Are our bodies really full of microplastics? Why a scientific ‘bombshell’ is a call for better methods, not a reason to dismiss the plastic crisis.
By Zengbo Wang, Bangor University
Over the past few years, a wave of alarming headlines has suggested that human bodies are rapidly becoming reservoirs for plastic pollution. High-profile studies have claimed to detect micro- and nanoplastics (MNPs) in human blood, placentas, arteries, testes, and even brain tissue.
However, a fierce debate has recently erupted within the scientific community, throwing many of these discoveries into doubt. Experts warn that several of these studies suffer from severe methodological flaws, leading to false positives and exaggerated concentrations. One chemist even described the doubts as a “bombshell” that forces us to re-evaluate what we actually know about microplastics in the body.
The false positive problem: When fat masquerades as plastic The primary challenge in measuring MNPs in human tissue is their microscopic size, which pushes the absolute limits of today’s analytical technology. A major flashpoint in this debate centres around a widely used technique called Py-GC-MS, which involves heating a sample until it vaporises to identify its molecular weight.
The problem? Human tissue is full of natural fats (lipids) that can produce chemical signals nearly identical to those of common plastics like polyethylene and PVC. This flaw was brutally highlighted in response to a widely publicised study claiming microplastic levels in human brains were rapidly rising. Critics pointed out that the human brain is approximately 60% fat, making it highly susceptible to false positives. One leading environmental analytical chemist bluntly labelled the brain study a “joke,” while others noted it is biologically implausible for particles of the reported size (3 to 30 micrometres) to cross into the bloodstream and organs in such massive volumes.
A world saturated in plastic: The contamination conundrum Beyond analytical misidentifications, researchers face an existential hurdle: we live in a world coated in plastic, making background contamination practically unavoidable.
Biological samples are extraordinarily vulnerable; medical operating theatres, where solid tissue samples are usually taken, are notoriously “full of plastic”. Critics argue that many studies—often led by medical professionals rather than specialised analytical chemists—failed to employ “standard good laboratory practices”. Crucial steps, such as running rigorous “blank” control samples to properly account for background contamination, were frequently overlooked in the rush to publish.
The call for a ‘forensic’ approach To ensure the integrity of future research, a coalition of over 30 international scientists, led by Imperial College London and the University of Queensland, has urgently called for the adoption of a “forensic science approach”.
Because no single measurement technique is perfect, this framework urges laboratories to combine multiple, independent testing methods on the exact same samples. By mirroring the rigorous standards of forensic laboratories—meticulously controlling contamination and clearly communicating confidence levels—scientists can ensure that early, suggestive data is no longer presented as definitive proof. As Professor Leon Barron of Imperial College London notes, “Finding ‘something’ in the human body is not the same as proving it is plastic, and certainly not the same as proving it is harmful”.
The political and public health stakes The stakes of getting this science right are incredibly high. Poor-quality evidence has fuelled public scaremongering, leading to predatory businesses offering unscientific, expensive treatments—sometimes costing up to £10,000—that falsely claim to “clean” microplastics from the blood.
Conversely, the petrochemical industry and lobbyists may seize upon these methodological debates to sow doubt about the broader harms of plastic pollution. Recognising the need for bulletproof data to inform policy, lawmakers in the United States have recently introduced bipartisan legislation such as the proposed Microplastics Safety Act and the Plastic Health Research Act to mandate and fund comprehensive federal research.
Science working exactly as it should What we are witnessing is not the debunking of the plastic crisis, but the vital, sometimes messy process of scientific self-correction. We know definitively that humans are exposed to MNPs daily through our environment, food, and water. Now, we must support the painstaking, rigorous work required to discover exactly how much plastic is inside us, and what it is doing to our health, so that society can take effective, evidence-based action.
References:
• Carrington, D. (2026). ‘A bombshell’: doubt cast on discovery of microplastics throughout human body. The Guardian.
• Packaging Europe. (2026). ‘Bombshell’ article casts doubt on studies of microplastics in the human body.
• Stewart, J. & O’Hare, R. (2026). Experts urge caution over microplastics in tissue claims and call for forensic approach to improve accuracy. Imperial College London News.
• The Acta Group. (2025). Microplastics in 2025: Regulatory Trends and Updates.
• Wikipedia Contributors. Microplastics and human health. Wikipedia, The Free Encyclopedia.