Reacción a "Evidence on the toxicity of microplastics in the human brain and strategies for their elimination examined"

This is undoubtedly a very complex issue that requires careful treatment. Experts in the study of micro- and nanoplastics, such as Dr. Dusan Materic and Dr. Melanie Bergmann, have pointed out that certain techniques (specifically, pyrolysis coupled with gas chromatography, which is used in the article) can generate false positives due to, among other factors, the presence of fatty tissues in cellular matter. If sample preprocessing is not carried out properly or if the method has not been validated to ensure complete cleaning after digestion, there is a risk of obtaining inaccurate data. This happens because signals can appear that resemble those of polyethylene, considering that, ultimately, the compounds released are molecules and fragments with common structures (based on carbon, hydrogen, and oxygen) that can lead to this ‘coincidence.’

What seems clear, in general terms, is that the Nature Medicine article uses methods that leave room for doubt, in addition to presenting inconclusive images. Although they reflect the effort made by the authors, they also highlight the need for further work to fully convince us that what has been detected is indeed plastic and not cross-contamination. The detection of plastics at these size scales is an extremely complex analytical process and, currently, the urgency to publish information about their presence in remote locations (including the human body) may contribute to the appearance of such high-profile publications.

Undoubtedly, the scientific community has reacted to this study, and although the precautionary principle always takes precedence, it will be necessary to expand this work, obtain more reliable data, and thus be able to develop policies that truly help improve human health.