This study investigates the presence and characteristics of microplastics (MPs) in indoor deposition samples from university classrooms. The research aims to analyze the physical and chemical properties of MPs, focusing on their distribution and potential sources. Key findings include: 1. **Physical Characterization**: - **Dominant Type**: Fibers of various colors (black, transparent, blue, red) were identified as the predominant type of MPs, likely originating from clothing. - **Size Range**: The average size of MPs ranged from 120 to 2222 μm, with significant variations across different classrooms. - **Morphological Changes**: Observations of MPs under a stereomicroscope revealed cracks, grooves, and other degradation signs, indicating potential conversion to nanoplastics over time. 2. **Chemical Characterization**: - **μRaman Analysis**: Eleven types of MPs were identified using μRaman spectroscopy, including polyamide 6, polypropylene, and polyamide 12. The majority of MPs were polyamide 6, polypropylene, and polyamide 12. - **Elemental Composition**: SEM–EDX analysis revealed that carbon, fluorine, and oxygen were the dominant elements, with varying concentrations among different MPs. 3. **Distribution and Sources**: - ** classroom 1**: Mainly PA 6, PP, and PA 12. - **classroom 2**: Mainly PA 6, PP, and PA 12. - **classroom 3**: Mainly PA 6, PP, and PA 12. - **classroom 4**: Mainly PA 6, PP, and PA 12. 4. **Comparison with Literature**: - The study's findings align with previous research on MPs in indoor environments but highlight the need for a comprehensive methodological approach combining optical microscopy, μRaman, and SEM–EDX. 5. **Limitations**: - Challenges in accurately counting MPs due to their varying sizes and visibility. - Limited sampling and potential bias in results. 6. **Conclusions and Recommendations**: - The study emphasizes the importance of understanding the structural components and contaminants of MPs to develop effective strategies for reducing indoor MP pollution. - Recommendations include standardized sampling procedures, more comprehensive data on MPs' prevalence and chemical composition, and further research on the dynamics of MP distribution in indoor environments. This research contributes to the growing body of knowledge on indoor MP contamination, providing valuable insights for public policy and public health strategies to minimize the risks associated with indoor MP pollution.This study investigates the presence and characteristics of microplastics (MPs) in indoor deposition samples from university classrooms. The research aims to analyze the physical and chemical properties of MPs, focusing on their distribution and potential sources. Key findings include: 1. **Physical Characterization**: - **Dominant Type**: Fibers of various colors (black, transparent, blue, red) were identified as the predominant type of MPs, likely originating from clothing. - **Size Range**: The average size of MPs ranged from 120 to 2222 μm, with significant variations across different classrooms. - **Morphological Changes**: Observations of MPs under a stereomicroscope revealed cracks, grooves, and other degradation signs, indicating potential conversion to nanoplastics over time. 2. **Chemical Characterization**: - **μRaman Analysis**: Eleven types of MPs were identified using μRaman spectroscopy, including polyamide 6, polypropylene, and polyamide 12. The majority of MPs were polyamide 6, polypropylene, and polyamide 12. - **Elemental Composition**: SEM–EDX analysis revealed that carbon, fluorine, and oxygen were the dominant elements, with varying concentrations among different MPs. 3. **Distribution and Sources**: - ** classroom 1**: Mainly PA 6, PP, and PA 12. - **classroom 2**: Mainly PA 6, PP, and PA 12. - **classroom 3**: Mainly PA 6, PP, and PA 12. - **classroom 4**: Mainly PA 6, PP, and PA 12. 4. **Comparison with Literature**: - The study's findings align with previous research on MPs in indoor environments but highlight the need for a comprehensive methodological approach combining optical microscopy, μRaman, and SEM–EDX. 5. **Limitations**: - Challenges in accurately counting MPs due to their varying sizes and visibility. - Limited sampling and potential bias in results. 6. **Conclusions and Recommendations**: - The study emphasizes the importance of understanding the structural components and contaminants of MPs to develop effective strategies for reducing indoor MP pollution. - Recommendations include standardized sampling procedures, more comprehensive data on MPs' prevalence and chemical composition, and further research on the dynamics of MP distribution in indoor environments. This research contributes to the growing body of knowledge on indoor MP contamination, providing valuable insights for public policy and public health strategies to minimize the risks associated with indoor MP pollution.