Development of a Water-Soluble Filter for Potential Use in the Toxicity Evaluation of Ambient Particulate Matter

Abstract Assessment of the toxicity of insoluble particulate matter (PM) in the atmosphere is crucially important. However, because of challenges associated with extracting insoluble PM from filters, the toxicity of insoluble PM remains largely uncharacterized. For this study, the water-soluble filter made of poly (vinyl alcohol) (PVA) was developed with high particle collection efficiency, durability, and weather resistance, which are necessary for ambient PM sampling. The PVA filter is water-soluble under certain conditions, allowing for the recovery of insoluble PM, which can be exposed directly to cells or animals for toxicological studies. The PVA filter was made from PVA nanofibers using the electrospinning (ES) method. Its durability and weather resistance were comparable to those of polytetrafluoroethylene (PTFE) and quartz fiber (QF) filters, and were superior to those of commercially available gelatin filters. The PVA filter particle collection efficiency was evaluated by comparing concentrations of inorganic elements (Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu and Zn) and water-soluble ionic components (Na+, NH4 +, K+, Mg2+, Ca2+, Cl−, NO3 −, and SO4 2−) in the PVA filter-collected ambient PM with those in the PTFE filter-collected PM. The concentrations of almost all measured components in the PVA filter-collected PM were comparable to those in the PTFE filter-collected PM. When the PVA filter dissolved in cell culture medium was exposed to cells, no significant difference was found in cell viability compared to a blank solution containing only culture medium, suggesting that the PVA filter has potential use for cell exposure experiments. Graphical Abstract