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By Tyne Eckmyn, Publishing Associate: Researcher and Writer at Save the Water™| February 28, 2026
Edited by Jaslene Szeto, Publishing Associate: Editor at Save the Water™
Recent years have seen growing concern around the possible effects of microscopic pieces of plastic. These are known as micro and nano plastics (MNPs), which are plastic particulates smaller than 5,000 micrometres and which may have effects on human health. Recently, however, members of the scientific community have raised concerns about the methodology and results of many of the studies that have driven this alarm.
Measuring microplastics in the human body is no easy task, and the scientific procedures used to do so are relatively new. One primary method, known as Py-GC-MS analysis, involves vaporizing tissue samples. Scientists then analyze the resulting gas to identify and quantify the presence of potential contaminant polymers.
Furthermore, contamination testing requires researchers to follow quality assurance and quality control (QA/QC) procedures. These can include:
Blank samples: Testing contamination-free (blank) samples to calibrate the equipment.
Field blanks: Exposing a clean sample to the lab environment and then testing it for airborne contaminants.
Duplicate samples: Testing two samples from the same location to confirm consistency in results.
The journal Toxilogical Sciences published a paper in 2024 examining MNP effects on human and dog testes. Also, Nature Medicine published a similar paper in 2025 on MNP accumulation in human brains. Both these research studies faced methodological criticism for their QA/QC procedures and their use of the Py-GC-MS test.
A journal article commenting on the 2024 paper found that the study included “no details on background contamination levels for sample collection, handling, and laboratory processing.” Furthermore, a letter responding to the 2025 paper noted that “the absence of reported QA/QC procedures makes it difficult to evaluate the extent to which contamination from reagents, labware or airborne particulates may have influenced the findings.” The letter also flagged that researchers “collected samples across different years and locations”, which can substantially influence the results. This was also published in the journal Chemosphere, where a 2023 study showed variability of blank sample results between laboratories and sampling procedures. Additionally, the second issue involves the use of Py-GC-MS to detect polymers in tissue samples. While the test “is a well-established tool for identifying and quantifying pure polymers”, a 2025 study assessing its use in tissue found it to be not a suitable analysis method.
A key reason for this is that many fat tissues can appear similar to plastic particles during testing, producing false positives.
The studies above are not the only ones to face methodological criticism. Despite this, MNP research remains critically important as we work to understand how plastics affect human health and the environment. In the short term, researchers should follow rigorous QA/QC protocols and combine Py-GC-MS with multiple analytical approaches. In the long term, the field needs better testing methods for identifying microplastics in tissue.
Lastly, it's also worth remembering that research studies often face many challenges. We should all be mindful and raise awareness of our health and potential contaminants — but we shouldn't panic over any single headline or early study.
Save the Water™ is a 501 (c)(3) non-profit organization with a mission to conduct research to identify and remove harmful contaminants in water and to raise public awareness about water contamination and its health impacts.
