• 한국산업보건학회지
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• 제21권4호
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• pp.193-200
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• 2011

Objectives: Blood lead and hyperhomocysteinemia have been found to be associated with cardiovascular disease. The objective of the present study was to assess the relationship of lead biomarkers on plasma homocysteine and blood pressure. Methods: To evaluate the effect of lead biomarkers including blood lead on plasma homocysteine and blood pressure in retired lead workers, 66 retired lead workers without any occupational exposure to organic solvent, mercury and arsenic were agreed to participate this study. For the control subjects 42 controls were recruited from same area of retired lead workers with consideration of demographic characteristics. Results: The mean levels of blood lead and ZPP of retired lead workers were significantly higher than control group. There were positive significant correlations between blood lead and plasma homocysteine, also systolic and diastolic blood pressure. The multiple linear regression analysis also reveled that plasma homocysteine was significantly associated with blood lead after adjusting for age, gender, body mass index, lead exposure, smoking and drinking. Diastolic blood pressure was significantly associated with blood lead, plasma homocysteine, and total cholesterol; whereas, systolic blood pressure was significantly associated with plasma homocysteine only. Conclusions: Blood lead showed significant association with plasma homocysteine and blood pressure even after more than mean 10 years from their retirements.

• 한국산업보건학회지
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• 제20권3호
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• pp.156-167
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• 2010

To evaluate the effect of lead biomarkers including bone lead on neurobehavioral test in retired lead workers, 131 retired lead workers without any occupational exposure to organic solvent, mercury and arsenic were agreed to participate this study. For the control subjects 56 non-occupationally lead exposed subjects were recruited from same area of retired lead workers with consideration of demographic characteristics. The mean levels of blood and bone lead of retired lead workers were significantly higher than control group and there were significant correlation among other lead biomarkers. Compared with controls without occupational lead exposure, lead exposured subjects had worse performance on 10 tests out of 12 neurobehavioral tests, but only two tests(Purdue pegboard nondominant and both hand) showed statistical significance of differences. In multiple linear regression analysis of neurobehavioral tests with lead biomarkers and demographic and lifestyle variables, age was associated negatively with 11 neurobehavioral tests, whereas log-transformed ZPP was associated with Purdue pegboard(both hand) and Santa Ana manual dexterity(non-dominant hand). On the other hand, tibia lead was associated Pursuit aiming test(correct) and Purdue pegboard(dominant hand) and calcaneal lead was associated with Purdue pegboard(dominant hand). This study confirmed that among all relevant variables age was most significantly associated with the poor performance of neurobehavioral tests. The blood lead did not have any significant association with neurobehavioral tests, but tibia and calcaneal bone lead and blood ZPP showed significant association with a few tests even after more than mean 9 years from their retirements.

• 한국산업보건학회지
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• 제29권2호
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• pp.195-207
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• 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
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• 제16권4호
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• pp.324-333
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• 2006

This study was designed to investigate the effect of bone demineralization and tibia lead on blood lead in retired lead workers. Two hundred thirty five(126 females and 109 males) retired lead workers who worked in 4 different lead factories and 101 non-occupationally lead exposed subjects(51 females and 51 males) were recruited from March 2004 to October 2004. Bone mineral density(BMD) was measured at left calcaneous bone area by broadband ultrasound attenuation(BUA) method with QUS-2(Metra Biosystems Inc, USA). The BUA value transformed into T-score by WHO standard conversion criteria. Tibia bone lead was measured for skeletal bone lead with K-xray fluorescence(K-XRF) and blood lead was analyzed with flameless atomic spectrophotometer. Hemoglobin, hematocrit, serum calcium and iron were also analyzed. In addition, information for smoking and drinking status and basic personal data such as age, gender and lead exposure were also collected using questionnaire inquiry. Blood lead was correlated with tibia lead (r=0.664) and these two variables were negatively correlated with BMD in bivariate analysis. BMD showed significant main effect on the change of blood lead independent to tibia lead without any effect modification of age or gender; the one T-score unit decrease of mineral bone density made $0.43{\mu}g/dl$ increase of blood lead. On the other hand, tibia lead showed effect modification with gender on blood lead; the slope of tibia lead on blood lead in male was steeper than in female and crossed at around zero of tibia lead. In the multiple regression analysis of blood lead and tibia lead on BMD after adjustment of related covariates, only blood lead showed statistically significant effect on BMD. This study confirmed that BMD and blood lead were significantly associated. To verify the causal association of BMD on blood lead and vice versa, further longitudinal studies are needed.

• 한국산업보건학회지
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• 제20권1호
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• pp.19-28
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• 2010

This study was designed to investigate the effect of increased blood and tibia lead on the change of bone mineral density in retired male lead workers. One hundred nine retired male lead workers who worked in 4 different lead industries and 51 nonoccupationally lead exposed male subjects were recruited from March 2004 to October 2004. Bone mineral density(BMD) was measured by broadband ultrasound attenuation(BUA) at left calcaneous bone area with broadband ultrasound attenuation method of QUS-2(Metra Biosystems Inc, USA). Tibia bone lead was measured for skeletal bone lead with K-xray fluorescence(K-XRF) and blood lead was analyzed with flameless atomic spectrophotometer. Hemoglobin, hematocrit, serum calcium and iron were also analyzed. In addition, information for smoking and drinking status and basic personal data such as age and lead exposure were also collected using questionnaire inquiry. Blood lead was correlated with tibia lead (r=0.711) and these two variables were negatively correlated with BUA in bivariate analysis. BUA and tibia lead showed significant main effects on the change of blood lead after adjusting covariates. The effect modification by the level of BMD (low: lower than the median of BUA and high: higher than the median of BUA) was observed between the association of tibia lead and blood lead after adjustment of covariates. The subjects who had higher BMD seemed to have lower blood lead by the increase of tibia lead than those of lower BMD. In the multiple regression analysis of blood lead and tibia lead on BUA after adjustment of covariates, only blood lead showed statistically significant effect on BUA. This study confirmed that BMD and blood lead were significantly associated. To verify the causal association of BMD on blood lead and vice versa, further longitudinal studies are needed.

• Safety and Health at Work
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• 제2권2호
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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.

• 한국벤처창업학회:학술대회논문집
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• 한국벤처창업학회 2017년도 통합학술대회
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• pp.15-35
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• 2017

본 연구는 주된 일자리에서 은퇴했거나 은퇴를 앞둔 베이비붐 세대 직장인들을 대상으로 은퇴 이후 창 재취업의도에 영향을 미치는 요인과 사회적자본의 매개효과를 규명하고자 한다. 2010년 이후 베이비붐 세대의 대규모 퇴직이 시작되고 있으나 경제적 노후준비를 충분히 확보하지 못한 상태에서의 대규모 은퇴는 노동시장의 불안정과 사회복지비용 지출증가 등 사회 경제적으로 커다란 이슈가 되고 있다. 퇴직 후 30년 이상의 새로운 커리어를 시도할 수 있는 준비를 하도록 개인의 인식변화와 제도적인 지원이 구체화 되어야 한다. 따라서 잠재적 은퇴자인 베이비부머 직장인들이 재직하는 기간 동안에 개인의 경력지향에 맞는 교육, 훈련, 재취업 프로그램을 체계적으로 지원받고, 네트워크나 신뢰 등 사회적자본을 강화하여, 은퇴 후 상대적으로 폭 넓은 창 재취업의 기회를 얻고, 퇴직 후에도 노동시장에 오랜 기간 머물도록 함으로써 경제적 안정과 공적연금 등 사회적 비용증가에 대한 해결책이 될 시사점을 얻을 수 있었다.

• Safety and Health at Work
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• 제1권1호
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• pp.69-79
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• 2010

Objectives: Various cytokines induced by inhalation of coal dust may mediate inflammation and lead to tissue damage or fibrosis, such as coal workers' pneumoconiosis (CWP). Methods: To investigate the relevance of serum cytokines in CWP, the levels of serum interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-${\alpha}$) as CWP biomarkers in 110 retired coal miners (22 controls and 88 CWP subjects) were related to cross sectional findings and 1-year progressive changes of the pneumoconiosis. Progressive changes of CWP were evaluated by paired comparison of chest radiographs. Analysis by a receiver operating characteristic curve assessed the biomarker potential of each cytokine. Results: The mean serum IL-8 level was significantly higher in CWP compared to controls and IL-8 levels correlated with the degree of CWP. The median serum TNF-${\alpha}$ level was significantly higher in subjects with progressive CWP compared to subjects without CWP progression. The area under the ROC curve for IL-8 (0.70) and TNF-${\alpha}$ (0.72) for CWP identification and progression, respectively, indicated the biomarker potential of the two cytokines. Serum cutoff values of IL-8 and TNF-${\alpha}$ were 11.63 pg/mL(sensitivity, 69%; specificity, 64%) and 4.52 pg/mL (sensitivity, 67%; specificity, 79%), respectively. Conclusion: The results suggest that high levels of serum IL-8 are associated with the presence of CWP and those of serum TNF-${\alpha}$ are associated with the progression of CWP.

• 분석과학
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• 제28권5호
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• pp.309-316
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• 2015

본 연구에서는 ICP-MS의 혈장 중 극미량의 납 분석법을 검증하기 위하여 Class 1,000 이내의 환경조건을 확보한 후 특이성, 일내 및 일간 정확도, 정밀도, 검정곡선 등을 확인하였다. 청정실의 부유 분진량을 측정한 결과, 0.3 µm 크기는 0.3~62개, 0.5 µm 크기는 0.0~28.3 개로 총 부유분진량이 최대 90.3개로 요구 환경에 부합하였다. 우태아 혈청 공시료로 조제한 시료의 MDL (Method detection limit)은 1.77 ng/L이고, LOQ (Limit of quantification)값은 5.55 ng/L 이었다. 검정곡선은 y=1.09×10⁻³ x+4.88×10⁻²이었고, 상관계수 r=0.9999이었다. 분석법 확립을 위한 특이성, 일내 및 일간 정확성, 정밀성, 그리고 검정곡선을 확인한 결과 50 ng/L 이상에서 분석법 확인 기준에 적합하였다. 이를 토대로 분석한 일반인의 혈장 중 납 농도 평균은 55.4 ng/L 이었으며, 현직 근로자는 440 ng/L 이었고, 퇴직 근로자는 132 ng/L 이었다.

• 벤처창업연구
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• 제12권5호
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• pp.177-189
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• 2017

본 연구는 주된 일자리에서 은퇴했거나 은퇴를 앞둔 베이비붐 세대 직장인들을 대상으로 은퇴 이후 창 재취업의도에 영향을 미치는 요인과 사회적자본의 매개효과를 규명하고자 한다. 2010년 이후 베이비붐 세대의 대규모 퇴직이 시작되고 있으나 경제적 노후준비를 충분히 확보하지 못한 상태에서의 대규모 은퇴는 노동시장의 불안정과 사회복지비용 지출증가 등 사회 경제적으로 커다란 이슈가 되고 있다. 퇴직 후 30년 이상의 새로운 커리어를 시도할 수 있는 준비를 하도록 개인의 인식변화와 제도적인 지원이 구체화 되어야 한다. 연구결과, 경력지향성과 사회적자본간의 영향관계에서 관리지향성은 사회적자본에 정(+)의 영향을 미치고 자율지향성은 영향을 미치지 않는 것으로 나타났다. 경력지향성과 창 재취업의도간의 영향관계에서 관리지향성은 창업의도에 영향을 미치지 않으나 재취업의도에 정(+)의 영향을 미치고, 자율지향성은 창업의도와 재취업의도 둘 다 정(+)의 영향을 미치는 것으로 나타났다. 사회적자본은 창 재취업의도에 정(+)의 영향을 미치며, 경력지향성과 창 재취업의도간의 영향관계에서 사회적자본의 매개효과가 확인되었다. 따라서 잠재적 은퇴자인 베이비부머 직장인들이 재직하는 기간 동안에 개인의 경력지향에 맞는 교육, 훈련, 재취업 프로그램을 체계적으로 지원받고, 네트워크나 신뢰 등 사회적자본을 강화하여, 은퇴 후 상대적으로 폭넓은 창 재취업의 기회를 얻고, 퇴직 후에도 노동시장에 오랜 기간 머물도록 함으로써 경제적 안정과 공적연금 등 사회적 비용증가에 대한 해결책이 될 시사점을 얻을 수 있었다.