reported that animals were subjected to mixed dust types generated from grinding dental prostheses (PMMA, Vitallium and porcelain dust, etc. The site is secure. Barrett TE, et al. Furthermore, 42.3% of the finely ground porcelain dust particles were smaller than 10m, which is a higher than the proportions of particles in the same size range for the other types of grinding dust. The porcelain dust induced higher levels of ROS than either the PMMA or Vitallium dust. 4a,c,e,g, no abrasive grinding dust was found to induce apoptosis of the RAW264.7 cells. Larger, nanometer scale particles (60.4 nm < dp < 777 nm) were characterized using a SMPS configured with a long DMA (DMA model 3934 and a condensation particle counter model 3022A; TSI Inc.). Three types of dental prosthesis grinding dust particles, PMMA dust, Vitallium dust, and dentin porcelain dust, were all toxic to RAW264.7 cells. Particles engulfed by macrophages are transported in vesicles. B13003). Zhou H, et al. The authors acknowledge financial support from the National Key Research and Development Program of China (No. Received 2019 Dec 19; Accepted 2020 Aug 17. Musculoskeletal Symptoms in Professional Musicians: Do Self-employed and Employer-employed Musicians Differ? The effects of dust on macrophages via the classical (type 1 helper T cell factor involvement) and selective activation (type 2 helper T cell factor involvement) pathways31. Received 2 April 2002; in final form 22 July 2002. McCawley et al. RC200060), Medical Engineering, Ministry of Science and Technology of China, and the 111 Project (No. In addition, the percentage of PMMA abrasive dust particles<5m was higher than that of the Vitallium abrasive dust. In West Texas, dust storms mainly take place in the spring or fall, but they may also happen at the other times of the year. Cardiovascular and inflammatory effects of intratracheally instilled ambient dust from Augsburg, Germany, in spontaneously hypertensive rats (SHRs). Learn more The three types of grinding dust particles showed had wide range of size distributions that significantly differed from each other. At 24h, the ROS fluorescence intensity of the three dust samples was slightly lower than that of the negative control group. All three types of fine dental prosthesis grinding dust led to ROS increases in the macrophages in a time-dependent manner. Some discrepancy was observed in the overlap region between the APS and the SMPS/LDMA. 3) showed that after the three types of prosthesis materials were ground, the grinding dust remained in contact with the RAW264.7 macrophages. Thakur SA, et al. Vitallium (h), porcelain (i). An open-label, 4-week, prospective clinical study evaluating the efficacy and safety of a novel targeted skin care line addressing five common skin conditions. When it comes to industrial facilities, many of their processes can create dust -- much of which is tiny, respirable dust. A number of publications have indicated that for low solubility, chemically inert materials the composition of ultrafine particles is of secondary importance (Oberdorster et al., 1995; Donaldson et al., 1998; Brown et al., 2001). Since the SMPS tends to overestimate particle counts at high diameters when particle counts at lower diameters are significantly higher (an artifact associated with particle residence time within the system), it is conceivable that, in the absence of such an artifact, better agreement between the SMPS and APS would be seen. Particle size distribution of the three dental prosthetic grinding dust particles before and after fine milling. Transmission electron microscope samples of the various grinding substrates were also collected. LDH activity was observed, in descending order, for the porcelain dust group, Vitallium group and PMMA group. Rogak et al. Everything is made much larger so you can visually see the comparison. found that rats exposed to three different quality levels of fine dust (including 250, 500 and 1,000gmll) presented with increases in the total number of inflammatory cells and levels of interleukin-615. This process includes grinding and measuring the particle size distribution. Effects of 300gmLl of the different types of dental prosthesis grinding dust particles on RAW264.7 after 24h of exposure: PMMA (a), Vitallium (c), porcelain (e), and the negative control (g); after 48h, PMMA (b), Vitallium (d), porcelain (f), and the negative control (h). The results showed that the three types of grinding dust had entirely different morphologies. The assumption was therefore made that the data from each SMPS could be interpreted in terms of particle equivalent-sphere projected area diameter. Arnoldussen YJ, et al. (or is it just me), Smithsonian Privacy 2ag. 5). Experimental study on the effect of selenium on lipid peroxidation and antioxidant enzymes in alveolar macrophages stained with dust. Statistical analysis was performed with SPSS 17.0 (IBM Corp., Armonk, NY, USA). using a rheostat (model 3PN751; Matheson Scientific) and a tachometer. ANTHONY T. ZIMMER, ANDREW D. MAYNARD, Investigation of the Aerosols Produced by a High-speed, Hand-held Grinder Using Various Substrates, The Annals of Occupational Hygiene, Volume 46, Issue 8, September 2002, Pages 663672, https://doi.org/10.1093/annhyg/mef089. Grinding upon the granite substrate gave a distribution that was relatively bimodal (Fig. For a better understanding of the source of the ultrafine mode arising from grinding on these substrates, the use of alternative sample collection methods or analytical methods such as electron energy loss spectroscopy (EELS) should be considered for future research (Brydson, 2000; Maynard, 2000). Notice, Smithsonian Terms of Grinding was accomplished using a Multipro (model 395; Dremel, Racine, WI), a variable speed tool with rotational speeds that can be varied from 5000 to 30000 r.p.m. It is generally assumed that aerosols generated during mechanical processes such as grinding are characterized by large particles formed through attrition. The size of the particle has various effects on the organisms exposed to them. The average fluorescence intensities were calculated for the various concentrations of each grinding dust. With increasing dust exposure time, the cell survival rate decreased. In addition, the multiple comparison analysis based on LSD showed that the effect of the porcelain dust group was higher than the PMMA group and the Vitallium group, and the difference was statistically significant (P<0.05). It showed evidence of charring at the grinding interface, supporting the hypothesis that frictional heating during grinding can lead to the formation of ultrafine particles. The classical activation pathway generates numerous inflammatory cytokines and free radicals32,33. The negative control cells showed a regular circular shape, but the surface of the cells exposed to prosthesis grinding dust was changed. A2, B2, and C2 were finely ground by an agate mortar for 2h, and their morphologies, sizes, chemical compositions, and cytotoxicity were examined. method of generation) (ACGIH, 1990; OSHA, 1997). 2. However, apart from these studies there is little in the literature to indicate the likely contribution of mechanical processes to ultrafine aerosols in the workplace. The chamber was HEPA filtered to remove aerosols within the chamber and the ventilation system was turned off. However, the grinding dust concentrations used in this experiment do not necessarily represent the actual concentrations of grinding dust that would actually enter the lungs during occupational exposure39. about navigating our updated article layout. The particle size distributions tended to be bimodal, with many substrates showing distinct ultrafine and coarse modes. Occupational health, Inflammasome, Inflammasome, Inflammasome, Occupational health. The high density particles produced from the steel substrate ( 7.9 kg/m3), together with uncertainty over their morphology, are probably responsible for the poor transformation between aerodynamic diameter and equivalent-sphere projected area diameter with the APS data. Dust is one of the most common natural resources of aerosol particles in the atmosphere. This grinding procedure and the verification that the particles size distribution shifted is a stepping stone for our future research on exposure of these particles to human lung cells. Brown DM, Wilson MR, MacNee W, Stone V, Donaldson K. (, Kusaka Y, Kumagai S, Kyono H, Kohyama N, Shirakawa T. (, Oberdorster G, Gelein RM, Ferin J, Weiss B. As the particle number or surface area per unit mass increases with decreasing particle size within an aerosol, the presence of sub-micrometer particles becomes increasingly significant as exposure metrics other than mass are considered. You might need to clean your shelves and brush off your favorite figures, and second, that visible dust is only a small percentage of all dust. Yang CJ, et al. The ROS levels increased significantly, similar to the results of this experiment. 5 and and66 The data were subjected to multiple linear regression and showed that the order of influence of the factors on LDH and ROS was the time of exposure to the dust, the dust concentration, and the dust type. ), and then, the histopathology of their lung tissue was examined. Implementing dust control equipment significantly reduces the risk of dust-related illnesses. gravimetric) sampling is typically conducted to characterize grinding operations (Lehmann and Frohlich, 1988; Thorpe and Brown, 1994) for comparison with various exposure criteria (ACGIH, 1990; NIOSH, 1992; OSHA, 1997). 2e). In this study, high-speed grinding was used to test the hypothesis that ultrafine particles do not form a substantial component of mechanically generated aerosols. Grinding typically occurs on a wide variety of substrates. Dust particles>10m enter through the nasal cavity and are deposited mainly in the back of the pharynx24. Fig. Radi S, et al. Shrestha S, et al. The https:// ensures that you are connecting to the Given the unlikely probability that aerosols were created from the grinding wheel, this measurement represented the aerosols produced primarily by the grinding tool motor. The lack of non-organic carbonaceous particles indicated that most of the ultrafine aerosol was associated with incomplete combustion and probably contained a large number of volatile components that evaporated in the TEM. 2b). Clearly, there is further research to be carried out in this area. with an unused sintered aluminum oxide grinding wheel. Processes and pieces of equipment that generate dust particles in industrial jobs include: With all these processes creating hazardous dust, steps to prevent dust and actively remove dust from the air must be taken.
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