• 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.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.11 no.2
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• pp.111-117
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• 2001

A cross-sectional study was performed to evaluate associations between lead biomarkers, lead-related symptoms, and ${\delta}$-aminolevulinic acid dehydratase (ALAD) genotype among 598 lead workers and 144 control office workers in storage battery industries, secondary smelting and litharge making industries. Lead inhibits the second enzymes, ALAD, in the heme synthesis pathway. ALAD gene, which codes for one of three isozymic proteins (termed ALAD1-1, ALAD1-2, and ALAD2-2), seems to modify the toxicokinetics of lead. The result as follows; The percents of total workers whose genotype of ALAD1-1 and ALAD1-2 were 88.4% and 11.6%, respectively. The zinc protoporphyrin in blood (ZPP) and ${\delta}$-aminolevulinic acid in urine (ALAU) of lead workers with ALAD1-2 were significantly lower than those of lead workers with ALAD1-1, but there were no significant difference between two genotype for blood lead, age, and work duration. The proportion of ALAD1-2 genotype in control office workers was 13.2%. The proportions of ALAD1-2 genotype of lead workers were 14.0%(their mean air lead level below $0.024mg/m^3$), 10.4%($0.025-0.049mg/m^3$), 11.8%($0.050-0.099mg/m^3$), and 9.4%(above $0.100mg/m^3$), respectively. In the logistic analysis of 15 lead related symptoms, 'arthralgia'(S7) symptom of ALAD1-2 was significantly lower (OR=0.481; 95% CI=0.248-0.932) than that of ALAD1-1, but 'feeling of irritation'(S11) of ALAD1-2 was significantly higher(OR=1.636; 95% CI=1.035-2.586) than that of ALAD1-1 after controlling possible confounder (blood lead, work duration, smoking and drinking habit).

• Toxicological Research
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• v.11 no.1
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• pp.57-62
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• 1995

To investigate the ultrastructural changes of kidney and clarify to a cause of its changes in lead intoxicated rats, the 0.5% lead acetate administed orally to the rats and those were sacrifled at 2 day, 1, 2, 4, 6 and 8 week after the treatment of lead acetate. Each extirpated kidney was histopathologically examined under the electron microscopy and histochemical examination was also carried out. Concomitantly, the activity of free radical metabolizing enzyme was determined. The blood levels of lead concentration showed a gradual increase from the first group reaching the plateau at the one or two week group with the slightly decreasing value throughout the whole course of the experiment. And the urinary ALA concentration showed a gradual increase from the first group to the 8 week group. In the kidney tissue of rat sacrified at 6 week, the proximal tubular cells showed dilatation of endoplasmic reticulum, mitochondrial swelling, increased numbers of secondary lysosomes and myelin figure-like residual bodies on electron microscope and oxygen free radicals are identified by histochemistry on light microscope whereas there were no differences in the activity of catalase and glutathione peroxidase between the lead acetate treated group and control group. But the activity of xanthine oxidase was more increased in lead acetate treated rats than control group. Furthermore, the superoxide dismutase activity was significantly increased in the experimental group than the control group. In conclusion, it is assumed the kidney damage in lead intoxicated rat may be induced by free radicals.

• Biomolecules & Therapeutics
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• v.13 no.1
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• pp.1-6
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• 2005

Lead and cadmium are potent environmental toxicants that affect populations living in Europe. Americas, and Asia. Identifying transporters for lead and cadmium could potentially 1 help us better understand possible risk factors. The iron transporter, divalent metal transporter 1 (DMT1), mediates intestinal transport of cadmium, and lead in yeast and fobroblasts overexpressing DMT1. In human intestinal cells knocking down expression of DMT1 attenuated uptake of cadmium and iron but not lead. A possible explanation is the expression of a second transporter for lead in intestine. In astrocytes, however, DMT1 appears to transport lead in an extracellular buffer at pH value. At neutral pH, transport was not mediated by DMT1 but rather by a transporter that is stimulated by bicarbonate and inhibited by 4,4'-diisothiocyanatodihydrostilbene-2,2'-disulfonic acid. The identity of this lead transporter will beverified by future study.