Electromagnetic Fields ; Threshold Limit Values

In order to prepare the fundamental data for the improvement of noisy working environments and the effective hearing conservation program on workers exposed to industrial noise, the authors surveyed the working processes and evaluated the noise levels on 56 manufacturing industries in Pusan area from April to July in 1985. The results were summarized as follows: 1. The noise level was the highest in shipbuilding and repairing(95.6 dBA), and followed by steel rolling(92.9 dBA), manufacture of motor vehicles(93.1 dBA), manufacure of fishing nets(92.9 dBA), manufacture of testiles(92.5 dBA), iron and steel foundries(89.3 dBA), manufacture of metal products(89.1 dBA), preserving and processing of marine foods(87.0 dBA), manufacture of rubber products(85.3 dBA), manufacture of plywood(84.9 dBA) and manufacture of paints(84.5 dBA). 2. Among fifty surveyed working processes, the noise level of twenty-one processes(42%) exceeded the threshold limit value for 8 hours per day. 3. As the allowable exposure times by governmental threshold limit values to industrial noise level(dBA), cocking of shipbuilding and repairing and plating(CGL) of steel rolling were the shortest(30 minutes), and followed by assembling(rivet) of manufacture of motor vehicles(1 hour) weaving of manufacture of textiles and shot, machine, pipe laying of shipbuilding and repairing(2 hours). 4. By the result of octave band analysis on noisy working processes in excess of 90 dBA, the sound level was the highest at 2,000 Hz or 4,000 Hz. 5. It was recognized that the measurement of overall sound pressure level was also effective as octave band analysis in evaluating the industrial noise.
Busan ; Hearing ; Iron ; Noise ; Rubber ; Steel ; Textiles ; Threshold Limit Values

OBJECTIVES: The level of benzene exposure in the petrochemical industry during regular operation has been well established, but not in turnaround (TA), where high exposure may occur. In this study, the characteristics of occupational exposure to benzene during TA in the petrochemical companies were investigated in order to determine the best management strategies and improve the working environment. This was accomplished by evaluating the exposure level for the workers working in environments where benzene was being produced or used as an ingredient during the unit process. METHODS: From 2003 to 2008, a total of 705 workers in three petrochemical companies in Korea were studied. Long- and short-term (< 1 hr) samples were taken during TAs. TA was classified into three stages: shut-down, maintenance and start-up. All works were classified into 12 occupation categories. RESULTS: The long-term geometric mean (GM) benzene exposure level was 0.025 (5.82) ppm (0.005-42.120 ppm) and the short-term exposure concentration during TA was 0.020 (17.42) ppm (0.005-61.855 ppm). The proportions of TA samples exceeding the time-weighted average, occupational exposure level (TWA-OEL in Korea, 1 ppm) and the short-term exposure limit (STEL-OEL, 5 ppm) were 4.1% (20 samples of 488) and 6.0% (13 samples of 217), respectively. The results for the benzene exposure levels and the rates of exceeding the OEL were both statistically significant (p < 0.05). Among the 12 job categories of petrochemical workers, mechanical engineers, plumbers, welders, fieldman and scaffolding workers exhibited long-term samples that exceeded the OEL of benzene, and the rate of exceeding the OEL was statistically significant for the first two occupations (p < 0.05). CONCLUSION: These findings suggest that the periodic work environment must be assessed during non-routine works such as TA.
Benzene ; Korea ; Occupational Exposure ; Occupations ; Threshold Limit Values

OBJECTIVES: The level of benzene exposure in the petrochemical industry during regular operation has been well established, but not in turnaround (TA), where high exposure may occur. In this study, the characteristics of occupational exposure to benzene during TA in the petrochemical companies were investigated in order to determine the best management strategies and improve the working environment. This was accomplished by evaluating the exposure level for the workers working in environments where benzene was being produced or used as an ingredient during the unit process. METHODS: From 2003 to 2008, a total of 705 workers in three petrochemical companies in Korea were studied. Long- and short-term (< 1 hr) samples were taken during TAs. TA was classified into three stages: shut-down, maintenance and start-up. All works were classified into 12 occupation categories. RESULTS: The long-term geometric mean (GM) benzene exposure level was 0.025 (5.82) ppm (0.005-42.120 ppm) and the short-term exposure concentration during TA was 0.020 (17.42) ppm (0.005-61.855 ppm). The proportions of TA samples exceeding the time-weighted average, occupational exposure level (TWA-OEL in Korea, 1 ppm) and the short-term exposure limit (STEL-OEL, 5 ppm) were 4.1% (20 samples of 488) and 6.0% (13 samples of 217), respectively. The results for the benzene exposure levels and the rates of exceeding the OEL were both statistically significant (p < 0.05). Among the 12 job categories of petrochemical workers, mechanical engineers, plumbers, welders, fieldman and scaffolding workers exhibited long-term samples that exceeded the OEL of benzene, and the rate of exceeding the OEL was statistically significant for the first two occupations (p < 0.05). CONCLUSION: These findings suggest that the periodic work environment must be assessed during non-routine works such as TA.
Benzene ; Korea ; Occupational Exposure ; Occupations ; Threshold Limit Values

China ; Occupational Exposure ; Threshold Limit Values ; Ultraviolet Rays

Electromagnetic Fields ; Environmental Exposure ; Humans ; Radiation Dosage ; Threshold Limit Values

Carcinogens ; Carcinogens, Environmental ; Retrospective Studies ; Threshold Limit Values

Benzene and toluene, which are widely used aromatic hydrocarbons in workplace, are recently proved to cause health hazards due to their toxic effects. This study investigated the influence of toluene on the urinary excretion of benzene metabolite by administering short term exposure limit(STEL) of these compounds(i.e., 13.8mg/kg of benzene and 108.8mg/kg of toluene) intraperitoneally into Sprague-Dawley rats. After administration, urinary phenol concentration of rat was measured by gas chromatography for every three hours. Data were analyzed by non-parametric statistical methods using Kruskal-Wallis multi-sample test and Mann-Whitney U test. The following results were obtained: 1. Administration of STFL-benzene increased urinary phenol concentration in rats. 2. Urinary phenol concentration was increased logarithmically according to the dosage of benzene. 3. Excretion of phenol in urine was decreased when benzene and toluene were administered simultaneously compared with administering benzene alone. In Summary, these results reveal that administration of STEL of toluene has antagonistic effect of urinary excretion of benzene metabolite in rats.
Animals ; Benzene* ; Chromatography, Gas ; Hydrocarbons, Aromatic ; Metabolism* ; Phenol ; Rats* ; Rats, Sprague-Dawley ; Threshold Limit Values ; Toluene

Formaldehyde (FA) used for preserving the body for anatomy dissection is harmful to the human body. In many countries, for the purpose of protecting the health of workers in the industrial field, the maximal allowable air concentration of FA has been set. The threshold limit values of time weighted average (TLV-TWA) and short-term exposure limit (TLV-STEL) of FA recommended by Ministry of Employment and Labor (MOEL) of Korea are less than 0.5 and 1 ppm, respectively. In the United States and Europe, TLV-TWAs of FA are recommended at between 0.3 and 2 ppm. In this study, we compared the air concentration of FA to domestic and foreign standards of FA in an anatomy laboratory equipped dissecting tables with inbuilt exhaust and an air diffuser/return system. We installed ten elevated dissection tables, 18 air diffusers on the ceiling, and 10 air returns at the bottom of both side walls. The concentration of FA was measured at five sites in the anatomy laboratory and above the cadavers on the dissecting tables at a height of 1.5 m from the floor using a Formaldemeter. The average concentration of FA in the anatomy laboratory (five sites) was 0.31 ppm (0.45 mg/m³), range 0.21 to 0.41 ppm (0.26~0.51 mg/m³). The average concentration of FA above the cadavers was 0.45 ppm (0.56 mg/m³), range 0.31 to 0.64 ppm (0.39~0.80 mg/m³). The average TWA of FA in the anatomy laboratory was 0.19 ppm (0.24 mg/m³), range 0.13 to 0.26 ppm. The average TWA of FA above the cadavers was 0.28 ppm (0.35 mg/m³), range 0.19 to 0.40 ppm. The anatomy laboratory dissecting tables equipped with inbuilt exhaust and air diffuser/return system met the criteria of the FA concentration recommended by MOEL of Korea and most foreign countries. This study was the first evaluation of the air concentration of FA in an anatomy laboratory equipped dissecting tables with inbuilt exhaust and an air diffuser/return system in Korea. We expect it will be not only used as a standard of comparison for anatomy laboratories, but as a reference for design and construction to improve air quality in Korean Medical Colleges.
Cadaver ; Employment ; Europe ; Formaldehyde* ; Human Body ; Korea ; Threshold Limit Values ; United States ; Ventilation

It is known that there appear some nonspecific and delicate changes in neuropsychiatric aspect on the workers when they are exposed for a long period to low concentrated organic solvents in the work places. Therefore, it give rise to the necessity of developing a program for the health supervisor stationed in the work place to supervise these neurobehavioral health affection. In addition to the questionnaire posed to the workers exposed to organic solvents, the study team conducted NCTB(Neurobehavioral Core Test Battery) respectively on an exposed group and a non-exposed group to organic solvents. The study team compared the results and decided whether or not to apply the results to the evaluation program of health affection. The study team divided 132 workers in 6 car repairing factories and 2 textile printing factories into exposed group and non-exposed group, pairing them off into 66 research objects according to their age, sex, and job. Neurobehavioral test was conducted on 6 items, except the POMS test, of NCTB developed by the World Health 0rganization (WHO) . The study team conducted examinations of working environment on the exposed and non-exposed groups of each work place. The analysis of the collected materials for examinations were conducted with GC-MS. The concentration of the mix-ture in the air, relative to their respective threshold limit values (TLV) was calculated according to the formula of the ACGIH and the Korean threshold limits. The results indicated that for two of eight factories samples the recommended concentration limits for mixtures was exceeded. Of the six tests, the'digit span forward','digit span backward'and'digit symbol' produced conspicuous statistical differences between the two groups (p<0.1) as a result of compairing the test values by means of paired t-test. The results of respective analysis of the car repairing factories and textile printing factories revealed that the textile printing factories had greater differences between the exposed and the non-exposed than in the car repairing factories. It is presumably because the textile printing workers are continuously exposed to the organic solvents during working hours, whereas the car repairing workers are exposed only when they are doing painting works. The NCTB is assessed very useful in examining the neurobehavioral health affection under the exposure to organic solvents, and, therefore, the study team expects that the NCTB will play an important part in the course of developing a health program for the workers exposed to organic solvents.
Paint ; Paintings ; Questionnaires ; Solvents* ; Textiles ; Threshold Limit Values ; Workplace ; World Health