Abstract：The Ultrafine quartz dust is one of the main types of mineral particles in atmospheric PM2.5. In the presented study, the dissolving characteristics of ultrafine quartz dusts with d50of 2.8 μm in the simulated human body conditions were measured for estimating their potential health risks by using Gamble solution. The Silicon concentration in Gamble solution were increased with the dissolving time continuance, but inhabited in some certain extents at strong acidic environment. SEM obervations showed that presented concave erosion and peeling phenomenon in the surface of quartz particles, but their interior surface remained intact. FTIR spectra showed that the Si-O-Si antisymmetric stretching vibrationoccurs changed in a certain degree. The results of XRD mieral phasemeasurements showed that the characteristic peaks and intensities of ultrafine silica dusts were not significantly changed. The results by Rietveld refinement method suggested that the crystalline lattice parameters (a, b, c and volume of the unit cell) of quartz regularly decreased in acidic environment. The presented results suggest that ultrafine quartz dusts are significant eroded in simulate body fluids not keeping interact crystal structure and pH value increases and tends to be stable in alkaline environment. Our study indicates that inhalable ultrafine quartz dusts with the exposed freshly surface and combines with dissolved Silicon in body fluid has potential threat to human health.
