• Bulletin of the Korean Chemical Society
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• v.20 no.5
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• pp.556-558
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• 1999

Lead-selective PVC membrane electrodes based on newly synthesized bis(crown ether)s containing 18-crown-6 moiety was prepared using standard PVC membrane composition. In order to monitor lead in environmental samples by lead sensor, especially good selectivity over alkali and alkaline earth metals has to be obtained. Thus, responses of the PVC membrane prepared with new bis(crown ether)s and Fluka ionophore V (crown ether) base to various cations include lead, alkali and alkaline earth metal ions were investigated for their use as a lead sensor. The polymeric liquid membrane based on trans-1 8-crown-6 ether exhibits the best overall potentiometric performances as a lead-selective electrode in terms of a wide linear dynamic range (between 10-6 and 10-2 M, Pb2+), excellent detection limit (less than 10-6 M) and good durability within limited error. The preferences of lead over other cations, such as Ag+, Hg2+, Na+, Ca2+ and even K+ in the aforementioned electrode are much better than the Fluka ionophore V system.

• Nuclear Engineering and Technology
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• v.56 no.2
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• pp.437-443
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• 2024

The development and testing of inspection equipment is necessary for the safe deployment of advanced nuclear reactors. One proposed advanced reactor design is Westinghouse's lead-cooled fast reactor (LFR). In this paper, the process of achieving adequate wetting for an ultrasonic under-lead viewing system is discussed and results presented. Such a device would be used for inspection in the molten lead core during reactor outages. Wider tests into the wetting of various materials in molten lead at microscale were performed using electron microscopy. The possible mechanisms and kinetics for materials wetting in lead, particularly stainless steel and nickel, are proposed and discussed.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.18 no.4
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• pp.293-302
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• 2008

Lead chromate is made by sodium dichromate and lead acetate, and has being used widely in the part of pigment, paints, inks, plastics and so on. Even though lead chromate has health hazards which like both lead and chromium, there are a few study about pigment workplaces using lead chromate in Korea. The purpose of this study is to evaluate workers' exposure levels and airborne lead and chromium concentration in the pigment workplaces using lead chromate. There are 20 workers in the total 5 workplaces. 10 workers(50%) have been exposed to lead and 3 workers(15%) have been exposed to chromium, which exceeded the American Conference of Governmental Industrial Hygienists(ACGIH) Threshold Limit Value (Pb: $0.05\;mg/m^3$, Cr: $0.012\;mg/m^3$) and Korean Ministry of Labor's Standard. Geometric mean (GM) of airborne lead was highest in pigment ($0.0421\;mg/m^3$), paint ($0.0020\;mg/m^3$) and PVC coloring ($0.0007\;mg/m^3$), respectively(p<0.05). The result of airborne chromium concentration was paint ($0.0033\;mg/m^3$), paint ($0.0004\;mg/m^3$) and PVC coloring ($0.0003\;mg/m^3$). Also the lead and chromium concentration in the manual process is each 30 times and 10 times higher than the value in automatic process(p<0.01). In the classified process by detail, the concentration of airborne lead was $0.0638\;mg/m^3$ in grinding & packaging, mixture & after-measuring ($0.0436\;mg/m^3$), filtration & drying ($0.0402\;mg/m^3$), lead nitrate & dissolution($0.0129\;mg/m^3$), pigment commitment & mixture ($0.0013\;mg/m^3$) and dispersion & grinding ($0.0010\;mg/m^3$) (p<0.05). Moreover the concentration of a sample in weighting & packaging was $0.0023\;mg/m^3$. The concentration of lead in workers' blood was pigment (15.12 ug/dl), paint (4.74 ug/dl) and PVC coloring (2.50 ug/dl), and some samples have exceeded biological exposure limit. In conclusion, the depending on their work industry and process, workers have been exposed to the high lead chromate.

• Korean Journal of Environment and Ecology
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• v.16 no.3
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• pp.233-238
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• 2002

In this study, we investigated the lead exposure conditions using feathers of pigeons as a monitor for lead pollution from rural (Duckjeok Island), central urban (Seoul), and industrial complex areas (Yochon, Ansan, Ulsan, and Busan) in Korea. The feathers were taken from breast body parts and their lead analysis was performed without washing the feathers to reflect lead particles attached to the surface. The tissue lead concentrations were also compared with levels of atmospheric concentrations. The lead levels in the feathers were increased when the atmospheric lead levels were higher, so that the lead levels in the feathers of the pigeons from the industrial complex area with highest atmospheric lead levels were about four times greater than those of the rural areas. A positive correlation was found between the lead concentration of the pigeon's livers and feathers in rural, and the Yochon industrial complex area with the lowest lead levels. This result means that most of lead in feathers is transported from body tissues during the molting period without attached atmospheric lead. Thus, the feather lead concentrations could be discussed in the light of the metabolism known to occur between the liver and feathers. However, there were not significant correlations in the other areas with higher atmospheric lead levels, and observed relatively higher lead accumulation ratio in feathers than in livers compared with rural and the Yochon industrial complex areas. It is therefore suggested that the former was more exposure conditions and mainly influenced by outer pollutant sources than by the metabolism as the latter.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.18 no.3
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• pp.248-251
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• 2008

During survey of blood lead concentration of workers who worked in lead refining industry, we found that some foreign workers showed increased blood lead level compared with that of domestic workers. The mean concentration of lead in blood for foreign workers (15%, 13 workers, mean age: 29) was 55.8 ug/dL which was over biological exposure index, while that of Korean workers (85%, 76 workers, mean age: 42) was 28.9 ug/dL. Some other biological markers of lead exposure such as ZPP and ${\delta}-ALA$ also showed elevated levels. Most of foreign workers stayed in dormitories near or in the factories that may cause to let them under the condition of 24 hours exposure of lead. The lack of safety manual on proper prevention of lead exposure in their own language for effective communication may be one of reasons of elevated blood lead concentration of foreign workers.

• Clinical and Experimental Pediatrics
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• v.59 no.3
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• pp.114-119
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• 2016

Purpose: This study aimed to assess the reference values and factors influencing blood lead levels among Korean adolescents. Methods: The study population consisted of 1,585 adolescents (801 males, 784 females; aged 10-19 years) who participated in the Korea National Health and Nutrition Examination Survey 2010-2013. We analyzed blood lead concentrations in relation to demographic/lifestyle characteristics for all participants. "Reference values" of blood lead levels were calculated as the upper limit of the 95% confidence interval of the 95th percentile. Results: The average "reference value" for blood lead concentrations among Korean adolescents was $2.25{\mu}g/dL$ ($2.49{\mu}g/dL$ for males, $2.07{\mu}g/dL$ for females), and the geometric mean of the blood lead concentrations was $1.34{\mu}g/dL$. Males had higher blood lead concentrations than females (male, $1.48{\mu}g/dL$; female, $1.19{\mu}g/dL$; P<0.001). Elementary school students had higher blood lead concentrations than junior and senior high school students ($1.44{\mu}g/dL$ vs. $1.31{\mu}g/dL$, P<0.001). Participants living in detached houses had higher blood lead concentrations than those living in apartments (P<0.001) and current smokers had higher concentrations than nonsmokers or participants with secondhand smoke exposure (P<0.05). Additionally, participants with excessive alcohol consumption had higher levels than non-drinkers (P<0.001). Conclusion: This study provides national reference data on blood lead concentrations stratified by demographic and lifestyle factors among Korean adolescents. Further studies are needed to elucidate the relationship between increased lead exposure and demographic factors including type of housing.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.10
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• pp.1433-1439
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• 2000

An experiment was carried out with 48 IVRI 2CQ rats 6-8 week old, weighing 50-100 g, to study the effect of lead exposure on antioxidant defense, lipid peroxide level, status of thiol groups and concentration of lead in the liver and kidneys at the end of the exposure and also after withdrawal of lead administration. Twenty four rats were given lead at a daily dose rate of 1 mg lead/2 ml of distilled water/kg body weight as lead acetate solution intraperitoneally for a period of 30 days. Another 24 control rats received 2 ml of sterile normal saline solution (0.85% NaCl)/kg body weight in an identical manner. A many-fold increase in concentration of lead was associated with a non-significant (p>0.05) decrease in the activities of superoxide dismutase (SOD) in the liver (27%) and kidneys (12%) and catalase in kidneys (22%). A significant (p<0.05) increase in lipid peroxide level was recorded in the liver (40%) compared with control values. There were significant (p<0.05) decreases in the total thiol and protein bound thiol contents in liver and an increase in non-protein bound thiol groups in the kidneys of lead exposed rats. During the 10 day observation period after withdrawal of lead administration, no significant change was observed with respect to any of the above parameters indicating that a 10 day withdrawal period was not enough for restoration of normality. It is concluded that the magnitude of response and the resultant changes in the lipid peroxide concentration, and the activities of SOD and catalase were not identical in the liver and kidneys of lead-exposed rats.

• Journal of Korean Medical Science
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• v.33 no.44
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• pp.278.1-278.12
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• 2018

Background: We evaluated the association of blood pressure (BP) with blood levels of cadmium, lead, and cadmium and lead together (cadmium + lead) in a representative sample of adolescents from Korea. Methods: We used 2010-2016 data from the Korean National Health and Nutrition Examination Survey. This cross-sectional study enrolled adolescents aged at 10-18 years-old who completed a health examination survey and had blood measurements of lead and cadmium. The association of adjusted mean differences in diastolic and systolic BP with doubling of blood lead and cadmium were estimated by regression of BP against ${\log}_2$-transformed blood metals and their quartiles after covariate adjustment. Adjusted odds ratio for prehypertension were calculated for ${\log}_2$-transformed blood levels of lead and cadmium and their quartiles. Results: Our analysis of adolescents in Korea indicated that blood levels of lead and cadmium were not significantly associated with increased BP or risk of prehypertension. However, the cadmium + lead level was associated with prehypertension. Previous studies showed that blood levels of lead and cadmium were associated with increased BP and risk of hypertension in adult populations. We found no such association in Korean adolescents. Conclusion: We found that the cadmium + lead level was associated with prehypertension. The differences between adults and adolescents are because adolescents generally have lower levels of these blood metals or because adolescents only rarely have hypertension.

• Nuclear Engineering and Technology
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• v.54 no.3
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• pp.959-964
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• 2022

Lead is an important material, both for fusion or fission reactors. The cross sections of natural lead should be validated because lead is a main component of lithium-lead modules suggested for fusion power plants and it directly affects the crucial variable, tritium breeding ratio. The presented study discusses a validation of the lead transport libraries by dint of the activation of carefully selected activation samples. The high emission standard ²⁵²Cf neutron source was used as a neutron source for the presented validation experiment. In the irradiation setup, the samples were placed behind 5 and 10 cm of the lead material. Samples were measured using a gamma spectrometry to infer the reaction rate and compared with MCNP6 calculations using ENDF/B-VIII.0 lead cross sections. The experiment used validated IRDFF-II dosimetric reactions to validate lead cross sections, namely ¹⁹⁷Au(n, 2n)¹⁹⁶Au, ⁵⁸Ni(n,p)⁵⁸Co, ⁹³Nb(n, 2n)^92mNb, ¹¹⁵In(n,n')^115mIn, ¹¹⁵In(n,γ)^116mIn, ¹⁹⁷Au(n,γ)¹⁹⁸Au and ⁶³Cu(n,γ)⁶⁴Cu reactions. The threshold reactions agree reasonably with calculations; however, the experimental data suggests a higher thermal neutron flux behind lead bricks. The paper also suggests ²⁵²Cf isotropic source as a valuable tool for validation of some cross-sections important for fusion applications, i.e. reactions on structural materials, e.g. Cu, Pb, etc.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.10a
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• pp.137-146
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• 1995

In this study, it was tested whether lead intoxication could change thiamine content and the thiamine related biochemical factor such as activity of transketolase in the brain, and whether the changes of the myelin composition :s well as the seizure threshold induced by lead intoxication in rats be related to these changes of thiamine status and thiamine related biochemical factors. In addition, it was also tested whether administration of excessive thiamine can reverse the toxic manifestation of lead in lead intoxicated animals. Five groups of Wistar rats were prepared: 1)Control group, 2)lead treated group, 3)thiamine treated group, 4)lead plus thiamine treated group and 5)thiamine deficiency group. Each group of animals was divided into three subgroups based on ages: 3, 7 and 10 weeks of age subgroups. Lead concentration, thiamine content, the activity of transketolase and myelin composition in brain areas and threshold of electric shock seizure were tested in each group. Lead concentrations in all brain regions of lead treated group were higher than those of control group, and those of lead plus thiamine treated group were significantly lower than those of lead treated group. Thiamine contents in the brain regions of lead treated group were significantly lower than those of control group, and those of lead plus thiamine treated group were recovered back to those of control group. Activities of transketolase of lead treated group were significantly lower than those of control group, while those of lead plus thiamine treated group were recovered back to those of control group. The cases of which was observed with the concomitant changes of thiamine content and transketolase activity in myelin content or constituent of all the brain regions tested were total amount of myelin protein in the cerebellum of 3 week old rats, and phospholipid in the cerebellum of 3 week old rats and the telencephalon of 16 week old rats. Thresholds of the electroshock seizure of lead-treated group and thiamine-deficient group in 3, 7 week old rats were significantly lower than those of control group, while those of the lead plus thiamine-treated group were similar to those of control group. Changes of the electroshock seizure threshold induced by lead intoxication were observed in 3 week and 7 week old animals with the concomitant decrement of thiamine content in all the brain regions tested. These observations were reversed by the supplementation with thiamine to those animals. However, the changes of seizure threshold induced by lead intoxication corelated with the changes of thiamine contents as well as. transketolase due to lead intoxication. The changes of myelin phospholipid as one of myelin composition and those of myelin Protein content only in the cerebellum of 3 week old rats correlated with the changes of the seizure threshold as well as thiamine content due to lead intoxication. The results from the present study may indicate that neurotoxicity of lead in rats may be mediated at least in part through the changes of thiamine status. Such changes of thiamine status may induce the changes of myelin composition such as myelin phospholipid and those of myelin protein content especially in the cerebellum of 3 week old rats which may eventually affect the threshold of seizure.