The detection of microplastic particles in human blood has been confirmed by multiple peer-reviewed studies, most notably a 2022 study published in Environment International that detected particles in 77% of participants. Subsequent research has confirmed and extended these findings. What remains under active investigation is the health consequence of this exposure — no study has yet established a causal link between blood microplastics and specific disease outcomes in humans.
The Claim
Social media posts and health-focused content frequently state that "microplastics have been found in human blood," often accompanied by alarming claims about health consequences. We investigated both the factual basis of the detection claim and the current state of evidence on health effects.
The Detection Evidence
The landmark study was published in March 2022 by Leslie et al. in the journal Environment International. Researchers collected blood samples from 22 anonymous, healthy adult donors in the Netherlands and analyzed them using pyrolysis gas chromatography-mass spectrometry — a technique that can identify plastic polymers at very low concentrations.
Microplastic particles were detected in 17 of 22 samples (77%). The most common types identified were polyethylene terephthalate (PET, used in plastic bottles), polystyrene, and polyethylene. Concentrations ranged from 1.1 to 7.4 micrograms per milliliter of blood.
Subsequent studies have confirmed the presence of microplastics in other human tissues including the lungs, placenta, liver, kidney, and — in a 2024 study — arterial plaque. The evidence that microplastics enter and circulate within the human body is now well-established in peer-reviewed literature.
What Remains Unknown: Health Effects
The more difficult question — and the one most commonly overstated in popular media — is whether the concentrations of microplastics detected in human tissue cause measurable harm. This is where the science is genuinely less settled.
A 2024 study in the New England Journal of Medicine found that patients with microplastics detectable in carotid artery plaque had a higher risk of heart attack, stroke, and death over a follow-up period compared to those without detectable plastics. This was the first human study to suggest a potential clinical consequence. However, it was observational — meaning it cannot establish that the microplastics caused the adverse outcomes, only that the two were associated.
Bottom Line
Microplastics have been found in human blood. This is confirmed by multiple peer-reviewed studies using rigorous analytical methods. The health implications of this exposure are an active and important area of research, with early signals of possible harm, but causation has not been established. Claims that microplastics "definitely cause" specific diseases go beyond what the current evidence supports.
Primary Sources
- Leslie HA, et al. Discovery and quantification of plastic particle pollution in human blood. Environment International. 2022.
- Amato-Lourenco LF, et al. Presence of airborne microplastics in human lung tissue. JAMA Network Open. 2021.
- Marfella R, et al. Microplastics and nanoplastics in atheromas and cardiovascular events. New England Journal of Medicine. 2024.
- WHO. Dietary and inhalation exposure to nano- and microplastic particles. WHO.int. 2022.