• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.1
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• pp.19-33
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• 2023

Objectives: The purpose of this study is to systematically identify situations where exposure levels are expected to be high by structuring domestic lead measurement data according to exposure processes and activities. Methods: Occupational exposure data on lead was collected from the results of the Evaluation of Reliability of Working Environment Measurement conducted by the government from 2019 to 2020. Lead exposure characteristics were analyzed by PROC (process category) and activity. The Risk Characterization Ratios (RCRs) of five PROCs according to ventilation type and lead content were evaluated using the MEASE (Metal's EASE) model. Results: The exposure data on lead (n=250) was classified into 12 PROCs and 12 activities, with an average concentration of 0.040 mg/m³ and about 14% exceeding the occupational exposure limit of 0.05 mg/m³. Processes with high exposure levels were PROC 7 (industrial spraying), 23 (open processing and transfer operations of molten metal), 24 (mechanical treatment), 25 (welding), and 26 (handling of powder containing lead). The results of evaluating RCR for the five PROCs were greater than 1 or close to 1 even if local exhaust ventilation was used. Conclusions: There is a possibility that the concentration of exposure is high in the casting and tapping of molten metal containing lead, mechanical treatment such as fracturing and abrasion, handling of powder, spraying, battery manufacturing, and waste battery recycling processes. It is necessary to implement chemical management policies for workplaces with such processes.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.10 no.1
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• pp.147-159
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• 2000

The NIOSH health hazard evaluation program (HHE program) was created in response to the mandate to determine the toxic effect and potential health hazard of workplace exposure, which is found in Occupational Safety and Health Act of 1970 and the Federal Mine Safety and Health Act of 1977, A primary benefit of HHE program is its ability to provide current health hazard data to employers and employees, which assists them in identifying solutions to occupational health and safety problems in their workplaces, The HHE program also stimulates research in the development and review of sampling methods and diagnostic tests and may prompt additional exposure assesment efforts and toxicological and epidemiological studies. HHE projects also provide human exposure-toxicity data that are used to asses the validity of existing occupational health standards and to support criteria for new standards of recommendation, The HHE request is classified into four categories: 1) category 1: As a administratively invalid, 2) category 2: These are valid requests for which a site visit is not essential to an appropriate response, 3) Category 3 : These are valid requests for which a site visit is necessary for an adequate evaluation, 4) These are valid request which present a complex problem or an opportunity for research, To carry out HHE program one or methods of investigation might be used: 1) direct observation and evaluation of production processes and employee work practices 2) employees exposure level and air contamination level 3) medical test or physical examinations of employees 4) private, confidential interviews with employees 5) review of employer's record of injuries and illness, employee exposure data, medical tests and job histories. After investigation and analysing the data, NIOSH issues a final report, giving finding and recommendation.

• Journal of Preventive Medicine and Public Health
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• v.28 no.4 s.51
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• pp.875-884
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• 1995

In order to investigate the level of lead exposure of workers in litharge making industry and to evaluate how lead exposure, personal habit such as smoking and drinking affect the prevalence of lead related symptoms and other study variables, we investigate 114 workers(24 office workers and 90 lead exposed workers) in a litharge making industry. Study variables chosen were blood lead(PbB), zinc protoporphyrin in whole blood(ZPP), Hemoglobin(Hb), hematocrit (Hct), SGOT and SGPT symptom questionnaires which had 15 lead exposure related symptoms were provided to all workers and filled up by themselves and reconfirmed by physician. The results obtained were as follows; 1. The mean value of PbB, ZPP and SGOT in lead exposed group were higher than those of non-exposed group, and there were no differences of means in other study variables. 2. The smoking and drinking rate of study subjects were 65.8% and 71.0% as a whole. Smoking rates were lower in non-exposed group than exposed group, but drinking rate were not. 3. There were no differences of mean values of study variables between smoker and non-smoker in non-exposed and exposed group, but there was a difference of mean value of SGOT between drinker and lion-drinker in lead exposed group. 4. While the symptom prevalence of lead exposed group were higher in neuromuscular category than non-exposed group, those of non-exposed group were higher or same with exposed group in gastrointestinal and general symptom category. 5. The symptom prevalence of smoker were higher than non-smoker regardless of exposure. 6. The symptom prevalence of drinker were only higher in gastrointestinal symptom category than non-drinker. 7. In multiple stepwise regression analysis of lead related symptoms as dependent variable and blood lead, smoking habit, drinking habit and work duration as independent variables, drinking habit contributed to the gastrointestinal symptom category, whereas blood lead and smoking contributed to the neuromuscular symptom category. For the total symptoms work duration and smoking habit contributed significantly.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.31 no.3
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• pp.255-265
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• 2021

Objectives: The purpose of this study is to analyze the exposure characteristics of inorganic acids. Methods: We analyzed exposure data (n = 363,146) for six inorganic acids (hydrogen fluoride, hydrogen bromide, hydrogen chloride, phosphoric acid, nitric acid, and sulfuric acid) collected between 2017 and 2019 in South Korea. Measurement characteristics and exposure levels (ELs) were analyzed by inorganic acid, industry category, enterprise size, and measurement year. Results: Measurement percentage dominated in time-weighted average (TWA, 91%) compared to short term exposure limit (STEL) and Ceiling. Most of the measurements (79.7%) were collected from the manufacturing category of industry. Medians of ELs were mostly low (≤3% of the threshold limit), with the exception of sulfuric acid (4.6% of TWA and 10.5% of STEL). The percentages of exceeding 1% of the occupational exposure limits (OELs) in TWA were relatively high for sulfuric acid (35.8%) and hydrogen chloride (16.5%) compared to the other acids (4.2%-6.6%). In addition, the percentages of exceeding 1% of OELs in STEL or Ceiling were higher for sulfuric acid (22.9%), hydrogen chloride (12.3%), and nitric acid (8.2%) compared to the other acids (1.2%-1.9%). The small-sized enterprises showed higher ELs in TWA; contrarily, the large-sized enterprises had higher ELs in STEL or Ceiling. Conclusions: The measurement characteristics and ELs identified in this study could be useful for establishing safety and health policies for inorganic acids.

• Environmental Analysis Health and Toxicology
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• v.25 no.2
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• pp.131-143
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• 2010

We performed the tests of acute and subchronic inhalation toxicity of methyl formate, which has limited toxicological data in spite of its widespread use and enhanced hazard consequent on its high volatility. The median lethal concentration ($LC_{50}$) was evaluated to be above 5,000ppm(12.27 mg/L). In the test with subchronic inhalation, there are no deaths, but with reduction of body weight, food intake, organ weight by exposure to 400 (0.98 mg/L) and 1,600 (3.92 mg/L) ppm, dose-dependently. There were statistical differences in some hematological and blood biochemical parameters as compared to control (e.g. neutrophile and lymphocyte in the 1,600 ppm group, calcium and A/G in 1,600 ppm group). Methyl formate under the exposure of 1,600 ppm showed the respiratory findings with nasal, it was confirmed that the chemical has respiratory hazard with 1,600 ppm inhalation exposure, induces nasal epithelial atrophy, olfactory cell degeneration/regeneration and the contraction of olfactory cells, etc. According to the notification with Ministry of Labor (No. 2009-68) for classification, labeling and MSDS of chemicals, it is suggested for methyl formate to be classified as category 4 in acute (10.0$4\leq20.0$ mg/L), category 2 (0.2$\leq$1.0 mg/L/6h, 90 days) in specific target organ-repeated exposure.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.4
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• pp.316-328
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• 2012

Objectives: This study was designed to provide the information regarding chemicals classification and health hazard by evaluating the toxicological effect through repeated inhalation exposure of methyl acrylate(MA) in Sprague-Dawley(SD) rat for 13 weeks. Methods: According to the notification with Ministry of Labor(No. 2009-68) and OECD Test Guideline 413, the rats were exposed to MA at concentration of 0, 56, 168, 280 ppm via whole body inhalation for 6 hours per day, 5 days per week, for 13 weeks. All animals were observed for mortality, morbidity and the change of body weight and food consumption were determined during the exposure period. Necropsy finding, organ weight, hematology, clinical biochemistry and histopathological examination following exposure were also performed. Results: There were no death and abnormal clinical signs relate to exposure MA. However, At 160 ppm and 280 ppm exposure groups, body weight and food consumption showed statistically significant decrease and histopathological changes in lung, trachea, nasal cavity, larynx were observed. Conclusions: MA was mainly affected respiratory tract. It is consequently provided to be classified as category 2(0.2 mg/L/6h < category 2 ${\leq}$ 1.0 mg/L/6h) for specific target organ toxicity following repeated exposure according to Standard for Classification and Labeling of Chemical Substance and Material Safety Data Sheet. The NOAEL(no observable adverse effect level) of MA was also determined to be lower than 56 ppm.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.451-454
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• 2002

In the present paper, the practicability of Commentray on Wind Loads of Korean Standard Design Loads fur Buildings, which has been enacted in Minstry of Construction and Transportation in June 2000, is validated by using the meteorological data measured at Homi-Cape, Pohang. Assuming that the vertical wind profile follows the power-law in a quasi-steady state, wind profile exponents are calculated by seasons by using wind data as collected through four monitoring towers. According to the Commentray on Wind Loads, Pohang is classified with its exposure category being B and the wind profile exponent being 0.22, while it is identified that the average wind profile exponent as calculated in this study is 0.26. Also, in this paper, a cross-correlation method is suggested in order to identify any meteorological correlation between measurement sites quantitatively.

• Tuberculosis and Respiratory Diseases
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• v.42 no.5
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• pp.713-722
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• 1995

Background: Chest X-ray of coal workers' pneumoconiosis and shipyard welders' lung show similar and regular opacities mostly, it is very difficult that we distinguish the former from the latter by only chest X-ray. so we performed this study to understand the progression of the disease and to provide the disease by considering pulmonary function and other factors in proportion to the profusion of small regular opacities of chest X-ray in both groups. Method: 430 coal workers' pneumoconiosis were compared with 311 shipyard welders' lung by the number, the age, the duration of dust exposure, %vital capacity(%VC), %FEV1.0, the type of ventilatory impairment, the combined pulmonary disease according to the profusion of small regular opacities on the chest radiographs, which were classified into category 0/1, category 1, and category 2. Result: 1) the percent of category 2 in coal workers' pneumoconiosis was 54.4%. the percent of category 1, and category 2 in welders' lung were 60.0%, 7.4%. the progression to the category 2 was higher in coal workers' pneumoconiosis than in welders' lung 2) The mean age was higher in coal workers' pneumoconiosis than in welders' lung, significantly increased in proportion to the progresion of profusion of small regular opacities in both groups 3) There was no difference in the duration of dust exposure by category 1/0, but the duration of dust exposure by category 1, 2 in coal workers' pneumoconiosis more significantly increased than in welders' lung. the duration in the proportion of category 2 to category 0/1, 1 significantly increased in the proportion to small regular opacities in coal workers' pneumoconiosis. but there was no significant difference in the proportion to small regular opacities in duration of dust exposure in welders' lung. 4) There was no significant difference of mean values of %VC(%vital capacity)in both groups except for category 1. the mean values of %VC had no relationship between the progression of small regular opacities in both groups. 5) The mean values of %FEV1.0 decreased more significantly in coal workers' pneumoconiosis than in welders' lung except for category 0/1. and decreased significantly in proportion to the profusion of small regular opacities in coal workers' pneumoconiosis. there was significant difference of %FEV1.0 in the proportion of category 2 to category 011 in welders' lung. 6) there were no significant difference of %FEV1.0, %VC in smoker and nonsmoker in both groups. 7) With regard to the type of ventilation in both groups in coal workers' pneumoconiosis 21.4 percent of patients belonged to the restrictive type, 11.6 percent to the obstructive type, 5.6 percent to the combined type, but in welders' lung 21.8 percent to the restrictive type, 2.9 percent to the obstructive type, 1.9 percent to the combined type. 8. in the pulmonary disease, the incidence of the pulmonary tuberculosis was the most in both groups, was more in coal workers' pneumoconiosis than welders' lung Conclusion: If we compare coal workers' pneumoconiosis with electric arc welders'lung by considering pulmonary function and other factors in proportion to the profusion of chest X-ray, I think that we will have the better result in understanding the progression of the disease and provision of the disease in both groups.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.31 no.4
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• pp.317-330
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• 2021

Objectives: By law, companies in Korea must periodically measure workers' exposure to harmful chemicals (the system is called the Work Environment Monitoring Program (WMP)[a]) and report the results to the government. The government also measures exposure to monitor the WMP's reliability (called Reliability Assessment (RA) for WMP[b]). The issue is that measured data from these two sources are so different that the objectivity of WMP needs to be confirmed by comparing the results using the European Centre for Ecotoxicology and Toxicology of Chemicals' Targeted Risk Assessment (ECETOC TRA). Methods: Step 1: Data collection from WMP reports submitted by companies (n=586) and RA for WMP written by the government (n=33). Step 2: Data Standardization by key information included. Step 3: Data conversion to input-variables required to run the ECETOC TRA model, and run the model with specific data (n=514) which meet the predetermined exposure scenario. Step 4: Statistical data analysis by process category (PROC) and ventilation type from each source ([A] and [B]). Step 5: Additional analysis of any unexpected results. Results: The process categories of the production and handling of Dichloromethane were classified into 12 PROCs, and ten of them were selected to run ECETOC TRA. Modeled values tended to be higher than measured values from both sources. For the measured values from WMP, RCR distribution by PROC was narrow (0.197-0.267, 95% CI) and did not have a relationship with ventilation type, which differs from the tendency of the modeling result. Meanwhile, the measured values from RA for WMP were relatively widely distributed (0.301-1.177, 95% CI) by PROC. In particular PROCs (13,19) were high enough to exceed 1. Also, they become low with better ventilation types and appear differently depending on the ventilation type, similar to the model result. Conclusions: This study revealed that ECETOC TRA might have the potential to serve as a screening tool for exposure assessment and to be used as assistive method for WMP to estimate exposure. Further empirical study is required to confirm its availability as a screening tool.

• Korean Journal of Clinical Laboratory Science
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• v.45 no.3
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• pp.102-107
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• 2013

Hepatitis A (HA) is an acute infectious disease of the liver caused by the Hepatitis A virus (HAV). In acute HA, the presence of anti-HAV IgM is detectable and about 3 weeks after exposure, its titre increases over 4 to 6 weeks. Anti-HAV IgG is detectable within a few days of the onset of symptoms. IgG antibodies continue to last for years after infection and provide lifelong immunity to the host. This study was performed to investigate the current seroprevalence of anti-HAV antibodies in Jeonbuk province, South Korea. A total of 591 (male 322, female 269) serum samples were collected in July 2011 to June 2012. We tested the antibodies of anti-HAV IgG and IgM using a Modular E170 (Roche Diagnostics, Germany), and analysed the serum alanine aminotransferase (ALT) levels by HITACH 7600-100 (HITACH, Japan). The overall seroprevalence of anti-HAV IgG was 84.6% (500/591), and the rate of females (85.9%) was higher than males (83.5%). According to the decade of age, seroprevalence of anti-HAV IgG were as follows; 68.8% (11/16) in the under 10 years old category, 100% (19/19) in the 10~19 category, 96% (48/50) in the 20~29 category, 83.6% (56/67) in the 30~39 category, 84.3% (123/146) in the 40~49 category, 83.3% (135/162) in the 50~59 category, 83.1% (54/65) in the 60~69 category, 78.1% (32/41) in the 70~79 category, and 88% (22/25) in the over 80 category. Total seroprevalence of anti-HAV IgM was 3.4% (20/591), and according to gender, the seroprevalence of male (3.1%) was very similar to that of female (3.7%). Through this study, we know that the seroprevalence of anti-HAV antibody in north-west Jeonbuk province, South Korea, was high. Only children under the age of 10 remain susceptible to HAV infection. Vaccination against HAV is not needed at the present time for the people of Jeonbuk province, South Korea, but a vaccination should be recommended and the improvement in sanitary conditions and personal hygiene should be highlighted.