University scientists contribute to international report on microplastic risk

Scientists from the University of Plymouth have contributed to a major European report summarising the current science on risks to humans and environment posed by microplastics.

The Evidence Review Report, published by SAPEA (Science Advice for Policy by European Academies), suggests microplastics and nanoplastics do not currently pose a widespread risk except in small pockets.

But that evidence is limited, and the situation could change if pollution continues at the current rate.

The report will inform the forthcoming scientific opinion from the European Commission’s Group of Chief Scientific Advisors, due in 2019, with that opinion being delivered directly to European Commissioners to help inform policy-making.

The experts who produced the report were nominated by academies across Europe. They included Associate Professor (Reader) in Psychology Dr Sabine Pahl and Professor Richard Thompson OBE, Head of the International Marine Litter Research Unit, who presented it to a meeting of the G7 in Washington.

They have collaborated on a number of research projects in recent years, highlighting the presence of microplastics and in particular, public attitudes towards them.

She said:

“This report is unique in that it brings together natural, political, social and behavioural science perspectives. It represents a real step forward because tackling the issues associated with plastic pollution is not just about harm and technology, but about a complex interrelated system of many different actors in society.

“As researchers, recognising this human dimension is crucial in moving forward because we need to understand what potential solutions will be accepted widely, slot in easily with current practices and have the least unexpected side effects. Bans and legislation are part of this process but changing hearts and minds could lead to more long term and sustainable transitions in behaviour and processes in the system.

“From the meeting in Brussels, we took away a large number of questions and our challenge is to provide the policy makers with the answers. At the University of Plymouth we have a culture of interdisciplinarity and integrative research so we are in a good position to address this challenge.”

The SAPEA report’s authors draw on a comprehensive examination of the best available evidence from the natural sciences and computer modelling, but link this to political, social and behavioural science insights.

They highlight that microplastics – first identified by Professor Thompson in a seminal piece of research published in 2004 – are already present across air, soil and sediment, freshwaters, seas and oceans, plants and animals, and in several components of the human diet. These particles come from a variety of sources, including plastic products, textiles, fisheries, agriculture, industry and general waste.

The report also notes that, in controlled experiments, high concentrations of these particles have been shown to cause physical harm to the environment and living creatures, including inducing inflammation and stress.

However, the authors point out that concentration levels measured in many real-world locations are well below this threshold – though there are also limitations in the measurement methods currently available.

Meanwhile, in other parts of the environment, there is no reliable evidence about the levels or effects of these particles, for example on human health. This is true especially of nanoplastics, which are very difficult to measure and evaluate.

In terms of social processes, the report reviewed media reporting on the topic of microplastics and concluded coverage had increased substantially recently. Media reporting shapes societal perception and action and the authors pointed out that different societal actors can differ greatly in how they assess risks.

For example, experts might look at toxicological thresholds whereas beach visitors might consider the moral ‘wrongness’ of plastic particles in the marine environment.

The report also pointed out that we need more analysis and quantification of behaviours that are linked to plastic pollution. We need to understand the impact of specific behaviours better so we don’t end up encouraging only symbolic behaviours, and look at impact together with feasibility.

The authors reviewed a range of determinants of behaviour from the psychological literature, stressing that knowledge alone is definitely not a powerful motivator. Merely giving people information about the problem is not enough to trigger change.

Analysing human decisions and behaviours will help define effective solutions to micro- and macro-plastic pollution that harness individual motivations and values as well as social dynamics. The SAPEA report draws on the social and behavioural sciences alongside the natural sciences to inform policy.

<p>A clump of acryllic fibres seen under microscopes at the University's Electron Microscopy Centre</p>
A clump of acrylic fibres seen under microscopes at Plymouth Electron Microscopy Centre
Marine litter
Our research furthers the understanding of litter on the environment and defining solutions

Professor Bart Koelmans, chair of the SAPEA working group that wrote the report, said:

“The evidence about nano- and microplastics remains uncertain, and it is by its nature complex, but so far there is no good reason to think they pose widespread risks to humans or the environment. Of course, a lack of evidence for risk doesn’t mean we should assume that there is no risk.

“As our social science colleagues have pointed out, it’s vital that we communicate clearly about uncertainties in the evidence, rather than just assuming that everything is fine just because we don’t know for sure. But one thing is for certain: concentrations of microplastics in the environment are increasing. If we keep polluting at the current rate, we will have a real problem in the future.”

Professor Sierd Cloetingh, Chair of the SAPEA board, added:

“Our report is extremely timely, given the significant level of interest in this critically-important topic. SAPEA has brought together world-class expertise from across a wide range of disciplines to consider the issues at stake. I look forward to SAPEA’s future collaborations with the European Commission’s Group of Chief Scientific Advisors, ensuring that scientific advice is informed by expertise from academies across Europe.”

International Marine Litter Research Unit

Marine litter is a global environmental problem with items of debris now contaminating habitats from the poles to the equator, from the sea surface to the deep sea.

Furthering our understanding of litter on the environment and defining solutions

Find out more about the International Marine Litter Research Unit