Presentation Information
[O12-P78]Microscopic Neighbors in Water: Microplastics in Aquatic Environments Around Sumiyoshi
*Suzuki Kaho1, *Yusa Arai1 (1. Tokyo Metropolitan High School of Science and Technology)
Keywords:
Micro plastic
1.Background and Objectives
Microplastics (MPs) have been detected not only in marine environments but also in rivers, lakes, and the atmosphere. Airborne microplastics (AMPs) can spread widely through wind and precipitation before settling onto the ground. Previous studies at our school also detected MPs in the atmosphere, suggesting origins such as building sealants and synthetic fibers. These findings indicate that atmospheric MPs may deposit into nearby water bodies. This study aimed to clarify the distribution of MPs in a Japanese garden pond and the Yokojikken River in Sumiyoshi, Tokyo. In addition, we examined the possibility of atmospheric origin based on particle characteristics and aimed to establish a simple analytical method applicable in high schools.
2.Methods
Water samples were collected from both sites. Water with sediment was collected in glass centrifuge tubes, and surface water was collected in plastic tubes. Samples in glass tubes were filtered using a PTFE membrane filter. Hydrogen peroxide was added for organic matter removal (48 h for 10% and 20%, 24 h for 30%), with filtration repeated after each step. The suction holder samples were stained with Nile Red. Glass tube samples were further diluted with ultrapure water and subjected to density separation using saturated sodium iodide solution, followed by filtration and Nile Red staining. All samples were observed using a digital microscope (DSX1000, OLYMPUS). Surface water from plastic tubes was used to measure pH and electrical conductivity (EC).
3.Results
MPs were detected in both water bodies. Most particles were fragments and fibers, showing similar characteristics despite environmental differences. The average pH was 7.65 in the pond and 7.68 in the river, both near neutral. EC differed greatly, with 32.25 mS/m in the pond and 3850 mS/m in the river. However, no clear relationship was found between water quality and MP characteristics.
4.Discussion
MPs were present in both sites, and their shapes were similar to those reported in atmospheric studies, suggesting possible atmospheric deposition. The similarity of MPs across different environments supports this idea. However, the limited sample size and lack of data on seasonal and meteorological factors prevent definitive conclusions. Future studies should include long-term monitoring and increased sampling. Collaboration with other schools and institutions would also improve understanding.
Microplastics (MPs) have been detected not only in marine environments but also in rivers, lakes, and the atmosphere. Airborne microplastics (AMPs) can spread widely through wind and precipitation before settling onto the ground. Previous studies at our school also detected MPs in the atmosphere, suggesting origins such as building sealants and synthetic fibers. These findings indicate that atmospheric MPs may deposit into nearby water bodies. This study aimed to clarify the distribution of MPs in a Japanese garden pond and the Yokojikken River in Sumiyoshi, Tokyo. In addition, we examined the possibility of atmospheric origin based on particle characteristics and aimed to establish a simple analytical method applicable in high schools.
2.Methods
Water samples were collected from both sites. Water with sediment was collected in glass centrifuge tubes, and surface water was collected in plastic tubes. Samples in glass tubes were filtered using a PTFE membrane filter. Hydrogen peroxide was added for organic matter removal (48 h for 10% and 20%, 24 h for 30%), with filtration repeated after each step. The suction holder samples were stained with Nile Red. Glass tube samples were further diluted with ultrapure water and subjected to density separation using saturated sodium iodide solution, followed by filtration and Nile Red staining. All samples were observed using a digital microscope (DSX1000, OLYMPUS). Surface water from plastic tubes was used to measure pH and electrical conductivity (EC).
3.Results
MPs were detected in both water bodies. Most particles were fragments and fibers, showing similar characteristics despite environmental differences. The average pH was 7.65 in the pond and 7.68 in the river, both near neutral. EC differed greatly, with 32.25 mS/m in the pond and 3850 mS/m in the river. However, no clear relationship was found between water quality and MP characteristics.
4.Discussion
MPs were present in both sites, and their shapes were similar to those reported in atmospheric studies, suggesting possible atmospheric deposition. The similarity of MPs across different environments supports this idea. However, the limited sample size and lack of data on seasonal and meteorological factors prevent definitive conclusions. Future studies should include long-term monitoring and increased sampling. Collaboration with other schools and institutions would also improve understanding.