Toward a Harmonized Framework for Standardization for Scalable and Reproducible Measurement of Microplastic and Nanoplastic Monitoring in Human Urine

Interest in measuring microplastics and nanoplastics (MNPs) in human urine has increased rapidly as concern grows regarding environmental exposures and potential health relevance. Early studies have provided important proof-of-concept evidence that urinary monitoring is feasible. However, the current literature remains limited by relatively small cohorts, predominantly cross-sectional one-time sampling, heterogeneous workflows, and reliance on centralized laboratory methods that may be difficult to scale for frequent longitudinal monitoring. As a result, key questions regarding baseline variability, temporal dynamics, and population-level distributions remain unresolved. This paper proposes a harmonized, technology-agnostic framework for urinary MNP monitoring focused on reproducibility, standardized workflows, contamination control, matrix robustness, transparent quality systems, and real-world scalability. The goal is not to prescribe a single analytical platform, but to define shared principles by which existing and future methods—including optical, spectroscopic, mass-based, and hybrid systems—can be evaluated. Such a framework may help transition the field from isolated exploratory studies toward repeatable and population-scale environmental exposure monitoring.