• Proceedings of the KSEEG Conference
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• 2004.12a
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• pp.9-28
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• 2004

Concern about arsenic is increasing throughout the world, including areas of the United States. Elevated levels of arsenic above current drinking-water regulations in ground and surface water can be the result of purely natural phenomena, but often are due to anthropogenic activities, such as mining and agriculture. The current study correlates arsenic speciation in acid mine drainage and mining influenced water with the important water-chemistry properties Eh, pH, and iron(III) concentration. The results show that arsenic speciation is generally in equilibrium with iron chemistry in low pH AMD, which is often not the case in other natural-water matrices. High pH mine waters and groundwater do not 짐ways hold to the redox predictions as well as low pH AMD samples. The oxidation and precipitation of oxyhydroxides depletes iron from some systems, and this also affects arsenite and arsenate concentrations differently through sorption processes.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.5
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• pp.727-733
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• 2006

This experiment was conducted to investigate the effect of arsenic ($As^{III}$) on lipid peroxidation, glutathione content and antioxidant enzymes in growing pigs. Ninety-six Duroc-Landrace-Yorkshire crossbred growing pigs (48 barrows and 48 gilts, respectively) were randomly assigned to four groups and each group was randomly assigned to three pens (four barrows and four gilts). The four groups received the same corn-soybean basal diet which was supplemented with 0, 10, 20, 30 mg/kg As respectively. Arsenic was added to the diet in the form of $As_2O_3$. The experiment lasted for seventy-eight days after a seven-day adaptation period. Malondialdehyde (MDA) levels, glutathione (GSH) contents and superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione-S-transferase (GST) activities were analyzed in serum, livers and kidneys of pigs. The results showed that pigs treated with 30 mg As/kg diet had a decreased average daily gain (ADG) (p<0.05) and an increased feed/gain ratio (F/G) (p<0.05) compared to the controls. The levels of MDA significantly increased (p<0.05), and the contents of GSH and the activities of SOD, CAT, GPx, GR and GST significantly decreased (p<0.05) in the pigs fed 30 mg As/kg diet. The results indicated that the mechanism of arsenic-induced oxidative stress in growing pigs involved lipid peroxidation, depletion of glutathione and decreased activities of some enzymes, such as SOD, CAT, GPx, GR and GST, which are associated with free radical metabolism.

• Nutrition Research and Practice
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• v.8 no.1
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• pp.46-53
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• 2014

Inorganic arsenic (iAs) is a toxic metalloid found ubiquitously in the environment. In humans, exposure to iAs can result in toxicity and cause toxicological manifestations. Arsenic trioxide ($As_2O_3$) has been used in the treatment for acute promyelocytic leukemia. The kidney is the critical target organ of trivalent inorganic As ($iAs^{III}$) toxicity. We examine if oral administration of astaxanthin (AST) has protective effects on nephrotoxicity and oxidative stress induced by $As_2O_3$ exposure (via intraperitoneal injection) in rats. Markers of renal function, histopathological changes, $Na^+-K^+$ ATPase, sulfydryl, oxidative stress, and As accumulation in kidneys were evaluated as indicators of $As_2O_3$ exposure. AST showed a significant protective effect against $As_2O_3$-induced nephrotoxicity. These results suggest that the mechanisms of action, by which AST reduces nephrotoxicity, may include antioxidant protection against oxidative injury and reduction of As accumulation. These findings might be of therapeutic benefit in humans or animals suffering from exposure to $iAs^{III}$ from natural sources or cancer therapy.

• Journal of Soil and Groundwater Environment
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• v.27 no.1
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• pp.25-30
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• 2022

Mackinawite (FeS), as a ubiquitous reduced iron mineral, is known as a key controller of redox reactions in anaerobic subsurface environment. The reaction of FeS with redox-sensitive toxic element such as arsenic is substantially affected by pH conditions of the given environments. In this study, the interaction of As(V) with FeS was studied under strict anaerobic conditions with various pH conditions. The pH-dependent arsenic removal tests were conducted under wide ranges of pH conditions and X-ray absorption spectroscopy (XAS) was applied to investigate the reaction mechanisms under pH 5, 7, and 9. The removal efficiency of FeS for As(V) showed the higher removal of As(V) under low pH conditions and its removal efficiency decreased with increasing pH, and no As(V) reduction was observed in 1 g/L FeS solution. However, XAS analysis indicated the reduction of As(V) to As(III) occurred during reaction between FeS and As(V). The reduced form of As(III) was particularly identified as an arsenic sulfide mineral (As₂S₃) in all pH conditions (pH 5, 7, and 9). As₂S₃ precipitation was more pronounced in pH 5 where the solubility of FeS is higher than in other pH conditions. The linear combination fitting results of XAS demonstrated that As(V) removal mechanism is concerted processes of As₂S₃ precipitation and surface complexation of both arsenic species.

• Proceedings of the KSEEG Conference
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• 2007.04a
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• pp.342-342
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• 2007

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• Bulletin of the Korean Chemical Society
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• v.27 no.6
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• pp.903-908
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• 2006

Various extraction procedures were investigated using reference materials and samples to evaluate extraction efficiency and effectiveness. Inductively coupled plasma mass spectrometry (ICP-MS) was used to measure total arsenic and to quantitate arsenic species when coupled to an HPLC (high pressure liquid chromatography). Arsenic species were extracted from rice flour (NIST SRM 1568a) with water/methanol mixtures using accelerated solvent extraction (ASE). Total arsenic extraction efficiency ranged from 42 to 64%, for water and various methanol concentrations. From spinach (NIST SRM 1570), freeze-dried apple, and rice flour (NIST SRM 1568a), arsenic species were extracted with trifluoroacetic acid (TFA) at 100 ${^{\circ}C}$. Total arsenic extraction efficiency was 90% for spinach, 75% for freeze-dried apple, and 83% for rice flour. Enzymatic extraction with alpha-amylase and sonication resulted in extraction efficiency of 104% for rice flour, 98% for freeze-dried apple, and 7% for spinach. Chromatograms of arsenic species extracted by the optimum extraction methods were obtained, and the species were quantified. Arsenite (As(III)), arsenate (As(V)), dimethylarsinic acid (DMA), and monomethylarsonic acid (MMA) were found in the apple sample, and DMA and As(V) in the rice flour sample. As(V) and MMA were found in three herbal dietary supplement samples.

• Reproductive and Developmental Biology
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• v.38 no.3
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• pp.107-114
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• 2014

Oral exposure of humans by excess amounts of arsenic may cause disturbances of the reproductive system. In the present study, such exposure was modelled in rats, with the support of sperm principal parameters and histopathological observations. Male Sprague-Dawley rats were randomly divided into three groups where the group I was served as a normal control, group II was received sodium meta-arsenite as arsenic (10 mg/kg b.w/day) and a combination of sodium meta-arsenite and sodium selenite (3 mg/kg b.w/day) in group III. After 6 weeks, there was no significant change in testis weight and in total motility of all the three experimental groups, whereas, rapid moving spermatozoa, moderately moving spermatozoa and slow moving spermatozoa were significantly decreased in arsenic treated rats as compared to control rats. The other sperm principal parameters like progressiveness, average path velocity, straightness linear velocity (VSL), curvilinear velocity (VCL), straightness, linearity sperm head elongation ratio, area, linearity amplitude of lateral head department (ALH) and beat cross frequency (BCF) were found to be reduced in arsenic intoxicated rats. These results are not correlated with the histological studies. On oral administration of selenium ameliorated the adverse effects of arsenic as compared to arsenic alone treated rats. Our findings clearly demonstrate that administration of selenium could prevent some of the deleterious effects of arsenic in the testis.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.2
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• pp.73-80
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• 2015

Arsenic which is found in several different chemical forms and oxidation states and causes acute and chronic adverse health effects is a toxic trace element widely distributed in soils and aquifers from both geologic and anthropogenic sources. Arsenic which has a mysterious ability to change color, behavior, reactivity, and toxicity has diverse chemical behavior in the natural environment. Arsenic which has stronger ability to readily change oxidation state than nitrogen and phosphorus due to a consequence of the electronic configuration of its valence orbitals with partially filled states capable of both electron donation and acceptance although the electronegativity of arsenic is greater than that of nitrogen and similar to that of phosphorus. Arsenate (V) is the thermodynamically stable form of As under aerobic condition and interacts strongly with solid matrix. However, it has been known that adsorption and oxidation reactions of arsenite (III) which is more soluble and mobile than As(V) in soils are two important factors affecting the fate and transport of arsenic in the environment. That is, the movement of As in soils and aquifers is highly dependent on the adsorption-desorption reactions in the solid phase. This article, however, focuses primarily on understanding the fate and speciation of As in soils and what fate arsenic will have after it is incorporated into soils.

• Journal of the Mineralogical Society of Korea
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• v.22 no.3
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• pp.177-189
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• 2009

Iron (oxyhydr)oxides commonly form as secondary minerals of high reactivity and large surface area resulting from alteration and weathering of primary minerals, and they are efficient sorbents for inorganic and organic contaminants. Accordingly, they have a great potential in industrial applications and are also of substantial interest in environmental sciences. Goethite (${\alpha}$-FeOOH) is one of the most ubiquitous and stable forms of iron (oxyhydr)oxides in terrestrial soils, sediments, and ore deposits, as well as a common weathering product in rocks of all types. This study focused on adsorption reaction as a main mechanism in scavenging arsenic using goethite. Goethite was synthesized in the laboratory to get high purity, and a variety of mineralogical and physicochemical features of goethite were measured and related to adsorption characteristics of arsenic. To compare differences in adsorption reactions between arsenic species, in addition, a variety of experiments to acquire adsorption isotherm, adsorption edges, and adsorption kinetics were accomplished. The point of zero charge (PZC) of the laboratory-synthesized goethite was measured to be 7.6, which value seems to be relatively higher, compared to those of other iron (oxyhydr)oxides. Its specific surface area appeared to be $29.2\;m^2/g$ and it is relatively smaller than those of other (oxyhydr)oxides. As a result, it was speculated that goethite shows a smaller adsorption capacity. It is likely that the affinity of goethite is much more larger for As(III) (arsenite) than for As(V) (arsenate), because As(III) was observed to be much more adsorbed on goethite than As(V) in equivalent pH conditions. When the adsorption of each arsenic species onto goethite was characterized in various of pH, the adsorption of As(III) was largest in neutral pH range (7.0~9.0) and decreased in both acidic and alkaline pH conditions. In the case of As(V), the adsorption appeared to be highest in the lowest pH condition, and then decreased with an increase of pH. This peculiarity of arsenic adsorption onto goethite might be caused by macroscopic electrostatic interactions due to variation in chemical speciation of arsenic and surface charge of goethite, and also it is significantly affected by change in pH. Parabolic diffusion model was adequate to effectively evaluate arsenic adsorption on goethite, and the regression results show that the kinetic constant of As(V) is larger than that of As(III).

• Korean Journal of Food Science and Technology
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• v.41 no.1
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• pp.1-6
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• 2009

This study investigated arsenic speciation and risk assesment in 30 samples of hijiki purchased from local market in 10 Korean cities. The mean arsenic concentration of the hijiki samples was 45.65 mg/kg (dryness; moisture content of 91.1${\pm}$1.6%), and the major arsenic compound was arsenate [As(V)]. The concentrations of As(V) and As(III), as inorganic arsenic compounds, were detected to be 40.36 mg/kg and 0.37 mg/kg, respectively, and made up 88.6% (40.46 mg/kg) of the arsenic in the hijiki. Among the samples, the highest inorganic arsenic concentration was identified at 9.19 mg/kg (wet), and for an adult with a body weight of 60 kg was within an acceptable level as 0.7% (6.43 mg/60 kg/week) when compared with the provisional tolerable weekly intake (PTWI) (900 mg/60 kg/week), and would be considered safe with respect to health-hazardous effects.