This toxic and persistent pollutant must be dealt with globally, say experts

The first study to coin the term “microplastics” was published in the journal Science 2 decades ago. Now, a new review by the same team argues we have enough evidence to inform our approach to tackle the global microplastics “pollution crisis.”

Microplastics, tiny pieces of plastic less than 5 millimeters in length, are a pervasive and persistent pollutant found throughout the environment. A new review, published in the journal Science, argues that we now have enough evidence to inform our approach to tackling the global microplastics "pollution crisis."

“In our view, science will be just as important guiding the way towards solutions as it has been in identifying the problems,” write the authors in their new paper.

The first study to coin the term "microplastics" was published in Science 2 decades ago. Now, the same team is calling for urgent action to address the problem of microplastics.

“Microplastics are solid plastic particles about half the size of a typical rice grain or smaller,” they write. “They originate from the manufacture of microplastics that are intentionally added to products, or from the breakdown of larger plastics during their use, waste management, or degradation in the environment.”

Existing national legislation alone is insufficient to address the problem of microplastics, they say, but the United Nations’ Plastic Pollution Treaty, which will undergo its 5th round of deliberations in November, presents a “tangible opportunity” for international action.

Richard Thompson, head of the International Marine Litter Research Unit at the University of Plymouth, UK, who led the review, says that after 20 years of research there is clear evidence of harmful effects from microplastic pollution on a global scale.

“That includes physical harm to wildlife, harm to societies and cultures, and a growing evidence base of harm to humans,” he says.

“Added to that is the fact that microplastics are persistent contaminants, and once in the environment they are virtually impossible to remove. There are still unknowns, but during the 20 years since our first study the amount of plastic in our oceans has increased by around 50%, only further emphasising the pressing need for action.”

Professor Sally Gaw of the University of Canterbury, New Zealand, who was not involved in the research says the authors argue for a “multi-disciplinary approach” to tackling the global microplastic pollution that integrates science and economics and social strategies.

“We have done this before to address other persistent and toxic pollutants, including organochlorine pesticides and asbestos. We can and must do this again,” she says.

“The key to stemming the release of plastics and ultimately microplastics will be choosing wisely – when is it appropriate or necessary to use plastics and if we need to use plastics what are the best strategies to reduce harm?”

Dr Joel Rindelaub of the University of Auckland, who was not involved in the research, says that plastic pollution doesn’t really disappear, it just breaks down into smaller and smaller pieces.

“Unfortunately, microplastic mitigation strategies have not developed to a level that can adequately address environmental plastic pollution.

“Thus, many researchers believe the most effective strategy to reduce plastic pollution would be to focus on preventative measures, as plastic production is currently increasing exponentially on a global level.

“Preventative strategies, like decreasing plastic production, have encountered several challenges, highlighting the importance of collaborative efforts between industries, governments, and consumers to limit plastic pollution and reduce risk to both humans and the environment.”

The review highlights the need for better sampling approaches and refinement in how microplastics are defined and categorised, which has hindered regulatory efforts so far.

Work towards a legally binding, international agreement on plastic pollution – based on a comprehensive approach that addresses the full life cycle of plastic, including its production, design, and disposal – has been underway since 2022. The fifth session of the Intergovernmental Negotiating Committee is scheduled for 25 November to 1 December 2024 in Busan, Republic of Korea.