Misinterpretation in microplastic detection in biological tissues: When 2D imaging is not enough.

Area of Science:

• Environmental Science
• Analytical Chemistry
• Marine Biology

Background:

• Microplastic contamination in the food chain is a global concern.
• Mytilus galloprovincialis (mussels) are key indicators due to their environmental prevalence.
• Accurate microplastic analysis is crucial for food safety and ecological risk assessment.

Purpose of the Study:

• To investigate the presence and location of microplastics in Mytilus galloprovincialis using Raman imaging.
• To differentiate between true microplastic internalization and artifacts from sample preparation.
• To highlight the importance of 3D analytical methods for microplastic detection.

Main Methods:

• Raman imaging (2D and 3D) was applied to cryosections of Mytilus galloprovincialis.
• Polystyrene microplastics (1 μm) were studied.
• Comparison of surface (2D) and volumetric (3D) imaging data was performed.

Main Results:

• 2D Raman imaging suggested microplastic presence in the epithelium.
• 3D Raman imaging revealed these particles were surface artifacts from cryotome blade drag, not internalized.
• Sample preparation can introduce significant misinterpretations in microplastic analysis.

Conclusions:

• Surface imaging alone is insufficient for confirming microplastic internalization in tissues.
• 3D Raman imaging is essential to avoid misinterpreting sample preparation artifacts as biological translocation.
• Methodological rigor, including 3D analysis, is critical for reliable microplastic research.