Reference Particles for Toxicological Studies of Wood Combustion: Formation, Characteristics, and Toxicity Compared to Those of Real Wood Combustion Particulate Mass

Abstract

Multiple studies show that particulate mass (PM) generated from incomplete wood combustion may induce adverse health issues in humans. Previous findings have shown that also the PM from efficient wood combustion may induce enhanced production of reactive oxygen species (ROS), inflammation, and cytotoxicity in vitro and in vivo. Underlying factors of these effects may be traced back to volatile inorganic transition metals, especially zinc, which can be enriched in the ultrafine fraction of biomass combustion particulate emission. In this study, nanoparticles composed of potassium, sulfur, and zinc, which are the major components forming inorganic fine PM, were synthesized and tested in vitro. In addition, in vitro toxicity of PM from efficient combustion of wood chips was compared with that of the synthesized particles. Cytotoxicity, cell cycle arrest, ROS generation, and tumor necrosis factor alpha release were related to zinc concentration in PM. Potassium sulfate and potassium carbonate did not induce toxic responses. In light of the provided data, it can be concluded that zinc, enriched in wood combustion emissions, caused the toxicity in all of the measured end points.

In vitro toxicological effects of zinc containing nanoparticles with different physico-chemical properties

“…The simultaneous dilution and cooling quenched the reactions, prevented re-condensation of the solvent and decreased the wall deposition losses of the produced particles. Furthermore, FSP-1 (ZnO rods) were previously produced with flame spray pyrolysis as described in detail by Torvela et al 2014.…”

“…The particle size distribution was determined using a scanning mobility particle sizer (SMPS, DMA 3081 with CPC 3775, TSI Inc.) and number concentration was measured using a condensation particle counter (CPC 3775,TSI Inc.). The properties of FSP generated particles were measured with the fast mobility particle sizer (FMPS 3091, TSI Inc.) (Torvela et al, 2014). The concentrations determined with the FMPS and SMPS were corrected with the dilution ratios.…”

“…Then samples were sonicated in an ultrasonic water-bath for 30 min. The procedures used in the sample preparation are described in detail by Uski et al 2015 andTorvela et al 2014.…”

Oxidative potential of size-fractionated atmospheric aerosol in urban and rural sites across Europe

“…While the trends in specic activity as a function of particle size at the urban background (15.5, 12.5, 4) and rural (14, 7.5, 5) (PM 3 , PM 7-3 , PM >7 respectively) sites are very similar to that observed with the ROS data (consistent decrease with increasing particle size), the trend is dramatically different at the canyon sites with median PM 7-3 activity of 20.5 compared with 7.5 in the PM 3 and 7 in the PM >7 . The canyon sites/cities contributing most signicantly to this "elevated" PM 7-3 specic activity were Stockholm (25)(26)(27)(28)(29)(30), Frankfurt (22) and Thessaloniki (20.5). The highest PM 3 specic activities were measured at urban background sites in Frankfurt (27), Stockholm (18) and London (17) (Fig.…”

“…Multiple studies have demonstrated various macrophage cell lines to respond to PM exposure with a release of pro-inam-matory signals. [25][26][27][28][29] Recent studies reported that PM-derived water-soluble transition metals (e.g. Fe, Ni, Cu, Cr, Mn, Zn and V) correlate signicantly with the oxidative potential of airborne PM across different urban areas and size ranges.…”