• Toxicological Research
• /
• 제17권
• /
• pp.135-138
• /
• 2001

Female Wistar rats were randomly divided into 5 groups: Control, received distilled water; Low lead, received 0.5 g/ιlead (as acetate) in drinking water; High lead, received 2.0 g/ιlead; Low lead + Minerals, received 0.5 g/ιlead in drinking water and received minerals (Ca$^{2+}$, 25 mg/kg/day; Fe$^{3+}$, 0.47 mg/ kg/day; Zn$^{2+}$, 0.33 mg/kg/day; Se, 0.83 $\mu\textrm{g}$/kg/day) by gavage; High lead + Minerals, received 2.0 g/ιlead and received the same minerals. Animals exposure to lead was from 10 days before mating till postnatal day 21; and the minerals was administered from the first day of pregnancy and during lactation. No statistical difference was found either in body weights or in blood lead levels between the pups received minerals and those only exposed to lead at the same dose. The developmental and behavioral teratological effects of lead on pups, such as time-lag of eye opening, pinna detachment, fur developing, incisor eruption, ear unfolding, and surface righting were observed in this study; and the minerals decreased the toxicity of lead either in low or in high lead exposure pups. The numbers of step-down were significantly increased in lead exposed animals, and the effect of intervention by the minerals was appeared only in the pups exposed to low lead. The ChAT activity and levels of glutamate and aspartate in hippocampus decreased in treated animals compared to control animals, no effect of intervention by the minerals was found. The results of this study indicate that the applied multi-minerals can alter the outcome of develop-mental lead poisoning in rats.s.s.s.

• Journal of Preventive Medicine and Public Health
• /
• 제11권1호
• /
• pp.76-82
• /
• 1978

In order to study the change of laboratory parameters of lead poisoning, 8 persona who had not been treated previously for lead poisoning (Group 1 and 6 persons who had been inadequately treated for few months for chronic lead poisoning at local clinic (Group 2) were examined. They had occupational exposure to lead for 3 to 18 years (mean, 7.6). In group 1 blood lead, urine lead, urine coproporphyrin and ${\delta}$-aminolevulinic acid levels before our treatment exceeded the critical levels of lead poisoning. In group 2 urine lead level exceeded but blood lead, urine coproporphyrin and ${\delta}$-aminolevulinic acid levels were within normal limits. All of them were treated with D-penicillamine for 4 months as inpatients at Industrial Accident Hospital. The dose of D-penicillamine was the same in all patients; 600 mg per day p.o. and the chelating agent was administer every other week. For laboratory analysis, 24 hour urine and 10 gm of whole blood were collected every 1 month on last day of non-administration period. The results were as follows: 1. It was found that urine lead level was decreased below the cirtical level of lead poisoning after 4 month's treatment with D-penicillamine and blood lead level was decreased more progressively below the critical level after 1 month treatment. 2. Urine coproporphyrin and ${\delta}$-aminolevulinic acid levels were decreased progressively to normal range after 1 month treatment. 3. Two months after treatment, blood lead, urine lead, urine coproporphyrin and ${\delta}$-aminolevulinic acid levels showed some increasing trends. 4. Urine lead level should be checked in a person who had been inadequately treated with chelating agents because blood lead, coproporphyrin and ${\delta}$-aminolevulinic acid might be in normal range.

• Bulletin of the Korean Chemical Society
• /
• 제25권8호
• /
• pp.1125-1129
• /
• 2004

This work assesses the potential of natural Analcime Zeolite as an adsorbent for preconcentration of lead (II) traces. Lead is quantitatively retained on 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol by column method with Analcime in the pH range of 5-6.5 and 2 mL $min^{?1}$ flow rate. Lead was removed from the column with 10.0 mL of 4 M hydrochloric acid and was determined by anodic stripping differential pulse voltammetry. 0.5ppb detection limit was obtained and linear dynamic range was 3 to $1.2{\times}10^5$ ppb in final solution with correlation coefficient of 0.999 and relative standard deviation of ${\pm}$ 1.2% (for eight replicate determination of 2.5 ${\mu}g\;mL^{?1}$ of lead). Various parameters such as the effect of pH, flow rate, instrumental conditions and interferences of some ions on the determination of lead have been studied in detail for optimization of conditions. The method was successfully applied for determination of lead in various samples.

• Journal of Preventive Medicine and Public Health
• /
• 제24권2호
• /
• pp.181-194
• /
• 1991

This study intended to obtain an useful information on the prevalence of subjective symptoms, and to clarify the interrelationships between blood lead and lead related symptoms in low level lead exposure. The 93 male workers exposed to lead and 56 male nonexposed workers were examined for their blood lead(PBB), Zinc-protoporphy(ZPP), hemoglobin(HB) and personnal history, and completed 15 questionnaires related to symptoms of lead absorption : also measured lead concentration in air (PBA) in the workplace. The results obtained were as follows ; 1. The means of blood lead (PBB), blood ZPP and hemoglobin (HB) among workers exposed to lead were $26.1{\pm}8.8{\mu}g/dl,\;28.3{\pm}26.0{\mu}g/dl$ and $16.2{\pm}1.2g/dl$ : whereas those of nonexposed workers were $18.7{\pm}5.1{\mu}g/dl,\;20.6{\pm}8.7{\mu}g/dl$ and $17.3{\pm}1.1g/dl$. The means of above three indicies between two groups showed significant difference statistically (p<0.05). 2. The means of blood lead (PBB), blood ZPP and hemoglobin of workers exposed .to different lead concentration in air were as follows : When it was below $25{\mu}g/m^3$, the indices were $24.7{\pm}79,\;26.1{\pm}26.8{\mu}g/dl\;and\;16.4{\pm}1.1g/dl$ respectively : These indices were $27.1{\pm}8.5,\;23.9{\pm}10.92{\mu}g/dl\;and\;16.2{\pm}1.3g/dl$ when the lead concentration in air was $25{\sim}50{\mu}g/m^3$ : and they were $3.4{\pm}9.3,\;42.3{\pm}31.3{\mu}g/dl\;and\;15.5{\pm}1.2g/dl$ when the concentration of lead was above $50{\mu}g/m^3$. Although there were statistical difference in blood lead and hemoglobin among three different lead concentration in air, there was no statistical difference of blood ZPP among the three groups with different exposure levels (p>0.05). 3. The most frequent by complained symptom was 'Generalized weakness and fatigue', and fewest symptom was 'Intermittent pains in abdomen' 4. Only two symptoms out of fifteen symptoms checked by themselves revealed significant difference between exposed and nonexposed groups. These were 'Intermittent pains of abdomen' and 'Joint pain or arthralgia' (p<0.05), No positive correlation was found between the levels of blood lead and symptom groups categorized as gastrointestinal, neuromuscular and constitutional symptoms, 5. Blood lead (r=0.3995) and ZPP (r=0.2837) showed statistically significant correlation with mean lead concentration in air, whereas correlations were not demonstrated between blood lead and lead related symptoms or blood ZPP and lead related symptoms. 6. Blood lead (PBB) and ZPP showed association (r=0.2466) and the equation PBB=23.75+0.0842 ZPP was derived. 7. On stepwise multiple regression, using blood lead level as a dependent variable and ZPP, hemoglobin (HB), age, work duration (WD) and symptom prevalence as a independent variables, only ZPP significantly contributed a lot to blood lead level. 8. While the ZPP measurement was found to be a good indicator in evaluating health effect of lead absorption in low level lead exposure, lead related symptoms were not sensitive enough to evaluate of lead absorption in low level exposure.

• 한국산업보건학회지
• /
• 제29권2호
• /
• pp.195-207
• /
• 2019

Objectives: This study was performed to confirm whether plasma lead can be used as a chronic biomarker for the biological monitoring of exposure to lead. Methods: Lead concentrations in 66 plasma samples from retired lead workers (G.M. 60.25 years, Median 61.00 years) and 42 plasma samples from the general population (G.M. 53.76 years, Median 56.50 years) were measured using ICP/Mass. Tibia, whole blood, hemoglobin, hematocrit, and blood zinc protophorphyrin (ZPP) concentrations and urinary ${\delta}$-aminolevulinic acid (${\delta}-ALA$) were measured for correlation analysis with plasma lead. Results: The geometric mean concentration of lead in plasma was $0.23{\mu}g/L$ for the retired lead workers and $0.10{\mu}g/L$ for the general population sample. A simple correlation analysis of biomarkers showed that plasma lead concentration among the retired lead workers was highly correlated with lead concentration in the tibia and with blood lead concentration, and the plasma lead concentration among the general population correlated with ZPP concentration in the blood. The lead concentration in the tibia and the lead concentration in the whole blood increased with length of working period. As the period in the lead workplace increased, the ratio of lead in plasma to lead concentration in whole blood decreased. Conclusion: This study confirmed the possibility of a chronic biomarker of lead concentration in blood plasma as a biomarker. In the future, comparative studies with specific indicators will lead to more fruitful results.

• 한국산업보건학회지
• /
• 제8권2호
• /
• pp.224-230
• /
• 1998

In order to provide a basic data for the prevention of the adverse effect of lead on health, We examined lead level in the blood and urine of 371 healthy men living in Choongchung-do from May to June, 1997. The results were as follows ; 1. Average lead level of all the subjects was $3.98{\pm}1.02{\mu}g/dl$ in blood, and $3.94{\pm}2.09{\mu}g/L$ in urine, respectively. Lead contents examined in this study were significantly lower than those of other investigators. 2. The lead levels of all the subjects in blood and urine had almost normal distribution. 3. Relation between lead content in blood and urine was a simple linear regression; its equation was "Lead level in blood=36.76+0.77 lead level in urine".

• 한국응용과학기술학회지
• /
• 제27권2호
• /
• pp.196-201
• /
• 2010

The influence of red lead($Pb_3O_4$) to curing and formation reaction properties when it was added in positive material of lead acid battery for vehicle use has been investigated. At the results, it was confirmed that the addition of red lead led 4BS crystal size to be smaller and increased the rates of 4BS formation and Pb consumption. Consequently the curing time was shortened to half compared with that of red lead-free one. In addition to this, the lead acid battery prepared by adding red lead showed 14% higher efficiency at the life cycle test than that without red lead.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2003년도 추계학술대회
• /
• pp.103-108
• /
• 2003

In this paper, the current lead for superconducting device is studied by numerical method. The current lead is cooled by surrounded $N_{2}$ gas by natural convection. The heat conduction equation for current lead and boundary layer equation for $N_{2}$ gas must be solved simultaneously. The boundary layer equation for $N_{2}$ gas is highly nonlinear for varied temperature of current lead. So the linearization method is adopted for simplicity. Numerical results using natural convection cooling are compared with the conventional cooling methods such as conduction cooling and vapor cooling methods. The main difference of natural convection cooing is the non-zero temperature gradient at the top of current lead for the minimum heat dissipation into superconducting devices. For the optimized conduction-cooling and vapor-cooling current leads, the temperature gradient at the top of current lead is zero. Also, the heat flow at the cold end is much smaller than conduction cooling case.

• Asian-Australasian Journal of Animal Sciences
• /
• 제18권8호
• /
• pp.1130-1134
• /
• 2005

An experiment was performed using 20 calves of about one-month old to investigate the effect of chelation therapy with calcium disodium ethylenediaminetetraacetate ($CaNa_2$EDTA) alone or along with antioxidant $\alpha$-tocopherol in lead loaded calves on blood trace minerals, erythrocytic sulfahydryl groups and some haematobiochemical parameters. Fifteen calves were given lead orally at a daily dose of 7.5 mg of 99% pure lead acetate/kg body weight for 28 days. Then the lead was withdrawn on day 28 and the calves were randomly divided into three groups. Each group of five animals was either treated with $CaNa_2$EDTA alone at the dose rate of 110 mg/kg body weight in two divided doses for 4 days or along with $\alpha$-tocopherol at the dose rate of 100 mg/kg body weight orally daily for 7 days, keeping the remaining five calves as lead-exposed untreated controls. Blood samples were collected at the end of the lead exposure (day 0) and thereafter on day 2, 4, 7 and 10 from the start of the chelation treatment. The treatment with EDTA alone led to slow but non-significant improvement in blood copper level, but incorporation of antioxidant $\alpha$-tocopherol in chelation therapy resulted in its significant decline, as recorded on day 7-post treatment. Withdrawal of lead or treatment with $CaNa_2$EDTA alone or along with $\alpha$-tocopherol enhanced the erythrocytic thiol contents and the levels of T-SH and P-SH became statistically (p<0.05) comparable to those of lead-exposed controls by day 7 and 4, respectively. There was no significant (p>0.05) change in serum urea, creatinine, total protein and albumin levels between the treatment groups. It is concluded from the present investigation that treatment with $CaNa_2$EDTA at the present dose rate is safe to be used for chelation in lead loaded calves.

• 한국문화재보존과학회:학술대회논문집
• /
• 한국문화재보존과학회 2004년도 제20회 발표논문집
• /
• pp.72-74
• /
• 2004

The color change of lead-containing pigments is one of the most serious diseases in watercolor, oil paintings and wall paintings. These pigments have a tendency to darken or brighten. It was proved that oxidation of lead containing pigments in the formation of brown-colored lead dioxide is a photochemical reaction under high humidity conditions. Therefore, we carried out some analogic experiments on the color change of three typical lead containing pigments ; $Pb_3O_4$, Pbo and $PbCo_3{\cdot}Pb(OH)_2$ at the conditions of illuminations under the high humidity ($2PbCo_3{\cdot}Pb(OH)_2$ R. H.). The reason for the chemical reactions are discussed and the results of these experiments are shown in some spectrograms, micrographs and X-ray micro-diffraction patterns. Important conclusions were drawn in our research. Due to the formation of brown $PbO_2$, red lead $(Pb_3O_4)$ and massicot (PbO) turned brown or dark when they were illuminated light under high humidity. We noticed that the brightening of red lead occurred d to admixture with chalk or lead white in egg yolk or linseed oil medium on exposure to light. Lead white used in oil paintings turned yellowish on dark.