• Journal of Preventive Medicine and Public Health
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• 제33권3호
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• pp.299-305
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• 2000

인천지역에 위치한 한 개 특수건강진단기관에서 1995년 1월부터 1997년 12월까지 3년간 1회 이상 건강진단을 받은 근로자 61,569명의 건강진단 수진결과 전산자료를 받아 같은 지역에 위치한 4개 직장의료보험조합에 이들 근로자의 사업장 이름을 전달하고 이들 피보험근로자의 폐암으로 인한 병 의원이용 전산자료를 취득하였다. 4개 조합에 속하여 의료보험 청구자료를 구할 수 있었던 근로자는 44,958명이었는데 관찰기간을 동일하게 하기 위하여 연구기간 3년 동안 의료보험 취득기간이 2년 미만인 근로자와 자료이상으로 판단되는 근로자 14,4202명과 비제조업 종사 근로자 1,054명을 제외한 28,884명을 분석 대상으로 하였다. 2개의 출처가 다른 자료를 주민등록번호를 이용하여 연결하여 새로운 데이터베이스를 구성하고 이를 이용하여 주물업 종사 근로자와 비주물업 종사 근로자의 폐암이 주상병명인 경우에 차이가 있는가를 분석하였다. 연구결과 3년 동안 병 의원을 이용한 전산자료 중 주상병명이 폐암인 근로자는 주물업 종사 근로자 1,591명 중 7명, 비주물업 종사 근로자 27,293명 중 12명으로 두 집단간에 유의한 차이가 있었다(비차비 10.04, 95% 신뢰구간 3.95-25.55, p<.001). 본 연구가 부정확한 상병명으로 대표되고 있는 의료보험 전산자료를 이용한 관계로 이 결과에 근거하여 주물업 종사 근로자들이 비주물업 종사 근로자들에 비하여 폐암발생률이 높다라고 단정적으로 결론을 내릴 수는 없지만 주물업 종사 근로자들에서 폐암 발생이 증가할 가능성을 뒷받침하는 근거 중 하나가 될 수 있다고 판단된다. 따라서 향후 제대로 설계된 코호트연구를 통하여 주물업 종사 근로자들의 폐암발생 위험도를 구하고 위험요인을 분석하는 연구가 필요하다고 판단된다.

• Journal of Preventive Medicine and Public Health
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• 제26권3호
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• pp.371-386
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• 1993

This study was carried out to evaluate diagnostic criteria of noise-induced hearing loss (NIHL) among-workers in an iron foundry. Of 1,093 workers under the observation of noise-specific health examination, 184 workers were selected by way of first and second screening audiometric examination. A questionnaire survey, otological examinations, Rinne test and audiometric test were performed and the results were as follows ; The degree of hearing impairment in the left ear was more severe than in the right ear (p<0.05). The difference between hearing threshold of the first and the second hearing test at 1,000 Hz was about 5 dB with a narrow range of deviations while the difference at 4,000 Hz was about -7 dB with a wide range. Of the total study workers, 84.8% were tested within 15 hours away from noise exposure, and the rest after 16 hours. This study has identified that mean hearing loss at 4,000 Hz showed a significant statistical difference among the two study groups while mean hearing loss by 4-divided classification did not. The same phenomena were observed between the group with and without tinnitus and between the group with and without difficulty in hearing (p<0.05). Among 184 workers, 10 workers (5.4%) diagnosed as NIHL by old diagnostic criteria in contrast to 150 workers diagnosed as NIHL by the new diagnostic criteria. There was a significant difference between the two groups in the average hearing loss at 4,000 Hz and 4-divided classification (p<0.01), but there were no significant differences in age, the duration of employment, blood pressure and the duration wearing the personal hearing protector (p>0.05). If we apply Early Loss Index (ELI) method, some workers in younger age group diagnosed as NIHL by the new diagnostic criteria were fallen into within the normal range. In the mean time older age group show reverse results in contrast to the above finding. It is too early to confirm the value of the usage of the new diagnostic criteria in hearing examination. Further study is called for to verify the value of this criteria.

• Journal of Preventive Medicine and Public Health
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• 제27권2호
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• pp.274-285
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• 1994

The effects of resin on the respiratory health have been investigated in 309 workers from four iron and steel foundries and the results compared with those from 122 workers who were not significantly exposed to resin gas and silica dust at the same industries. Phenol-formaldehyde resin was used in the core making and molding processes and workers were exposed to their decomposition products as well as to silica dust containing particulates. The subjects were grouped according to formaldehyde, dust and other gas exposures, and smoking habits were considered also in thi analysis. Standardized respiratory symptom questionnaire was administered by trained interviewers. Chest radiograph, pulmonary funtion tests, and methacholine challenge tests were done. Environmental measurements at the breathing zone were carried out to determine levels of formaldehyde, respiable dust and total dust. Foundry workers had a higher prevalence of symptoms of chronic bronchitis with chronic phlegm and chronic cough when exposed to dust. Exposure to gas was significantly associated with lowered $FEV_1$ and obstructive pulmonary function changes. Exposure to formaldehyde and phenol gas was associated with wheezing symptom among workers, but $FEV_1$ changes after methacholine challenge were not significantly different among different exposure groups. When asthma was defined as the presence of bronchial hyperreactivity with more than 20% decrease in $FEV_1$ after methacholine challenge, 17 workers out of 222 tested had asthma. Fewer asthmatic welters were found among groups exposed to formaldehyde, gas and dust, which indicates a healthy worker effects ill a cross-sectional study. The concentration of formaldehyde gas ranged from 0.24 to 0.43 ppm among studied foundries. The authors conclude that formaldehyde and phenol gas from combusted resin is probably the cause of asthmatic symptoms and also a selection force of those with higher bronchial reactivity away from exposures.

• 한국환경보건학회지
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• 제8권1호
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• pp.67-80
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• 1982

In order to evaluate the psychosomatic health status of metal manufacturing industries workers and their working environments, the present study was conducted from March 1, 1981 to the end of September 1981. The data was obtained from the samples of metal manufacturing industries in Kyung-In Area and their 1, 162 employees. In addition, the 803 urban residents including students, office clerks, and general publics were sampled as control groups to compare with factory employees in psychosomatic analysis. The basic tool employed in the present study was the Todai Health Index (THI) which modified CMI and was developed by Tokyo University Research Team of Japan. The results of the present study were summarized as follows: 1. Working environments of the factories 1) The data shows that fabrication shop produced the highest noise level ranging from 91 to 96 dB (A) and iron and steel shop had the lowest noise level ranging from 81 to 86 dB (A). 2) Dust concentration was the highest in iron foundry shop ($3.8 mg/m^3$) and the lowest in fabrication shop ($1.2 mg/m^3$). 3) WBGT above threshold limit values (T.L.V.) was noted in steel shop (38$\circ$C) and iron foundry shop (34$\circ$C) 4) The concentration of Sulfur dioxide ($SO_2$)was 30.5ppm at steel shop and 12.0ppm at iron foundry shop. 5) The concentration of carbon monoxide (CO) was 140.0ppm at steel shop and 110.5ppm at iron foundry shop. 6) The atmospheric lead concentration was $0.49 mg/m^3$ at soldering shop. 2. The responses of psychosomatic complaints were much higher in steel shops group than in other manu-facturing group, except the response of aggressiveness. 3. The responses of psychosomatic complaints were much higher in industrial workers than in urban residents, except the responses of depression and aggressiveness (p < 0.01 ). 4. The psychosomatic symptoms which industrial workers and urban residents complained frequently were nervousness. agressiveness and lie scale in order. 5. The responses of psychosomatic complaints by sex were much higher in female group than in male group, except the response of aggressiveness. 6. The responses of psychosomatic complaints by age were that both the female and male group showed an increasing tendency in the all items, except the response of depression as age was increasing. 7. The responses of psychosomatic complaints by the length of services were that both the female and male group showed a tendency of increasing in physical symptoms as work years increased. 8. The responses of psychosomatic complaints were higher in unmarried group in the score of nervousness, aggressiveness, mental irritability and irregular life.

• 대한예방의학회:학술대회논문집
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• 대한예방의학회 1993년도 제45차 추계 학술대회 연제집
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• pp.81-82
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• 1993

• Korean Chemical Engineering Research
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• 제44권2호
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• pp.136-148
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• 2006

주물공장에서는 주철을 녹여서 다양한 기계부품을 만든다. 다양한 기계부품을 만들기 위해 목형을 주물사에 넣은 후 주입구를 만들어 녹인 주철을 투입한다. 주물공장은 furan 공정을 포함해 많은 공정으로 이루어지며, 이 중 furan 공정은 목형에 주물사를 부어 넣는 공정이다. Furan 공정의 첫 단계는 주물사가 서로 엉겨 붙어 있게 하기 위해 접착성을 가지는 고분자 물질인 furan류를 주물사에 섞게 되고 녹은 주철이 목형으로 들어가는 것이며 고온에 의해 많은 유해 VOC류가 발생하게 된다. 또 공정조업에서 furan용 모래를 목형이 든 주물형틀에 부어 넣게 되고, 이때도 유독가스와 분진이 발생하게 되며 이 분진은 furan 물질을 포함하고 있어 조업자의 건강에 치명적인 요소가 되며, 이로 인해 조업기피현상이 심화되어 인력수급에 문제가 되고 나아가 사업 경영에 큰 걸림돌이 되고 있다. 본 연구는 이러한 조업기피의 원인을 제거하고 쾌적한 조업환경을 제공하기 위해 유해 VOC류와 집진을 동시에 수행할 수 있는 유해 VOC 및 분진 동시제거 시스템을 최적 설계하고 나아가 현장에 적용 설치하였다. 그 결과 설치 후 포름알데히드의 경우 VOC 0 ppm, 분진 $4{\mu}g/m^3$으로 조업환경이 개선되었으며, 조업자들의 조업 기피 요인을 해소하였다. 또한, 우리는 회사의 고용 문제를 해결하고, 작업의 생산성을 향상시킬 수 있었다.

• 대한예방의학회:학술대회논문집
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• 대한예방의학회 1993년도 제45차 추계 학술대회 연제집
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• pp.119-120
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• 1993

• 한국안전학회지
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• 제15권1호
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• pp.112-120
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• 2000

We have compared the regulations of hot environment workpaces between Korea and ACGIH, then pointed out some insufficiences of Korean regulations for occupational hygiene and safety. And investigated the heat stress characteristics of laboratory, lathe and foundry working. The metabolic heat loads of those workplaces were obtained as 120, 300 및 660 kcal/hr based on WBGT index. WBGT index could be depended on weather condition, therefore useful for controlling working and rest times etc, but Belding-hatch index was represented by strength of working, definitely this would be convinient result for arranging countermeasures of workers in hot environments by estimating metabolic heat and signs of fatigue.

• 한국주조공학회지
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• 제41권2호
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• pp.144-152
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• 2021

세계 주조산업의 현황 분석을 바탕으로 최근 20년간의 한국 주조산업의 국제경쟁력을 살펴보았다. 한국 주물 총 생산량은 252만톤, 1업체당 생산량인 주물 생산성은 2,831톤으로 모두 세계 8위이고, 3년 전에 비해 총 생산량은 한 순위 내려간 상황이고, 주물생산성은 순위를 유지하고 있다. 한국은 10대 주물강국 중 유일하게 생산량이 감소한 국가로 분석된다. 세계 상황과 비슷하게 한국의 주물제품은 회주철 38%, 구상흑연주철 31%, 알루미늄 15%, 주강 9%로 구성된다. 본 조사에서는 한국의 주조산업 통계를 얻기 위해 2020년 4월부터 약 9개월간의 용역사업을 실시하였다. 한국 표준 산업분류에 의해 각종 통계조사와 표본 심층조사를 통하여 국내 주조산업의 다양한 내용을 평가하였다. 각 기업체의 수와 지역별 분포, 종사자 수와 외국인 비율, 각 직능별 분포도 확인하였고, 기업 규모에 따른 R&D 투자현황도 살펴보았다. 그와 함께 주조산업의 버는 힘을 측정하기 위해 매출액, 수출액, 영업 및 순수익률 등을 분석하였다. 또한 각 기업에서 중점적으로 활용하는 공정에 따라 주조산업을 세분하여 분류하고, 각 공정별 매출, 수출, 수익률 현황도 파악하여, 활용 공정별 현황도 기초 조사하였다. 이러한 자료를 바탕으로 국내 주조산업이 지속성장하기 위한 다음과 같은 분야에 대해 다양한 제언을 제시하였다; 세계 순위, 한계 기업 구조조정, 국내 기술인력 양성, 기업규모별, 공정별 차별화된 지원정책.

• 한국주조공학회지
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• 제24권1호
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• pp.26-33
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• 2004

The pressure of the mold flux acting on the meniscus shell was investigated through the coupling analysis of heat transfer in the mold and fluid flow in the flux caused by the mold oscillation. Finite element method was employed to solve the conservation equation associated with appropriate boundary conditions. As reported by previous workers, the axial pressure is positive on the negative strip time and negative on the positive strip time. A maximum pressure is predicted toward the top of the meniscus shell which has the thin shell arid a maximum value is in proportion to the relative mold oscillation velocity. The relative mold oscillation velocity was changed by the effect of meniscus level fluctuation. Therefore the pressure of the mold flux acting on the meniscus shell was different each cycle of the mold oscillation due to the irregularity of relative mold oscillation velocity.