An Effect Factor for Macro- and Microplastic Ingestion Impacts on Marine Ecosystems for Use in Life Cycle Impact Assessment

Method

What this research did

This study compiled the largest dataset on plastic ingestion in marine vertebrates to date, drawing from population-level ingestion prevalence data of macro- and microplastic debris from peer-reviewed literature and global databases. By delineating species ranges across eight major ocean basins, we estimated species-specific exposure to floating plastic debris and derived dose-response relationships linking ingestion prevalence to plastic concentration.

A field-based species sensitivity distribution was constructed from these relationships, yielding a global effect factor expressed as the potentially affected fraction (PAF) of species per unit of plastic concentration, covering both macro- and microplastics as a single, combined impact pathway for the first time.

Significance

Why this research matters

Plastic ingestion is the most widespread and well-documented mechanism by which marine species are affected by plastic pollution, yet it has remained absent from Life Cycle Impact Assessment. This effect factor fills a critical gap by allowing plastic ingestion to be assessed alongside other stressors, such as ecotoxicity and climate change, within the same sustainability framework. Combined with the existing entanglement effect factor, it now enables comprehensive coverage of macroplastic physical impacts in LCA, directly supporting more credible environmental assessments of plastic products and policies.

The way forward

The way forward

Several important limitations of this work point toward the next frontiers of research. First, this study is restricted to marine air-breathing vertebrates — a well-studied but narrow slice of the species affected by plastic ingestion globally. Fish, invertebrates, and benthic organisms are known to ingest plastics at scale but remain unaccounted for.

Second, the framework does not yet extend to terrestrial ecosystems: soil organisms, freshwater species, and land-based vertebrates all encounter plastic debris, yet no equivalent effect factors exist for these compartments. Third, the effect factor is grounded in ingestion prevalence rather than measured biological consequences — it captures exposure, not harm. Translating ingestion into actual physical effects (gastrointestinal impaction, starvation, reproductive failure, mortality) at the population level remains a fundamental methodological challenge that future models will need to address. Finally, the geographic coverage of the underlying data is uneven: records from Africa, Asia, and the Southern Ocean are severely underrepresented, likely masking significant impacts on endemic and range-restricted species. Closing these gaps — through expanded field monitoring, cross-taxonomic modeling, and effect-based dose-response frameworks — is essential if plastic ingestion impacts are to be fully integrated into Life Cycle Assessment and used as a credible basis for policy.