Microplastics in the indoor laboratory environment: A study on deposition rate, size, shape, polymer, and source

This study examined the abundance, size, shape, color, and polymer composition of microplastics (MPs) in a laboratory environment. The deposition rate of MPs ranged from 178 to 427 particles per square meter per day (p/m²/d), with an average of 286 ± 104 p/m2/d. Fragments were the most common shape, followed by pellets and fibers. Most MPs were found in the 53-300 µm and 300-500 µm size ranges. Micro-Fourier Transform Infrared Spectroscopy (FTIR) analysis identified polyethylene (PE), cellulose nitrate (CN), polypropylene (PP), and cellulose, with PE being the most prevalent polymer. The color analysis revealed that white and black were the most common colors, with PE mostly white, PP brown, and cellulose and CN appearing in various colors. The identified polymers suggest that the MPs found in the laboratory likely originate from routine laboratory activities, including handling of reagent bottles and caps, as well as from materials used in laboratory infrastructure such as walls, furniture, air conditioner (AC), and curtains.