Characterization of Aerosolized Micro-/Nanoplastic Aerodynamic Diameter

GINA M. MORENO, Richard Cavalere, Andrea J. Tiwari, Maynard Havlicek, Daniel Bissell, Phoebe A. Stapleton, Rutgers University

     Abstract Number: 763
     Working Group: Instrumentation and Methods

Abstract
Plastics and small plastics particles are ubiquitous in all environmental compartments including surface waters, soil, atmosphere, and biota. Micro- and nano-plastics (MNPs) include particles 5mm-1nm in one dimension. Smaller sized MNPs have the potential to aerosolize. Toxicity due to inhalation of MNPs is not well understood. Modeling shows that aerosolized MNPs' deposition sites within the nasal passageway or deeper respiratory tract greatly depends on particle size. Toxicological endpoints from exposure to MNPs may result in inflammation, oxidative stress, or translocation into systemic tissue. Characterization of aerosolized particle size distribution is critical to understanding the physiologic outcomes of MNP inhalation based on particulate size. The purpose of this study was to thoroughly characterize the size range of aerosolized polyamide particles. Using our custom rodent inhalation facility (IEStechno Morgantown, WV), to produce a low (1.01 ± 0.17 mg/m3) and high (9.98 ± 3.14 mg/m3) concentration of polyamide particles (Arkema, King of Prussia, PA) we measured the aerosolized particle size distribution in real-time a scanning mobility particle sizer (SMPS), coupled with an aerodynamic particle sizer® spectrometer (APS) (both from TSI, Shoreview, MN) quantifying particles 1nm-1000nm and 0.5µm-20µm respectively. Multi-day studies were conducted to assess intra- and inter-day variability. The data were merged, and a multi-peaked plot revealed a bimodal distribution of particles, with the most predominant size fractions at each concentration were 83.64 ± 11.75 nm (SMPS) and 3.11 ± 0.04 µm (APS) at the low concentration and 137.81 ± 29.53 nm (SMPS) and 3.234 ± 0.04 µm (APS) at the high concentration, indicating variation in particle size distribution at low and high concentrations. Particulate size is critical in determining toxicologic outcome from inhaled MNPs. The 83 billion metric tons of plastic already produced inevitably are degrading and rapidly. This will produce higher concentrations of MNPs, which is a human health risk.