• 한국환경과학회지
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• 제23권11호
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• pp.1843-1850
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• 2014

PS-D2EHPA beads were prepared by immobilizing di-2-ethylhexyl-phosphoric acid (D2EHPA) with polysulfone (PSf). The removal experiments of Cu(II) and Pb(II) by the prepared PS-D2EHPA beads were conducted batchwise. The removal efficiency of Cu(II) and Pb(II) by PS-D2EHPA beads was increased with increasing pH of solution. The removal rate of Cu(II) and Pb(II) was well described by the pseudo-second-order kinetic model. The maximum removal capacity of Cu(II) and Pb(II) obtained from Langmuir isotherm were 2.58 mg/g and 12.63 mg/g, respectively. External mass transfer coefficients for the removal of Cu(II) and Pb(II) by PS-D2EHPA beads were obtained $0.61{\times}10^{-2}{\sim}5.87{\times}10^{-2}/min$ and $1.55{\times}10^{-2}{\sim}8.53{\times}10^{-2}/min$, respectively and diffusion coefficients were obtained $1.32{\times}10^{-4}{\sim}3.98{\times}10^{-4}cm^2/min$ and $1.80{\times}10^{-4}{\sim}2.28{\times}10^{-4}cm^2/min$, respectively.

• 환경위생공학
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• 제18권1호
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• pp.30-40
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• 2003

The study subjects included the workers who were estimated to have been exposed in a low density of lead-laden glaze from pottery manufacturers. They were evaluated in terms of PbB and PbU as indices of lead concentration in the body, and Hb, Hct, ALAD, and FEP as indices of biochemical lead poisoning. Consequently, the study results revealed the relationship between each of indices and its effectiveness to indicate the degree of occupational lead exposure. 1. The mean of PbB was $22.85{\;}{\mu}g/d{\ell}$(range; $4.2~44.7{\;}{\mu}g/d{\ell}$) and PbU $45.69{\mu}g/d{\ell}$(range; $6.7~87.5{\mu}g/d{\ell}$), to indicate the level of lead exposure in the subjects. 2. While there was a high, linear correlation between PbB, PbU and FEP (r=0.835, r=0.855, respectively), a low correlation existed between PbB and ALAD(r=-0.240). 3. While there was a high, linear correlation between PbU and FEP(r=0.825), a low correlation existed between PbU and ALAD(r=-0.352). The above results suggest that FEP can be used as a highly useful biochemical index of lead poisoning, based on its high correlation with PbB and PbU indicating lead concentration in the body.

• 융합보안논문지
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• 제22권4호
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• pp.109-118
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• 2022

전 세계 국가들이 개인정보보호의 중요성을 인식하고 법률, 가이드라인, 지침 등의 다양한 형태로 정보주체의 권리보호에 대해 논의해왔다. 개인정보보호를 위한 사전 예방적 차원에서 공통적으로 강조하고 있는 개념 중 하나가 PbD(Privacy by Design)이며 정보주체의 프라이버시 보호를 위해 필수적인 요소로 주목받기 시작하였다. 그러나 시스템 개발이나 서비스 운영에 있어서 사전에 개인의 프라이버시를 최우선적으로 고려하자는 PbD 개념이 아직은 선언적 차원에만 머물고 있어서 이를 실제로 구현하기 위한 구체적 방법에 대한 논의는 상대적으로 부족하다. 이에 본 연구에서는 GDPR의 기본 원칙과 정보주체의 권리를 기준으로 어떠한 원칙과 권리가 우선적으로 고려되어 PbD가 구현되어야 하는지를 논의하였다. 이를 통해 국내 환경에서 시스템이나 서비스 개발 시 우선 시 해야 할 프라이버시 고려사항을 제시하여 PbD의 적용을 위한 방안을 제시했다는 점에서 본 연구의 의의가 있다.

• Journal of Preventive Medicine and Public Health
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• 제30권4호
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• pp.741-751
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• 1997

Measurement of blood lead (PbB) and blood zinc protoporphyrin (ZPP) are most common biological indices to identify the individual at risk for excess or the health sequences by lead exposure. Because PbB is known most important and reliable index of lead exposure, PbB is often regarded as a gold standard to detect lead exposure. But in Korea PbB is a secondary test item of detailed health check-up with positive finding of screening test in most occasion. Our lead standard requires all lead workers to take annual heath-check twice a year for investigation of their health effect due to lead exposure. Blood ZPP is one of most important index to detect high lead absorption in lead workers as a screening test. Measurement of blood ZPP is known ,well to correlate with PbB in steady state of exposure in most lead workers and is often used as a primary screening test to detect high lead absorption of lead workers with the advantage of simplicity, easiness, portability and low cost. The current cut-off criteria of blood ZPP for further detailed health check-up is $100{\mu}g/d\ell$ which is supposed to match the level of $40{\mu}g/d\ell$ of PbB according to our standard. Authors tried to investigate the validity of current criteria of cut-off level $(100{\mu}g/d\ell)$ of blood ZPP and possible another better cut-off level of it to detect the lead workers whose PbB level over $40{\mu}g/d\ell$. The subjects in our study were 212 male workers in three small scale storage battery industries. Blood ZPP, PbB and hemoglobin (Hb) were selected as the indices of lead exposure. The results were as follows. 1. The mean of blood ZPP, PbB and Hb in lead workers were $79.5{\pm}46.7{\mu}g/d\ell,\;38.7{\pm}15.1{\mu}g/d\ell,\;and\;14.8{\pm}1.2g/d\ell$, respectively. There were significant differences in blood ZPP, PbB and Hb by industry (P<0.01). 2. The percents of lead workers whose blood ZPP were above $100{\mu}g/d\ell$ in the group of work duration below 1, 1-4, 5-9 and above 10 years were 8.6%, 17.2%, 47.6%, and 50.0%, respectively. The percents of lead workers whose PbB were above $40{\mu}g/d\ell$ in those were 31.4%, 40.4%, 71.4%, and 86.4%, respectively. 3. The percents of lead workers whose PbB were below $40{\mu}g/d\ell$, $40-59{\mu}g/d\ell$ and above $60{\mu}g/d\ell$ were 54.7%, 34.9% and 10.4%, respectively. Those of lead workers whose blood ZPP were below $100{\mu}g/d\ell$, $100-149{\mu}g/d\ell$ and above $150{\mu}g/d\ell$ were 79.2%, 13.7% and 7.1%, respectively. 4. Simple linear regression of PbB on blood ZPP was statistically significant (P<0.01) and as PbB was $40{\mu}g/d\ell$, blood ZPP was $82.1{\mu}g/d\ell$. 5. While the highest sensitivity and specificity of blood ZPP test to detect lead workers with PbB eve. $40{\mu}g/d\ell$ were observed in the cut-off level of $50{\mu}g/d\ell$ and $100{\mu}g/d\ell$ of blood ZPP, respectively, the highest validity (sensitivity+specificity) of blood ZPP to detect lead workers with PbB over $40{\mu}g/d\ell$ was observed in the cut-off level of around $70{\mu}g/d\ell$ of blood ZPP. But even with optimal cut-off level of around $70{\mu}g/d\ell$ of blood ZPP, still 25.0% of false negative and 20.7% false positive lead workers were found. As the result of this study, it was suggested that reconsideration of current blood ZPP cut-off of our lead standard from $100{\mu}g/d\ell$ to somewhat lower level such as around $70{\mu}g/d\ell$ and the inclusion of PbB measurement as a primary screening test for lead workers was highly recommended for the effective prevention of lead workers.

• 한국식품위생안전성학회지
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• 제17권3호
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• pp.146-151
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• 2002

2001년 1-12월 서울시 가락농수산물시장에서 총 951건의 수산물(어류 34종 468건, 패류 17종 373건, 갑각류 10종 39건 그리고 두족류 등 11종 71건)을 대상으로 중금속 함량[average(minimum∼maximum), Unit:mg/kg]을 분석한 결과, Hg 0.025(N.D.∼0.19), Cd 0.288(N.D.∼l.85), Pb 0.227(ND∼l.68)이었다. Hg의 경우, 패류[0.033(N.D.∼0.19)]>두족류 등[0.026N.D.∼0.11)]>갑각류[0.026(N.D.∼0.09)]>어류[0.018(N.D.∼0.19)]순이었고, 가장 높은 함량은 미꾸라지 (0.19)와 꼬막(0.19)이었으며, Pb의 경우 패류[0.223(N.D.∼1.38)]>어류[0.213(N.D.∼1.68)]>두족류 등 [0.151(N.D.∼0.39)]>갑각류[0.144(N.D.∼0.44)]순이었고, 가장 높은 함량은 미꾸라지 (1.68)>빙어(1.44)>바지락(1.38)>뱀장어(1.35) 순이었다. 한편, Cd의 경우 패류[0.288(N.D.∼1.85)] 중 가장 높은 함량은 꼬막(1.85)이었다.

• 한국세라믹학회지
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• 제33권7호
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• pp.802-808
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• 1996

PbTiO3 thin films were fabricated onto MgO(100) single crystal substrate by reactive D. C magnetron sput-tering of Pb and Ti metal in an oxygen and argon gas mixture. The annealing of the thin films resulted in the decrease of both the c-axis orientation ratio and the lattice parameter. It is well known that the c-axis lattice parameter of thin film is dependent on the Pb/(Pb+Ti)ratio and the residual stress in the film The PbTiO3 thin films with a Pb/(Pb+T) ratio ranging from 0.45 to 0.57 were fabricated and annealed. The structure of the film the c-axis orientation ratio and the lattice parameter were not dependent on the Pb/(Pb+Ti) ratio before and after annealing. These experimental results proved that the decrease of the c-axis lattice parameter under the annealing conditions was due to the relaxation of the intrinsic stress in the film. This relaxation of the intrinsic stress caused the decrease of the c-axis orientation ratio and this phenomenon can be explained by c-axis growth lattice model.

• 한국환경보건학회지
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• 제37권4호
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• pp.258-266
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• 2011

Objectives: The aim of this study is to examine the possible changes over the past ten years in the estimated daily dietary lead intake (Pb-D) stemming from the variation of daily intake amounts for each food group. The following factors were considered; 1. time trends in Pb-D as the estimated values, 2. the time trend in Pb-D by food groups 3. the most influential food groups for dietary Pb intake. Methods: Estimated Pb-D was drawn from food consumption according to food groups reported in the Korean National Health and Nutrition Survey and the lead contents of each food group as reported in 23 prior publications. Results: The estimated Pb-D in a 2009 survey was 40.8 ${\mu}g/day$, of which 22.5 ${\mu}g/day$ (55.1%) was of plant origin and 18.3 ${\mu}g/day$ (44.9%) was of animal origin. Meats and poultry, fish and shellfish among foods of animal origin and beverages of plant origin had the largest contribution in Pb-D among the food groups. Conclusion: Over past ten years, daily lead intakes have slightly increased among men. Otherwise, no clear variation is apparent among women.

• 한국환경보건학회지
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• 제47권1호
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• pp.36-44
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• 2021

Objectives: The study aims to examine the variation over roughly the past 10 years (from 2008 to 2018) in the estimated daily dietary Pb intake (Pb-D) based on the variations of daily intake amount and Pb content in respective food groups. The following factors were considered: (1) variation of estimated value of Pb-D, (2) Pb contents in each food group and (3) the most influential food group for dietary Pb intake. Methods: Estimated values of Pb-D were taken from food consumption by the food groups reported in the Korean National Health and Nutrition Survey and the Pb content of each food group as reported in 19 previous publications. Variation from 2008 to 2018 of Pb intake was calculated from daily intake amount and Pb content in each food group. Results: The survey showed that main Pb intake sources were the food groups 'meats and poultry' and 'fish and shellfish'. These food groups showed gradually increased Pb exposure from 2008 to 2018. Estimated daily Pb intake was 42.18 to 57.68 ㎍/day for men and 30.97 to 42.54 ㎍/day for women. Both men and women showed slightly increased dietary Pb intake from 2008 to 2018. The food groups 'meats and poultry' and 'fish and shellfish' proved the highest Pb intake food groups. Estimated Pb intake from 'meats and poultry' was 8.47 to 12.98 ㎍/day and that of 'fish and shellfish' was 5.63 to 10.10 ㎍/day. Conclusion: Over the past ten years, daily Pb intake has slightly increased in men and women. The food groups 'meats and poultry' and 'fish and shellfish' might be the main variation factors of Pb intake.

• Toxicological Research
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• 제30권4호
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• pp.267-276
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• 2014

Exposures to lead (Pb) are associated with neurological problems including psychiatric disorders and impaired learning and memory. Pb can be absorbed by iron transporters, which are up-regulated in hereditary hemochromatosis, an iron overload disorder in which increased iron deposition in various parenchymal organs promote metal-induced oxidative damage. While dysfunction in HFE (High Fe) gene is the major cause of hemochromatosis, the transport and toxicity of Pb in Hfe-related hemochromatosis are largely unknown. To elucidate the relationship between HFE gene dysfunction and Pb absorption, H67D knock-in Hfe-mutant and wild-type mice were given drinking water containing Pb 1.6 mg/ml ad libitum for 6 weeks and examined for behavioral phenotypes using the nestlet-shredding and marble-burying tests. Latency to nestlet-shredding in Pb-treated wild-type mice was prolonged compared with non-exposed wild-types (p < 0.001), whereas Pb exposure did not alter shredding latency in Hfe-mutant mice. In the marble-burying test, Hfe-mutant mice showed an increased number of marbles buried compared with wild-type mice (p = 0.002), indicating more repetitive behavior upon Hfe mutation. Importantly, Pb-exposed wild-type mice buried more marbles than non-exposed wild-types, whereas the number of marbles buried by Hfe-mutant mice did not change whether or not exposed to Pb. These results suggest that Hfe mutation could normalize Pb-induced behavioral alteration. To explore the mechanism of repetitive behavior caused by Pb, western blot analysis was conducted for proteins involved in brain dopamine metabolism. The levels of tyrosine hydroxylase and dopamine transporter increased upon Pb exposure in both genotypes, whereas Hfe-mutant mice displayed down-regulation of the dopamine transporter and dopamine D1 receptor with D2 receptor elevated. Taken together, our data support the idea that both Pb exposure and Hfe mutation increase repetitive behavior in mice and further suggest that these behavioral changes could be associated with altered dopaminergic neurotransmission, providing a therapeutic basis for psychiatric disorders caused by Pb toxicity.

• 센서학회지
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• 제33권2호
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• pp.93-97
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• 2024

With the development of promising future mobility and urban air mobility (UAM) technologies, the demand for LIDAR sensors has increased. The SWIR photodetector is a sensor that detects lasers for the 3D mapping of lidar sensor and is the most important technology of LIDAR sensor. An SWIR photodetector based on QDs in an eye-safe wavelength band of over 1400 nm has been reported. QDs-based SWIR photodetectors can be synthesized and processed through a solution process and have the advantages of low cost and simple processing. However, the organic ligands of QDs have insulating properties that limit their ability to improve the sensitivity and stability of photodetectors. Therefore, the technology to replace organic ligands with inorganic ligands must be developed. In this study, the organic ligand of the synthesized PbS QDs was replaced with a MAPI inorganic ligand, and an SWIR photodetector was fabricated. The analysis of the characteristics of the manufactured photodetector confirmed that the photodetector based on MAPI-capped PbS QDs exhibited up to 26.5% higher responsivity than that based on organic ligand PbS QDs.