Fuzzy approaches for the complex problem of microplastic fibre pollution

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Figure 3. Scenario matrix introducing four scenarios developed during workshop

Microplastic fibres make up a significant proportion of marine microplastic pollution. How can we reduce the flow of microfibre pollution?

Jan 26, 2020

Vilde Margrete Salberg, Andy M. Booth, Susie Jahren and Paula Novo

(This post is part of the Plastics theme for the Q1, 2020)

The widespread microplastic pollution of our oceans and coastlines is well documented and governments and consumers have rallied to remove microplastics from selected consumer products, such as microbeads in cosmetics [1]. However, cutting out some types of microplastic can seem like an impossible challenge. Microplastic fibres, shed during washing of clothes and other synthetic textiles [2], make up a significant proportion of marine microplastic pollution [2]. They are ubiquitous in the marine environment, having been found from urban coastlines to the remote Arctic [3, 4]. Although we still know relatively little about their environmental fate and effects, negative impacts have been shown for a range of freshwater and marine organisms and their habitats [5].

Despite increased focus, little attention has been paid to social aspects such as the economic impacts of marine microplastic fibre pollution (e.g. economic losses associated with potential effects on ecosystems and the goods and services derived from them) and the importance of people’s choices regarding consumption and prioritisation of concerns about the issue [6].

Both the scale and large degree of uncertainty around microplastic fibre pollution has made this problem difficult to manage as it transcends economic, social, and ecological systems [7].

Marine microplastic pollution has therefore been defined as a 'wicked' environmental problem owing to the lack of an optimal solution, the potential for unintended consequences of any action due to the difficulties of testing in real ocean conditions, and because it is rooted in both social, ecological and economic systems. A wicked problem is one that is difficult or impossible to solve due to its complex nature.

Story Index
  • Microplastic fibre pollution
  • How can we reduce the flow of microfibre pollution?
  • Fuzzy Cognitive maps as a tool
  • Workshop for FCM of the problem
  • Scenario matrix description
  • Conclusion
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Earthzine announces Plastics theme for first quarter of 2020

Earthzine announces Plastics theme for first quarter of 2020

How can we reduce the flow of microfibre pollution?

Understanding this complex environmental problem requires involvement of relevant stakeholders and interdisciplinary research approaches to develop solutions that are viable to implement [7]. The inclusion of relevant stakeholders from outside academic disciplines is considered important to represent the full spectrum of values and interests in research and policy measures [8].

Figure 1. Stakeholders from industry, state agency and research discussing a system map (FCM) during the workshop about microfibre pollution. Image credit: Susie Jahren.

Figure 1. Stakeholders from industry, state agency and research discussing a system map (FCM) during the workshop about microfibre pollution. Image credit: Susie Jahren.

Approaches such as participatory modelling and scenario development allow for integration of a broader knowledge base and for stakeholder participation throughout the research processes [9], [10]. They also facilitate interdisciplinary participation and can contribute to a more integrated and holistic view of the problem [11]. Here, we have used a combination of Fuzzy Cognitive Mapping (FCM) as a participatory modelling approach and a qualitative scenario development approach to identify key uncertainties and address important research gaps in relation to microplastic fibre pollution.

Fuzzy cognitive mapping

FCM is a tool used to model complex systems and can be based on the perceptions and knowledge of stakeholders contributing to the model-building process [11]. This tool was used to map out the problem to gain a more complete picture and it was also used to run scenarios to see how the modelled system might react to changes [10]. Scenarios were run by first calculating a steady state to see what direction the system might take under current conditions. One or more variables within the model were then clamped to see how the system might change from this steady state under different conditions. FCMs were created through one-on-one interviews. Interview participants were first asked a set of open-ended questions related to the sources, pathways and fate of microplastic fibres to establish the necessary variables. They were then asked to draw lines between the variables to represent how they related to each other. Finally, participants indicated the direction and strength of the links by defining them as either positive (+) or negative (-) relationships and scoring them on a scale of 1 (weak) to 3 (strong). Positive relationships indicate the level of the variable being affected will increase if the level of the variable affecting it increases, while the converse occurs for negative relationships. The FCMs were finalized in a common workshop (Oslo, Norway, 2019) with relevant stakeholders from the textile industry, wastewater treatment plants (WWTPs), the research community and state agencies (Figure 1). Variables relevant for the scenario runs were also identified by the participating stakeholder during the workshop.

Workshop on Fuzzy cognitive mapping of the problem

A total of 20 FCMs were produced prior to the workshop, which included a range of variables representing mitigatory measures (e.g. ‘Domestic mitigation actions’ and ‘Waste management’) and sources (e.g. ‘Domestic laundry’) relevant for microplastic fibre pollution. Based on five stakeholder maps developed through aggregation of the 20 FCMs before the workshop and one community map finalised in the workshop (Figure 2), two different scenarios were run: 1) a green shift in consumption and production of textiles, where the green shift is defined by increased awareness and knowledge among consumers, law makers and industry, leading to stricter regulations and industry routines, as well as innovation and improved waste management, and 2) increased textile consumption and production. Results indicated that the modelled system is highly complex and that individual stakeholder groups viewed the system very differently. All stakeholder groups saw a decrease in microplastic fibre release to marine ecosystems in the Green Shift-scenario. Increased textile consumption and production led to a significant increase in microplastic fibre release and decrease in environmental health. Most of the groups also saw an increase in environmental health under this scenario. By comparing scenario results it was possible to see that the social processes and deliberations in the workshop led participants to rethink and view the system differently.

Figure 2. Community fuzzy cognitive map based on individual stakeholder maps finalised during the workshop

Figure 2. Community fuzzy cognitive map based on individual stakeholder maps finalised during the workshop

Through qualitative scenario development, potential future developments around microplastic fibre pollution and indicators to track the development were investigated. Examples of such indicators include levels of environmental toxins or microplastic fibres in WWTP or marine waters, sale of new textiles and the kind of textile being sold, and product lifetimes.

Scenario matrix description

The scenario development approach followed a four-step process where the driving forces were identified first. Two of these were represented by an axis each, where the ends represented highest and lowest possible levels. The two axes were combined to form a scenario matrix with four scenarios, as shown in Figure 3. After the scenarios were defined, intervention points and indicators to track developments around the problem were deliberated.

The two scenarios on the left side of the matrix were viewed as less desirable, while development along the Green shift axis was viewed as important. Both scenarios on the right side were seen to result in lower releases of microplastic fibres and environmental toxins, but a lack of regulation of production systems in scenario 2.4 was thought to cause a slower development in this direction due to the absence of a level-playing field under this condition. In contrast, scenario 2.2 was considered as creating a level playing field between companies and offering room for new business models to be developed.

Figure 3. Scenario matrix introducing four scenarios developed during workshop

Figure 3. Scenario matrix introducing four scenarios developed during workshop

Findings from the two approaches highlighted key uncertainties and research needs around microplastic fibre pollution. For instance, research needs regarding the environmental impacts of natural fibres in comparison with synthetic fibres was a major focus. Furthermore, the way consumers react to new information about the system and influence policy making was discussed. It was a belief among most of the stakeholder groups that regulation and policies were important leverage points. To track developments within the system and whether or not regulations are efficient, indicators were discussed and more research into the usefulness of these as part of a monitoring system was suggested. Implementation of effective regulations and policies was a central topic in both workshops, and it was agreed that this would be an important step on the path towards reducing microplastic fibre pollution.  

Research needs within several fields were identified, which served to highlight the importance of using interdisciplinary research approaches moving forward. Integrated research on social, economic, environmental and technical aspects needs to be undertaken to attain a deeper understanding of the issue and its potential policy options. Multidisciplinary and multi-stakeholder projects with longer timeframes could serve as arenas for such research. As part of such projects, indicators for monitoring should be identified. These could be indicators for industry and municipalities to monitor, or they could be higher-level indicators for countries or regions to monitor. Development of new business models and the kind of models developed were also suggested as important indicators in this work.

Conclusion

The complex nature of 'wicked' environmental problems requires new interdisciplinary research approaches that can contribute to the creation of adaptable knowledge systems and management methods. Participatory modelling and scenario development have the potential to be valuable tools that enable identification of priority research needs and knowledge gaps inspired by new thinking.

This article has been prepared as part of the MICROFIBRE project, which is funded by the Norwegian Research Council (Grant Agreement No. 268404).

References

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Author biographies:

Vilde Margrete Salberg is a former MSc student in Ecological Economics from the University of Edinburgh. Email: vildem.salberg@gmail.com.

Andy M. Booth is a Senior Researcher in environmental chemistry at SINTEF Ocean, Trondheim, Norway and coordinator of the MICROFIBRE project. Follow on Twitter @norway_badger. Email: andy.booth@sintef.no.

Susie Jahren is a Senior Business Developer at SINTEF Industry with specialisation in sustainable polymers and circular economy.  Follow on Twitter @sintefsusie.  Email susie.jahren@sintef.no.

Paula Novo is a lecturer and researcher in ecological economics at Scotland’s Rural College. She is the Deputy Programme Director of the MSc Ecological Economics at the University of Edinburgh and Scotland’s Rural College. Email: paula.novo@sruc.ac.uk.