Are microplastics in the human body harmful?
Detection of microplastics in human tissue is well established, and the first studies linking them to clinical outcomes are appearing. Causal harm pathways and dose–response relationships are still being characterised — the evidence is leaning but not yet saturated.
Claim
Microplastics at currently observed human tissue concentrations cause measurable harm to human health.
Answer
Microplastics are now reliably detected in human blood and tissues Leslie 2022. A 2024 cohort study found that patients with microplastics in carotid plaque had a higher rate of cardiovascular events Marfella 2024, and mechanistic in-vitro and animal work reports inflammatory and oxidative-stress effects Toxicol 2023.
Reviews caution that exposure characterisation and dose–response curves remain immature Vethaak 2021. The weighted evidence leans toward harm, but the mass is well short of saturation for the domain — the signature of an emerging, not settled, question.
Consensus score
The score is computed deterministically from the citations below, following the methodology in the manuscript (§5). Nothing is hand-tuned per entry — change the evidence and the number moves.
| Citation | sᵢ | mᵢ | tᵢ | e^(−tᵢ/T) | mᵢ·e^(−tᵢ/T) | sᵢ·mᵢ·e^(−tᵢ/T) |
|---|---|---|---|---|---|---|
| Marfella 2024 | +1 | 7.0 | 2y | 0.819 | 5.73 | +5.73 |
| Leslie 2022 | 0 | 4.0 | 4y | 0.670 | 2.68 | +0.00 |
| Vethaak 2021 | 0 | 5.0 | 5y | 0.607 | 3.03 | +0.00 |
| Toxicol 2023 | +1 | 4.0 | 3y | 0.741 | 2.96 | +2.96 |
| Σ over citations | 20.0 | 14.41 Mₚ | +8.69 Xₚ·Mₚ |
Reading it: the verdict is Emerging evidence · Yes. Direction comes only from Xₚ (tanh is always positive); certainty comes from tanh(Mₚ/W₀) = 0.52. Because Cₚ = 50 when Xₚ = 0 regardless of mass, a balanced stalemate and an unstudied question both read as 50 — which is why Mₚ is always shown alongside the score.
Citations · 4
Microplastics and human health
Polystyrene microplastics induce oxidative stress and inflammation in human cell lines
Discovery and quantification of plastic particle pollution in human blood
References
Provenance
Score changelog
Generated from citation evidence| Revision | Score Cₚ | Mass Mₚ | Center Xₚ |
|---|---|---|---|
| Current revision | 66 | 14.4 | +0.60 |
| 28 May 2026 | 66↑ +5 | 14.4 | +0.60 |
| 6 May 2026 | 61 | 11.2 | +0.55 |