An increasing number of peer-reviewed articles has reported the presence of microplastics in the human body, including the brain (FPF reported), blood (FPF reported), heart (FPF reported), central nervous system (FPF reported), placenta (FPF reported), and testis and semen (FPF reported). In addition, micro- and nanoplastic exposure has been associated with disease outcomes such as inflammatory bowel disease (FPF reported), autism spectrum disorder (FPF reported), and cancer (FPF reported and here). But how trustworthy are these findings, and what are their implications?
In a Nature commentary article published on March 10, 2025, Jun-Li Xu, associate professor at University College Dublin, and his three co-authors, outline how to arrive at robust science allowing for effective regulation and protection of human and environmental health. The authors highlight that most of the studies on microplastic presence in humans are based on small sample sizes (<50 samples) and lack the appropriate controls to demonstrate microplastics did not originate from inadvertent contamination during sampling or processing. Furthermore, studies often lack biological plausibility, for example when particles >10µm are reported that can probably not enter human tissues due to their large size.
To advance microplastic research and arrive at robust conclusions, the scientists call for an interdisciplinary working group that “could encourage cross-disciplinary collaboration, and help to establish standards and develop consensus around what is biologically plausible.” They propose that the working group generates a checklist on what researchers need to report when submitting their manuscript, e.g. to make sure that the risk of contamination is minimized. In addition, Xu and co-authors highlight data sharing to verify results independently and communicate the limitations of studies.
Reference
Xu, J. -L., et al. (2025). “Are microplastics bad for your health? More rigorous science is needed Are microplastics bad for your health? More rigorous science is needed.” Nature. DOI: 10.1038/d41586-025-00702-2
