You would be hard-pressed to find a corner of the world free from microplastics, plastic particles measuring less than five millimetres. They contaminate our drinking water, accumulate in the food we eat and have been found in the human body, including in blood, organs, placenta, semen and breast milk.

In April, delegates from across the world came together in Ottawa for the fourth session of the Intergovernmental Negotiating Committee to develop a legally binding international treaty on plastic pollution. The meeting offered a unique opportunity to identify strategies for addressing the human and environmental health impacts of plastics, including microplastics.

But do we really know what it would take to mitigate the rising amounts of microplastics in the environment?

This article is part of our series Our lakes: their secrets and challenges. This summer, The Conversation and La Conversation invite you to take a fascinating dip in our lakes. With magnifying glasses, microscopes and diving goggles, our scientists scrutinize the biodiversity of our lakes and the processes that unfold in them, and tell us about the challenges they face. Don’t miss our articles on these incredibly rich bodies of water!

In the Great Lakes, plastic pollution along the shorelines poses a major challenge: 86 per cent of litter collected on Great Lakes beaches is either partially or completely composed of plastic. This is worrisome, given the lakes supply 40 million people with drinking water and represent a combined GDP of US$6 trillion. Yet, recent studies show levels of microplastics reaching up to thousands of particles per cubic metre in some areas of the lakes.

Mismanaged plastic waste

Improving waste management alone is unlikely to address microplastic pollution in the Great Lakes. Consider one of the most common pieces of litter on a beach: a 500 ml plastic bottle. If that bottle is not picked up and placed in a landfill or recycled, over the years it will break down into microplastics; the complete disintegration of the bottle into 100 micrometre size particles would produce 25 million microplastics.

Based on reported concentrations of microplastics and water flow rates of the Great Lakes, we can estimate the yearly amounts of plastic that need to be entering the lakes to match the concentrations of microplastics currently observed.

For Lake Superior, this adds up to the same mass of plastic contained in 1,000 bottles. But Lake Superior is the cleanest of the Great Lakes. For Lakes Huron, Michigan, Erie and Ontario, the corresponding estimates are 3,000, two million, 18,000, and nine million bottles, respectively.

According to the Canadian government’s own estimation, Canadians living in the Great Lakes Basin throw away more than 1.5 million tons of plastic waste each year, equivalent to 64 billion 500 ml bottles. If we include the United States, the total amount of plastic waste in the Great Lakes Basin rises to 21 million tons per year (or 821 billion 500 ml bottles).

For Canada and the U.S., the fraction of mismanaged plastic waste that leaks into the environment because it is not recycled, incinerated or landfilled is estimated to be between four and seven per cent.

According to our calculations, this means that it would take less than 0.001 per cent of the total mass of plastics consumed annually within the Great Lakes Basin to generate the number of microplastics present in the lakes. In other words, just 0.02 per cent of the mismanaged plastic waste already explains the microplastic concentrations in the Great Lakes — the other 99.8 per cent ending up as macro- to micro-sized litter in soils, waterways, ponds, beaches and biota.

What these calculations imply is that the shedding of even very minor, and arguably unavoidable, microplastic particles over the lifetime of a product can lead to significant accumulations of environmental microplastics, including in areas far removed from their source.

While better plastic waste management can help alleviate microplastics pollution, we should not count on it to bring down the microplastics concentrations in all five Great Lakes.

Curbing pollution

Microplastic pollution comes not only from plastic litter in the environment, but also from plastic that is thrown in the trash bin. Even long-lived plastics, such as those that are used in the construction industry, shed microplastics through natural wear and tear.

Once they enter an ecosystem, microplastics become extremely difficult and expensive to clean up. Recycling is the best option currently available, but even this process has been shown to produce microplastics.

At present, less than 10 per cent of plastic is recycled worldwide. With plastic production predicted to triple by 2060, achieving a fully circular plastic economy — where all plastic produced is recycled without shedding microplastic particles — faces huge economic, social, environmental and technological challenges.

And it would take many years to establish such a system, all while microplastic pollution continues to worsen. If we are serious about reducing microplastics concentrations in the environment, the reasonable course of action would be to start reducing plastic production and consumption now.

Lewis Alcott, Lecturer in Geochemistry, University of Bristol; Fereidoun Rezanezhad, Research Associate Professor, Department of Earth & Environmental Sciences, University of Waterloo; Nancy Goucher, Knowledge Mobilization Specialist, University of Waterloo; Philippe Van Cappellen, Professor of Biogeochemistry and Canada Excellence Research Chair Laureate in Ecohydrology, University of Waterloo, and Stephanie Slowinski, Research Biogeochemist, University of Waterloo

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

Bonus Video added by Informed Comment:

Northern Michigan Environmental Action Video: “Microplastics in the Great Lakes with Art Hirsch”

( ProPublica ) – Last year, I became obsessed with a plastic cup.

It was a small container that held diced fruit, the type thrown into lunch boxes. And it was the first product I’d seen born of what’s being touted as a cure for a crisis.

Plastic doesn’t break down in nature. If you turned all of what’s been made into cling wrap, it would cover every inch of the globe. It’s piling up, leaching into our water and poisoning our bodies.

Scientists say the key to fixing this is to make less of it; the world churns out 430 million metric tons each year.

But businesses that rely on plastic production, like fossil fuel and chemical companies, have worked since the 1980s to spin the pollution as a failure of waste management — one that can be solved with recycling.

Industry leaders knew then what we know now: Traditional recycling would barely put a dent in the trash heap. It’s hard to transform flimsy candy wrappers into sandwich bags, or to make containers that once held motor oil clean enough for milk.

Now, the industry is heralding nothing short of a miracle: an “advanced”type of recycling known as pyrolysis — “pyro” means fire and “lysis” means separation. It uses heat to break plastic all the way down to its molecular building blocks.

While old-school, “mechanical” recycling yields plastic that’s degraded or contaminated, this type of “chemical” recycling promises plastic that behaves like it’s new, and could usher in what the industry casts as a green revolution: Not only would it save hard-to-recycle plastics like frozen food wrappers from the dumpster, but it would turn them into new products that can replace the old ones and be chemically recycled again and again.

So when three companies used ExxonMobil’s pyrolysis-based technology to successfully conjure up that fruit cup, they announced it to the world.

“This is a significant milestone,” said Printpack, which turned the plastic into cups. The fruit supplier Pacific Coast Producers called it “the most important initiative a consumer-packaged goods company can pursue.”

“ExxonMobil is supporting the circularity of plastics,” the August 2023 news release said, citing a buzzword that implies an infinite loop of using, recycling and reusing.

They were so proud, I hoped they would tell me all about how they made the cup, how many of them existed and where I could buy one.

Let’s take a closer look at that Printpack press release, which uses convoluted terms to describe the recycled plastic in that fruit cup:

“30% ISCC PLUS certified-circular”

“mass balance free attribution”

It’s easy to conclude the cup was made with 30% recycled plastic — until you break down the numerical sleight of hand that props up that number.

It took interviews with a dozen academics, consultants, environmentalists and engineers to help me do just that.

Stick with me as I unravel it all.

So began my long — and, well, circular — pursuit of the truth at a time when it really matters.

This year, nearly all of the world’s countries are hammering out a United Nations treaty to deal with the plastic crisis. As they consider limiting production, the industry is making a hard push to shift the conversation to the wonders of chemical recycling. It’s also buying ads during cable news shows as U.S. states consider laws to limit plastic packaging and lobbying federal agencies to loosen the very definition of what it means to recycle.

It’s been selling governments on chemical recycling, with quite a bit of success. American and European regulatorshave spent tens of millions subsidizing pyrolysis facilities. Half of all U.S. states have eased air pollution rules for the process, which has been found to release carcinogens like benzene and dioxins and give off more greenhouse gases than making plastic from crude oil.

Given the high stakes of this moment, I set out to understand exactly what the world is getting out of this recycling technology. For months, I tracked press releases, interviewed experts, tried to buy plastic made via pyrolysis and learned more than I ever wanted to know about the science of recycled molecules.

Under all the math and engineering, I found an inconvenient truth: Not much is being recycled at all, nor is pyrolysis capable of curbing the plastic crisis.

Not now. Maybe not ever.

In traditional recycling, plastic is turned into tiny pellets or flakes, which you can melt again and mold back into recycled plastic products.

Even in a real-life scenario, where bottles have labels and a little bit of juice left in them, most of the plastic products that go into the process find new life.

The numbers are much lower for pyrolysis.

CBS Sunday Morning video: “Critics call out plastics industry over recycling ‘fraud'”

It’s “very, very, very, very difficult” to break down plastic that way, said Steve Jenkins, vice president of chemicals consulting at Wood Mackenzie, an energy and resources analytics firm. “The laws of nature and the laws of physics are trying to stop you.”

Waste is heated until it turns into oil. Part of that oil is composed of a liquid called naphtha, which is essential for making plastic.

There are two ingredients in the naphtha that recyclers want to isolate: propylene and ethylene — gases that can be turned into solid plastics.

To split the naphtha into different chemicals, it’s fed into a machine called a steam cracker. Less than half of what it spits out becomes propylene and ethylene.

This means that if a pyrolysis operator started with 100 pounds of plastic waste, it can expect to end up with 15-20 pounds of reusable plastic. Experts told me the process can yield less if the plastic used is dirty or more if the technology is particularly advanced.

I reached out to several companies to ask how much new plastic their processes actually yield, and none provided numbers. The American Chemistry Council, the nation’s largest plastic lobby, told me that because so many factors impact a company’s yield, it’s impossible to estimate that number for the entire industry.

With mechanical recycling, it’s hard to make plastic that’s 100% recycled; it’s expensive to do, and the process degrades plastic. Recycled pellets are often combined with new pellets to make stuff that’s 25% or 50% recycled, for example.

But far less recycled plastic winds up in products made through pyrolysis.

That’s because the naphtha created using recycled plastic is contaminated. Manufacturers add all kinds of chemicals to make products bend or keep them from degrading in the sun.

Recyclers can overpower them by heavily diluting the recycled naphtha. With what, you ask? Nonrecycled naphtha made from ordinary crude oil!

This is the quiet — and convenient — part of the industry’s revolutionary pyrolysis method: It relies heavily on extracting fossil fuels. At least 90% of the naphtha used in pyrolysis is fossil fuel naphtha. Only then can it be poured into the steam cracker to separate the chemicals that make plastic.

So at the end of the day, nothing that comes out of pyrolysis physically contains more than 10% recycled material (though experts and studies have shown that, in practice, it’s more like 5% or 2%).

Ten percent doesn’t look very impressive. Some consumers are willing to pay a premium for sustainability, so companies use a form of accounting called mass balance to inflate the recycled-ness of their products. It’s not unlike offset schemes I’ve uncovered that absolve refineries of their carbon emissions and enable mining companies to kill chimpanzees. Industry-affiliated groups like the International Sustainability and Carbon Certification write the rules. (ISCC didn’t respond to requests for comment.)

To see how this works, let’s take a look at what might happen to a batch of recycled naphtha. Let’s say the steam cracker splits the batch into 100 pounds of assorted ingredients.

There are many flavors of this kind of accounting. Another version of free attribution would allow the company to take that entire 30-pound batch of “33% recycled” pouches and split them even further:

A third of them, 10 pounds, could be labeled 100% recycled — shifting the value of the full batch onto them — so long as the remaining 20 pounds aren’t labeled as recycled at all.

As long as you avoid double counting, Jenkins told me, you can attribute the full value of recycled naphtha to the products that will make the most money. Companies need that financial incentive to recoup the costs of pyrolysis, he said.

But it’s hard to argue that this type of marketing is transparent. Consumers aren’t going to parse through the caveats of a 33% recycled claim or understand how the green technology they’re being sold perpetuates the fossil fuel industry. I posed the critiques to the industry, including environmentalists’ accusations that mass balance is just a fancy way of greenwashing.

The American Chemistry Council told me it’s impossible to know whether a particular ethylene molecule comes from pyrolysis naphtha or fossil fuel naphtha; the compounds produced are “fungible” and can be used for multiple products, like making rubber, solvents and paints that would reduce the amount of new fossil fuels needed. Its statement called mass balance a “well-known methodology” that’s been used by other industries including fair trade coffee, chocolate and renewable energy.

Legislation in the European Union already forbids free attribution, and leaders are debating whether to allow other forms of mass balance. U.S. regulation is far behind that, but as the Federal Trade Commission revises its general guidelines for green marketing, the industry is arguing that mass balance is crucial to the future of advanced recycling. “The science of advanced recycling simply does not support any other approach because the ability to track individual molecules does not readily exist,” said a comment from ExxonMobil.

If you think navigating the ins and outs of pyrolysis is hard, try getting your hands on actual plastic made through it.

It’s not as easy as going to the grocery store. Those water bottles you might see with 100% recycled claims are almost certainly made through traditional recycling. The biggest giveaway is that the labels don’t contain the asterisks or fine print typical of products made through pyrolysis, like “mass balance,” “circular” or “certified.”

When I asked about the fruit cup, ExxonMobil directed me to its partners. Printpack didn’t respond to my inquiries. Pacific Coast Producers told me it was “engaged in a small pilot pack of plastic bowls that contain post-consumer content with materials certified” by third parties, and that it “has made no label claims regarding these cups and is evaluating their use.”

I pressed the American Chemistry Council for other examples.

“Chemical recycling is a proven technology that is already manufacturing products, conserving natural resources, and offering the potential to dramatically improve recycling rates,” said Matthew Kastner, a media relations director. His colleague added that much of the plastic made via pyrolysis is “being used for food- and medical-grade packaging, oftentimes not branded.”

They provided links to products including a Chevron Phillips Chemical announcement about bringing recycled plastic food wrapping to retail stores.

“For competitive reasons,” a Chevron spokesperson declined to discuss brand names, the product’s availability or the amount produced.

In another case, a grocery store chain sold chicken wrapped in plastic made by ExxonMobil’s pyrolysis process. The producers told me they were part of a small project that’s now discontinued.

In the end, I ran down half a dozen claims about products that came out of pyrolysis; each either existed in limited quantities or had its recycled-ness obscured with mass balance caveats.

Then this April, nearly eight months after I’d begun my pursuit, I could barely contain myself when I got my hands on an actual product.

I was at a United Nations treaty negotiation in Ottawa, Ontario, and an industry group had set up a nearby showcase. On display was a case of Heinz baked beans, packaged in “39% recycled plastic*.” (The asterisk took me down an online rabbit hole about certification and circularity. Heinz didn’t respond to my questions.)

This, too, was part of an old trial. The beans were expired.

Pyrolysis is a “fairy tale,” I heard from Neil Tangri, the science and policy director at the environmental justice network Global Alliance for Incinerator Alternatives. He said he’s been hearing pyrolysis claims since the ’90s but has yet to see proof it works as promised.

“If anyone has cracked the code for a large-scale, efficient and profitable way to turn plastic into plastic,” he said, “every reporter in the world” would get a tour.

If I did get a tour, I wondered, would I even see all of that stubborn, dirty plastic they were supposedly recycling?

The industry’s marketing implied we could soon toss sandwich bags and string cheese wrappers into curbside recycling bins, where they would be diverted to pyrolysis plants. But I grew skeptical as I watched a webinar for ExxonMobil’s pyrolysis-based technology, the kind used to make the fruit cup. The company showed photos of plastic packaging and oil field equipment as examples of its starting material but then mentioned something that made me sit up straight: It was using pre-consumer plastic to “give consistency” to the waste stream.

Chemical plants need consistency, so it’s easier to use plastic that hasn’t been gunked up by consumer use, Jenkins explained.

But plastic waste that had never been touched by consumers, such as industrial scrap found at the edges of factory molds, could easily be recycled the old-fashioned way. Didn’t that negate the need for this more polluting, less efficient process?

I asked ExxonMobil how much post-consumer plastic it was actually using. Catie Tuley, a media relations adviser, said it depends on what’s available. “At the end of the day, advanced recycling allows us to divert plastic waste from landfills and give new life to plastic waste.”

I posed the same question to several other operators. A company in Europe told me it uses “mixed post-consumer, flexible plastic waste” and does not recycle pre-consumer waste.

But this spring at an environmental journalism conference, an American Chemistry Council executive confirmed the industry’s preference for clean plastic as he talked about an Atlanta-based company and its pyrolysis process. My colleague Sharon Lerner asked whether it was sourcing curbside-recycled plastic for pyrolysis.

If Nexus Circular had a “magic wand,” it would, he acknowledged, but right now that kind of waste “isn’t good enough.” He added, “It’s got tomatoes in it.”

(Nexus later confirmed that most of the plastic it used was pre-consumer and about a third was post-consumer, including motor oil containers sourced from car repair shops and bags dropped off at special recycling centers.)

Clean, well-sorted plastic is a valuable commodity. If the chemical recycling industry grows, experts told me, those companies could end up competing with the far more efficient traditional recycling.

To spur that growth, the American Chemistry Council is lobbying for mandates that would require more recycled plastic in packaging; it wants to make sure that chemically recycled plastic counts. “This would create market-driven demand signals,” Kastner told me, and ease the way for large-scale investment in new chemical recycling plants.

I asked Jenkins, the energy industry analyst, to play out this scenario on a larger scale.

Were all of these projects adding up? Could the industry conceivably make enough propylene and ethylene through pyrolysis to replace much of our demand for new plastic?

He looked three years into the future, using his company’s latest figures on global pyrolysis investment, and gave an optimistic assessment.

At best, the world could replace 0.2% of new plastic churned out in a year with products made through pyrolysis.

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(The Conversation) – Plastic pollution and climate change have common culprits – and similar solutions.

The penultimate round of negotiations for a global pact on plastic ended yesterday in Ottawa. Nearly 200 countries have agreed that a treaty must tackle plastic pollution at every stage of its existence, from oil rigs and refineries to factories, shops and homes. But when Rwanda and Peru proposed cutting the amount of plastic produced worldwide by 40% over the next 15 years, the UN talks faltered.

This stalemate has been, at least partially, engineered by the same companies stalling climate action: fossil fuel firms and their petrochemical partners.

This roundup of The Conversation’s climate coverage comes from our weekly climate action newsletter. Every Wednesday, The Conversation’s environment editor writes Imagine, a short email that goes a little deeper into just one climate issue. Join the 30,000+ readers who’ve subscribed.

Most plastics are derived from fossil fuels. Oil and gas companies extract these fuels and petrochemical firms refine and synthesise plastic from them. Reports suggest that the number of lobbyists representing both industries at the negotiations is increasing.

Recycled lobbying tactics

Reducing plastic production is the most effective way to cut pollution according to a recent study. Since a proposal for phasing down production failed to gain enough support in Ottawa however, it’s unclear what the agreement – expected later this year – will eventually look like.

“Will it be ambitious, with strict binding measures focusing on all stages of the plastics life cycle (including the ‘upstream’ stages associated with resource extraction, manufacturing and processing)?” ask Antaya March, Cressida Bowyer and Steve Fletcher, researchers who study the plastic waste epidemic at the University of Portsmouth.

“Or will it be a weaker treaty, with voluntary and country-led measures that focus mainly on waste management and pollution prevention (the ‘downstream’ stages)?”

Profit-minded petrochemical companies have long insisted that downstream strategies, like ramping up recycling, are the best way to manage plastic waste. An investigation showed this was disingenuous: plastic producers knew more than three decades ago that recycling was complicated, expensive and ineffective – despite what their marketing departments said.

Today, the global recycling system is a mess, says Kutoma Wakunuma, an associate professor of information systems at De Montfort University:

CBC The National Video: “Why it’s so hard to end plastic pollution”

“Although plastic waste can be seen as a trade between developed and developing countries, which allows the latter to be paid in exchange for dealing with that waste, this trade isn’t an equal one.”

Wakunuma describes how waste pickers in several African countries sift the imported refuse of richer nations for plastic bottles and other recyclable items. These workers, predominantly women, may be paid four pence a kilogram for what they manage to salvage, she says.

“And that waste sometimes ends up burned, rather than being recycled. In 2020, 40% of the UK’s plastic waste was sent to Turkey, where instead of being recycled some of it was illegally dumped and burned.”

Two billion people worldwide lack dedicated rubbish collection services. Many of them breathe toxic fumes from the open burning of plastic according to waste management experts Costas Velis and Ed Cook at the University of Leeds. This is a serious and overlooked health crisis, they say.

The recycling facilities of developing countries are overwhelmed. Yet oil firms see these places – where environmental regulations are typically weaker – as promising markets for more single-use plastic that is cheap and difficult to recycle says Deirdre McKay, a reader in geography and environmental politics at Keele University.

Turn off the taps

Fossil fuels and petrochemicals have a long history: the first synthetic chemicals were derived from coal. In the future, global demand for oil and gas will fall as more buildings and vehicles run on renewable electricity – but emissions will remain high if fossil fuel firms are allowed to continuing ploughing money into making plastics instead say industry sustainability experts Fredric Bauer (Lund University) and Tobias Dan Nielsen (IVL Swedish Environmental Research Institute).

Some of the solutions to plastic waste and climate change are the same. Like scrapping fossil fuel subsidies, which keep plastic production (and fossil fuel extraction) artificially cheap.

More generally, evidence supports the idea of phasing out plastic production to curb mounting pollution – and something similar is true for climate change.

“There is a wealth of scientific evidence demonstrating that a fossil fuel phase-out will be essential for reining in the greenhouse gas emissions driving climate change,” says Steve Pye, an associate professor of energy systems at UCL.

“Since no new fields need to be brought into development, global production of oil and gas should be falling.”

A legally binding agreement that aims to curtail plastic production could be the best outcome from the final summit in Busan, South Korea in late November. But even this may not deter countries and companies that make a lot of money from plastic. With equivalent climate legislation, “legally binding” in practice has meant campaigners having to drag governments and corporations through the courts for years to make them keep their promises says Rebecca Willis, a governance expert at Lancaster University.

At the very least, campaigners on both plastic waste and climate change can benefit from combining their efforts.

“The environment appears to be drowning in plastic for the same reason that global temperatures continue to rise,” says McKay. “Fossil fuels have remained cheap and abundant.”

Jack Marley, Environment + Energy Editor, The Conversation

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

The Nile is one of the world’s most famous rivers. It’s also Africa’s most important freshwater system. About 300 million people live in the 11 countries it flows through. Many rely on its waters for agriculture and fishing to make a living.

The Nile’s two main tributaries, the Blue Nile and the White Nile, come together in Sudan’s capital city, Khartoum. This industrial hub has grown rapidly over the past few decades.

The Nile is not immune to the same pollutants that affect rivers all over the world. Plastic debris is of particular concern. Over time plastics break down into smaller pieces known as microplastics. These are tiny plastic particles with a maximum size of five millimetres, all the way down to the nanoscale. Recent research found that

rivers are modelled to export up to 25,000 tons of plastics from their sub-basins to seas annually. Over 80% of this amount is microplastic.

This has huge negative consequences for biodiversity and the climate. As microplastics degrade, scientists have found, they produce greenhouse gases. Airborne microplastics may influence the climate by scattering and absorbing solar and terrestrial radiation, leading to atmospheric warming or cooling depending on particle size, shape and composition. It also negatively affects animal and human health. Microplastics have been shown in laboratory studies to be toxic to animals and cells.

Much of the research about microplastics in African waters has focused on marine and coastal areas. To address this gap, I conducted a study to assess the presence of microplastics in the River Nile in Khartoum. My students and I tested for the presence of microplastics in Nile tilapia. This popular African freshwater fish species forms the basis of commercial fisheries in many African countries, including Sudan.

Photo by Islam Hassan on Unsplash

The results do not make for happy reading. In the 30 freshly caught fish we surveyed, we found a total of 567 microplastic particles. This shows that the River Nile is contaminated with microplastics that can be consumed or absorbed in various ways by the tilapia and other aquatic organisms.

Our sample

The fish used in our study were caught just after the meeting point of the two Niles, known in Arabic as Al-Mogran.

We visited the Al-Mawrada fish market in the Omdurman area, which is also alongside the Nile. All 30 specimens we bought were freshly caught.

We dissected the fish to remove their digestive tracts. The individual tracts were treated so they would digest any organic matter they contained without interfering with the analysis of microplastics. The resulting solution was subject to another extraction procedure and we then conducted physical and chemical analyses.

Every specimen had microplastics in its digestive tract.

The number ranged from as few as five to as many as 47 particles per single fish. In total we identified 567 particles. This is high compared to studies that have reported microplastics in tilapia species in other rivers and lakes. There is, as yet, no global guideline or standard for what might be an “acceptable” number.

Shape, size and colour

We detected different sizes of microplastics (0.04mm to 4.94mm), shapes (fibres, fragments, films, foams and pellets) and colours. The most common were very small (less than 1mm), fibrous – they appear slender and elongated – and coloured (dyed).

These characteristics make sense because of how fish and other aquatic organisms feed. Nile tilapia are versatile feeders: they consume a variety of organisms including phytoplankton, aquatic plants, invertebrates, detritus, bacterial films, as well as other fish and fish eggs. That puts them at a high risk of ingesting microplastics.

Nile tilapia are also more likely to consume particles that are within a similar size range as their natural prey, as well as the same shape and colour.

Smaller microplastics are especially good carriers for other pollutants such as heavy metals, resulting in additional health risks. Their small size also makes it easier for them to move into organs like the liver. Studies have found microplastics in the tissues, muscles, livers, blubber and lungs of other aquatic as well as marine mammal species.

Fibres, the most dominant shape found in our specimens, stay in the intestine for longer than other microplastic shapes. This, too, can lead to health problems for the fish. Coloured microplastics contain dyes, many of which contain toxic chemicals.

This all has serious implications for human health, as people catch and eat the fish, which introduces those microplastics and associated chemicals into their bloodstreams.

Pollution sources

Where does all this plastic originate? For starters, 65% of plastic waste in Khartoum is disposed of in open dumps. From there, it contaminates water bodies and other parts of the environment.

Image by Refaat Naiem from Pixabay

The city’s wastewater treatment system is ineffective. The three wastewater treatment plants in Khartoum state, Karary, Wd-Daffiaa and Soba, are outdated and do not meet local and international standards. That means untreated effluent from domestic, industrial and agricultural activities is another probable source of microplastic pollution.

There are also countless recreational sites along the River Nile in Khartoum. The Nile Street is the most popular in the capital city, hosting water sports, restaurants, cafes, clubs, event venues and hotels, as well as the tea ladies (women who serve hot beverages from makeshift mobile cafes along the banks of the river). However, waste disposal and collection practices are sorely lacking, so plastic litter from these leisure activities leaks into the river.

No easy fix

Tackling microplastic pollution is not easy. It will require technological advances, as well as the collective efforts of consumers, producers, governments and the scientific community.

As consumers, we need to change our behaviour around plastic products, especially single-use plastics. For example, opt for fabric shopping bags instead of plastic bags; use glass and metal containers. Recycling is also important.

Governments must enforce waste management regulations and improve waste management practices, as well as helping to improve public awareness. Strategies and policies must explicitly feature microplastics.

Scientists can not only fill the knowledge gaps around microplastics. Communicating scientific findings is crucial; so too is developing innovations to protect against microplastics and their harmful effects.

I would like to thank and acknowledge my student Hadeel Alamin, who conducted this study with me.

Dalia Saad, Researcher, School of Chemistry, University of the Witwatersrand, University of the Witwatersrand

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

(The Conversation) – Microplastic pollution is a global environmental problem that is ubiquitous in all environments, including air, water and soils.

Microplastics are readily found in treated wastewater sludge — also known as municipal biosolids — that eventually make their way to our agricultural soils.

Our recent investigation of microplastic levels in Canadian municipal biosolids found that a single gram of biosolids contains hundreds of microplastic particles. This is a much greater concentration of microplastics than is typically found in air, water or soil.

Given that hundreds of thousands of tonnes of biosolids are produced every year in Canada, we need to pay close attention to the potential impacts such high levels of microplastics might have on the environment and find ways to reduce microplastic levels in Canada’s wastewater stream.

Municipal biosolids

Municipal biosolids are produced at wastewater treatment plants by settling and stabilizing the solid fraction of the municipal wastewater inflow.

In Canada and around the world, municipal biosolids are used to improve agricultural farmland soil. This is because they are rich in nutrients needed for plant growth, such as phosphorus and nitrogen.

Municipal biosolid applications are carefully regulated in Canada for heavy metals, nutrients and pathogens. However, guidelines for emerging contaminants, such as microplastics, are not currently available.

While current wastewater treatment plants are not explicitly designed to remove microplastics, they are nevertheless efficient at removing nearly 90 per cent of microplastic contaminants. The removed microplastics are often concentrated in the settled sludge and eventually end up in the biosolids.

Microplastics in municipal biosolids

Previous studies have shown that municipal biosolid waste is an important pathway for microplastics to enter the broader terrestrial ecosystems, including agricultural fields.

In collaboration with scientists from Environment and Climate Change Canada and Agriculture and Agri-Food Canada, we conducted the first pan-Canadian assessment of microplastics in municipal biosolids. We analyzed biosolid samples from 22 Canadian wastewater treatment plants across nine provinces and two biosolid-based fertilizer products.

We found hundreds of microplastic particles in every gram of biosolids. The most common type of microplastic particles we observed were microfibres, followed by small fragments. We found small amounts of glitter and foam pieces too.

Microplastic concentrations in municipal biosolids are substantially higher than other environmental networks in Canada like water, soil and river sediments. This provides further evidence that microplastics are concentrated in biosolids produced at wastewater treatment plants.

Reducing microplastics

Wastewater treatment plants are well-equipped to remove large plastics like bottle caps and plastic bags from municipal wastewater. However, microplastic particles are so small they can’t be caught by current treatment infrastructure, so they end up concentrating in wastewater sludge.

As wastewater streams concentrate microplastics, they also offer an opportunity to reduce the plastic pollution that is entering the environment. While researchers across Canada are working to find insights on the short- and long-term ecological consequences of microplastic pollution on soil ecosystems, one solution is already clear.

Microplastics can be reduced at sources via systematic reductions in the use of single-use plastics, washing clothing with synthetic fibre less frequently and removing microfibres using washing machine filters. These approaches will help minimize the amount of microplastics that get into the wastewater stream and, ultimately, into the broader terrestrial and aquatic environments.

Building new technologies at our wastewater treatment plants to remove microplastics through physical or chemical means should also be explored.

We need to better understand the impact of high concentrations of microplastic on agro-ecosystems where biosolids are applied, including its impacts on soil-dwelling organisms like earthworms and insects. We also need to start building national guidelines for microplastic levels in biosolids and agricultural soils.

Branaavan Sivarajah, Postdoctoral Fellow, Department of Geography and Environmental Studies, Carleton University and Jesse Vermaire, Associate Professor, Institute of Environmental Science, Carleton University

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

Featured image: In Canada and around the world, biosolids are widely used to improve agricultural farmland soil. Biosolids being sprayed on an agricultural field.
(Branaavan Sivarajah), Author provided

Plastic pollution has become such major problem that it’s threatening our human rights. That’s the view of two UN special rapporteurs (human rights advisers) who recently issued a joint statement, warning against the “overwhelming toxic tidal wave” of plastic endangering us and the environment “in a myriad of ways over its life cycle”. They called for urgent action on dealing with this global crisis.

Such a call could not be timelier, as governments have achieved disappointingly little so far. Yes, most restrict single-use plastic bags, or some other type of single-use plastics. But such measures are clearly not enough.

Even the UN treaty on plastic pollution, which has been agreed in principle and is currently being negotiated, is unlikely to produce fundamental change, at least in the short term. And there is no guarantee any new measures it leads to would have a different fate from the many existing plastic pollution laws that governments fail to implement.

Amid growing concerns over plastic pollution and weak governmental response to it, individuals and communities have been seeking action by resorting to courts. I recently published an academic study on the global tug of war over plastic going on in courts in more than 30 countries.

I found lots of different approaches. Some argue that their governments do not implement the existing laws. For instance, a group in the Philippines has persuaded the country’s supreme court to review the government’s implementation of solid waste management law.

Others claim that their governments do not consider the impacts of plastic pollution when allowing new factories making plastic products. One group of Māori in New Zealand recently appealed a decision to expand a billion-bottle-per-year water plant.

Some seek compensation from plastic-producing companies for dumping waste into rivers, such as the Texas residents who won a US$50 million (£39 million) settlement after finding billions of plastic pellets in their local waterways.

Local governments are also increasingly turning to courts claiming that businesses deceptively market their plastic products as recyclable. Cases like these send a clear message to the governments and businesses that individuals and communities are concerned about the impacts of plastic pollution and want more decisive action to stop it.

But at the same time, all these cases are only one part of the picture. Increasing restrictions on plastic products also result in claims brought by businesses that oppose such measures, including the producers of plastic products as well as supermarkets and restaurants, and ask the courts to quash them.

Image by Rosy from Pixabay

Cases where businesses argue that restrictions on plastic products cause economic loss or are scientifically unsubstantiated are very common throughout the world.

Businesses also regularly challenge provinces or cities that adopt additional restrictions to the ones imposed by national authorities. Such cases send the message that our society is still massively dependent on plastic products, and so measures to address plastic pollution need to be systemic.

The role of courts in tackling plastic pollution

The courts’ involvement has direct consequences for any attempts to tackle this global crisis and for action on environmental and health protection more generally. For example, businesses might be able to persuade a court to declare local anti-plastic pollution measures invalid.

This happened in Mexico recently when the nation’s supreme court ruled a ban on single-use plastics by the state of Oaxaca was unconstitutional. The success of such cases can prompt other businesses to challenge local environmental and health protection measures.

On the other hand, if a court upholds such measures, other local governments may decide to follow the example of their neighbours and introduce such measures as well. If anti-plastic pollution measures already exist, they can be used to persuade the courts that further action should be taken.

Similarly, by holding businesses accountable for pollution resulting from various stages of plastic life cycle, courts help protect vulnerable individuals and communities from various human rights violations caused by plastic pollution.

No single country has a comprehensive response to plastic pollution. But many are gradually tightening up measures on single-use plastics which moves the world closer towards a comprehensive regulatory response to this crisis.

Courts will undoubtedly continue playing an important role in this process. Those concerned about plastic pollution will keep pressing for tighter regulation, while those who oppose regulation will have more restrictions to challenge.

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Sam Varvastian, Lecturer in Law, Cardiff University

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

(The Conversation) – People once believed the planet could always accommodate us. That the resilience of the Earth system meant nature would always provide. But we now know this is not necessarily the case. As big as the world is, our impact is bigger.

In research released today, an international team of scientists from the Earth Commission, of which we were part, identified eight “safe” and “just” boundaries spanning five vital planetary systems: climate change, the biosphere, freshwater, nutrient use in fertilisers and air pollution. This is the first time an assessment of boundaries has quantified the harms to people from changes to the Earth system.

“Safe” means boundaries maintaining stability and resilience of our planetary systems on which we rely. “Just”, in this work, means boundaries which minimise significant harm to people. Together, they’re a health barometer for the planet.

Assessing our planet’s health is a big task. It took the expertise of 51 world-leading researchers from natural and social sciences. Our methods included modelling, literature reviews and expert judgement. We assessed factors such as tipping point risks, declines in Earth system functions, historical variability and effects on people.

Alarmingly, we found humanity has exceeded the safe and just limits for four of five systems. Aerosol pollution is the sole exception. Urgent action, based on the best available science, is now needed.

So, what did we find?

Our work builds on the influential concepts of planetary boundaries by finding ways to quantify what just systems look like alongside safety.

Importantly, the safe and just boundaries are defined at local to global spatial scales appropriate for assessing and managing planetary systems – as small as one square kilometre in the case of biodiversity. This is crucial because many natural functions act at local scales.

Here are the boundaries:

1. Climate boundary – keep warming to 1℃

We know the Paris Agreement goal of 1.5℃ avoids a high risk of triggering dangerous climate tipping points.

But even now, with warming at 1.2℃, many people around the world are being hit hard by climate-linked disasters, such as the recent extreme heat in China, fires in Canada, severe floods in Pakistan and droughts in the United States and the Horn of Africa.

At 1.5℃, hundreds of millions of people could be exposed to average annual temperatures over 29℃, which is outside the human climate niche and can be fatal. That means a just boundary for climate is nearer to 1°C. This makes the need to halt further carbon emissions even more urgent.

2. Biosphere boundaries: Expand intact ecosystems to cover 50-60% of the earth

A healthy biosphere ensures a safe and just planet by storing carbon, maintaining global water cycles and soil quality, protecting pollinators and many other ecosystem services. To safeguard these services, we need 50 to 60% of the world’s land to have largely intact natural ecosystems.

Recent research puts the current figure at between 45% and 50%, which includes vast areas of land with relatively low populations, including parts of Australia and the Amazon rainforest. These areas are already under pressure from climate change and other human activity.

Image by Rosina Kaiser from Pixabay

Locally, we need about 20-25% of each square kilometre of farms, towns, cities or other human-dominated landscapes to contain largely intact natural ecosystems. At present, only a third of our human-dominated landscapes meet this threshold.

3. Freshwater boundaries: Keep groundwater levels up and don’t suck rivers dry

Too much freshwater is a problem, as unprecedented floods in Australia and Pakistan show. And too little is also a problem, with unprecedented droughts taking their toll on food production.

To bring fresh water systems back into balance, a rule of thumb is to avoid taking or adding more than 20% of a river or stream’s water in any one month, in the absence of local knowledge of environmental flows.

At present, 66% of the world’s land area meets this boundary, when flows are averaged over the year. But human settlement has a major impact: less than half of the world’s population lives in these areas. Groundwater, too, is overused. At present, almost half the world’s land is subject to groundwater overextraction.

4. Fertiliser and nutrient boundaries: Halve the runoff from fertilisers

When farmers overuse fertilisers on their fields, rain washes nitrogen and phosphorus runoff into rivers and oceans. These nutrients can trigger algal blooms, damage ecosystems and worsen drinking water quality.

Yet many farming regions in poorer countries don’t have enough fertiliser, which is unjust.

Worldwide, our nitrogen and phosphorus use are up to double their safe and just boundaries. While this needs to be reduced in many countries, in other parts of the world fertiliser use can safely increase.

5. Aerosol pollution boundary: Sharply reduce dangerous air pollution and reduce regional differences

New research shows differences in concentration of aerosol pollutants between Northern and Southern hemispheres could disrupt wind patterns and monsoons if pollutant levels keep increasing. That is, air pollution could actually upend weather systems.

At present, aerosol concentrations have not yet reached weather-changing levels. But much of the world is exposed to dangerous levels of fine particle pollution (known as PM 2.5) in the air, causing an estimated 4.2 million deaths a year.

We must significantly reduce these pollutants to safer levels – under 15 micrograms per cubic metre of air.

We must act

We must urgently navigate towards a safe and just future, and strive to return our planetary systems back within safe and just boundaries through just means.

To stop human civilisation from pushing the Earths’s systems out of balance, we will have to tackle the many ways we damage the planet.

To work towards a world compatible with the Earth’s limits means setting and achieving science-based targets. To translate these boundaries to actions will require urgent support from government to create regulatory and incentive-based systems to drive the changes needed.

Setting boundaries and targets is vital. The Paris Agreement galvanised faster action on climate. But we need similar boundaries to ensure the future holds fresh water, clean air, a planet still full of life and a good life for humans.

We would like to acknowledge support from the Earth Commission, which is hosted by Future Earth, and is the science component of the Global Commons Alliance

Steven J Lade, Resilience researcher at Australian National University, Australian National University; Ben Stewart-Koster, Senior research fellow, Griffith University; Stuart Bunn, Professor, Australian Rivers Institute, Griffith University; Syezlin Hasan, Research fellow, Griffith University, and Xuemei Bai, Distinguished Professor, Australian National University

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For many Muslims breaking fast in mosques around the world this Ramadan, something will be missing: plastics.

The communal experience of iftars – the after-sunset meal that brings people of the faith together during the holy month starting on March 22, 2023 – often necessitates the use of utensils designed for mass events, such as plastic knives and forks, along with bottles of water.

But to encourage Muslims to be more mindful of the impact of Ramadan on the environment, mosques are increasingly dispensing of single-use items, with some banning the use of plastics altogether.

As a historian of Islam, I see this “greening” of Ramadan as entirely in keeping with the traditions of the faith, and in particular the observance of Ramadan.

The month – during which observant Muslims must abstain from even a sip of water or food from sun up to sun down – is a time for members of the faith to focus on purifying themselves as individuals against excess and materialism.

But in recent years, Muslim communities around the world have used the period to rally around themes of social awareness. And this includes understanding the perils of wastefulness and embracing the link between Ramadan and environmental consciousness.

The ban on plastics – a move encouraged by the Muslim Council of Britain as a way for Muslims “to be mindful of [God’s] creation and care for the environment” – is just one example.

Many other mosques and centers are discouraging large or extravagant evening meals altogether. The fear is such communal events generate food waste and overconsumption and often rely on nonbiodegradable materials for cutlery, plates and serving platters.

Photo by Kizkopop on Unsplash

Quranic environmentalism

While the move toward environmental consciousness has gained traction in Muslim communities in recent years, the links between Islam and sustainability can be found in the faith’s foundational texts.

Scholars have long emphasized principles outlined in the Quran that highlight conservation, reverence for living creatures and the diversity of living things as a reminder of God’s creation.

The Quran repeatedly emphasizes the idea of “mizan,” a kind of cosmic and natural balance, and the role of humans as stewards and khalifa, or “viceregents,” on Earth – terms that also carry an environmental interpretation.

Recently, Islamic environmental activists have highlighted the numerous hadith – sayings of the Prophet Muhammad that provide guidance to followers of the faith – that emphasize that Muslims should avoid excess, respect resources and living things, and consume in moderation.

Although present from the outset of the faith, Islam’s ties to environmentalism received major visibility with the works of Iranian philosopher Seyyed Hossein Nasr, and a series of lectures he delivered at the University of Chicago in 1966. The lectures and a subsequent book, “Man and Nature: The Spiritual Crisis in Modern Man,” warned that humans had broken their relationship with nature and thus placed themselves in grave ecological danger.

Nasr blamed modern and Western science for being materialistic, utilitarian and inhuman, claiming it had destroyed traditional views of nature. Nasr argued that Islamic philosophy, metaphysics, scientific tradition, arts and literature emphasize the spiritual significance of nature. But he noted that numerous contemporary factors, such as mass rural-to-urban migration and poor and autocratic leadership, had prevented the Muslim world from realizing and implementing the Islamic view of the natural environment.

Scholars and activists expanded on Nasr’s work through the 1980s and 1990s, among them Fazlun Khalid, one of the world’s leading voices on Islam and environmentalism. In 1994, Khalid founded the Islamic Foundation for Ecology and Environmental Sciences, an organization dedicated to the maintenance of the planet as a healthy habitat for all living beings. Khalid and other Muslim environmentalists suggest that Islam’s nearly 2 billion adherents can participate in the tasks of environmental sustainability and equity not through Western models and ideologies but from within their own traditions.

Partnering with the United Nations Environment Program, Khalid and other leading scholars crafted Al-Mizan, a worldwide project for Muslim leaders interested in Muslims’ religious commitments to nature. “The ethos of Islam is that it integrates belief with a code of conduct which pays heed to the essence of the natural world,” Khalid wrote in “Signs on the Earth: Islam, Modernity, and the Climate Crisis.”

Going beyond an eco-Ramadan

Environmental crises disproportionately affect the world’s poorest populations, and academics have highlighted
the particular vulnerabilities of Muslim communities around the world, such as the victims of devastating floods in Pakistan in 2022.

By highlighting Islamic principles, policies and community approaches, academics have shown how Islam can represent a model for environmental stewardship.

This push for environmental consciousness extends beyond Ramadan. In recent years, Muslims have tried to introduce green practices into the shrine cities in Iraq during pilgrimage seasons in Ashura and Arbaeen.

Photo by kilarov zaneit on Unsplash

This has included awareness campaigns encouraging the 20 million pilgrims who visit Arbaeen annually to reduce the tons of trash they leave every year that clog up Iraq’s waterways. Quoting from Shiite scholarship and drawing on testimonials from community leaders, the Green Pilgrim movement suggests carrying cloth bags and reusable water bottles, turning down plastic cutlery, and hosting eco-friendly stalls along the walk.

Muslim-owned businesses and nonprofits are joining these wider efforts. Melanie Elturk, the founder of the successful hijab brand Haute Hijab, regularly ties together faith, fashion, commerce and environmentalism by highlighting the brand’s focus on sustainability and environmental impact. The Washington, D.C., nonprofit Green Muslims pioneered the first “leftar” – a play on the word “iftar” – using leftovers and reusable containers.

These efforts are but a few of the diverse ways that Muslim communities are addressing environmental impact. The greening of Ramadan fits into a broader conversation about how often communities can tackle climate change within their own frameworks.

But Islamic environmentalism is more than just the dispensing of plastic forks and water bottles – it taps into a worldview ingrained in the faith from the outset, and can continue to guide adherents as they navigate environmentalism, a space where they may otherwise be marginalized.

Noorzehra Zaidi, Assistant Professor of HIstory, University of Maryland, Baltimore County

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As a conservation biologist who studies plastic ingestion by marine wildlife, I can count on the same question whenever I present research: “How does plastic affect the animals that eat it?”

This is one of the biggest questions in this field, and the verdict is still out. However, a recent study from the Adrift Lab, a group of Australian and international scientists who study plastic pollution, adds to a growing body of evidence that ingesting plastic debris has discernible chronic effects on the animals that consume it. This work represents a crucial step: moving from knowing that plastic is everywhere to diagnosing its effects once ingested.

From individual to species-level effects

There’s wide agreement that the world is facing a plastic pollution crisis. This deluge of long-lived debris has generated gruesome photos of dead seabirds and whales with their stomachs full of plastic.

But while consuming plastic likely killed these individual animals, deaths directly attributable to plastic ingestion have not yet been shown to cause population-level effects on species – that is, declines in population numbers over time that are linked to chronic health effects from a specific pollutant.

MBARI: “Microplastics in the ocean: A deep dive on plastic pollution in Monterey Bay”

One well-known example of a pollutant with dramatic population effects is the insecticide DDT, which was widely used across North America in the 1950s and 1960s. DDT built up in the environment, including in fish that eagles, osprey and other birds consumed. It caused the birds to lay eggs with shells so thin that they often broke in the nest.

DDT exposure led to dramatic population declines among bald eagles, ospreys and other raptors across the U.S. They gradually began to recover after the Environmental Protection Agency banned most uses of DDT in 1972.

Ingesting plastic can harm wildlife without causing death via starvation or intestinal blockage. But subtler, sublethal effects, like those described above for DDT, could be much farther-reaching.

Numerous laboratory studies, some dating back a decade, have demonstrated chronic effects on invertebrates, mammals, birds and fish from ingesting plastic. They include changes in behavior, loss of body weight and condition, reduced feeding rates, decreased ability to produce offspring, chemical imbalances in organisms’ bodies and changes in gene expression, to name a few.

However, laboratory studies are often poor representations of reality. Documenting often-invisible, sublethal effects in wild animals that are definitively linked to plastic itself has remained elusive. For example, in 2022, colleagues and I published a study that found that some baleen whales ingest millions of microplastics per day when feeding, but we have not yet uncovered any effects on the whales’ health.

Scarring seabirds’ digestive tracts

The Adrift Lab’s research focuses on the elegant flesh-footed shearwater (Ardenna carneipes), a medium-size seabird with dark feathers and a powerful hooked bill. The lab studied shearwaters nesting on Lord Howe Island, a tiny speck of land 6 miles long by one mile wide (16 square kilometers) in the Tasman Sea east of Australia.

This region has only moderate levels of floating plastic pollution. But shearwaters, as well as petrels and albatrosses, are part of a class known as tube-nosed seabirds, with tubular nostrils and an excellent senses of smell. As I have found in my own research, tube-nosed seabirds are highly skilled at seeking out plastic debris, which may smell like a good place to find food because of algae that coats it in the water. Indeed, the flesh-footed shearwater has one of the highest plastic ingestion rates of any species yet studied.

Marine ecologist Jennifer Lavers, head of the Adrift Lab, has been studying plastic debris consumption in this wild shearwater population for over a decade. In 2014 the lab began publishing research linking ingested plastic to sublethal health effects.

In 2019, Lavers led a study that described correlations between ingested plastic and various aspects of blood chemistry. Birds that ingested more plastic had lower blood calcium levels, along with higher levels of cholesterol and uric acid.

In January 2023, Lavers’ group published a paper that found multiorgan damage in these shearwaters from ingesting both microplastic fragments, measuring less than a quarter inch (five millimeters) across, and larger macroplastic particles. These findings included the first description of overproduction of scar tissue in the birds’ proventriculus – the part of their stomach where chemical digestion occurs.

This process, known as fibrosis, is a sign that the body is responding to injury or damage. In humans, fibrosis is found in the lungs of longtime smokers and people with repeated, prolonged exposure to asbestos. It also is seen in the livers of heavy drinkers. A buildup of excessive scar tissue leads to reduced organ function, and may allow diseases to enter the body via the damaged organs.

A new age of plastic disease

The Adrift Lab’s newest paper takes these findings still further. The researchers found a positive relationship between the amount of plastic in the proventriculus and the degree of scarring. They concluded that ingested plastic was causing the scarring, a phenomenon they call “plasticosis.”

Many species of birds purposefully consume small stones and grit, which collect in their gizzards – the second part of their stomachs – and help the birds digest their food by pulverizing it. Critically, however, this grit, which is sometimes called pumice, is not associated with fibrosis.

Scientists have observed associations between plastic ingestion and pathogenic illness in fish. Plasticosis may help explain how pathogens find their way into the body via a lacerated digestive tract.

Seabirds were the first sentinels of possible risks to marine life from plastics: A 1969 study described examining young Laysan albatrosses (Phoebastria immutabilis) that had died in Hawaii and finding plastic in their stomachs. So perhaps it is fitting that the first disease attributed specifically to marine plastic debris has also been described in a seabird. In my view, plasticosis could be a sign that a new age of disease is upon us because of human overuse of plastics and other long-lasting contaminants, and their leakage into the environment.

In 2022, United Nations member nations voted to negotiate a global treaty to end plastic pollution, with a target completion date of 2024. This would be the first binding agreement to address plastic pollution in a concerted and coordinated manner. The identification of plasticosis in shearwaters shows that there is no time to waste.

Matthew Savoca, Postdoctoral researcher, Stanford University

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