• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.26 no.1
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• pp.11-19
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• 2016

Objectives: Exposure to volatile organic compounds such as trichloroethylene(TCE) and perchloroethylene(PCE), along with Agent Orange, that were issued around Camp Carroll US Army Base situated in Waegwan, Chilgok-gun, Gyeongsangbuk-do Province, Korea. The main objective of this study was to assess the exposure to TCE and PCE of residents of the area surrounding Camp Carroll. Methods: The TCE, PCE and trichloroethanol(TCEOH) concentrations in blood and trichlroroacetic acid(TCA) and TCEOH concentrations in urine were measured and analyzed in a total of 1,033 residents around Camp Carroll. TCA and TCEOH are metabolites of TCE and PCE, respectively. The information on demographic characteristics and exposure variables in relation to underground water were obtained through a questionnaire completed by the subjects. Results: TCE, PCE and TCEOH concentrations were not detected in blood. Detection rates of TCA and TECOH concentrations in urine were 98.5% and 36.6%, respectively. Creatinine-corrected average TCA and TCEOH concentrations were $12.23{\pm}23.81{\mu}g/g$ and $0.66{\pm}4.31{\mu}g/g$, respectively. A significant difference was not shown between the drinking group and no drinking group for underground water, which was assumed as a potential route of exposure to TCE and PCE through the consumption of ground water. However, females drinking ground water showed a significantly higher mean level of TCA in urine than did males. There was no significant difference according to drinking ground water as a potential source of exposure to TCE and PCE in residents around Camp Carroll. Conclusions: Considering the statistical analysis of factors affecting exposure to TCE and PCE in ground water along with previous reports, TCA in urine as exposure to TCE and PCE might not be appropriate because it is found in chlorinated drinking water. Therefore, TCA concentration in urine may be the result of drinking of chlorinated water.

• Journal of Ecology and Environment
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• v.29 no.5
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• pp.453-460
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• 2006

Upo wetland is the largest inland wetland in Korea as Ramsar Convention Area. The purposes of the study were to investigate the levels of heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) in the sediment and Cipangopaludina chinensis malleata from three sites of the wetland and to assess the potential of the gastropod as a bioindicator for heavy metal levels. The gastropods were dissected into shell and soft tissue without the digestive and excretive organs. The levels of Cd, Cu and Pb were below the guideline of Soil Environment Conservation Act and the heavy metals except Cr were slightly different among the sites. Cd was higher in Upo site ($0.32{\mu}g/g$) than Sajipo site ($0.28{\mu}g/g$). Cu and Zn showed the highest value in Sajipo as $43.5{\mu}g/g\;and\;39.8{\mu}g/g$, respectively while the concentrations of Pb and Zn were the highest in Upstream as $58.8{\mu}g/g\;and\;138{\mu}g/g$, respectively. In the soft tissues and shells of the gastropod, the overall common trend in the concentrations of the heavy metals was revealed with the following order: Zn > Cu > Cr > Ni > Pb > Cd and Ni > Zn > Cr > Cu > Pb > Cd, respectively. Although the soft tissues exhibited higher concentrations of the heavy metals except Ni than the shell in the gastropod, the levels of Cd and Pb in the gastropod were generally below the restrictive values set up by Korea Food & Drug Administration. From Duncan's Multiple Range Test (DMRT) results, the concentrations of Pb and Zn in the sediments among the sites were reflected on the soft tissue (Pb) and the shell (Pb and Zn) of the gastropod in the same order. The lower value of coefficient of variation (CV) in Pb concentration of the shell than in that of the soft tissue supports the usefulness of the shell as a bioindicator for Pb pollution. Although the CV value in the shell was a little higher than in the soft tissue, DMRT results and the stability of incorporated Zn into the shell support the use of the shell of the gastropod as a potential bioindicator for long-term contamination of Zn.

• Journal of the Korean Applied Science and Technology
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• v.34 no.4
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• pp.839-850
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• 2017

The objective of this study was to investigate the effect of diets with different omega-6 (n-6) and omega-3 (n-3) fatty acid ratios (0, 1.2: 1, 8: 1, 19: 1) on mechanisms of partitioning of in vivo hepatic glycerolipid metabolism in next generation rats. Biomonitoring techniques were used in rats (jugular vein cannula were attached). The range of $^{14}CO_2$ exhaled by glycerolipid metabolism was 7.05-20.17% in the group having diet with n-6/n-3 ratio less than 8:1. It was the lowest in the control group. Total glycerolipid was the highest in the control group. For groups with different n-6/n-3 ratio, it had the following order: 19:1>8:1>1.2:1. Secreted triglyceride was decreased by 36.35%, 20.93%, and 13.72% in 1.2:1,8:1, and 19:1 groups, respectively, compared to that in the control group. The ratio of phospholipid to total glycerolipid was 1.38, 1.29, and 1.17 times higher in 1.2:1, 8:1, and 19:1 groups, respectively, compared to that in the control group. The ratio of $^{14}CO_2$ to total glycerolipid was 1.61, 1.52, and 1.29 times higher in 1.2:1, 8:1, and 19:1 groups, respectively, compared to that in the control group.

• Journal of Environmental Health Sciences
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• v.45 no.5
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• pp.541-555
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• 2019

Objectives: The aim of this study is to examine heavy metal exposure levels in the blood and urine of a nationally representative adult population in Korea, and to identify the major influence factors for exposure through linkage analysis using questionnaire data. Methods: Biological samples and questionnaire data were collected from adults aged 18 and over who had participated in the Korean National Environmental Health Survey from 2009 to 2017. Lead, mercury, and cadmium exposure levels were presented with geometric mean and 95th percentiles. Multiple regression analysis was performed to determine the factors affecting heavy metal concentrations. Results: Blood lead levels increased slightly in Cycle 2 compared to Cycle 1, but decreased in Cycle 3. Blood and urinary mercury and urinary cadmium levels decreased over time. The main influence factors included gender, age, and smoking status for blood lead levels; gender, age, and intake of fish at least once a week for blood mercury levels; and age for urinary cadmium levels. Conclusion: The Korean National Environmental Health Survey is an effective tool for confirming over-time changes in exposure to lead, mercury, and cadmium in Korean adults and to identify its influence factors. The results of this study are expected to present basic data for calculating reference values and baseline exposure levels for environmental chemicals in Korean adults.

• Journal of Environmental Health Sciences
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• v.47 no.1
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• pp.64-77
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• 2021

Objective: Biological monitoring of trace elements in human blood samples has become an important indicator of the health environment. The purpose of this study was to detect and evaluate multiple metal items in blood samples based on ICP-MS, to perform comparative evaluation with the existing analysis method, and to develop and verify a new method. Methods: 100 μL of whole blood from 80 healthy subjects was used to analyze ten metals (Sb, tAs, Cd, Pb, Mn, Hg, Mo, Ni, Se, Tl) using ICP-MS. Verification of the analysis method included calculation of linearity, accuracy, precision and detection limits. In addition, a comparative test with the conventional graphite furnace atomic absorption spectroscopy (GF-AAS) method was performed. In the case of Pb, Cd, and Hg in whole blood, cross-analysis between Pb, Cd, and Hg analysis methods was performed to confirm the difference between the existing method and the new method (ICP-MS). Results: The coefficient of determination (R2) was 0.999 or higher in seven items and 0.995 or higher in three items. The Pb result showed that Pearson's correlation coefficient was very high at 0.983, and the intraclass correlation coefficient was 0.966. The Cd result showed that Pearson's correlation coefficient was 0.917 between the existing method and the new analysis concentration value. Its intraclass correlation coefficient was 0.960, and there was no significant difference between the two groups. Hg had a low correlation at 0.687, and the intraclass correlation coefficient was 0.761, which was lower than that of Pb and Cd. The intra-day and inter-day accuracy of Pd and Cd were satisfactory, but Hg did not meet the criteria for both accuracy and precision when compared with the conventional analysis method. Conclusion: This study can be meaningful in that it proposes a more efficient and feasible analysis method by verifying a blood heavy metal concentration experiment using multiple simultaneous analyses. All samples were processed and analyzed using the new ICP-MS. It was confirmed that the agreement between the two methods was very high, with the agreement between the current and new methods being 0.769 to 0.998. This study proposes an efficient simultaneous methodology capable of analyzing multiple elements with small samples. In the future, studies of various applications and the reliability of ICP-MS analysis methods are required, and research on the verification of accurate, precise, and continuous analysis methods is required.

• Journal of Environmental Health Sciences
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• v.48 no.4
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• pp.227-235
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• 2022

Background: Abandoned metal mines are classified as vulnerable areas with the highest level of soil contamination among risk regions. People living near abandoned metal mines are at increased risk of exposure to toxic metals. Objectives: This study aimed to evaluate the correlation between soil contamination levels in areas around abandoned metal mine and the blood lead levels of local residents. Moreover, we assess the possibility of using soil contamination levels as a predictive indicator for human exposure level. Methods: Data from the Survey of Residents around Abandoned Metal Mines (2013~2017, n=4,421) and Investigation of Soil Pollution in Abandoned Metal Mines (2000~2011) were used. A random coefficient model was conducted for estimation of the lower level (micro data) of the local resident unit and the upper level (macro data) of the abandoned metal mine unit. Through a fitted model, the variation of blood lead levels among abandoned metal mines was confirmed and the effect of the operationally defined soil contamination level was estimated. Results: Among the total variation in blood lead levels, the variation between abandoned mines was 18.6%, and the variation determined by the upper-level factors such as soil contamination and water contamination was 8.1%, which was statistically significant respectively. There was also a statistically significant difference in the least square mean of blood lead concentration according to the level of soil contamination (p=0.047, low: 2.32 ㎍/dL, middle: 2.38 ㎍/dL, high: 2.59 ㎍/dL). Conclusions: The blood lead concentration of residents living near abandoned metal mines was significantly correlated with the level of soil contamination. Therefore, in biomonitoring for vulnerable areas, operationally defined soil contamination can be used as a predictor for human exposure level to hazardous substances and discrimination of high-risk abandoned metal mines.

• Korean Journal of Ecology and Environment
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• v.56 no.2
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• pp.161-171
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• 2023

The medium-large cladoceran species Simocephalus spp. predominantly occur in habitats with developed aquatic vegetation. Accordingly, due to Simocephalus' high contribution to zooplankton community biomass in the lake's littoral zone and wetland habitats, estimating their biomass is important to understand the matter cycling based on biological interactions within the aquatic food web. In this study, we reviewed the length-weight regression equations used previously to estimate Simocephalus biomass, directly measured S. serrulatus' body specification (length, width and area) and their biomass(dry weight) using instruments such as a microscopic digital camera and a microscale, and performed regression analysis between each other. When S. serrulatus biomass was estimated using the equation (Kawabata and Urabe, 1998) presented in 『Biomonitoring Survey and Assessment Manual』, Korea, errors between estimates and measures were relatively large compared to the S. serrulatus species-specific biomass estimate equation developed by Lemke and Benke (2003). In addition, both equations showed not only increasing trends in error (estimate-measure) with increasing S. serrulatus' body length, but also in error variance among similar-sized individuals. The results of regression analysis with dry weight by body specifications indicated that the most appropriate equation for estimating the biomass of S. serrulatus was derived from the width-dry weight exponential regression equation (R²=0.9555). The review and development study of such species-specific biomass estimation equations for zooplankton can be used as a tool to understand their role and function in aquatic ecosystem food webs.

• Journal of Ecology and Environment
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• v.48 no.1
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• pp.32-48
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• 2024

Background: Longitudinal connectivity in river systems strongly affects biological components related to ecosystem functioning, thereby playing an important role in shaping local biodiversity and ecosystem health. Environmental DNA (eDNA)-based metabarcoding has an advantage of enabling to sensitively diagnose the presence/absence of species, becoming an efficient/effective approach for studying the community structure of ecosystems. However, little attention has been paid to eDNA-based biomonitoring for river systems, particularly for assessing the river longitudinal connectivity. In this study, by using eDNA we analyzed and compared species diversity and composition among artificial barriers to assess the longitudinal connectivity of the fish community along down-, mid- and upstream in the Hotancheon from the Geum River basin. Moreover, we investigated temporal variation in eDNA fish community structure and species diversity according to season. Results: The results of species detected between eDNA and conventional surveys revealed higher sensitivity for eDNA and 61% of species (23/38) detected in both methods. The results showed that eDNA-based fish community structure differs from down-, mid- and upstream, and species diversity decreased from down to upstream regardless of season. We found that there was generally higher species diversity at the study sites in spring (a total number of species across the sites [n] = 29) than in autumn (n = 27). Nonmetric multidimensional scaling and heatmap analyses further suggest that there was a tendency for community clusters to form in the down-, mid- and upstream, and seasonal variation in the community structure also existed for the sites. Dominant species in the Hotancheon was Rhynchocypris oxycephalus (26.07%) regardless of season, and subdominant species was Nipponocypris koreanus (16.50%) in spring and Odontobutis platycephala (15.73%) in autumn. Artificial barriers appeared to negatively affect the connectivity of some fish species of high mobility. Conclusions: This study attempts to establish a biological monitoring system by highlighting the versatility and power of eDNA metabarcoding in monitoring native fish community and further evaluating the longitudinal connectivity of river ecosystems. The results of this study suggest that eDNA can be applied to identify fish community structure and species diversity in river systems, although some shortcomings remain still need to be resolved.

• Journal of Environmental Health Sciences
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• v.50 no.1
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• pp.25-35
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• 2024

Background: There are concerns about the health effects of various environmental pollution exposures among residents living near coal-fired power plants (CFPP). Objectives: This study attempted to compare the concentrations of heavy metals in blood and urine and those of urinary volatile organic compound (VOC) metabolites according to the residential separation distance. Methods: Participants in the study totaled 334 people who have lived for more than 10 years in areas within 10 km of a CFPP. The separation distance was analyzed in quartiles by dividing it into Q1 (88 people), Q2 (89 people), Q3 (89 people), and Q4 (68 people). We explained the purpose of this study to the participants and collected blood and urine after obtaining signatures on a participation agreement. Results: The study participants were 102 males (30.5%) and 232 females (69.5%), with an average age of 71. The average length of residence and distance were 43.8 years and 4,800 meters. The geometric mean concentrations of Pb, Cd, and Hg in blood and As and Cd in urine were respective 1.35 ㎍/dL, 1.43 ㎍/L, 3.16 ㎍/L. They were 167.88 ㎍/g for creatinine and 1.58 ㎍/g creatinine. The metabolite concentrations of VOCs were 50.67 ㎍/g creatinine in t, t-muconic acid (t, t-MA), 10.73 ㎍/g creatinine in benzyl mercapturic acid, 317.05 ㎍/g creatinine in phenylglyoxylic acid, 123.55 ㎍/g creatinine in methylhippuric acid, and 190.82 ㎍/g creatinine in mandelic acid. The concentration of Pb in the blood and Cd and t, t-MA in the urine of residents within affected area of the CFPP showed statistically significant differences among distance groups. Conclusions: The concentration of urinary VOCs metabolites, especially t, t-MA, differed according to the distance groups of residents within the affected area of CFPP (p<0.05).

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.4
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• pp.298-310
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• 2007

This study compared the correlation between the accumulated copper content in earthworms and the copper concentration rate of soil measured using several methods to extract heavy metals from soil. For the experiment, a microcosm soil test was carried out using copper contaminated soil from the vicinity of copper-roofed buildings and earthworms (Eisenia fetida). Soils from the study area were used to produce 6 treatments; control, 1C (contamination level with the lowest treated copper concentration rate), 2C, 4C, 8C, and 16C (contamination level with the highest treated copper concentration rate). Microcosm soil test using the 6 treatments proved that as the copper content in soil and the experiment time increased, the growth rate of and the accumulated copper concentration rate in earthworms increased as well. The degree of the increase corresponded to the order of the treated copper concentration levels in microcosm soils. Standard method of the ministry of environment and EPA method 3051 were used to obtain the copper concentration in soil and the total copper content in soil, respectively. The correlation coefficient (r) of 0.9875~0.9993 between the copper content extracted by the standard method and the total copper content shows high positive correlation. The correlation coefficient of the copper content in soil extracted by the standard method and the accumulated copper content in earthworms, and the correlation coefficient of the total copper content in soil and the accumulated copper content in earthworms were ranged from 0.9193 to 0.9728 and from 0.9282 to 0.9844, respectively, showing highly significant positive correlation. Due to the high correlation between the copper concentration in soil and the accumulated copper content in earthworms, it is concluded that earthworms are suitable to be used as biological indicator species or for bio-monitoring against copper contamination of soil.