Predicting the global environmental distribution of plastic polymers

Area of Science:

• Environmental Science
• Environmental Chemistry
• Ecotoxicology

Background:

• Plastic pollution is a significant global environmental issue.
• Understanding the mass distribution and accumulation of various plastic types is crucial for effective mitigation strategies.

Purpose of the Study:

• To provide the first quantitative global prediction of the mass distribution of six widespread polymers, plastic fibers, and rubber.
• To identify environmental compartments and sub-compartments where these materials accumulate.
• To establish baseline data for plastic transport, accumulation, ecotoxicity studies, and risk assessments.

Main Methods:

• Probabilistic material flow analysis for the year 2015.
• Utilized literature-derived input values and transfer coefficients between environmental compartments.
• Quantified mass distribution across four environmental compartments and 11 sub-compartments.

Main Results:

• Estimated annual environmental input of 3.2 Mt polyethylene, 1.3 Mt polypropylene, 0.5 Mt polystyrene, 0.3 Mt polyvinyl chloride, 1.6 Mt polyethylene terephthalate, and 2.4 Mt plastic fibers.
• Predicted accumulation of 4.9 Mt in soil, 4.8 Mt in oceans, and 1.8 Mt in freshwater systems (including rubber).
• Identified urban soils (33%) and ocean shorelines (25%) as major plastic accumulation hotspots; freshwater and ocean floors are hotspots for dense plastics.

Conclusions:

• This study provides critical quantitative data on the global distribution and accumulation of diverse plastic materials in the environment.
• Findings highlight specific environmental compartments and locations as critical accumulation zones, informing targeted pollution control efforts.
• The generated data serves as a foundation for future research in plastic ecotoxicity and risk assessment, aiding in the development of effective plastic pollution mitigation strategies.