In Reply

Letters to the Editor regarding the article Microplastics State of the Evidence on Health Effects and Public Perception by Robin Janzik, Holger Sieg, Albert Braeuning, and Gaby-Fleur Böl in issue 20/2025

Our article (1) presents the current state of knowledge on microplastics quite intentionally with a focus on the evidence regarding effects on human health. The effects on, say, climate and environment are important aspects, but they were not part of our analysis. Saha et al. allege a distortion of the scientific knowledge; this is unjustified on the background of established scientific standards of toxicological risk assessment as the basis of our article.

It is correct that plastic particles can contain different chemicals of toxicological relevance and can bind these or release them. The discovery of such substances in the environment does not, however, in and of itself imply a health risk for humans, and neither do general references to questions outside robust concepts that are directly related to toxicology and health, such as the planetary boundaries. What is crucial is the extent and duration of exposure to the relevant chemicals. The European Food Safety Authority (EFSA) has done calculations regarding the exposure to certain contaminants through microplastic particles and concluded that, for example, the contribution of microplastics to the exposure to bisphenol A in the consumption of mussels is below 2%, which forms no basis for deducing any additional health-related concerns (2).

Although we agree in principle completely with the call by Saha et al.—namely, that doctors need to be comprehensively informed about the potential health risks of microplastics—we consider it as imperative to do so in a differentiated manner and on the basis of scientific facts and methods, and our article constitutes an important contribution in this setting. In a recently published commentary in Nature (3), this position is summarized as follows in a paragraph with the title “Too serious for uncertainty”: “[A]n understanding of the links between people’s exposure to nanoplastics and microplastics and their health will emerge only through robust science.”

DOI: 10.3238/arztebl.m2025.0245

Dr. phil. Robin Janzik

Conflict of interest statement

The author declares that no conflict of interest exists.

References

1. Janzik R, Sieg H, Braeuning A, Böl GF: Microplastics: State of the evidence on health effects and public perception. Dtsch Arztebl Int 2025; 122: 546–51.

2. EFSA Panel on Contaminants in the Food Chain (CONTAM): Presence of microplastics and nanoplastics in food, with particular focus on seafood. EFSA J 2016; 14: e04501.

3. Xu JL, Wright S, Rauert C, Thomas KV: Are microplastics bad for your health? More rigorous science is needed. Nature 2025; 639: 300–2.