Prevalence and Concentration of Microplastics in Human Biological Matrices: A Systematic Review and Meta-Analysis
Keywords:
Biological Monitoring, Cross-Sectional Studies, Environmental Exposure, Environmental Pollutants, Epidemiology, Particulate Matter, Plastics, HumansAbstract
Background: Microplastics are ubiquitous environmental contaminants, which have been detected in many human biological matrices, but information on the presence, concentration and polymer types of microplastics in different matrices is fragmented. This systematic review and meta-analysis aimed to pool data on the detection rates, particle-based concentrations, and relative abundances of polypropylene (PP) and polyethylene (PE) in human biological samples. Methods: The study followed PRISMA 2020 guidelines. PubMed, Scopus, Web of Science, and Google Scholar were searched between January 2021 and April 2026. Original research publications that reported quantitative detection rates, mean concentrations, or polymer proportions in human tissues or fluids were considered. The risk of bias was assessed using the modified NOS, JBI, and ROBINS-I tool, and the certainty of evidence was graded using the GRADE approach. Meta-analysis was conducted using the Revman Tool. Results: Fifteen studies satisfied the inclusion criteria. Nine studies contributed to the detection rate meta-analysis (343 persons), providing a pooled prevalence of 0.91 (95% CI: 0.78-0.98), with significant heterogeneity (I²=87%). Seven studies (133 samples) reported particle-based concentration data, with a pooled mean of 16.0 particles/g (95% CI: 8.3-23.6; I² = 92%). The polymer proportions showed considerable heterogeneity (I²≥87%), with individual-based proportions of 0.49 (95% CI: 0.28-0.70) for PP and 0.48 (95% CI: 0.19-0.78) for PE, and particle-based proportions of 0.23 (95% CI: 0.10-0.43) for PP and 0.15 (95% CI: 0.05-0.36) for PE. Conclusion: Microplastics were found in the majority of human biological samples, albeit in varying amounts; the most often discovered polymers were PP and PE.
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Copyright (c) 2026 Aliya Ahmed Abdellah Ahmed, Shareefa Bint-e Umar, Khadeejah Qadir, Zehra S. Sharif (Author)
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