Novel Method for Measuring Nanoplastic Concentrations in Soil Using Spectroscopy: Contributing to Understanding the Distribution of Plastic Particles Dispersed in the Geosphere Environment

Summary of the AIST Press Release on June 14, 2024,
>>Japanese

　The research team consisting of Geo-Environmental Risk Research Group Member Kyouhei Tsuchida (currently in a doctoral program at Waseda University), Yukari Imoto and Takeshi Saito (Chief Researchers), and Junko Hara (Research Group Leader) of the Research Institute for Geo-Resources and Environment, Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology (AIST), along with Professor Yoshishige Kawabe from Waseda University developed a technology for measuring nanoplastic concentrations in soil. The increasing amount of plastic waste has become a social problem in recent years. Plastics with a size of 1 µm or less in particular are called nanoplastics, and there are concerns about their impact on the human body. Nanoplastics are thought to enter the human body through ingestion or inhalation, making it essential to understand their concentration in the geosphere, including soil, for assessing their risk to humans. Conventional methods can only detect plastic in soil with a minimum size of approximately 1 µm, leaving the distribution of nanoplastics in soil unclear. The technology developed in this study uses the difference in the absorbance spectra of nanoplastics and soil particles to calculate the concentration of nanoplastics in soil samples. This method does not need to separate soil organic matter or soil particles from nanoplastics, overcoming the limitations of conventional methods.

Fig. 1 A simple method to measure nano/microplastic concentrations in soil