Senathirajah · Journal of hazardous materials 2021 · exposure modeling and literature synthesis · n=59 studies

Estimation of the mass of microplastics ingested - A pivotal first step towards human health risk assessment.

Cited 1084 times in the scientific literature.

Level 5 - mechanism / opinion, no new human data

Level 5 by design analogy; theoretical exposure modeling and data synthesis without direct human measurement.

PubMed 33130380 · doi:10.1016/j.jhazmat.2020.124004 · record verified 2026-08-29

What was done

Authors extracted particle count and mass data from 59 published studies covering various sources of microplastic exposure. Using conservative assumptions to standardize the heterogeneous literature, they calculated an average mass for individual microplastics in the 0–1 mm size range and derived a global average human ingestion rate.

What was found

Globally, humans are estimated to ingest an average of 0.1 to 5 g of microplastics per week across various exposure pathways.

Why it matters

This study provides an early attempt to convert heterogeneous microplastic particle counts into a standardized mass metric required for quantitative human toxicological risk assessments.

Limits

The estimate spans a wide 50-fold range (0.1–5 g/week), reflecting high uncertainty. The analysis relies on theoretical modeling and conservative assumptions rather than direct human biomonitoring, excludes particles outside the 0–1 mm range, and did not evaluate clinical toxicity or health outcomes.

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