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Park J.H.,Seoul National University | Park J.H.,Daegu Technopark Bio Industry Center | Kwon J.-T.,Seoul National University | Minai-Teherani A.,Seoul National University | And 6 more authors.
Toxicological Research | Year: 2013

In the workplace, the arsenic is used in the semiconductor production and the manufacturing of pigments, glass, pesticides and fungicides. Therefore, workers may be exposed to airborne arsenic during its use in manufacturing. The purpose of this study was to evaluate the potential toxicity of particulate matters (PMs) doped with arsenic (PMs-Arsenic) using a rodent model and to compare the genotoxicity in various concentrations and to examine the role of PMs-Arsenic in the induction of signaling pathway in the lung. Mice were exposed to PMs 124.4 ± 24.5 μg/m3 (low concentration), 220.2 ± 34.5 μg/m3 (middle concentration), 426.4 ± 40.3 μg/m3 (high concentration) doped with arsenic 1.4 μg/m3 (Low concentration), 2.5 μg/m3 (middle concentration), 5.7 μg/m3 (high concentration) for 4 wks (6 h/d, 5 d/wk), respectively in the whole-body inhalation exposure chambers. To determine the level of genotoxicity, Chromosomal aberration (CA) assay in splenic lymphocytes and Supravital micronucleus (SMN) assay were performed. Then, signal pathway in the lung was analyzed. In the genotoxicity experiments, the increases of aberrant cells were concentration-dependent. Also, PMs-arsenic caused peripheral blood micronucleus frequency at high concentration. The inhalation of PMs-Arsenic increased an expression of phosphorylated Akt (p-Akt: protein kinase B) and phpsphorylated mammalian target of rapamycin (p-mTOR) at high concentration group. Taken together, inhaled PMs-Arsenic caused genotoxicity and altered Akt signaling pathway in the lung. Therefore, the inhalation of PMs-Arsenic needs for a careful risk assessment in the workplace. Source


Lee J.H.,Hoseo University | Lee S.-B.,Korea Institute of Science and Technology | Bae G.N.,Korea Institute of Science and Technology | Jeon K.S.,HCT Co. | And 9 more authors.
Inhalation Toxicology | Year: 2010

Seven CNT (carbon nanotube) handling workplaces were investigated for exposure assessment. Personal sampling, area sampling, and real-time monitoring using an SMPS (scanning mobility particle sizer), dust monitor, and aethalometer were performed to characterize the mass exposure, particle size distribution, and particle number exposure. No workplace was found to exceed the current ACGIH (American Conference of Governmental Industrial Hygienists) TLVs (threshold limit values) and OELs (occupational exposure levels) set by the Korean Ministry of Labor for carbon black (3.5mg/m3), PNOS (particles not otherwise specified; 3mg/m3), and asbestos (0.1 fiber/cc). Nanoparticles and fine particles were most frequently released after opening the CVD (chemical vapor deposition) cover, followed by catalyst preparation. Other work processes that prompted nanoparticle release included spraying, CNT preparation, ultrasonic dispersion, wafer heating, and opening the water bath cover. All these operation processes could be effectively controlled with the implementation of exposure mitigation, such as engineering control, except at one workplace where only natural ventilation was used. © 2010 Informa UK Ltd. Source


Kim J.-E.,Korea Advanced Institute of Science and Technology | Lim H.-T.,Korea Advanced Institute of Science and Technology | Woo C.-G.,Nanotechnology and Thermal Processing Laboratory | Choi M.,Nanotechnology and Thermal Processing Laboratory | And 9 more authors.
Journal of Toxicology and Environmental Health - Part A: Current Issues | Year: 2010

Carbon nanotubes (CNT) are known to have widespread industrial applications; however, several reports indicated that these compounds may be associated with adverse effects in humans. In this study, multiwalled carbon nanotubes were administered to murine lungs intratracheally to determine whether acute and chronic pulmonary toxicity occurred. In particular, pristine multiwalled carbon nanotubes (PMWCNT) and acid-treated multiwalled carbon nanotubes (TMWCNT) were used in this study. In broncheoalveolar lavage fluid (BALF) cell analysis, PMWCNT induced more severe acute inflammatory cell recruitment than TMWCNT. Histopathologically, both PMWCNT and TMWCNT induced multifocal inflammatory granulomas in a dose-dependent manner. The observed granulomas were reversible, with TMWCNT-induced granulomas diminishing faster than PMWCNT-induced granulomas. Although the area of granuloma reduced with time, hyperplasia and dysplastic characteristics such as mitotic figures, anisokaryosis, and anisocytosis were still observed. These findings demonstrate that MWCNT induces granulomatous inflammation, and the duration and pattern of inflammation seem to vary depending upon the types of MWCNT to which mice are exposed. Therefore, toxicity studies on various types of CNT are needed as the responsiveness to these compounds differs. Copyright © Taylor & Francis Group, LLC. Source


Jeong G.N.,Pusan National University | Jo U.B.,Pusan National University | Ryu H.Y.,Korea Environment and Merchandise Testing Institute | Kim Y.S.,Korea Environment and Merchandise Testing Institute | And 3 more authors.
Archives of Toxicology | Year: 2010

To investigate the effects of silver nanoparticles on the histological structure and properties of the mucosubstances in the intestinal mucosa, Sprague-Dawley rats were divided into four groups (10 rats in each group): vehicle control, low-dose group (30 mg/kg), middle-dose group (300 mg/kg), and high-dose group (1,000 mg/kg), and administered silver nanoparticles (60 nm) for 28 days, following OECD test guideline 407 and using GLP. The control sections contained no silver nanoparticles; however, the treated samples showed luminal and surface particles and the tissue also contained silver nanoparticles. A dose-dependent increased accumulation of silver nanoparticles was observed in the lamina propria in both the small and large intestine, and also in the tip of the upper villi in the ileum and protruding surface of the fold in the colon. The silver nanoparticle-treated rats exhibited higher numbers of goblet cells that had released their mucus granules than the controls, resulting in more mucus materials in the crypt lumen and ileal lumen. Moreover, cell shedding at the tip of the villi was frequent. Lower amounts of neutral and acidic mucins were found in the goblet cells in the silver nanoparticle-treated rats, plus the amount of sialomucins was increased, while the amount of sulfomucins was decreased. In particular, in the colon of the silver nanoparticle-treated rats, sialyated mucins were detected in the lamina propria, the connective tissue under the epithelia. Therefore, the present results suggest that silver nanoparticles induce the discharge of mucus granules and an abnormal mucus composition in the goblet cells in the intestines. © 2009 Springer-Verlag. Source


Cho J.H.,Sungkyunkwan University | Kulkarni A.,Sungkyunkwan University | Kim H.,Sungkyunkwan University | Yoon J.U.,HCT Co. | And 3 more authors.
Journal of Mechanical Science and Technology | Year: 2010

Silver nanoparticles are among the fastest growing product categories in the nanotechnology industry. Several experimental studies reported earlier for its toxicity and its associated risks. Uniform distribution of nanoparticle concentration in inhalation toxicity exposure chambers is important in the conduct of inhalation experimental evaluation. However, relatively little is known. Several factors, including nanoparticle size, degree of mixing, and chamber design, may influence the nanoparticles distribution in whole-body exposure chamber. In the present work we investigated numerically the silver nanoparticles concentration distribution and particle trajectory in the whole body inhalation toxicity test chamber. A three dimensional numerical simulation was performed using the commercially available computational fluid dynamics code Fluent with two models, discrete phase model (DPM) and fine particle model (FPM) to calculate spatial particle trajectories and concentration. The simulated results show that the silver nanoparticle trajectories and concentration distribution are dependent on inhalation toxicity chamber geometry. © 2010 The Korean Society of Mechanical Engineers and Springer-Verlag Berlin Heidelberg. Source

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