Polymer prioritization framework: A novel multi-criteria framework for source mapping and characterizing the environmental risk of plastic polymers

Abstract

Plastics are an intrinsic part of modern life with many beneficial uses for society. Yet, there is increasing evidence that plastic and microplastic pollution poses a risk to the environment and human health. Microplastics are increasingly grouped as a complex mix of polymers with different physicochemical and toxicological properties. This study attempts to assess the hazardous properties of common polymer types through the development of an integrated multi-criteria framework. The framework establishes a systematic approach to identify plastic polymers of concern. A semi-quantitative method was devised using twenty-one criteria. We used a case study from Victoria, Australia, to evaluate the effectiveness of the framework to characterize the environmental risk of common polymer types. A wide range of data sources were interrogated to complete an in-depth analysis across the material life cycle. We found that three polymers had the highest risk of harm: polyvinyl chloride, polypropylene, and polystyrene; with dominant sectors being: building and construction, packaging, consumer and household, and automotive sectors; and greatest leakage of plastics at the end-of-life stages. Our findings illustrate the complexity of microplastics as an emerging contaminant, and its scalability supports decision-makers globally to identify and prioritize management strategies to address the risks posed by plastics. ENVIRONMENTAL IMPLICATION: The hazardous nature of mismanaged plastics is an international concern. The negative impacts on the environment and human health are increasingly coming to light. Consequently, resource constraints limits the ability to address all problems. Our work adopts a holistic approach to evaluate the risk of harm from microplastics across the entire life cycle to allow for targeted management measures. The hazard assessment of common polymer types developed using a multi-criteria framework, presents a systematic approach to prioritize polymers at any scale. This allows for the development of optimal investments and interventions to ensure that high-risk environmental problems are addressed first.

Keywords: Decision framework; Life cycle; Material flow; Microplastics; Plastic pollution; Polymer; Source mapping.