Unravelling The Deposition of Indoor Microplastics at Various Heights Across Rooms

¹ Faculty of Civil Engineering & Technology, Universiti Malaysia Perlis, Kompleks Pusat Pengajian Jejawi 3, Arau, Perlis, 02600, Malaysia
² Sustainable Environment Research Group (SERG), Centre of Excellence Geoploymer and Green Technology (CeGeoGTech), Universiti Malaysia Perlis, Perlis, Arau, 02600, Malaysia
³ Air Resources Research Laboratory, Malaysia Japan International Institute of Technology, UTM, Kuala Lumpur, 54100, Malaysia
⁴ Centre of American Education, Sunway University, Selangor, Bandar Sunway, 47500, Malaysia
⁵ National Instiute for Research and Development in Environmental Protection, Splaiul Independenţei 294, Bucharest, Romania, 060031

^* Corresponding author: sarayasina@unimap.edu.my

Abstract

Microplastics (MP) are widely present in both outdoor and indoor environments. Extensive research has thoroughly documented the potential negative impacts of MPs on human health. This study utilized a deposited sample method for 3 weeks, with eight-hour daily exposures, using funnels and bottles to investigate the properties of MPs in the office and laboratory settings of the Faculty of Civil Engineering & Technology (FCET), Universiti Malaysia Perlis. The characteristics examined included the deposition rate, size, form, and colour of the microplastics. Samples were collected at three different heights. The samples underwent pre-treatment procedures, such as physical counting and categorization (size, colour and shape). Micro-Raman analysis was performed to determine the primary polymer types. The deposition rate in the office was found to be 4,960 counts/(m².h), while the rate in the laboratory was 6,940 counts/(m².h). Human activities and the appearance of synthetic materials, especially from textiles, play a big role in the deposition rate of MPs in the environment. During the day, the rates were higher than at night. The results of the study showed that indoor MPs come in many different colours, with transparent and black being the most common. About 42% of the size range of fibrous MPs was between 200 µm and 2000 µm, and more than 15% of the particles were between 20 µm and 200 µm. Most of the time, fragments were smaller than strands. The most abundance polymers detected in both rooms were polycarbonate (PC), pigments and polymethyl methacrylate (PMMA).