Global Plastic Waste Trade May Amplify Microplastic Pollution, Study Finds

International plastic waste trade could be contributing to microplastic pollution when exported material is processed through poorly controlled recycling, dumping or open burning, according to a new scientific review published in npj Emerging Contaminants.

MONTREAL (Scrap Monster): Global trade in plastic waste could be amplifying microplastic pollution by shifting discarded material into regions where recycling, dumping and disposal systems may not adequately control environmental leakage, according to a new research review.

The review, published September 2 in npj Emerging Contaminants, examines how international plastic waste flows can contribute to the generation and redistribution of microplastics across terrestrial, aquatic and atmospheric environments.

The researchers argue that the environmental consequences of plastic waste do not end when material is exported for recycling. The conditions under which that material is sorted, processed, recycled or discarded can determine whether it remains in a controlled material stream or fragments into smaller plastic particles.

What the Study Actually Estimates

The review estimates that approximately 14 million tonnes of plastic waste are traded globally each year.

Depending on regional waste-management conditions, researchers estimate that roughly 20% to 60% of that material may be mismanaged. This corresponds to approximately 3 million to 8 million tonnes potentially entering uncontrolled waste pathways annually.

The paper also presents an illustrative mass-flow scenario in which up to 60% of traded plastic waste is mismanaged and approximately 26% of that mismanaged fraction fragments into microplastics over a decade.

Under those assumptions, roughly 2.2 million tonnes of the approximately 14 million tonnes traded globally could eventually become microplastic releases.

That is equivalent to about 15% to 16% of the total traded volume, but the researchers caution that the calculation carries substantial uncertainty because fragmentation rates vary by polymer type, environmental conditions and waste-management practices.

China’s 2018 Import Restrictions Reshaped Global Waste Flows

The geography of the international plastic waste trade changed substantially after China introduced its National Sword policy in 2018, restricting imports of plastic and other waste.

Plastic scrap flows subsequently shifted toward Southeast Asia, Turkey, Mexico and parts of Africa.

The review argues that some receiving regions face limited waste-management infrastructure, which can increase the likelihood of informal recycling, illegal dumping, open burning and other poorly controlled treatment methods.

Between 2016 and 2018, plastic waste exports from high-income countries to Southeast Asia increased sharply, according to data reviewed by the researchers.

Packaging Design Can Make Recycling More Difficult

Packaging represents one of the most significant uses of plastic globally, although the researchers caution that available trade data does not allow the precise share of packaging within global plastic waste exports to be calculated.

Flexible films, multilayer laminates, sachets and mixed-material packaging are considered particularly challenging because they can be difficult to sort, separate and recycle economically.

Complex combinations of polymers and additives can reduce recycling efficiency and increase the likelihood that lower-value material is discarded, burned or processed under less controlled conditions.

The researchers therefore call for greater use of simpler mono-material packaging systems, reduced use of unnecessary multilayer structures and improved transparency around polymer and additive composition.

Recycling Processes Can Also Release Microplastics

The review stresses that recycling itself is not automatically free of microplastic emissions.

Mechanical recycling processes such as shredding, grinding and washing can generate small plastic particles, particularly where facilities lack effective containment, filtration or wastewater controls.

The researchers point to closed-loop water systems, particle-capture technologies, improved dust controls and systematic monitoring as potential ways to reduce unintended emissions from recycling plants.

This does not mean recycling should be avoided. Instead, the study argues that recycling systems should be designed to prevent material loss and microplastic generation throughout processing.

What This Means for Recyclers and Waste Operators

For recycling companies, the findings shift part of the discussion from simply measuring tonnes collected or processed toward examining what happens to material throughout the full recycling chain.

Facility controls around shredding, washing, wastewater, dust and residual material could become increasingly important as regulators and customers place greater emphasis on preventing microplastic leakage.

Traceability may also become more important for internationally traded material. Knowing where exported plastic ultimately goes, how it is processed and whether the receiving facility meets appropriate environmental standards could become a larger part of demonstrating responsible recycling.

Researchers Call for Stronger Traceability and Producer Responsibility

The review proposes a broader science-policy framework linking international waste trade, environmental monitoring and microplastic mitigation.

Among the recommended measures are stronger shipment traceability, improved monitoring of environmental releases and more effective extended producer responsibility systems.

Extended producer responsibility places greater responsibility on companies that place packaging and other plastic products on the market for their collection and end-of-life management.

The researchers also argue that recyclability alone is not sufficient. Product design, collection systems, treatment quality and the final destination of discarded material all influence whether plastic remains in a circular material system or escapes into the environment.

Significant Research Gaps Remain

The authors emphasize that evidence directly quantifying the relationship between global plastic waste trade and microplastic pollution remains limited.

Current models often do not fully incorporate international waste flows, informal recycling, open dumping or the microplastic emissions associated with processes such as open burning and mechanical recycling.

More standardized monitoring, reporting and environmental assessment will be needed to quantify how much microplastic pollution can be directly attributed to traded plastic waste.

The review also notes that while microplastics have been detected in food, drinking water and human tissues, significant uncertainty remains around the long-term human-health risks associated with exposure.

Waste Trade Is Becoming a Broader Supply-Chain Issue

The findings place international waste trade within a broader debate over whether environmental responsibility should follow material beyond national borders.

Exporting plastic for recycling can reduce domestic disposal requirements, but the environmental benefit depends on whether the material is ultimately managed under conditions that prevent leakage, uncontrolled burning and fragmentation.

For the recycling industry, the study reinforces a growing focus on material traceability, design for recycling, stronger processing controls and investment in waste-management infrastructure across both exporting and receiving markets.