• 한국산업보건학회지
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• 제11권2호
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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).

• Nutritional Sciences
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• 제4권2호
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• pp.91-97
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• 2001

The purpose of this study was to assess the nutritional status of Korean workers with occupational exposure to lead by estimating nutrients and flood intakes so that we can eventually establish the dietary guidelines to be recommended for the lead workers. Food consumption survey was conducted by a 24-hr recall method with 135 lead workers and 50 non-exposed controls. Food intake data were convened into nutrients intake using computer aided nutritional analysis program. Mean daily energy intake and percentage of recommended daily allowance (RDA) of male lead workers were 2138 local and 87% of RDA while those of control were estimated as 2234 kcal and 91% of RDA. Mean daily intakes of nutrients of male lead workers were 78 g (111% RDA) for protein 502 mg (71% RDA) for calcium, 11.7 mg (97% RDA) for iron, 665 $\mu$g R.E (95% RDA) for vitamin A, 1.39 mg (108% RDA) for thiamin, 1.14 mg (77% RDA) for riboflavin, 15 mg N.E (92% RDA) for niacin and 66 mg (94% RDA) for vitamin C. On average, male lead workers showed significantly lower protein, calcium, iron, sodium, potassium, niacin and vitamin C intakes than control group while cholesterol intake of the male lead workers was significantly higher than that of control group. Intakes of calcium of male lead workers were Less than 75% RDA meaning that nutritional intake of calcium of male lead workers was insufficient and could possibly result in nutritional deficient. Some food groups such as milk, meat and fish must be strongly suggested to improve nutritional status of lead workers. Continuing nutrition monitoring and appropriate nutrition intervention for lead workers most be conducted further.

• 한국산업보건학회지
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• 제28권2호
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• pp.158-165
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• 2018

Objectives: We analyzed the problems that work environment measurement results don't lead to workplace improvement in the Work Environment Measurement System to propose an alternative. Methods: We reviewed reports and articles written by the Korea Occupational Safety and Health Agency and academic circles to identify the problems in the current Work Environment Measurement System and suggest an alternative. Results: One of the reasons that the Work Environment Measurement has not resulted in workplace improvement is that there were no proper regulating systems for managing the workplace improvement plans or improvement results. Moreover, there are not enough professional manpower in ministry of labor to evaluate the improvement plans and results from the Work Environment Measurement. Therefore, all of the workplace whose Work Environment Measurement results exceed the occupational exposure limit (OEL) should be managed by regional ministry of labor, and outside experts and new system for verifying improvement are needed. Conclusions: To accomplish the purpose of Work Environment Measurement, it is necessary to improve the work environment according to the results of Work Environment Measure. For this, it is necessary for the government to manage the fulfillment of workplace improvement plans and for measurement agencies to secure expertise.

• Journal of Radiation Protection and Research
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• 제39권4호
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• pp.213-217
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• 2014

중재방사선을 이용한 의료적 시술이나 진단은 꾸준히 증가하고 있다. 특히 환자에 근접하여 이루어지는 중재방사선시술의 특성상 시술자에 대한 직무피폭의 관리 및 감시가 중요하다. 개인선량계를 통해 측정되는 방사선 방호 실용량인 심부선량은 중재방사선시술의 경우 균질한 방사선장에 의해 전신에 고르게 노출되는 경우가 아니므로 유효선량을 항상 대표할 수는 없다. 따라서 본 연구에서는 C-arm을 이용한 대표적인 중재방사선시술에 대해 수학적 모의피폭체와 몬테카를로 방법을 이용한 계산과 개인선량계를 이용한 실측을 통해 개인선량당량과 장기별 선량을 평가하고자 하였다. 주요 장기별 선량평가 결과는 개인선량계로 측정된 선량 값보다 낮았으나, 갑상선과 같은 장기는 전신 연조직 선량보다 상당히 높은 것으로 평가되었다. 중재방사선시술자에 대한 적절한 방사선방호를 위해 납치마의 착용과 같은 전신 방호와 더불어 갑상선 방호와 같은 추가적인 방호조치가 고려되어야 할 것이다.

• International Journal of Safety
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• 제3권1호
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• pp.6-9
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• 2004

This paper deals with the noise evaluation technique of a reciprocating air-compressor and its noise reduction. The reciprocating air-compressors are widely used in the small, medium sized industrial firms, and lots of their employees are affected and irritated by their noise in the workplace. Thus, noise control actions should be taken appropriately by considering the hearing loss due to the occupational noise exposure. Lead-wrapping techniques are employed to identify the contribution of principal noise sources which are generally known as motor, belts, suction/discharge valves, moving pistons, and flow-induced noise caused by edges or discontinuities along the flow path e.g. expansions, contractions, junctions and bends etc .. As a result, main noise sources of the air-compressor can be categorized by the suction/discharge noise, valve noise, and compressed-air tank noise. Based on the investigations, mufflers are designed to reduce both the suction/discharge noise and the compressed-air tank noise. Instead of the conventional valve plate, polyethylene resin is used as a new one for the reduction of valve impact noise. In addition, attempts are made to reduce the valve noise propagation to the cylinder head and the compressor tank by using the insulation casings. As a result of the countermeasure plans, it can be achieved that the noise reduction of the air-compress is up to 10dB.

• Safety and Health at Work
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• 제9권1호
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• pp.95-100
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• 2018

Background: Respiratory protection equipment (RPE) is the last resort to control exposure to workplace air pollutants. A comprehensive respiratory protection program (RPP) ensures that RPE is selected, used, and cared properly. Therefore, RPP must be well integrated into the occupational health and safety requirements. In this study, we evaluated the implementation of RPP in Iranian petrochemical industries to identify the required solutions to improve the current status of respiratory protection. Methods: This cross-sectional study was conducted among 24 petrochemical industries in Iran. The survey instrument was a checklist extracted from the Occupational Safety and Health Administration respiratory protection standard. An index, Respiratory Protection Program Index (RPPI), was developed and weighted by analytic hierarchy process to determine the compliance rate (CR) of provided respiratory protection measures with the RPP standard. Data analysis was performed using Excel 2010. Results: The most important element of RPP, according to experts, was respiratory hazard evaluation. The average value of RPPI in the petrochemical plants was $49{\pm}15%$. The highest and lowest of CR among RPP elements were RPE selection and medical evaluation, respectively. Conclusion: None of studied petrochemical industries implemented RPP completely. This can lead to employees' overexposure to hazardous workplace air contaminants. Increasing awareness of employees and employers through training is suggested by this study to improve such conditions.

• 한국환경보건학회지
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• 제35권2호
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• pp.86-94
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• 2009

This study analyzed the concentration of the lead in blood (n=774) from May, 2007 to Oct 2007. The subject was residents in G, Y, H industrial area, Jeollanam-do, in which exposure to the lead is expected due to the adjacency of the industrial complex. As to the lead concentration in the blood of the residents in the whole exposed region and the comparing region, $2.81{\mu}g/dl$ in the exposed region group, and $2.86{\mu}g/dl$ in the comparing region group Respectively, which indicates that the concentration of the comparing group was higher than that of the exposed group. The geometric mean concentration of lead in blood was $3.26{\mu}g/dl$ as to men, and $2.46{\mu}g/dl$ as to women, which indicates that the concentration of men is higher than that of women (p<0.01). The lead concentration for each age group increased in proportion to age except those under 10 for some substances (p<0.01). As to geometric mean concentration in blood according to the smoking history of the subject, the concentration of the smoking group and the non-smoking group was $3.57{\mu}g/dl$ and $2.66{\mu}g/dl$ respectively, which indicates the former is higher than the latter (p<0.01). To clarify the factors affecting the heavy metal concentration in blood among the subjects, the multiple regression analysis was conducted. As a result, it turned out that as to lead content in blood, gender, age, smoking all affect the lead concentration of the subjects ($R^2$=23.3%).

• Tuberculosis and Respiratory Diseases
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• 제76권2호
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• pp.75-79
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• 2014

Trichloroethylene (TCE) is a toxic chemical commonly used as a degreasing agent, and it is usually found in a colorless or blue liquid form. TCE has a sweet, chloroform-like odor, and this volatile chlorinated organic chemical can cause toxic hepatitis, neurophysiological disorders, skin disorders, and hypersensitivity syndromes. However, the hypersensitivity pneumonitis (HP) attributed to TCE has rarely been reported. We hereby describe a case of HP associated with TCE in a 29-year-old man who was employed as a lead welder at a computer repair center. He was installing the capacitors on computer chip boards and had been wiped down with TCE. He was admitted to our hospital with complaints of dry coughs, night sweats, and weight losses for the past two months. HP due to TCE exposure was being suspected due to his occupational history, and the results of a video-associated thoracoscopic biopsy confirmed the suspicions. Symptoms have resolved after the steroid pulse therapy and his occupational change. TCE should be taken into consideration as a potential trigger of HP. Early recognition and avoidance of the TCE exposure in the future is important for the treatment of TCE induced HP.

• 한국환경보건학회지
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• 제46권3호
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• pp.267-275
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• 2020

Objectives: The causes of dementia have been reported in various ways, but there has been little research on the interrelationship between heavy metals and dementia, and the results also show little consistency. Therefore, it is imperative to compare the levels of heavy metal exposure between the dementia-suffering group and a control group to confirm the correlation between the level of heavy metal exposure and the likelihood of dementia. Methods: In order to assess the dementia level of the elderly, the Global Deterioration Scale (GDS) and Mini Mental State Examination (MMSE) were applied. To analyze the concentration of heavy metals in the blood, blood was collected from the veins of study subjects and measured using Inductively Coupled Plasma-mass spectrometry (ICP-MS). Results: There was a statistically significant correlation between lead and manganese concentrations in the blood and the MMSE and GDS. It was found that there was a statistically significant correlation between cadmium concentration in the blood and the GDS, but the MMSE was less relevant. It was found that the blood mercury concentration and the MMSE and GDS were less relevant. The lead concentration in the blood was 0.95±0.74 ㎍/dL in the dementia patient group and 0.33±0.22 ㎍/dL in the normal group, while cadmium was 0.69±0.37 ㎍/L in the dementia group and 0.18±0.10 ㎍/L in the normal group. Mercury was 0.81±0.31 ㎍/L in the dementia group and 1.16±0.80 ㎍/L in the normal group. Manganese was 6.83±2.01 ㎍/L in the dementia group and 4.78±1.59 ㎍/L in the normal group. All of these show statistically significant differences. Conclusions: As the concentration of lead, cadmium and manganese in the blood increases, the MMSE scores and GDS scores were found to worsen, and it was confirmed that there is a correlation between heavy metal exposure and cognitive degradation.

• 한국환경보건학회지
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• 제38권4호
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• pp.311-322
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• 2012

Objective: The effect of lead on blood pressure remains controversial in spite of the numerous studies which have been conducted in the recent years. The aim of this study was to evaluate the effects of exposure to lead on blood pressure among non-smokers. Methods: In this cross sectional study, 1416 male and female non-smokers were enrolled, aged 20 years or older, from the Korean National Health and Nutrition Examination Survey 2008. Blood pressure, blood lead levels (BLLs), height, weight, and cotinine level were measured for all subjects. Results: Geometric mean BLLs of the participants was 2.20 ${\mu}g$/dl. BLLs were higher in the older, male, and lower education groups than the younger, female and higher education groups. After adjusting for age, sex, education and BMI through multiple regression analysis, a significant positive association between systolic blood pressure (p = 0.0357), diastolic blood pressure (p = 0.0111) and BLLs. Also, among the normal BMI group (18.5 kg/$m^2$ < BMI < 25 kg/$m^2$), we also found a significant positive association between diastolic blood pressure and BLLs (p = 0.0370). Conclusion: The present study showed that blood lead serves as a good predictor of blood pressure changes and that there was a statistically significant association between blood lead and blood pressure, especially diastolic blood pressure.