• Environmental Analysis Health and Toxicology
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• v.7 no.1_2
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• pp.53-57
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• 1992

Amount of lead burden in a tissue reflects poisoning of lead in that tissue, so is the removal of lead directly connected to curement of lead poisoning. The purpose of present study was to investigate the relative effects of penicillamine and thiamine tetrahydrofurfuryl disulfide (TTFD) or thiamine propyl disulfide (TPD) in the removal of lead from rat brain tissue treated with excessive lead. Wistar rat pups of both sexes were used in this experiment. Within 1 day of parturition, experimental mothers nursing their pups as well as rat pups were given drinking water containing 0.2% lead acetate, TTFD 20mg/1.2 L (2 mg/kg/day), TPD 20 mg/1.2 L (2mg/kg/day), penicillamine 40 mg/1.2 L (40 mg/kg/day), 0.2% lead acetate+TTFD 20mg/1.2 L (2 mg/kg/day), 0.2% lead acetate+ TPD 20 mg/1.2 L (2 mg/kg/day) or 0.2% lead acetate+ penicillamine 40 mg/1.2 L (40 mg/kg/day) ad libitum, throughout the entire period of experiment. Rat pups in the control group received normal tap water. The animals were sacrificed by decapitation on the day when they become 2 or 8 weeks of age. Brains were dissected into five regions: telencephalon, diencephalon, midbrain, pons/medulla and cerebellum. The dissected brain tissues were lyophillized and then solubilized by acid mixture (nitric acid + sulfuric acid). Lead levels in the solubilized brain tissues were measured by the inductively coupled plasma. In lead-exposed rats, lead levels were significantly higher than those of control group in all brain legions, lead levels in brain regions of TTFD or TPD group were generally lower than those of control group. The simultaneous administration of lead with TTFD or TPD to animals caused significant decrement of lead from all brain regions. In the elimination of lead from brain regions, effectiveness of TTFD or TPD was equivalant to penicillamine.

• Korean Journal of Heritage: History & Science
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• v.36
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• pp.241-266
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• 2003

Glass pieces excavated from Mireuksa Temple dated $7^{th}$ century A.D. were characterized by chemical composition, specific gravity and melting point. Lead isotope ratios of lead glasses were also compared with those of lead ore to attribute which lead ore was delivered for making lead glass. It was known that some lead glasses found in Japan were similar with those of Mireuksa Temple as comparing the data of chemical composition and lead isotope ratios. Characteristics of lead glass from Mireuksa Temple Thirty five glass pieces of Mireuksa Temple were analyzed for five oxides and found that all was lead glass system(PbO-$SiO_2$) with the range of 70~79% for PbO and 20~28% for $SiO_2$. The concentrations of oxides such as $Al_2O_3$, $Fe_2O_3$ and CuO were below 0.4%, 0.3% and 0.9%, respectively. Principal component analysis(PCA) as a statistical method was carried out to classify glasses with the similarities of chemical concentrations. The result of PCA has shown that three groups of glasses were created according to the excavation positions and two major oxides(PbO and $SiO_2$) greatly contributed to the dispersion of glasses on principal component 1(PC1) axis and trace element oxides($Al_2O_3$ and $Fe_2O_3$) for PC2 axis. Most of lead glasses were greenish by the efficacy of iron and copper oxides and some showed yellowish-green. The gravity of lead glasses was about 4.4~5.4 and estimated melting point was near $670^{\circ}C$. Lead isotope ratios of glasses were analyzed and found quite close to a lead ore from the Bupyeong mine in Gyeonggi-do. Comparison with lead glasses found in Japan Lead glasses of Mireuksa Temple were compared with those of Japan on the basis of chemical and physical data. Chemical compositions of Japanese lead glasses dated $7^{th}{\sim}8^{th}$ century A.D. were nearly similar with those of Mireuksa Temple but lead isotope ratios of those were separated into two groups. Three distribution maps of lead ores of Korea, Japan and China with lead isotope ratios were applied for lead glasses found in Japan. The result have shown that the locations of lead glasses from Fukuoka Prefecture coincided with the region of northen part of Korea and similar with those of Mireuksa Temple and lead glasses from Nara Prefecture dated $8^{th}$ century A.D. were located in the region of Japanese lead ore. This research has demonstrated that lead glasses of Mireuksa Temple conveyed to Miyajidake site, Fukuoka Prefecture around $7^{th}$ century A.D. and glass melting pots and glass beads excavated from Nara Prefecture confirmed the first use of Japanese lead ore for production of lead glasses from the end of $7^{th}$ century A.D.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.335-335
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• 1994

Possibility whether lead ingestion can cause selective toxicity to central serotonergic nervous system in rats was tested. Three groups of wistar rats; 1)Control, 2) Low dose and 3) High dose groups, were prepared. In prenatally lead-exposed rats, until parturition from dams, rat pups were intoxicated via placenta of mother rats having received drinking water containing either 0%(control ), 0.05%(low dose) or 0.2%(high dose) of lead acetate respectively, In postnatally lead-exposed rats, right after parturition from dams rat pups received drinking water containing either 0％ (control), 0.05%(low dose) or 0.2％(high dose) of lead acetate. At 2, 4, 6 and 8 weeks of age, tryptophan hydroxylase (TPH) activity and Na$\^$+//K$\^$+/-ATPase activity were measured in 4 areas of rat brain; Telencephalon, Diencephalon, Midbrain and Pons/Medulla. TPH activities were assayed by modified method of Beevers et al. (1983) using L-(5-$^3$H)-tryptophan as substrate. TPH activity was determined as a criterion of lead poisoning to central serotonergic nervous system and Na$\^$+//K$\^$+/-ATPase activity as a criterion of non specific lead poisoning to any kinds of tissues. Selective toxicity of lead poisoning to central serotonergic nervous system was evaluated by the changes of TPH activities without concomitant changes of Na$\^$+//K$\^$+/-ATPase activities. In prenatally lead-exposed rats. this selectivity was found in Telencephalon (2 weeks of age), Diencephalon/Midbrain (2 weeks of age), Midbrain (4 and 6 weeks of age), Pons/Medulla (2, 4 and 6 weeks of age) In rats exposed to low dose of lead and Pons/Medulla (2 weeks of age) to high dose of lead. In postnatal Iy lead-exposed rats, this selectivity was found in Telencephalon (8 weeks of age), Diencephalon(8 weeks of age), Pons/Medulla (6 and 8 weeks of age) in rats exposed to low dose of lead and Pons/Medulla (8 weeks of age) to high dose of lead. These results suggest that lead poisoning may exhibit selective toxicity to central serotonergic nervous system.

• Safety and Health at Work
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• v.2 no.2
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• pp.87-96
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• 2011

In 1967, the problem of occupational lead exposure came to public attention in Korea. Since then, regular progress has been made in lowering workplace lead exposures, instituting new workplace controls, and implementing health examinations of exposed workers. Past serious lead poisoning episodes made it possible to introduce biological monitoring programs on a voluntary basis in high-lead-exposure facilities in Korea. Industry-specific occupational health services for lead workers in Korea during the last 22 years can be categorized into three phases. During the first phase (1988-1993), efforts were directed at increasing awareness among workers about the hazards of lead exposure, biological monitoring of blood zinc protoporphyrin began, and a respiratory protection program was introduced. During the second phase (1994-1997), a computerized health management system for lead workers was developed, blood-lead measurement was added to biologic monitoring, and engineering controls were introduced in the workplace to lower air-lead levels to comply with air-lead regulations. Finally, during the third phase (1998-present), a new biomarker, bone-lead measurement by X-ray fluorescence, was introduced. Bone-lead measurement proved to be useful for assessing body burden and to demonstrate past lead exposure in retired workers. Occupational health service practice for lead workers, including the industry-specific group occupational health system, has brought considerable success in the prevention of lead poisoning and in reducing the lead burden in Korean lead workers during the last several decades. The successful achievement of prevention of lead poisoning in Korea was a result of the combined efforts of lead workers, employers, relevant government agencies, and academic institutes.

• Environmental Engineering Research
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• v.12 no.3
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• pp.101-108
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• 2007

Fixation of lead contaminants in the solidification/stabilization using Portland cement has been investigated by X-ray diffraction, scanning electron microscopy and compressive strength. The presence of lead was observed to produce lead carbonate sulfate hydroxide ($Pb_4SO_4(CO_3)_2(OH)_2$), lead carbonate hydroxide hydrate ($3PbCO_3{\cdot}2Pb(OH)_2{\cdot}H_2O$) and two other unidentified lead salts in cavity areas and was observed to significantly retard the hydration of cement. By 28 days, howevere, the XRD peaks of most of the lead precipitates have essentially disappeared with only residual traces of lead carbonate sulfate hydroxide and lead carbonate hydroxide hydrate evident. After 28 days of curing, hydration appears well advanced with a strong portlandite peak present though C-S-H gel peaks are not particularly evident. Lead species produced with the dissolution of lead precipitates are fixed into the cement matrix to be calcium lead silicate hydrate (C-Pb-S-H) during cement-based solidification.

• Journal of the Mineralogical Society of Korea
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• v.28 no.2
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• pp.187-193
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• 2015

The purpose of the present study is to trace the provenance of lead raw materials using the lead isotope ratio of 9 lead glasses excavated from the Sarira hole of Mireuksaji stone pagoda and to determine correlation between them and other lead glasses excavated from the Wanggungri site. The results of chemical analysis of the 9 lead glasses show that they are common lead glass system($PbO-SiO_2$) with respect to the contents of PbO (70 wt.%) and $SiO_2$ (30 wt.%). The lead isotope ratios of them plot to northern Korean peninsula when applied to the distribution map of lead isotopes of East Asia. On the other hand, southern Korean peninsula is verified as the main deposits of the lead ore in the distribution map of lead isotopes of South Korea. With respect to the results, it is notable that the provenance of the 9 lead glasses can be very different depending on the distribution map. In addition, a comparative study between them and the lead glasses excavated from the Wanggungri which was built in the same region and period shows that their lead isotopes are highly correlated.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2001.11a
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• pp.91-91
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• 2001

Nramp2, also known as DMT1 and DCT1, is a 12-transmembrane domain protein responsible for dietary iron uptake as well as metal ions such as lead, manganese, zinc, copper, nickel, cadmium, and cobalt. High expression of DMT1 increase lead uptake, and DMT1-dependent lead transport was H -dependent and inhibited by iron ions. The molecular mechanism of lead transport in CNS is as yet unknown. although interactions between iron and lead at the level of absorption have been known for some time. The process of lead uptake into astrocytes was not known yet. Nramp2 may mediate transport of heavy metal into astrocytes. We investigated whether Nramp2 mediate transport of lead into astrocytes. And we do whether Nramp2 was expressed highly by deprivation of iron in Astrocytes, and lead uptake into astrocytes was influenced by expression of Nramp2. Immortalized human fetal astrocyte(SV-FHA) cells were cultured in medium containing Dulbecco's modified Eagle's medium and treated with Deferoxamine. Northern blot analysis was done for determining mRNA level of DMT1 and lead uptake assay was done in incubation condition of pH 5.5 and 7.4.

• Journal of Environmental Health Sciences
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• v.32 no.1 s.88
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• pp.1-7
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• 2006

This study was performed to investigate airborne lead concentration and surface lead contents in preschool facilities. Arithmetic mean of indoor lead concentration in urban area was $44.7\;ng/m^3$ (Geometric mean $32.1\;ng/m^3$) whereas outdoor concentration was $39.5\;ng/m^3$ (GM $22.8\;ng/m^3$). In rural area, airborne lead concentrations were $14.2\;ng/m^3\;(GM\;7.9 ng/m^3),\;12.6\;ng/m^3\;(GM\;5.6 ng/m^3)$, respectively. There is statistical significance of the lead concentrations among the locations of preschool facilities. About $37\%$ of qualitative lead check samples was positive and mainly was found in lead based paint. Though lead concentrations on the floor and window sill were well below the US EPA and HUD standard (floor $40\;{\mu}g/ft^2\;(4.3\;{\mu}g/100\;cm^2)$, window sill $250\;{\mu}g/ft^2\;(26.9\;{\mu}g/100\;cm^2)$, respectively), there were much samples which exceed the standard, i.e., $29\%$ of surface wall, $20\%$ of the desk and chair, $100\%$ of painted wood box of tested samples. In view of our study and hazard of lead to children, we recommended that the contents of lead in preschool facilities should be lowered as possible.

• Toxicological Research
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• v.6 no.2
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• pp.131-142
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• 1990

The selective toxicity of lead was tested in central catecholaminergic nervous system of postnatally lead exposed rats. Three groups of animals were prepared; 1) rats exposed to low dose of lead (0.05%PbAc); 2) rats exposed to high dose of lead(0.2%PbAc); 3) age-matched normal control rats. At2, 4, 6 and 8 weeks of age brain and body weight gain, and lead concentrations in brain tissues were measured. At the same ages tyrosine hydroxylase and Na-K ATPase activities were measured in the 4 brain areas of each animal. Body weight gain was decreased after 6 weeks of age in rats exposed to high dose of lead. Concentrations of lead in whole brain tissues were increased from 0.37 to 0.83 (ng/mg wet tissue) in these animals. in lead exposed rats, tyrosine hydroxylase activities were higher but Na-K ATPase activities were lower than those of age-matched control animals. Brain areas where tyrosine hydroxylase activities were detected without concomitant changes of Na-K ATPase activities were pons-medulla (2 weeks of age) and telencephalon (6 weeks of age) in rats exposed to low dose of lead, and those in rats exposed to high dose of lead were midbrain (4 and 6 weeks of age). These data indicate that catecholaminergic nervous system in the brain areas described above could selectively be affected by lead.

• Journal of radiological science and technology
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• v.41 no.6
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• pp.611-616
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• 2018

Lead apron is harmful to the human body because it is made at heavy metals, and when worn for long periods of time, it causes pain. Therefore, this paper intended to improve the defects of lead apron by using new material shields. For the comparative evaluation of lead and new material shieldes, the shielding rate and weight were measured and tested based on lead 0.5 mmPb. The rate of shielding was 97% based on lead at 0.5 mm thickness, while The new material shield T3 showed similar shielding rates as lead in 8 layers, and in T2 these values were measured in 11 layers. In addition, similar shielding rate was measured in 12 layers at B2, and 8 layers in BF, and 4 layers in $BF_2$. Comparing the weight of cases when commercialized with apron, T3, T2 and B2 were heavier than lead apron. But BF, $BF_2$ were lighter than the lead apron. Based on the results of the experiment, T3 and T2 can be used as an alternative to lead if human or environmental hazards are considered a priority. However, BF and $BF_2$ should be used if the reduction of external exposure is considered a priority.