Analytical challenges and advances in detecting microplastics in human tissue and organ samples

Microplastic contamination of biological matrices is a pressing concern in environmental and biomedical research. While their presence has been confirmed in human blood, placentas, lungs, and other tissues, accurate identification remains an analytical challenge. Obstacles include the small size and heterogeneous composition of microplastics, as well as spectral interference from complex organic matter. This review systematically analyzes-following PRISMA 2020 guidelines-the current state of microplastic detection in human tissues, evaluating 218 studies (2000-2024). We focus on the primary techniques: Fourier Transform Infrared (FTIR) and Raman spectroscopy, and Pyrolysis-Gas Chromatography/Mass Spectrometry (Py-GC/MS). Our analysis confirms FTIR as the most widely employed technique, followed by Raman and Py-GC/MS, with each method exhibiting distinct advantages and limitations in sensitivity, specificity, and sample preparation requirements. A critical finding is the widespread lack of robust quality assurance; notably, few studies consistently implemented blank controls and spike-recovery experiments, thereby compromising the reproducibility and reliability of data. In response, we propose a consolidated framework of best practices for sample handling, contamination control, and analytical validation. This review underscores the urgent need for standardized, validated protocols to refine analytical techniques, ensure consistent results, and ultimately support accurate risk assessment of human exposure to microplastics.