Comparative Evaluation of Urine, Sputum, and BALF for Human Microplastic Exposure Monitoring Using a Multicriteria...

Area of Science:

• Environmental Health
• Toxicology
• Biomonitoring

Background:

• Microplastic (MP) contamination in human biological systems is a growing global health concern.
• Effective biomonitoring is crucial for understanding human exposure and health impacts.
• The optimal biological matrix for human MP detection and monitoring is currently under investigation.

Purpose of the Study:

• To evaluate the suitability of urine, sputum, and bronchoalveolar lavage fluid (BALF) as matrices for human microplastic detection.
• To compare these matrices based on detection sensitivity, polymer diversity, sample availability, and practical feasibility.
• To establish a framework for selecting the most appropriate matrix for different human microplastic biomonitoring scenarios.

Main Methods:

• A multicriteria decision analysis (MCDA) framework, inspired by the analytic hierarchy process (AHP), was employed.
• Data were collated from a recent observational study involving 30 patients and existing peer-reviewed literature.
• Key assessment criteria included detection sensitivity, polymer diversity, sample availability, and practical feasibility.

Main Results:

• Sputum showed the highest median microplastic concentration (9.4 particles/mL), while urine had the lowest (2.7 particles/mL).
• Bronchoalveolar lavage fluid (BALF) demonstrated the greatest polymer diversity, identifying 6 different polymer types.
• Urine achieved the highest composite MCDA score (26/35) for population studies, followed by sputum (25/35) for respiratory assessment, and BALF (21/35) for mechanistic studies.

Conclusions:

• No single biological matrix is universally optimal for all human microplastic biomonitoring objectives.
• Urine is recommended for broad population studies due to its non-invasive nature and reproducibility.
• Sputum and BALF are valuable for targeted assessments of respiratory exposure and deep-lung exposure mechanisms, respectively.
• A matrix-specific strategy is essential for advancing accurate and meaningful human microplastic biomonitoring.