Field Survey of Indoor Microplastic in Four Regions of Japan

In recent years, the plastics pollution of 5mm or less size (microplastics) in marine ecosystems has been a global issue. The presence of microplastics (microfibers) is also a major concern in indoor environments of the residetial house. Many sources of microplastics in the marine environment also exist in the indoor environment. In the modern age where we spend most of our time indoors, the indoor environment is related to the health of residents, so it is important to investigate the presence and contamination status of microplastics in the indoor environment. There is limited the number of studies on microplastics in the indoor environment. In our previous studies have confirmed the presence of microplastics in indoor environments Kanto area including Tokyo of Japanese residential houses. The purpose of this study is to investigate the concentration of indoor microplastics in four regions; Kanto area including Tokyo, Chubu area, Tohoku area, and Kansai area. We focused on the indoor microplastics in settled dust on the floor of residential houses, and the survey was conducted on the 16 residential houses. Micro-Fourier transform infrared (µ-FT-IR) spectrophotometry was used for the qualitative analysis of microplastics. The detected components in the settled dust were cellulose, polyamide (PA), polyacrylamide (PAM), polyacrylonitrile (PAN), polybutylene terephthalate (PBT), polyethylene (PEs), polyester (PE), polyethylene terephthalate (PET), polypropylene (PP), polyvinyl acetate (PVAL).