| With the rapid development of economy and society, air pollution, as a product, is becoming an increasingly serious issue and has a strong impact on the living and working environment, causing much harm to human health. Frequent haze weather make people aware of the seriousness of the atmospheric particulate matter(PM) pollution, however, the existing related r esearches are limited to atmospheric particulates’ physicochemical characteristics of and dose effect on human health, and seldom focus on the detailed study of damage mechanism. PM can penetrate into human body through respiratory system and digestive system which is harmful to health.In this paper, the mineral dust(quartz, calcite, nano-Si O2, nano-Ca CO3) and natural dustfall is the researching object. To study its dissolution characteristics in the different simulated body fluids, we reseached various m ineral characterization before and after the treatment by XRD, SEM, ICP and other methods to explore the mechanism of atmospheric particles reaction.In addition, quartz and calcite are regarded as the main research object in this paper. we investigated element dissolution of quartz and calcite dissoluting in simulated body fluids, and studied dissolution mechanism.Experiments were conducted to study the dustfull dissolution in simulated body fluids by researching surface morphology, phase composition and el ement dissolution, in order to understand the mineral powder dissolution characteristics in human body fluid better.Several kinds of mineral dust dissolving in the different simulated body fluids, p H of mixed suspension changed fastest. At the initial stage of the reaction, the p H changed fastest generally in the first 4h. p H value of solution changed little after 1d reaction, tending to be stable. From 6d to 8d, p H slightly increased.In these different reacting system, the role of 8D, p H of solution basically stabled between 8~8.5, and system is alkaline. Compared with other mineral dust, p H value of nano-Si O2 solution is low, calcite and nano-Ca CO3 is very similar in p H changing trend.The structure of mineral dust play a decisive role in dissolution, and generally carbonate minerals is easier to dissolve than silicate minerals. Acidic condition can promote the dissolution of calcite and Ca CO3 but existing certain extent inhabitation to quartz and nano Si O2. The results are agree with the results of previous studies. In the process of dissolution calcite can quickly dissolutein simulated body fluid, however quartz, feldspar and mica is very slow. Contact with the human body, atmospheric particles dissoluted, with p H increasing rapidly, which promotes the releasing of Si, therefore, dustfall can Influence the human body acid environment.It will not only promote the releasing of Si but also have a further exacerbating damage on human body.FTIR spectra showed that the mineral dust infrared absorption peak d id not change significantly. The dissolution for 8 days did not significantly affect the functional groups on the surface of minerals.Obviously, the peak intensity and peak shape of ultrafine silica and calcite dusts changed to some extent after 8 days dissolution. FTIR spectra showed that the Si-O-Si antisymmetric stretching vibrationoccurs changed in a certain degree.XRD phase tests showed that the peak intensity and peak shape of ultrafine mineral dusts were not significantly changed. It may be due to the stability of the structure.The presented results of this study showed that ultrafine dusts were significant corrosion in body fluids, but did not cause the collapse of crystal structure, mineral particle structure remained intact.indicating that min eral dissolution occurs in the surface and dissolutionprocess is a very l ong process. |
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