Objectives: Particulate contaminants, such as total and respirable dusts, can harm the health of farm workers via several routes. The principal aims of this field study were to determine the concentrations and emissions of particulate contaminants: total and respirable dusts, in the different types of swine houses used in Korea, and allow objective comparison between Korea and the other countries in terms of swine housing types. Methods: The swine houses investigated in this research were selected with respect to three criteria: the manure removal system, ventilation mode and growth stage of pigs. Measurements of total and respirable dust concentrations and emissions in the swine houses were carried out on 5 housing types at 15 different farm sites per housing type. The swine houses investigated were randomly selected from farms situated within the central districts in Korea: province of Kyung-gi, Chung-buk and Chung-nam. Results: The total and respirable dust concentrations in the swine houses averaged
The principal aim of this field study was to determine the concentrations and emissions of gaseous contaminants such as ammonia and hydrogen sulfide in the different types of pig buildings in Korea and allow objective comparison between Korea and the other countries in terms of pig housing types. This field study was performed from May to June and from September to October in 2002. Pig buildings investigated in this research were selected in terms of three criteria; manure removal system, ventilation mode and growth stage of pig. Measurements of concentration and emission of ammonia and hydrogen sulfide in the pig buildings were done in 5 housing types and the visited farms were 15 sites per each housing type. Concentrations of ammonia and hydrogen sulfide were measured at three locations of the central alley in the pig building and emission rates of them were estimated by multiplying the average concentration(
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.
The objectives of this study were (1) an investigation of the current status of the hazardous substances, (2) a comparative analysis of classification system of hazardous substances between Korea and other countries, (3) a development of the new classification system in Korea, finally a review of prerequisites for effective enforcement of the new system. The results are summarized as follows : 1) The backbone of classification system of hazardous substances in Korea is based on Japanese classification system and EC(European Committee) guideline of hazardous substance. There are many problems in managing and handling of hazardous substances due to discordant of Japanese and EC system. It is desirable to revise the classification system to be harmonized with international guideline for example, guideline of IFCS(The Inter-governmental Forum on Chemical Safety) and EC guideline. 2) There are several problems in definitions of corrosive, sensitizing and irritation in MSDS Code of Ministry of Labour. It is desirable to reform those definitions. 3) Among the hazardous substances under the current system, there are several substances such as, beta-propiolactone, methyl bromide, ethyleneimine, etc that are not used and produced in Korea. It is desirable to exclude the substances from the list of controlled substances. 4) The section 39, about 'substance that designated to attach warning label' in Korea Occupational Safety and Health Act(OSHAct) should be eliminated, because above section is unnecessary under the MSDS system. 5) The researchers recommend to establish a new list of hazardous substance which are controlled by OSHAct. It is desirable that the new list is consist of two types. The first type is 'a list of the specially controlled substances' and the other is 'the generally controlled substances'. 6) It is recommended that the specially controlled substances should include hazardous substances that are highly toxic and widely used in Korea. And the generally controlled substances should include hazardous substances that can be analysed by instrument and carry threshold. limit values(TLV's).
This study was carried out to evaluate the harmful factors in working environments and to investigate the labor productivity after improvement of environments, surveying 93 industrial establishments of 10 industries located in Youngdeungpo industrial area in Seoul. The results obtained were as follows: 1) The highest noise level of 125dB(A) was indicated at the rolling process of transport equipment manufacturing industry. 2) The best illumination level was shown in precise machinery industry and the worst was indicated in rubber products, metallic products and transport equipment manufacturing industries. 3) Thermal conditions were above threshold limit value (TLV) at more than two processes of all industries except printing industry. 4) The highest dust concentration was determined in textile and wearing manufacturing industry. 5) Organic solvents were detected at 52 processes in 93 industrial establishments and 33 processes of them showed higher than TLV. The results about harmful chemicals were as follows: a) sulfur dioxide ($SO_2$)was determined higher than TLV on welding process of metallic product manufacturing industry and heat treatment process of transport equipment manufacturing industry. b) Carbon monoxide (CO) concentration was 700ppm at heat treatment process of transport equipment manufacturing industry, indicating 14 times of TLV. c) vinylchloride concentration in the air of PVC raw material mixing process and PVC preparation process of chemical product manufacturing industry was determined higher than TLV. d) Hydrochloride (HCl) concentration in the air of wire expanding process of transport equipment manufacturing industry was determined higher than TLV. 7) Higher values of lead concentration than TLV were determined at lead welding metallic product manufacturing industry and type planting process of process of printing industry, $1.8mg/m^3$ and $0.3mg/m^3$ respectively. 9) 22, 968 of 52, 855 workers (i.e. 43.5%) in 93 industries were exposed to various harmful agents. 10) It was found that the improvement of illumination in electric apparatus manufacturing industry (from 20~40 lux to 420 lux) resulted in an increase in productivity of 6.5% per capita and a decrease in faulty products of 19%. 11) Improvement of environments using local exhaust ventilation system resulted in a decrease of harmful substances lower than TLV and an increase in productivity of 11.4%. 12) Improvement of shovelling tools based on ergonomics resulted in a reduction in energy expenditure of 25.3% and an increase in productivity of 32.2% per capita.
Objectives: The 12 occupational exposure limits(OELs) for chromium and its compounds in Korea were set by applying the American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Values (TLVs). However, this is significantly different from the TLVs after the existing TLVs were integrated and withdrawn in 2018, so it is necessary to review the revision. Methods: Various documents related to chromium OELs were reviewed, including the ACGIH TLV Documentations for chromium and its compounds. A field survey was conducted targeting workplaces handling chromium and its compounds. Based on this, a revised OELs were proposed and a socio-economic evaluation was conducted. Results: The OELs for chromium compounds in Korea was first enacted in 2002, and in 2007, the OELs for chromium (hexavalent) compounds (insoluble) was lowered from 0.05 mg/m3 to 0.01 mg/m3. In 2008, the OELs for strontium chromate was newly established as 0.0005 mg/m3, and in 2018, the OELs for calcium chromate was newly established as 0.001 mg/m3. Total chromium and hexavalent chromium were measured for each of 6 samples at 2 welding sites, 4 plating sites, and 2 spray coating sites. When omparing the average of the results measured by ICP, a total chromium analysis method, and the analysis results by IC, a hexavalent chromium analysis method, only workplace 4 was the same, and total chromium was evaluated more, and total chromium was evaluated at 0.0004 to 0.0027 mg/m3. And hexavalent chromium was evaluated as non-detection ~ 0.0014 mg/m3. Amendment ①: The exposure standard for hexavalent chromium is not divided into water soluble, insoluble, chromium ore processing, and other hexavalent chromium compounds, and is integrated into 0.01 mg/m3, which is the level of chromium (hexavalent) compound (insoluble)., OELs for chromium (metal) and chromium (trivalent) compounds are integrated into chromium (trivalent) compounds, and the exposure level is maintained. Amendment ②: As in the amendment ①, the OELs are integrated, but the level is lowered to 0.005 mg/m3, which is the OELs of OSHA, and there is a grace period of 4 years. Amendment ③: As in the amendment ①, the OELs are integrated, but the level is lowered to 0.0002 mg/m3, which is the exposure standard of ACGIH, and there is a grace period of 5 years. Conclusions: Amendment ①: The change in the OELs is insignificant, so the cost required is small, and the benefit/cost ratio is greater than 1, so there is no problem in applying the amendment. Amendment ②: In all scenarios except chromium 6(insoluble), the benefit/cost ratio is greater than 1, so it is thought that there will be no major problem in applying the amendment. Amendment ③: Since the benefit/cost ratio is less than 1 in all scenarios, it is thought that the total social benefit that can be obtained when applying the amendment is not large.
The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70
The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70