. “One of the properties we have observed is that it is quite slippery, meaning it has very low friction.”

PDMS is used in shampoos to make hair shiny and slippery, and is also used as a food additive in oils to prevent liquids from foaming when bottled.

Sudip Kumar Lahiri, a post-doctoral researcher in Golovin’s lab and lead author of the study, reasoned that reducing the friction that occurs during wash cycles with a PDMS-based fabric finish could prevent fibres from rubbing together and breaking off during laundering.

One of the biggest challenges the researchers faced during their study was ensuring the PDMS brushes stayed on the fabric. Lahiri, who is a textile engineer by trade, developed a molecular primer based on his understanding of fabric dyes.

Lahiri figured the type of bonding responsible for keeping dyed apparel colourful after repeated washes would work for the PDMS coating as well.

Neither the primer nor the PDMS brushes work separately to decrease the microplastic-fibre shedding. But together, they created a strong finish that reduced the release of microfibres by more than 90 per cent after nine washes.

“PDMS brushes are environmentally friendly because they are not derived from petroleum like many polymers used today,” says Golovin, who was awarded a Connaught New Researcher award for this work.

“With the addition of Sudip’s primer, our coating is robust enough to remain on the garment and continue to reduce micro-fibre shedding over time.”

Images, taken by a scanning electron microscope, of uncoated (top left, right) and coated (bottom left, right) nylon fabrics after nine washing cycles (Image courtesy of Sudip Lahiri)

Since PDMS is naturally a water-repellent material, the researchers are currently working on making the coating hydrophilic so that coated fabrics will be better able to wick away sweat. The team has also expanded the research to look beyond nylon fabrics, including polyester and synthetic-fabric blends.

“Many textiles are made of multiple types of fibres,” says Golovin. “We are working to formulate the correct polymer architecture so that our coating can durably adhere to all of those fibres simultaneously.”

Governments around the world have been looking for ways to minimize the debris that comes from washing synthetic fabrics since it can accumulate in oceans, lakes and rivers, threatening marine life and entering the human food chain through its presence in food and tap water. One example is washing machine filters, which have emerged as a leading fix to stop microplastic fibres from entering waterways. In Ontario, legislative members have introduced a bill that would require filters in new washing machines in the province.

“And yet, when we look at what governments around the world are doing, there is no trend towards preventing the creation of microplastic fibres in the first place,” says Golovin.

“Our research is pushing in a different direction, where we actually solve the problem rather than putting a Band-Aid on the issue.”

U of T researchers use machine learning to speed up counting of microplastics

Christopher.Sorensen — Mon, 25 Apr 2022 15:38:10 +0000

U of T researchers use machine learning to speed up counting of microplastics

Christopher.Sorensen Mon, 04/25/2022 - 11:38

Cutline

Weiwu Chen, a graduate research assistant in civil and mineral engineering, counts microplastics using a microscope in Associate Professor Elodie Passeport's lab (photo by Shuyao Tan)

Safa Jinje

Topic

Faculty of Applied Science & Engineering

Artificial Intelligence

Microplastics are all around us – in the water we drink, the food we eat and the air we breathe. But before researchers can understand the real impact of these particles on health, they need faster and more effective ways to quantify what is there.

Two recent studies by researchers at the ��߲ݴ�ý's Faculty of Applied Science & Engineering have proposed new methods that use machine learning to make the process of counting and classifying microplastics easier, faster and more affordable.

“It’s really time consuming to analyze a water sample for microplastics,” says Elodie Passeport, an associate professor in the departments of civil and mineral engineering and chemical engineering.

“It can take up to 40 hours to fully analyze a sample the size of a mason jar – and that specimen is from one point in time. It becomes especially difficult when you want to make comparisons over time or observe samples from different bodies of water.”

Last month, the United Nations Environment Programme endorsed a historic resolution to end plastic pollution, which it called “a catastrophe in the making” endangering human health, marine and costal species and global ecosystems.

A stormwater sample, left, is juxtaposed with the plastic particles manually picked out of the sample, right (photo by Kelsey Smyth)

Microplastics can take hundreds to thousands of years to biodegrade. But it is not just visible plastic refuse that's an issue: over time plastic breaks down into smaller and smaller particles. Those pieces that are less than five millimetres in size but greater than 0.1 micrometres are defined as microplastics.

Researchers who study the effects of microplastics are still trying to understand how these tiny pieces could affect human and environmental health in ways that are different from the bulk material.

Though past studies have demonstrated the presence of microplastics in various environments, the standards for how to quantify their levels – and critically, how to compare different samples over time and space — are still emerging. Passeport worked with Shuyao Tan, a PhD student in chemical engineering, and Joshua Taylor, an associate professor in the department of electrical and computer engineering, to address the challenge of analysis.

“We asked ourselves whether there could be a crude measurement that could predict the concentration of microplastics,” Passeport says.

“In collaboration with Professor Taylor, who has expertise in machine learning and optimization, we established a prediction model that employs a trained algorithm that can estimate microplastic counts from aggregate mass measurements.”

“Our method has guaranteed error-tracking properties with similar results to manual counting, but it’s less costly and faster, allowing for the analysis of multiple samples from multiple points to estimate microplastic pollution,” she adds. 

The team’s investigation, published in January in ACS ES&T Water, has the advantage of allowing researchers to manually process only a fraction of their collected samples and predict the quantity of the rest using an algorithm, without introducing additional error or variance.

“Researchers working on microplastic analysis need to know how many plastic particles there are, the kinds of particles, the polymers and shapes,” says Tan.

“With this information, they can then study the effects of microplastic pollution on living organisms – as well as where this pollution is coming from, so they can deal with it at the source.”

Classical quantification methods using visible light microscopy require the use of tweezers to count samples one-by-one under an optical microscope – a labour-intensive endeavour that is prone to human error.

A scanning electron microscope (SEM) plate holding microplastic samples, left, and the SEM used for the project, right. (Photo by Bin Shi)

In an investigation published in Science of The Total Environment, PhD candidate Bin Shi in the department materials science and engineering, who is supervised by Associate Professor Jane Howe, employed deep learning models for the automatic quantification and classification of microplastics.

Shi used scanning electron microscopes to segment images of microplastics and classify their shapes. When compared to visual screening methods, this approach provided a greater depth of field and finer surface detail that can prevent false identification of small and transparent plastic particles.

“Deep learning allows our approach to speed up the quantification of microplastics, especially since we had to remove other materials that could create false identifications, such as minerals, substrate, organic matter and organisms,” says Shi.

“We were able to develop accurate algorithms that can effectively quantify and classify the objects in such complex environments.”

The diversity in the chemical composition and shapes of microplastics can create difficulties for many researchers, especially since there is no standardized method to quantify microplastics.

Shi collected microplastic samples in various shapes and chemical compositions – such as beads, films, fibres, foams and fragments – from sources such as face wash, plastic bottles, foam cups, washing and drying machines and medical masks. He then processed images of the individual samples using the scanning electron microscope to create a library of hundreds of images.

The project is the first labelled open-source dataset for microplastics image segmentation, which allows researchers from all over the world to benefit from this new method and develop their own algorithms specific to their research interests.

“This method also has the potential to go down to the scale of nanoplastics, which are particles smaller than 0.1 micrometres,” Shi says.

“If we can continue to expand our library of images to include more microplastic samples from different environments with varied shapes and morphologies, we can monitor and analyze microplastic pollution much more effectively.”

For now, the goal of Passeport and Tan’s predictive model is to be a diagnostic tool that can help researchers identify areas where they should concentrate their analytical efforts with more in-depth technologies.

The team also hopes this method can empower citizen scientists to monitor microplastic pollution in their own environments.

“Individuals can collect samples, filter and dry them to get the weight and then use a trained algorithm to predict the amount of microplastics,” Passeport says.

“As we continue our work, we want to introduce some automatic training sample selection methods that will allow individuals to just click a button and automatically select the training sample,” adds Tan.

“We want to make our method easy so that they can be used by anyone, without them needing any knowledge of machine learning and mathematics.” 

U of T Trash Team and PortsToronto battle plastic pollution in Lake Ontario

Christopher.Sorensen — Thu, 18 Feb 2021 13:57:53 +0000

U of T Trash Team and PortsToronto battle plastic pollution in Lake Ontario

Christopher.Sorensen Thu, 02/18/2021 - 08:57

Cutline

U of T Assistant Professor Chelsea Rochman and Chris Sawicki, PortsToronto's vice-president of infrastructure, planning and environment, at the launch of the Seabins pilot in the Toronto Harbour in 2019 (all photos courtesy of Chelsea Rochman)

Sarah MacFarlane

Topic

Cities

It’s a collaboration founded on a shared vision: a cleaner future for Toronto’s waterways.

Chelsea Rochman’s lab at the ��߲ݴ�ý is committed to reducing aquatic waste in Toronto by exploring innovative litter-capturing technologies and engaging the public on the issue of plastic pollution.

In her search for partners who shared her vision of a cleaner future for Toronto’s waterways, it wasn’t long before Rochman encountered PortsToronto – a government-business enterprise that owns and operates Billy Bishop Airport, the Port of Toronto and the Outer Harbour Marina.

Key collaborators from PortsToronto with the U of T Trash Team at the Urban Litter Challenge community cleanup in 2019.

With its goal of protecting and preserving Toronto’s waterfront by supporting sustainable transportation infrastructure, marine safety, environmental protection and community programming, PortsToronto has been an active supporter of the U of T Trash Team, a group of students and volunteers who focus on engaging the public and decreasing plastic pollution through a variety of programs, including litter cleanups and sustainability workshops.

PortsToronto even made a $150,000 donation to the Rochman lab last year.

“We've gotten closer every year and started working together in more capacities,” says Rochman, who joined the department of ecology and evolutionary biology in the Faculty of Arts & Science as assistant professor in 2017.

“PortsToronto staff come to our cleanups every year. Now, we're talking about further things we can do together down the road to continue to get litter out of the water and also communicate with the public.”

The U of T Trash Team was founded by Rochman, who serves as head of operations and program lead of scientific programming and application; Susan Debreceni, program lead of volunteer engagement and community programs; and Rafaela Gutierrez, program lead of social science and educational programs.

Cassy Sherlock quantifying and characterizing microplastics trapped in macrophytes captured in the Seabins at the Outer Harbour Marina in summer 2020.

“The year 2021 marks the 110th anniversary of our organization and more than a century of PortsToronto’s stewardship of our city’s great waterfront,” says Geoffrey Wilson, CEO of PortsToronto. “In tandem with our own sustainability efforts, collaborating with the U of T Trash Team was a natural step for us in our ongoing mission to preserve and protect the waters of the Toronto Harbour for future generations.

“Lending our partnership, support and infrastructure to this dedicated team of researchers has, and will continue to, lead to innovative, evidence-based solutions to tackle the serious issue of plastic pollution in waterways here at home and throughout the Great Lakes.”

One strategy for reducing aquatic pollution is the use of floating trash bins called Seabins, which can collect more than four kilograms of waste per day – as much as 1.4 metric tonnes per year – including debris and microplastics as tiny as two millimetres in size. Seabins are a crucial aspect of the partnership between the U of T Trash Team and PortsToronto.

“PortsToronto owns and operates the Seabins,” says Rochman. “The U of T Trash Team does research in Lake Ontario to inform where in the Toronto Harbour would be useful to have Seabins, and then we quantify and characterize the impact – how much debris we're capturing and what type of debris it is, which can be used to inform policy.”

Small microplastic pieces entrained in macrophytes captured by the Seabins in the Outer Harbour Marina in summer 2020.

In the summer of 2019, PortsToronto launched two of their Seabins in Toronto’s Outer Harbour Marina and the U of T Trash Team studied the results. In just 19 hours, the bins collected nearly 2,000 pieces of plastic, many of which were less than five millimetres in size.

While the COVID-19 pandemic delayed the full-scale launch of the Seabins last year, the U of T Trash Team and PortsToronto persevered and ultimately piloted three Seabins at the Outer Harbour Marina.

“Within the three bins we captured hundreds to thousands of pieces of small debris every week,” Rochman says. “We also did visual audits where we had people from our team walking along the harbour and looking at where there were hotspots of litter accumulation within the slips. And that informs where the Seabins can go next year.

“We also standardized our protocols for how we quantify the debris. We spent a lot of time trying to figure out the best method that can be shared with other people who are also tracking litter so that we can all have standardized data. Those methods are being used by people as far away as California and Vancouver.”

Small microplastic pieces entrained in macrophytes captured by the Seabins in the Outer Harbour Marina in summer 2020.

The team even created an app called Data Trapper, which allows users to test methods and share their data.

Rochman says PortsToronto’s recent gift has helped the U of T Trash Team build a foundation by allowing them to transition volunteers to full-time paid positions – and that the support of PortsToronto has had a profound impact on the U of T Trash Team since they first began working together in 2017.

“They believed in us,” Rochman says. “They gave us that confidence to build who we are.”

It’s just the beginning. Rochman says she’s looking forward to what PortsToronto and the U of T Trash Team will be able to accomplish together in the future.

“We hope to increase our impact in the harbour, increase awareness and try to spread the litter diversion beyond the Toronto Harbour,” she says. “We plan to have four Seabins along the waterfront that are actively trapping and diverting litter out of Lake Ontario. We also plan to do a design competition with PortsToronto to think about the type of technology that could be placed near the mouth of the Don River to divert the litter that's coming in from upstream. And then raising awareness and increasing waste literacy among the public is one of our main goals to share lessons learned more broadly.”

'An unacceptable plastic future': U of T ecologists sound alarm in new study of global waterways

Christopher.Sorensen — Thu, 17 Sep 2020 21:53:52 +0000

'An unacceptable plastic future': U of T ecologists sound alarm in new study of global waterways

Christopher.Sorensen Thu, 09/17/2020 - 17:53

Cutline

Ascension Island in the South Atlantic Ocean is yet another remote island littered in plastic waste (photo by Marcus Eriksen)

Sean Bettam

Topic

Breaking Research

Ecologists at the ��߲ݴ�ý are sounding the alarm after measuring the scale of human response needed to reduce future levels of plastic in the world’s aquatic ecosystems and manage what’s already floating around out there.

The researchers published a study this week in the journal Science that outlines the accelerating pace of plastic emissions that enter the Earth’s waterways each year.

They found that the world is on track to emit about 53 million megatonnes of plastic into lakes, rivers and oceans by 2030 – even if extraordinary measures are taken across the planet to reduce and mitigate plastic waste.

“Unless growth in plastic production and use is halted, a fundamental transformation of the plastic economy to a framework based on recycling is essential, where end-of-life plastic products are valued rather than becoming waste,” says Chelsea Rochman, an assistant professor in the department of ecology and evolutionary biology in the Faculty of Arts & Science and a senior author of the study.

“Even if governments around the world meet their ambitious global commitments, and other countries join those efforts to curb plastic pollution, worldwide annual emissions to rivers, lakes and oceans could be as much as 53 million metric tonnes by the year 2030,” adds Stephanie Borrelle, a David H. Smith Postdoctoral Fellow at U of T and lead author on the study.

“That’s far beyond the eight million metric tonnes amount that was declared unacceptable in 2015.”

The group estimates that 24 to 34 million metric tonnes of plastic emissions currently enter aquatic ecosystems every year. They then modelled future scenarios using existing mitigation strategies: reducing production of plastic waste, which includes bans, improving the management of plastic waste that is produced and continuous recovery – meaning cleanup – from the environment.

The researchers found that even with parallel efforts in all three solutions, the level of effort required within each is enormous: first, a 25 per cent to 40 per cent reduction in the production of plastic across all economies; second, increasing the level of waste collection and management to at least 60 per cent across all economies — with a change from six per cent to 60 per cent in low-income economies; and, third, recovery of 40 per cent of annual plastic emissions through cleanup efforts.

“To put that last number into people power, the cleanup alone would require at least one billion people participating in Ocean Conservancy’s annual International Coastal Cleanup,” says Borrelle. “This would be a Herculean task given this is 660 times the effort of the 2019 cleanup.”

The researchers note, however, that even if the prescribed effort is realized, the world remains locked into an unacceptable plastic future.

“The global community must co-ordinate a fundamental transformation of the plastics economy, one that reduces the amount of virgin plastic production and reimagines how we make use and dispose of plastic materials,” says Rochman.

The research was supported by the U.S. National Science Foundation through the National Socio-Environmental Synthesis Center.

Plastic that saves the planet? U of T startup's novel resin helps industry go green

rahul.kalvapalle — Wed, 11 Mar 2020 20:44:27 +0000

Plastic that saves the planet? U of T startup's novel resin helps industry go green

rahul.kalvapalle Wed, 03/11/2020 - 16:44

Cutline

EcoPackers co-founders and U of T alumnae Kritika Tyagi, Chang Dong and Nuha Siddiqui (photo courtesy of EcoPackers)

Rahul Kalvapalle

Topic

Alumni

Creative Destruction Lab

Innovation & Entrepreneurship

Rotman School of Management

Rotman Commerce

Startups

ThisIsThePlace

Nuha Siddiqui was browsing a World Economic Forum report on the future of the plastics industry when she came across an ominous prediction. “It stated that by 2050, there would be more plastic than fish in the ocean,” Siddiqui recalls.

That was back in 2016, when Siddiqui was a second-year Rotman Commerce student at the ��߲ݴ�ý. The grim forecast spurred Siddiqui, who, at the time, was also president of the U of T chapter of global social entrepreneurship network Enactus, to research the plastic industry and figure out where she could have an impact. Four years later, Siddiqui is now CEO of a fast-growing startup that has raised millions of dollars in venture funding and is working with global plastic manufacturing giants to replace their plastic components with a non-toxic eco-resin.

While Ecopackers got its start making non-toxic, biodegradable packing peanuts – hence the name – from agricultural by-products, the company has since expanded its focus to the wider plastics industry.

“We came to realize that the real value of our products wasn’t necessarily the packaging or the end products, but the input and the science around what we were doing,” Siddiqui says.

The road from packing peanut-producer to plastics input-supplier was navigated with the help of U of T's expansive entrepreneurship network, which is on full display this week as part of the university’s annual Entrepreneurship Week event.

Unlike other products made from bioplastics, the biodegradable packing peanuts initially produced by Ecopackers didn’t require industrial composting, and were safe enough to compost in the backyard. Siddiqui would even eat them in front of venture capital investors to show how safe and natural they were compared to traditional packing peanuts made from non-biodegradable polymers like Styrofoam.

In 2018, the company graduated from the Canadian government’s Next 36 entrepreneurship initiative before joining the Creative Destruction Lab, an international seed-stage accelerator based at U of T’s Rotman School of Management. It was then that Siddiqui and fellow Ecopackers co-founders Kritika Tyagi and Chang Dong, decided that focusing on packing peanuts would limit their business and social impact prospects.

Determined to spare no detail in their quest to create a profitable and scalable social enterprise, the Ecopackers team traveled to China to better understand plastics manufacturing and identify opportunities for the industry’s eco-friendly transformation. Their idea: create a resin that’s functionally similar to materials already used in the plastic industry, but make it fully compostable – so it could replace non-biodegradable polymers like polystyrene and polypropylene in the manufacture of single-use plastic products ranging from cutlery and straws to casings for beer kegs.

“We were one of the only eco-focused companies out there that wasn’t going against the plastic manufacturers,” says Siddiqui. “We were actually trying to work with them to develop products that worked with their technology.”

The approach paid off. This past December, Ecopackers raised $4.3 million in pre-seed and seed financing, including an investment from Creative Destruction Lab founder Ajay Agrawal.

The startup is now working on a pilot project with brewing giant AB InBev to explore using the eco-resin as a plastic alternative in beer keg casing, as part of the company's 100+ Sustainability Accelerator program. Ecopackers is also engaged in pilot projects with companies in Canada, China, Taiwan and Hong Kong, and is hiring engineers, scientists and analysts to join its growing team.

Siddiqui says Ecopackers' vision is to lead the eco-friendly transformation of single-use plastic manufacturing without necessarily forcing drastic changes in consumer behaviour.

“We can try as much as possible to get consumers to use reusable bottles, cups and straws, but at the end of the day it’s what our society has been dependent on for years,” Siddiqui says. “I don’t think it’s necessarily a bad thing, but how we’re using the materials and producing the products is wrong and that’s what we really need to change.

“Our alternatives allow you to still use the same products you’re used to, but in a compostable way.”

She says the feedback from manufacturers has been encouraging since they appreciate the eco-resin’s compatibility with existing technology as well as its affordable cost compared to current plastic alternatives.

Ecopackers has created a resin that’s functionally similar to materials already used in the plastics industry, but is fully compostable (photo courtesy of Ecopackers)

Going forward, Siddiqui aims to grow Ecopackers into a global operation with a headquarters in Toronto and multiple manufacturing sites located near areas of high demand. The company already has an R&D office in Shenzhen, China in addition to its Toronto office.

“We want to make sure we’re locally manufacturing wherever our customers are, so we can be conscious of our own environmental footprint as well,” she says.

Siddiqui is quick to credit U of T’s entrepreneurship community with helping her take a project that she conceived as an undergraduate student and turn it into a thriving business.

“We entered the Creative Destruction Lab with a very different business and different mindset,” she says. “Throughout our time there, we were able to put together an incredible group of advisers, investors from the most amazing funds, and we got first-hand advice on scaling and thinking about things differently.”

Asked about her long-term goals for the company, Siddiqui casts her mind back to the WEF report’s projection about plastic out-weighing fish in the ocean by 2050.

“We have a contrasting goal,” she says. “By 2050, we’d like all single-use plastic to be made from Ecopackers.”

Microplastic pollution is everywhere, but scientists are still learning how it harms wildlife: U of T experts

Christopher.Sorensen — Tue, 28 Jan 2020 19:57:51 +0000

Microplastic pollution is everywhere, but scientists are still learning how it harms wildlife: U of T experts

Christopher.Sorensen Tue, 01/28/2020 - 14:57

Cutline

Large plastics break up into tiny particles called microplastics that can persist in the environment for hundreds of years (photo via Shutterstock)

Chelsea Rochman

Kennedy Bucci

Topic

Ecology & Environmental Biology

Plastic pollution is a growing global concern. Large pieces of plastic have been found almost everywhere on Earth, from the most visited beaches to remote, uninhabited islands. Because wildlife are regularly exposed to plastic pollution, we often ask what effects plastics have on the animals.

Over time, macroplastics (plastic debris larger than five millimetres in size) break up into tiny particles called microplastics (smaller than five millimetres), which can persist in the environment for hundreds of years.

Macroplastics are known to cause detrimental effects for wildlife. Individual animals can ingest large pieces or become entangled in plastic items, such as fishing gear, and suffocate or starve to death. Although there is no question that macroplastics are harmful to wildlife, the effects of microplastics are not as straightforward.

While many studies find microplastics can affect the gene expression, growth, reproduction or survival of an animal, others conclude that microplastics have no negative effects. The lack of clear consensus makes it more difficult for decision-makers to enact effective policies to mitigate plastic pollution.

Not all plastics are the same

We recently took a deep dive into the research that has looked at how plastic pollution affects aquatic and terrestrial wildlife.

We found that while macroplastics continue to cause detrimental effects to individual animals, they are also causing larger-scale changes to populations of animals, communities and ecosystems. For example, plastic pollution can introduce invasive species to new habitats by transporting organisms hundreds of kilometres from their native range, changing the composition of species in a community.

The effects of microplastics, however, are much more complicated. Of the studies we included in our review, nearly half (45 per cent) found that microplastics caused an effect. Some studies saw that microplastics caused animals to have shorter lives, eat less or swim slower, and others saw changes in the number of offspring produced, and changes in the genes being expressed. Yet, 55 per cent of the studies didn’t detect any effects.

Why do some studies detect effects while others do not? There are several possibilities. For one, the researchers used different experimental designs in their lab experiments.

There’s also the issue of using the term microplastics, which refers to a complex mixture of plastics that vary in material (such as polyethylene, polystyrene or polyvinyl chloride), the chemicals associated with them (including additives, fillers and dyes), as well as their size and shape. Each of these characteristics, along with how much plastic the animal is exposed to in the experiment, could affect their potential to detect an effect.

Microfibres and microbeads

For example, we saw that when studies exposed crustaceans to polystyrene, a type of plastic used to make disposable containers, lids and cutlery, the crustaceans generally produced more offspring. But when they were exposed to polyethylene or polyethylene terephthalate, which is used to make plastic bags and beverage bottles, the crustaceans produced fewer offspring.

We also found that studies using smaller particles are more likely to detect an effect. This may be because smaller particles are more easily consumed by small organisms, or because they can move across the cell membrane and cause harmful effects such as inflammation.

Microbeads are found in exfoliating products such as face cleansers and toothpaste. Several countries have banned their production and sale (photo by Shutterstock)

When it came to the shape of the plastic, microfibres (from clothing or rope) and fragments were more likely to have a negative effect on the organism compared to spheres (from facial cleansing products). For example, one study found that microfibres were more toxic to a species of marine shrimp than microplastic fragments or spheres.

Finally, one might expect animals to be more harmed when they are exposed to higher concentrations of microplastics. While it’s true that crustaceans were more likely to die when exposed to increasing doses of microplastics, the effect on reproduction was more complex. The number of offspring increased with extremely high doses, but decreased at lower doses, similar to what is seen in the environment.

Many types, many outcomes

Based on our review, we believe future research needs to recognize the complexity of microplastics and scientists need to design their tests strategically so that we can really understand how the different types, sizes, shapes, doses and the duration of exposure to microplastics affect wildlife.

Several countries, including Canada, the United Kingdom and United States have recently banned plastic microbeads – the spherical beads and fragments in face wash, body scrubs and toothpaste – because they were contaminating the environment and could cause negative effects in aquatic animals. Although this legislation reduces one type of microplastic in the environment, it is irrelevant to countless others.

Only if we have a better understanding of how the different types, shapes and concentrations of microplastics affect wildlife can we make better policy decisions. If, for example, microfibres are indeed found to be more harmful than spheres, we could focus our attention on keeping these fibres from entering our waterways from known sources, such as from washing machines.

Chelsea Rochman is an assistant professor of ecology and evolutionary biology at the ��߲ݴ�ý. Kennedy Bucci is a PhD student in the department of ecology and evolutionary biology at the ��߲ݴ�ý.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Is there plastic in our drinking water? Probably – and U of T researchers are studying how concerned we should be

Christopher.Sorensen — Fri, 19 Jul 2019 16:03:21 +0000

Is there plastic in our drinking water? Probably – and U of T researchers are studying how concerned we should be

Christopher.Sorensen Fri, 07/19/2019 - 12:03

Cutline

These tiny plastic particles were extracted from Toronto’s harbour by U of T researchers Chelsea Rochman and Bob Andrews (photo by Tyler Irving)

Tyler Irving

Topic

Global Lens

Faculty of Applied Science & Engineering

Is there plastic in your drinking water? The ��߲ݴ�ý’s Bob Andrews and Chelsea Rochman say there is – but, unfortunately, they don’t have much more information to share.

“If someone asks me how microplastics in drinking water influence human health, I have to say that we have no idea,” says Rochman, an assistant professor in the department of ecology and evolutionary biology in U of T’s Faculty of Arts & Science.

“But we should be concerned that the mismanagement of our waste has come back to haunt us.”

Plastic never really goes away. While some waste plastic is recycled or incinerated, most ends up in landfills or worse. A world-leading expert on the fate of plastic waste, Rochman has documented how it ends up in oceans, lakes, rivers, as well as along their shores and even in the bodies of aquatic animals.

“All of the big stuff that you see eventually gets broken down by sunlight into smaller and smaller pieces,” she says.

When plastic pieces become small enough that a microscope is required to see them – anywhere from a few millimetres down to a few micrometres – they are referred to as microplastics. As with larger plastic pieces, microplastics are found widely in the environment. Rochman and her team have even extracted them from the bodies of fish for sale in a commercial market.

Concern over microplastics has been floating just below the surface for some time, but it wasn’t until the fall of 2017 that the issue of microplastics in drinking water hit headlines in a big way.

A non-profit group called Orb Media took samples of tap water from around the world, found microplastics in most of their samples, and released their results to the media. As a member of both the Drinking Water Research Group and the Institute for Water Innovation, Andrews, a professor in U of T’s department of civil and mineral engineering in U of T’s Faculty of Applied Science & Engineering, knew that his collaborators would be curious about the story.

“Within hours, I got calls from a couple of the major water providers in southern Ontario that I work with, asking me what we were doing on this topic,” Andrews says.

Chelsea Rochman and Bob Andrews have joined forces to develop new techniques for analyzing microplastics and nanoplastics in drinking water (photo by Tyler Irving)

Yet, despite his experience collaborating with drinking water providers on treatment and technology, Andrews had not researched the issue of microplastics before. So he sought advice from Rochman.

She was skeptical at first.

“I said, ‘I don’t think they’re going to be there, but sure, let’s filter some water and have a look,’” says Rochman. “We did, and they were there.”

The traditional approach to dealing with drinking water contaminants, such as heavy metals or organic compounds, is for scientists to determine a target threshold below which the risk to human health is considered minimal. Drinking water authorities then invest in treatment technologies designed to keep the levels of these contaminants below the threshold.

But there is no existing threshold for microplastics, and developing one will be complex for several reasons.

First, plastic interacts differently with the body depending on how big the pieces are. “What we’ve seen in animals is that larger pieces usually just get excreted,” says Rochman. “But the smaller particles can actually leave the gut and go into tissues, which is when you can get inflammation and other problems.”

Another challenge: There are no standardized methods for testing levels of microplastics in drinking water. Different teams employing different techniques could obtain different results, making it hard to compare scientific studies with one another.

Contamination is also an issue since tiny plastic particles shed from clothes, carpets and upholstery can get into the samples and skew the results.

These challenges are further compounded by the fact that microplastics can break down into even smaller particles known as nanoplastics. Nanoplastics may behave differently from microplastics, but information is scarce because methods for detecting them haven’t been invented yet.

“Right now, we don’t have good techniques for handling nanoplastic particles,” says Andrews. “One strategy we’re considering is to concentrate them, burn them, and analyze the gas to determine what types of plastic are there. We’d then have to back-calculate to determine their initial concentrations.”

Andrews and his team also have experience testing the toxicity of various compounds on cells grown in the lab. While they may one day go down this route for nanoplastics, for now Andrews and Rochman emphasize the importance of improved analysis as a key step towards developing policies to address the challenge of microplastics.

“California has already passed laws mandating the monitoring of microplastics in drinking water and in the ambient environment,” Rochman says.

“I think it’s good that those bills happened because they are now forcing this global methods development program, which we’re helping lead. We don’t want to throw out numbers until we feel that we have a sound method.”

The collaboration between Rochman and Andrews is funded in part by U of T’s XSeed program, an interdivisional research-funding program designed to promote multidisciplinary research. XSeed projects include one principal investigator from U of T Engineering and one from another university division – in this case, the Faculty of Arts & Science.

“Dealing with microplastics is the kind of challenge that truly does require people from different disciplines to work together,” says Andrews. “Neither of us could do this alone.”

Sea of troubles: Chelsea Rochman explores how plastic is breaking down – and where it’s ending up

noreen.rasbach — Tue, 30 Apr 2019 22:07:35 +0000

Sea of troubles: Chelsea Rochman explores how plastic is breaking down – and where it’s ending up

noreen.rasbach Tue, 04/30/2019 - 18:07

Cutline

Microplastics, which are less than five millimetres in size, include pellets from industry, microbeads from personal care products and tire particles from urban runoff (photo by Paul Weeks)

Katrina Onstad

Topic

Ontario Impact

Graduate Students

When Chelsea Rochman was six years old and a little anxious in the aftermath of her parents’ divorce, she was taken to a child psychologist. The doctor asked: If you could have three wishes, what would they be? One is forgotten, but, 30 years later, Rochman can clearly recall the other two wishes: the ability to see better (she’s had glasses since she was nine months old), and an end to all the trash in the world.

Today Rochman is an assistant professor of ecology and evolutionary biology at the ��߲ݴ�ý researching microplastics, particles of plastic often barely visible to the naked eye (wish one). More specifically, she’s interested in how they pollute lakes, rivers and oceans (wish two), affecting ecosystems and – ponder this the next time you eat fish – the food chain. The research on microplastics taking place in the Rochman Lab at U of T is rippling out of academia, informing policy change including a recent multi-country ban on microbeads – those non-biodegradable exfoliators that made many of us suspicious of our face wash.

An unusual, zigzagging personal path has taken Rochman from aspiring Hollywood actress to speaking at a United Nations meeting about the need to reduce plastic use. At 37, she’s become a frontline ambassador for a critical environmental issue that almost no one wanted to talk about a decade ago.

Standing in a sun-drenched lab off Spadina Crescent this past January, Rochman holds up a bagel-sized Petri dish dotted with tiny specimens of coloured plastic, some smaller than the pin on a thumbtack. “They’re pretty, huh? I kind of want to take a picture and blow it up,” she says in her super-fast voice, vowels loping in a singsong way.

Several students in lab coats murmur agreement. One sits in front of a microscope using tiny pincers to examine a microfibre found in the stomach of a Lake Ontario fish. Another tells Rochman she’s identified a pre-production pellet from a chemical company that was likely destined to become a bottle until it rolled down the drain and into a harbour.

Since the 1950s, when plastic was heralded as the miracle material of the postwar era, humans have created more than seven billion tonnes of it and only nine per cent has ever been recycled. The rest has been incinerated, landfilled or has broken into fragments that end up in our soil, air and water.

The smallest pieces, at less than five millimetres, are called “microplastics,” and Rochman started thinking about them as a marine ecology undergrad at UC San Diego. During a visit to a largely uninhabited research facility on an island off Australia’s coast in 2006, she noticed metres of trash strewn across the beach. The turtles in the rehabilitation centre were, she says, “pooping plastic.” She had some questions, and Google led her to the Great Pacific Garbage Patch, an 80,000-tonne mass of debris floating between Hawaii and California, largely made up of microplastics created by sun and waves eroding bigger plastics. More questions: What about the chemicals in the plastics? How exactly do they make their way to fish and wildlife like those pooping turtles? Rochman decided to do her graduate work at UC Davis studying how plastic pollution affects ecosystems and food webs.

For one UC Davis study, Rochman went to the supermarket and bought some fish. It turned out that one in four contained microplastics, a number that now seems low: Every fish in the Great Lakes has plastic in it, she says. A newly published Rochman Lab study found more than 100 synthetic microfibres in the stomach of a single fish. Many of the 23 to 36 trillion microfibres that annually end up in Lake Ontario watersheds come from our own clothes, released during laundering. But the study shows that a large percentage of those fibres could be prevented from entering the environment by adding a simple commercial filter, available at hardware stores, to a washing machine.

This is good news because microplastics can harm the growth, feeding and reproductive cycles of fish. Less known is exactly what concentration of plastic in the environment is dangerous for humans – a largely unstudied area. “I’m not working on it yet, but we do work on human exposure to microplastics via seafood and drinking water,” says Rochman.

Chelsea Rochman, an assistant professor of ecology and evolutionary biology at U of T, is researching microplastics (photo by Paul Weeks)

“Contaminants are everywhere but we don’t really know yet the answer to the questions, ‘How bad is bad? What’s a tolerable amount?’ We have to figure out how to stop it from reaching a tipping point for human health.”

Microplastics are a terrestrial concern, too. A fridge-like HEPA filter whirrs in a corner of Rochman’s lab in an attempt to keep the room free of dust and particles from clothes and carpets. “I don’t think seafood is our biggest source of plastic. I think it’s drinking water and dust falling on our food,” Rochman says, gesturing at a sunbeam in a window, catching specks. “See that? Microplastics.”

For a native of Tucson, Ariz., dust makes a more sensible preoccupation than marine life. But Rochman’s parents were hippie-ish, and she spent much of her childhood outdoors, hiking and swimming. On Earth Day in high school, she ditched class to gather bags of trash in the desert. Rachel Carson’s seminal environmentalist book Silent Spring inspired Rochman. “I was fascinated with natural disasters. Now I study anthropogenic disasters,” she says.

Rochman initially majored in atmospheric sciences at the University of Arizona, but the program was cancelled during her second year. She’d always acted, so she made a dizzying pivot to performing arts major. After two years, she packed up her car and drove to Hollywood where she did the la-la land thing: waitressing, taking classes and auditioning. Extra work on The West Wing and Curb Your Enthusiasm brought a non-speaking role as a bridesmaid in American Pie 3, the teen sex comedy franchise that was by then a case study in diminishing returns. “A terrible movie. Ten days on set and it turned me off the whole industry. It was icky and my brain was bored.”

Rochman reinvented again, ending up at UC San Diego as a biology major and working at the aquarium down the hill. There, she discovered a love of teaching, revelling in field excursions like driving a tank of sharks to a school and taking children snorkelling and kayaking.

That affection for students has been on display since arriving at U of T three years ago. When we met, 25 lab students had been at her house the night before for a taco party in honour of a seminar speaker. Rochman started the U of T Trash Team in 2017, taking students on garbage-picking excursions off campus for research and to spread waste literacy. Last summer, the team unearthed 31 kilograms of trash at the mouth of the Don River in less than two hours. Now Rochman is working with Ports Toronto to find technology to prevent litter from entering Lake Ontario and to educate the public about waste.

Kennedy Bucci, a second-year PhD student who came to U of T specifically to work with Rochman, helped catalogue the heaps of straws and bottles that hot day. “I’ve learned from Chelsea that if we do science in our bubble, there’s not much point,” she says. “She really believes that what matters is when you bring research to the public and policy-makers.”

To that end, Rochman consulted on the G7 Ocean Plastics Charter, an international agreement to halt marine dumping, spearheaded by Canada. She’s also a science adviser to the non-profit Ocean Conservancy, and frequently finds herself at the table with representatives from Dow and Coca-Cola, trying to explain why reducing production is as important as recycling plastic waste. “It’s still frustrating, but at least they’re listening. They know microplastics are real.” This is a change from the denial phase of a few years ago, when Rochman was regularly mocked on industry blogs.

For a long time, the community of microplastic scientists was, well, micro, but lately, Rochman has noticed a boom in research and academic postings. The interest is nascent, not unlike climate change study a generation ago, and it’s an uphill battle: plastic production is expected to increase by about 40 per cent over the next decade. But Rochman’s voice is now part of a louder chorus advocating for practical responses: proper recycling; less usage; and policy change around production, including taxation.

“I have all these optimistic students around me so I don’t get too jaded,” she says. “They’re hopeful, so I have hope, too.” And surely hope is at least as powerful as a wish.

Chelsea Rochman’s outreach program, the U of T Trash Team, is supported by more than $25,000 in donations from the American Chemistry Council, the Canadian Plastics Industry Association, the Ocean Conservancy and the Alliance for the Great Lakes.

This article first appeared in the ��߲ݴ�ý Magazine. Read more of the Spring 2019 issue.

Cities and countries aim to slash plastic waste within a decade

Christopher.Sorensen — Mon, 22 Apr 2019 18:42:05 +0000

Cities and countries aim to slash plastic waste within a decade

Christopher.Sorensen Mon, 04/22/2019 - 14:42

Cutline

Plastics pile up at Thilafushi, an artificial island created as a landfill, in the Maldives (photo by Shutterstock)

Chelsea Rochman

Diane Orihel

Topic

Global Lens

Environment