Methodological Controversies in Microplastic Detection: A Critical Analysis of Pyrolysis-GC-MS False Positives in Human Tissue Studies

Recent high-profile studies reporting widespread microplastic contamination in human organs have ignited considerable scientific debate. This paper explores the methodological challenges involved in detecting micro- and nanoplastics (MNPs) within biological tissues, focusing particularly on the limitations of Pyrolysis-Gas Chromatography–Mass Spectrometry (Py-GC-MS). A critical examination indicates that lipid-rich tissues—especially brain tissue, which is composed of roughly 60% fat—can generate pyrolysis products that closely resemble polyethylene, potentially resulting in systematic false positives. The review includes seven formally disputed studies and an additional eighteen studies identified for insufficient consideration of matrix interferences. This controversy underscores fundamental problems in analytical chemistry when operating near the boundaries of current detection capabilities and raises concerns about the validity of alarming claims regarding microplastic accumulation in human organs. The analysis highlights the urgent need for robust validation protocols, stringent contamination controls, and standardized methodologies before definitive conclusions about human health risks from microplastic exposure can be drawn.