Plastic pollution is currently one of the most pressing environmental issues in the world, as thousands of plastic products produced every day overwhelm countries’ efforts to recycle them. This issue is so worrisome that it has incited efforts to write a global treaty negotiated by the United Nations. Approximately, 8 million tons of plastic waste escapes into the oceans every year. Pressed to find viable solutions to this ever-growing problem, the UN Environment Programme (UNEP) and the International Water Management Institute (IWMI) released a study in December 2020, which offered numerous methods and solutions to tackle the plastic pollution crisis in our waters. We spoke to Javier Mateo-Sagasta, Senior Researcher and Coordinator – Water Quality, IWMI, to learn more about the risks of plastic pollution.
Question: UNEP and IWMI jointly developed a study on water pollution by plastics and microplastics: A review of technical solutions from source to sea. Is plastic pollution a worldwide pressing issue? And if yes, why so?
Answer: Absolutely. More than 8.3 billion tons of plastic have been produced to date, with growing levels piling up in landfills and impacting the environment. With the amount of plastics expected to reach 12 billion tons by 2050, it is clear that plastic pollution is already an urgent and growing problem.
Plastic debris is a major challenge. Research shows how it can harm landscapes and endanger wildlife and ecosystems. The Covid-19 pandemic has exacerbated this issue, with a significant rise in single-use plastic and disposable masks.
But once larger plastic items and textiles are in the environment, they tend to degrade to smaller particles over time through natural weathering processes, which creates a whole new problem. Each kilogram of plastic can break down to potentially billions of particles of microplastic – measuring 5mm or less.
While less is known about the long-term impacts of microplastics, they are already ubiquitous in the environment and there is growing concern about the threat they may pose to human health, animals and ecosystems.
One thing is for sure: the world need not and should not wait for microplastics to become an irreversible problem before dealing with them. And the recent study from UNEP and IWMI explores technical solutions for doing just that.
Q) How does plastic pollution harm our waters?
A) Of all the plastic waste ever produced, it’s estimated that only nine per cent is recycled. The rest ends up in landfills, dumps and the environment, and often finds its way into rivers, lakes and oceans.
Microplastics are sometimes intentionally added to products, including in certain cosmetics, seed coatings, paint and washing powders. They are also generated through natural weathering processes, general wear and tear, synthetic textile production and tire usage.
Approximately eight million tons of plastic litter flow to the ocean every year, with two thirds of primary microplastics in the oceans believed to have originated from eroding tires and washing synthetic fabrics, which releases fibers into the water.
Potential hazards associated with microplastics can be physical, chemical or biological; the particles have the potential to cause gut or respiratory problems in animals, for example, or carry toxic chemicals.
Q) What is the main goal of this study and who is the target audience?
A) By looking at some of the most effective technical solutions currently in use to reduce plastic contamination from source to sea, the study aims to equip policymakers and practitioners with context-specific information to help them make better decisions about how to address the issue of plastic pollution.
There is no “ one size fits all” solution to tackling plastic and microplastic pollution. Where there is data available, the report explores effectiveness and capital expenditure along with operation and maintenance costs of various technologies, reviewing their suitability under different conditions.
We hope that decision makers will use it as a resource to set priorities on tackling plastic pollution sustainably, and to implement the solutions that best fit their local context.
Q) The study focuses on wastewater management. Why is wastewater treatment key to reduce plastic and microplastic pollution from the source to the sea?
A) There are a number of pathways through which plastics and microplastics can enter water bodies, such as via run-off from land and roads, and through wastewater. Wastewater produced in urban residential, domestic, commercial and industrial settings is full of contaminants including plastics. A key part of tackling plastic pollution involves stopping untreated wastewater – often packed with these minuscule particles – from entering the environment in the first place.
While treating wastewater is the norm in many developed countries, it is the exception in low- and middle-income countries. The report reviews the costs and effectiveness of removing plastics and microplastics via different wastewater treatment technologies, but it goes beyond. The study also looks at solutions to prevent contamination at the source, treat wastewater and run-off before they reach treatment plants, treat contaminated sewage sludge and treat freshwater. There is also a section to help guide the selection of cost-effective combinations of technologies for specific local contexts.
Q) What innovative tech solutions does the study highlight to address water contamination by plastics and microplastics?
A) The study explores 24 technical solutions for managing plastic and microplastic contamination of water, which include:
- Introducing debris-cleanup boats, debris sweepers and sea-bins to remove plastics and other wastes carried into water bodies;
- Protecting large bodies of water by introducing wetlands along coastlines;
- Secondary and tertiary wastewater treatment which relies on membrane filtration to prevent microplastics entering rivers and lakes;
- Advanced coagulation technology to make water contaminated with microplastics drinkable;
- Promoting sustainable waste management practices to reduce plastic leakage.
Q) Why is it important for policymakers to provide not only technical solutions, but also appropriate legislation, economic instruments, education, awareness campaigns and research to reduce plastic pollution?
A) Although policy tools and behavioral change campaigns were not a major focus of the report, they are key to backing up technical solutions and ensuring that they can be implemented effectively.
For instance, policy tools such as levies or bans can help limit or prevent the use of plastic items such as plastic bags or other single-use plastics.
Consumer decisions also affect the volume of microplastics released into the environment. Public education programs can help improve general understanding of plastic pollution, as well as encouraging changes in consumer attitudes and practices. Targeted messaging that prioritizes gender-sensitivity and highlights the links between consumer choices and waste, is key.
Supporting and investing in more research on the impact of microplastics is key to tackling this global issue. Fully understanding the health and environmental risk they pose – both presently and looking ahead to the future – is essential so that governments and other authorities can set water quality standards and make informed decisions to prevent pollution.
Q) What countries or regions are at the forefront in tackling this type of water pollution?
A) On the one hand, in many developing countries, waste recycling is almost non-existent and tends to be informal, largely due to the cost of technologies and a lack of capacity to pay for operation and maintenance. In Africa and Asia, for example, between 70-85 per cent of plastic waste is estimated to be mismanaged.
On the other hand, in regions like North America, Europe and Oceania, per capita plastic use is higher, but plastic waste is better managed. Here we are starting to see some promising initiatives. In the Netherlands, for instance, 24 per cent of municipal waste is recycled and 27 per cent composted. Most of the rest is incinerated, which allows for energy to be recovered – mainly through electricity generation. In Sweden, the government is considering introducing a tax on harmful chemicals in clothing and shoes, to ensure that only high-quality textiles are used.
These and other emerging success stories allow us to be optimistic, and we hope our recent report contributes to accelerating change towards a more sustainable future free of plastic waste.
To further explore the technical solutions reviewed in the study, the report authors have additionally published a catalogue of technologies, covering examples of applications, opportunities, barriers and typical costs of implementation. This can be downloaded via the UNEP website.