• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.3
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• pp.263-271
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• 2014

Objectives: Along with the several cases of pulmonary disorders caused by exposure to indium that have been reported in Japan, China, and the United States, cases of Korean workers involved in processes that require handling of indium compounds with potential risk of exposure to indium compounds have also been reported. We performed biological monitoring for workers in various target manufacturing processes of indium, indium oxide, and indium tin oxide(ITO)/indium zinc oxide(IZO) in domestic factories. Materials: As biological exposure indices, we measured serum concentrations of indium using inductively coupled plasma mass spectrometry, and Krebs von den Lungen 6(KL-6) and surfactant protein D(SP-D) using enzyme-linked immunosorbent assays. We classified the ITO/IZO target manufacturing process into powdering, mixing, molding, sintering, polishing, bonding, and finishing. Results: The powdering process workers showed the highest serum indium level. The mixing and polishing process workers also showed high serum indium levels. In the powdering process, the mean indium serum concentration in the workers exceeded $3{\mu}g/L$, the reference value in Japan. Of the powdering, mixing, and polishing process workers, 83.3%, 50.0%, and 24.5%, respectively, had values exceeding the reference value in Japan. We suppose that the reason of the higher prevalence of high indium concentrations in powder processing workers was that most of the particles in the powdering process were respirable dust smaller than $10{\mu}m$. The mean KL-6 and SP-D concentrations were high in the powdering, mixing, and polishing process workers. Therefore, the workers in these processes who were at greater risk of exposure to indium powder were those who had higher serum levels of indium, as well as KL-6 and SP-D. We observed significant differences in serum indium, KL-6, and SP-D levels between the process groups. Conclusions: Five among the seven reported cases of "indium lung" in Japan involved polishing process workers. Polishing process workers in Korea also had high serum levels of indium, KL-6, and SP-D. The outcomes of this study can be used as essential bases for establishing biological monitoring measures for workers handling indium compounds, and for developing health-care guidelines and special medical surveillance in Korea.

• The Journal of the Petrological Society of Korea
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• v.24 no.2
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• pp.141-147
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• 2015

Using laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), we evaluated the reliability of trace element abundance data measured from the silicate rock references of JR-3, JG-3, JGb-1 and JB-1b using glass discs made by alkali fusion. For 28 elements including rare earth elements, relative standard deviations (RSD) are better than 7% in case when the concentrations of the elements in the rock samples are greater than 10 ppm. However, RSD shows somewhat increased values for the concentrations less than 10 ppm, but never exceeds 25%. Compared with previously reported averages of the compiled abundance data, our data display satisfactory results for the most cases with differences less than 10%. We suggest that LA-ICP-MS analysis using fused glass beads is a reliable, precise and time-saving method of trace element analysis for the silicate rocks spanning from mafic to felsic compositions.

• Journal of the Korean Chemical Society
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• v.41 no.4
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• pp.180-185
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• 1997

Zinc, cadmium, lead and copper were simultaneously determined by depositing metals at - 1.200 V vs. a Ag/AgCl(sat. KCl) reference electrode for 150 seconds on a hanging mercury drop electrode(HMDE) or a thin mercury film electrode(TMFE), followed by scanning towards anodic direction using differential pulse voltammetric(DPASV) and square wave voltammetric(SWASV) techniques. The linear calibration curves were obtained for four metal ions simultaneously determined by DPASV with a HMDE in the concentration range between 20 and 100 ppb. However, the linear calibration plots were obtained only for $Cd^{2+}$ and $Pb^{2+}$ in the simultaneous determinations with a TMFE in the concentration range up to 100 ppb using DPASV and up to 10 ppb using SWASV. DPASV with a TMFE was about 15 times more sensitive than DPASV with a HMDE for simultaneous determinations of $Cd^{2+}$ and $Pb^{2+}$. SWASV was about 5 times more sensitive than DPASV at a TMFE. Concentrations of zinc in seven different sediment samples determined by DPASV with a HMDE and inductively coupled plasma-mass spectrometry were compared, resulting with an excellent correlation coefficient of 0.9993 and with no significant difference between two methods after t-test.

• Journal of the Mineralogical Society of Korea
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• v.23 no.4
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• pp.357-365
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• 2010

Optically stimulated luminescence (OSL) of quartz is commonly applied to the age dating of Quaternary sediments. However, one of the issues is that some of the quartz samples are not suitable to OSL dating. Mineralogical analysis of the quartz samples with diverse OSL signals are required to strengthen the reliability and applicability of the OSL dating. We analysed the OSL signal characteristics of sedimentary quartz samples from diverse geological environments and measured their trace element contents using laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Quartz samples could be grouped into ones suitable to OSL dating and ones unsuitable on the basis of their OSL signal characteristics. The average trace element contents ranged from 73 to 260 ppm (Al), and from 61 to 248 ppm (Ti) with minor Li, Mg, Cr, Mn, and Fe contents below 40 ppm. We did not find any significant variation of trace element contents of quartz samples consistent with their OSL signal characteristics. This indicates unknown mineralogical factors causing diverse OSL characteristics which should be confirmed by further analysis of sufficient set of samples.

• Korean Journal of Food Science and Technology
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• v.46 no.3
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• pp.283-287
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• 2014

This study determined the hazardous heavy metal content of mushrooms from markets in Seoul, Korea. One hundred and fifty mushroom samples were digested by the microwave method then the hazardous heavy metal (Pb, Cd, As, Cr, Ni and Hg) content was determined by the inductively coupled plasma-mass spectrometry (ICP-MS) and mercury analyzer. The average values of heavy metals in the samples were as follows: (mean [minimum-maximum], ${\mu}g/kg$); Pb 7.8 (1.9-30.0), Cd 45.3 (0.7-292.4), As 54.6 (24.2-229.3), Cr 42.6 (8.4-334.3), Ni 22.4 (up to 180.4), and Hg 8.9 (2.0-25.0). The contents of hazardous heavy metal in mushrooms were lower than those reported previously and also lower than the Provisional Tolerable Weekly Intake (PTWI) limit prescribed by the FAO/WHO. Thus, it could be suggested that the hazardous heavy metals levels in the mushrooms of retail market were adequately safe for consumption.

• Journal of Nutrition and Health
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• v.37 no.3
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• pp.193-201
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• 2004

The objective was to evaluate the factors influencing on the growth of children aged 3 - 6 years by mini dietary assessment and anthropometric indices in 556 children and by analyzing mineral contents of hair from 273 children by inductively coupled plasma mass spectrometry (ICP-MS). The mean concentration of zinc (Zn) in hair was 68.9 $\pm$ 31.1 ppm and the zinc level of 91 ％ children was less than 60％ of the reference value of 180 ppm. The mean content of lead (Pb) in hair was 1.76 $\pm$ 1.20 ppm, but only 67％ of 273 children was within the reference value of 2 ppm and the lead level of 33％ of children was 2 - 4 times higher than the reference value. The level of Zn was negatively correlated with Pb content (r = -0.305, p 〈 0.01). Hair Zn content, regardless of age, was significantly positively correlated with height (r = 0.214) and body weight (r = 0.159). The height of 95.3％ children was belonged to the normal range of 90 - 109.9％ of standard value and the body weight of 49.8％ children was in the range of 90 - 109.9％ of standard value. However, 8.1 ％ children was overweighted (110 - 119.9％ of standard) and 9.4％ children was obese (120 - 149.9％ of standard) and 0.9％ children was severe obese (〉 150％) which resulted in total 10.3％ obese. Contrary to our expectation, 32.8％ children was underweight (70 - 89.9％ of standard) and 36％ of the underweight children showed the low content of zinc (10 - 49 ppm) in hair. There was no significant correlation between dietary intake of Zn and hair Zn content. Hair Zn content was low even though children consumed greater than 75％ of their requirement for zinc. Regardless of dietary intake of Zn, hair Zn level was rather negatively correlated to the content of Pb in hair. 38.8％ children had an unbalanced diet which resulted in lower intake of calorie, Ca, Zn, vitamin B$_2$ compared with those consuming variety of foods. Therefore, it would be needed that new approach for nutrition education to improve eating habit having the unbalanced diet in preschool children. It might be also suggested to develop new food products to complement the nutrients of Zn, Ca, Fe as snacks or dietary supplement for Korean preschool children.

• Safety and Health at Work
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• v.10 no.3
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• pp.377-383
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• 2019

Objectives: Exposure to fine particles in urban air has been associated with a number of negative health effects. High levels of fine particles have been detected at underground stations in big cities. We investigated the exposure conditions in four occupational groups in the Stockholm underground train system to identify high-exposed groups and study variations in exposure. Methods: $PM_1$ and $PM_{2.5}$ were measured during three full work shifts on 44 underground workers. Fluctuations in exposure were monitored by a real-time particle monitoring instrument, pDR, DataRAM. Qualitative analysis of particle content was performed using inductively coupled plasma mass spectrometry. Nitrogen dioxide was measured using passive monitors. Results: For all underground workers, the geometric mean (GM) of $PM_1$ was $18{\mu}g/m^3$ and of $PM_{2.5}$ was $37{\mu}g/m^3$. The particle exposure was highest for cleaners/platform workers, and the GM of $PM_1$ was $31.6{\mu}g/m^3$ [geometric standard deviation (GSD), 1.6] and of $PM_{2.5}$ was $76.5{\mu}g/m^3$ (GSD, 1.3); the particle exposure was lowest for ticket sellers, and the GM of $PM_1$ was $4.9{\mu}g/m^3$ (GSD, 2.1) and of $PM_{2.5}$ was $9.3{\mu}g/m^3$ (GSD, 1.5). The $PM_1$ and $PM_{2.5}$ levels were five times higher in the underground system than at the street level, and the particles in the underground had high iron content. The train driver's nitrogen dioxide exposure level was $64.1{\mu}g/m^3$ (GSD, 1.5). Conclusions: Cleaners and other platform workers were statistically significantly more exposed to particles than train drivers or ticket sellers. Particle concentrations ($PM_{2.5}$) in the Stockholm underground system were within the same range as in the New York underground system but were much lower than in several older underground systems around the world.

• Korean Journal of Community Nutrition
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• v.26 no.1
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• pp.48-55
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• 2021

Objectives: This study was conducted to estimate the dietary iodine intake of Koreans by a Total Diet Study (TDS) which provides 'closer-to-real' estimates of exposure to hazardous materials and nutrients through an analysis of table-ready (cooked) samples of foods. Methods: Dietary intake data from 2013-2017 Korea National Health and Nutrition Examination Survey (KNHANES) was used to select representative foods (RFs) for iodine analysis. A total of 115 RFs were selected and 158 'RF × cooking method-combination' pairs were derived by pairing each RF to corresponding cooking method(s) used more frequently. RFs were collected from 9 mega-markets in 9 metropolitan cities nationwide and mixed into composites prior to cooking preparation to a 'table ready' state for iodine analysis by inductively coupled plasma mass spectrometry. Iodine intake of Koreans was estimated based on the food intake data of the 2016-2018 KNHANES. Results: High iodine content was detected in seaweeds such as sea mustard and kelp. The mean iodine intake/capita/day was 418.4 ㎍ and the median value was 129.0 ㎍. Seaweeds contributed to 77.4% of the total iodine intake and the contribution by food item was as follows: sea mustard (44.0%), kelp (20.4%), laver (13.1%), milk (3.9%), egg (3.5%). Compared to the Dietary Reference Intakes for Koreans 2020, the proportion of people with iodine intake exceeding the tolerable upper intake level or below the estimated average requirement was high in the physiologically vulnerable groups (infants, children, pregnant women, and lactating women). Conclusions: The results, drawn from a TDS, are regarded closer to real estimates for iodine intake of Koreans compared with values in existing literature, which were based on a very limited variety of foods. On the other hand, it seems necessary to seek out solutions for the problematic iodine intake among physiologically vulnerable groups through in-depth analyses on food intake data collected with significant scale & quality.

• Journal of Environmental Health Sciences
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• v.47 no.6
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• pp.530-539
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• 2021

Background: In South Korea, areas around abandoned metal mines are designated as regions with high arsenic (As) contamination. However, studies assessing urinary As exposure, As metabolism, and relevant genetic polymorphisms in residents of these metal mine areas are lacking. Objectives: To identify factors associated with As exposure and evaluate the effects of MTHFR, As3MT, and GSTO1 genetic polymorphisms on As metabolism in residents of abandoned metal mine areas by measuring urinary As species. Methods: Urinary As species (arsenite [As³⁺], arsenate [As⁵⁺], monomethyl arsonic acid, and dimethylarsinic acid) were isolated using high-performance liquid chromatography in combination with inductively coupled plasma mass spectrometry (HPLC-ICP-MS). Four genetic polymorphisms (MTHFR A222V, MTHFR E429A, GSTO1 A140D, As3MT M287T) were analyzed in 144 residents of four areas around abandoned metal mines. Results: The study sample was comprised of 34.7% men and 65.3% women, with a mean age of 70.7±10.9 years. The urinary inorganic As concentration was higher among those consuming more than half locally produced rice (0.31 ㎍/L) than those consuming less than half such rice (0.18 ㎍/L). The urinary dimethylarsinic acid concentration was higher in the group that had consumed seafood in the past day (31.68 ㎍/L) than in those who had not (22.37 ㎍/L). Furthermore, individuals heterozygous in the MTHFR A222V and GSTO1 A140D polymorphism had higher urinary arsenic species concentrations than did individuals with a wild type or homozygous for the variant allele. Conclusions: Consumption of locally produced rice was associated with inorganic As exposure, whereas seafood consumption was associated with organic As exposure among residents of abandoned metal mine areas. There was no clear association between MTHFR A222V and GSTO1 A140D polymorphisms and As metabolism.

• Korean Journal of Community Nutrition
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• v.27 no.3
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• pp.245-253
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• 2022

Objectives: This study was conducted to find out if the dietary iron intake of Koreans estimated by 2 different methods (iron content sources) using the food intake data from the Korea National Health and Nutrition Examination Survey (KNHANES) are comparable. One method was based on the KNHANES's Food & Nutrient Database (FND) derived mainly from the Korean Food Composition Table and the other used the iron content (IC) of food samples processed in the Korean Total Diet Study (KTDS). Methods: Dietary intake data from the 2013-2016 KNHANES was used to select representative foods (RFs) in KTDS for iron analysis. Selection of the RFs and cooking methods for each RF (RF × cooking method pair) was performed according to the 'Guidebook for Korean Total Diet Studies' and resulted in a total of 132 RFs and 224 'RF × cooking method' pairs. RFs were collected in 9 metropolitan cities nationwide once or twice (for those with seasonality) in 2018 and made into 6 composites each, based on the origin and season prior to cooking. Then, the RF composites prepared to a 'table ready' state for KTDS were analyzed by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Dietary iron intake of the Korean population was estimated using only RFs' intake data based on the 2 sources of iron content, namely FND-KNHANES and IC-KTDS. Results: RFs in KTDS covered 92.0% of total food intake of Koreans in the 2016-2018 KNHANES. Mean iron intake of Koreans was 7.77 mg/person/day by IC-KTDS vs 9.73 mg/person/day by FND-KNHANES. The major food groups contributing to iron intake were meats (21.7%), vegetables (20.5%), and grains & cereals (13.4%) as per IC-KTDS. On the other hand, the latter source (FND-KNHANES) resulted in a very different profile: grains & cereals (31.1%), vegetables (16.8%), and meats (15.3%). While the top iron source was beef, accounting for 8.6% in the former, it was polished rice (19.2%) in the latter. There was a 10-fold difference in the iron content of polished rice between 2 sources that iron intakes excluding the contribution by polished rice resulted in very similar values: 7.58 mg/person/day by IC-KTDS and 7.86 mg/person/day by FND-KNHANES. Conclusions: This study revealed that the dietary iron intake estimated by 2 different methods were quite comparable, excluding one RF, namely polished rice. KTDS was thus proven to be a useful tool in estimating a 'closer-to-real' dietary intake of nutrients for Koreans and further research on various nutrients is warranted.