A comparative study of wood sawdust and plastic smoke particulate matter with a focus on spectroscopic, fluorescent, oxidative, and neuroactive properties

Abstract

Here, water-suspended smoke aerosol preparation was synthesized from biomass-based fuel, i.e., a widespread product for residential heating, wood sawdust (WP) (pine, poplar, and birch mixture), and its properties were compared in parallel experiments with the smoke preparation from plastics (PP). Molecular groups in the PM preparations were analyzed using Raman and Fourier-transform infrared spectroscopy. WP was assessed in neurotoxicity studies using rat cortex nerve terminals (synaptosomes). Generation of spontaneous and H₂O₂-evoked reactive oxygen species (ROS) detected using fluorescent dye 2',7'-dichlorofluorescein in nerve terminals was decreased by WP. In comparison with PP, WP demonstrated more pronounced reduction of spontaneous and H₂O₂-evoked ROS production. WP completely inhibited glutamate receptor agonist kainate-induced ROS production, thereby affecting the glutamate receptor-mediated signaling pathways. WP decreased the synaptosomal membrane potential in fluorimetric experiments and the synaptosomal transporter-mediated uptake of excitatory and inhibitory neurotransmitters, L-[¹⁴C]glutamate and [³H] γ-aminobutyric acid (GABA), respectively. PP decreased the ambient synaptosomal level of [³H]GABA, whereas it did not change that of L-[¹⁴C]glutamate. Principal difference between WP and PP was found in their ability to influence the ambient synaptosomal level of [³H]GABA (an increase and decrease, respectively), thereby showing riskiness in mitigation of synaptic inhibition by PP and triggering development of neuropathology.

Keywords: Air pollution particulate matter; Environmentally derived health threats; Neurotoxicity; Oxidative potential; Plastics; Wood sawdust.