Clinical analysis of chronic mild occupational carbon disulfide poisoning / 中国职业医学

Objective: To analyze clinical features and electroneuromyography (ENMG) results of chronic mild occupational carbon disulfide poisoning cases. Methods: A total of 344 patients diagnosed with chronic mild occupational carbon disulfide poisoning based on GBZ 4-2002 Diagnostic Criteria of Occupational Chronic Carbon Disulfide Poisoning were selected as study subjects from 2006 to 2019 using the retrospective study method. Their clinical data was collected and analyzed. Results: The main symptoms of the study subjects were dizziness, headache, insomnia, dreaming, memory impairment, numbness and weakness in the distal extremities. Positive signs mainly included symmetrical glove and stocking distribution like sensory disorders in the distal extremities, and the weakening or absent Achilles tendon reflex and knee reflex. The incidence of symptoms and signs increased with the length of service (all P<0.01). The incidence of fundus and venous changes in patients was 41.3%, which increased with the length of service (P<0.01). ENMG examination showed varying degrees of abnormalities in the peripheral motor and/or sensory nerves in all patients, with a higher incidence of motor nerve abnormalities than sensory nerve abnormalities (21.1% vs 3.7%, P<0.01). The incidence of motor nerve abnormality was higher on the right side than the left side (23.7% vs 18.5%, P<0.01). The incidences of motor nerve abnormalities from high to low in the order were median nerve, common peroneal nerve, ulnar nerve and posterior tibial nerve (34.9% vs 27.9% vs 16.6% vs 5.1%, P<0.01). The incidences of sensory nerve abnormalities from high to low in the order were median nerve, ulnar nerve and sural nerve (5.2% vs 5.1% vs 0.7%, P<0.01). The incidences of left ulnar nerve, right ulnar nerve and right median nerve were higher in male patients than in female patients (15.2% vs 5.3%, 24.0% vs 11.7%, 44.8% vs 28.7%, all P<0.05), while the incidences of the left and right common peroneal nerve in lower extremity motor nerve were lower in male patients than in female patients (18.4% vs 52.1%, 21.2% vs 46.8%, all P<0.01). Conclusion: Chronic mild occupational carbon disulfide poisoning was mainly manifested as multiple peripheral nerve injury. ENMG results showed that the distal motor nerve conduction abnormalities were more sensitive than the sensory nerve conduction abnormalities, with a higher degree of impairment in the upper limb than the lower limb, and more impairment in the right side than the left side.

Study on determination of 2-thioxothiazolidine-4-carboxylic Acid in urine by high performance liquid chromatography / 中华劳动卫生职业病杂志

Objective: To establish a high performance liquid chromatography method for the determination of 2-thioxothiazolidine-4-carboxylic acid (TTCA) in urine. Methods: After acidification with hydrochloric acid, TTCA in urine was first extracted by ethyl acetate with excessive sodium chloride, then gradient separated by a symmetry C18 column and then detected by a diode array detector. The quantification was based on a working curve of external standard method. Results: The linear relationship of TTCA in urine was good in the range of 0.03-10.00 mg/L, and the correlation coefficient was 0.9999. The detection limit and minimum quantitative concentration of TTCA in urine were 0.008 mg/L and 0.027 mg/L. The intra-assay precision of the method was 0.9%-1.4%, the inter-assay precision was 1.3%-3.5%, and the average recovery was 85.0%-92.7% while the concentrations of TTCA in urine was 0.8, 2.0 and 8.0 mg/L, respectively (n=6) . Conclusion: The gradient elution high performance liquid chromatography method has simple operation and high sensitivity, and it is suitable for the determination of TTCA on a low level in urine for occupational workers exposure to carbon disulfide.

Determination of creatinine and 2-thiothiazolidine-4-carboxylic acid in urine by ultra high performance liquid chromatography tandem mass spectrometry / 中华劳动卫生职业病杂志

Objective: To establish an ultrahigh performance liquid chromatography tandem mass spectrometry method for the determination of creatinine (Cre) and 2-thiothiazolidine-4-carboxylic acid (TTCA) in urine. Methods: In October 2020, the end-of-shift urine samples of the monitored subjects were taken, and the filtrate was prepared by centrifugation. After separated by ultra high performance liquid chromatography C18 column, acetonitrile and 0.2% acetic acid aqueous solution were used as mobile phases for gradient elution, the three quadrupole tandem mass spectrometry adopted an electrospray ion source (ESI) , the ion source temperature was 500 ℃ , and the air curtain gas flow rate was 31.4 L/min, qualitative and quantitative analysis of Cre and TTCA were carried out under the multiple reaction monitoring mode. Results: The linear range of Cre was 1.0-1 000.0 μg/L, the linear equation was y=947.3x-1605.6, and the correlation coefficient was 0.9994. The detection limit and the limit of quantitation were 0.3, 1.0 μg/L. When the addition concentrations were 50.0, 150.0 and 450.0 μg/L, the recovery rates were 92.8%-94.6% , the intra assay precisions were 3.6%-5.7% , and the inter assay precisions were 3.4%-5.4%. The linear range of TTCA was 0.1-200.0 μg/L, the linear equation was y=1164.7x-2243.9, and the correlation coefficient was 0.9991. The detection limit and the limit of quantitation were 0.03, 0.1 μg/L. When the addition concentrations were 10.0, 40.0 and 160.0 μg/L, the recovery rates were 90.8%-93.6%, the intra assay precisions were 4.6%-7.4%, and the inter assay precisions were 4.4%-6.9%. Conclusion: The sample pretreatment process of the ultra high performance liquid chromatography tandem mass spectrometry method for the determination of Cre and TTCA in urine is simple, and the continuous determination of Cre and TTCA in urine can be realized only by switching mass spectrometry parameters under the same chromatographic conditions, which is accurate and efficient, and each performance index of the method meets the determination requirements.

The intervention effect of N-carbamoyl glutamic acid on embryo implantation disorder induced by carbon disulfide and its possible molecular mechanism / 中华劳动卫生职业病杂志

Objective@#To explore the preventive effect and possible molecular mechanism of dietary supplementation of N-carbamylglutamate (NCG) in the implantation of carbon disulfide (CS2) into embryo implantation disorders.@*Methods@#embryo implantation disorder model was established by single intraperitoneal exposure to CS2 on the 3rd, 4th, and 5th days after pregnancy. Endometrial tissues were collected for 24h after exposure to CS2 for western-blot and immunohistochemical staining.@*Results@#The number of embryo implantation was increased in NCG+CS2 group, compared with CS2 alone group. Day 4 of pregnancy when CS2-exposed after 24 h, the expression of pAKT protein in NCG+CS2 group was significantly increased (P<0.05), the expression level of pAMPK protein in NCG+CS2 group was significantly decreased, compared with CS2 alone group, respectively. Immunohistochemical results showed that pAKT, pAMPK, AKT and AMPK proteins were expressed in luminal epithelial cells, glandular epithelial cells and stromal cells of endometrium; Day 4 of pregnancy when CS2-exposed after 24 h, deep staining of ATK and pAKT protein in NCG+CS2 group, the AMPK and pAMPK protein staining became lighter.@*Conclusion@#Dietary supplementation of NCG can interfere with the embryo loss induced by CS2 by altering the total amount of AKT/AMPK molecules.

Embryo implantation dysfunction via the decreased uterine dendritic cells's non-immune function after exposed to carbon disulfide / 中华劳动卫生职业病杂志

Objective@#To study the effect of CS2 on dendritic cells (DCs) in the uterus and the expression of vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor(fms-like tyrosine kinase-1, Flt-1), and to explore the toxic mechanism of CS2-induced embryo implantation dysfunction.@*Methods@#The Kunming mice were randomly divided into control group,gestational day 4(GD4) exposure group and GD5 exposure group. The endpoints of each group(GD5, GD6, GD7) was set up according to their respective exposure time points. The mice in the exposure group were given intraperitoneal injection of CS2 at an injection dose of 631.4 mg/kg and the control group was given olive oil. The effect of CS2 on DCs in the uterus of pregnant mice was observed by flow cytometry. The levels of VEGF and Flt-1 were measured by Real-time quantitative polymerase chain reaction (qPCR) and enzyme-linked immunosorbent assay (ELISA).@*Results@#In the GD4 and GD5 exposure groups, the number of DCs in the uterus of pregnant mice decreased at all endpoints and the GD5 endpoint in the GD4 exposure group decreased by 21%(P=0.039), when compared with the control group. In the GD4 exposure group, the levels of VEGF mRNA and protein in the uterus of the pregnant mice were 79% and 30% lower than those in the control group, respectively (P=0.03、P=0.017); the levels of Flt-1 mRNA and protein at the endpoints of GD6 and GD7 in the uterus decreased by 54%, 36%, 60% and 56%, respectively, when compared with the control group(P=0.017、P=0.012、P=0.004、P=0.007). In the GD5 exposure group, the levels of VEGF mRNA and protein in the uterus of pregnant mice at the endpoint of GD7 decreased by 62% and 36%, when compared with the control group (P=0.005、P=0.035); the levels of Flt-1 mRNA and protein in the uterus at the endpoint of GD7 decreased by 60% and 44%, respectively, when compared with the control group (P=0.004、P=0.009).@*Conclusion@#CS2 reduced the number of DCs in the uterus of pregnant mice, and affected the non-immune function of DCs, which affected uterine angiogenesis, this may be one of the mechanisms of CS2-induced embryo implantation dysfunction.

Determination of Volatile Sulfur Compounds in Seawater and Atmosphere / 分析化学

Volatile sulfur compounds ( VSCs) in the marine environment has significant implications for global climate change. In the present study, a gas chromatographic analytical method was set up to determine the concentrations of VSCs in seawater and atmosphere, and the optimized experimental conditions were established. For the analysis of VSCs in atmosphere, multistage traps and gas chromatography-mass spectrometry ( GC-MS ) were used, with the precisions of 7. 7% -15. 1% and the detection limits of 0. 23-4. 7 ng. Moreover, for the analyses of VSCs in seawater, pre-concentration and gas chromatography coupled with flame photometric detector ( GC-FPD) were utilized, with the precisions of 3. 5%-5. 3% and the detection limits of 2. 5-3. 5 ng. This method was applied to analyze the VSCs in Qingdao coastal seawater and atmosphere, and the average concentrations of carbonyl sulfide, dimethyl sulfide and carbon disulfide in the seawater were (268 ± 58 ) , ( 1264 ± 278 ) , ( 19 ± 2 ) pmol/L, and ( 543 ± 39 ) , ( 29 ± 9 ) , ( 56 ± 20 ) ( ×10-12 , V/V) in the atmosphere, respectively.

Determination of Volatile Sulfur Compounds in Seawater and Atmosphere / 分析化学

Volatile sulfur compounds ( VSCs) in the marine environment has significant implications for global climate change. In the present study, a gas chromatographic analytical method was set up to determine the concentrations of VSCs in seawater and atmosphere, and the optimized experimental conditions were established. For the analysis of VSCs in atmosphere, multistage traps and gas chromatography-mass spectrometry ( GC-MS ) were used, with the precisions of 7. 7% -15. 1% and the detection limits of 0. 23-4. 7 ng. Moreover, for the analyses of VSCs in seawater, pre-concentration and gas chromatography coupled with flame photometric detector ( GC-FPD) were utilized, with the precisions of 3. 5%-5. 3% and the detection limits of 2. 5-3. 5 ng. This method was applied to analyze the VSCs in Qingdao coastal seawater and atmosphere, and the average concentrations of carbonyl sulfide, dimethyl sulfide and carbon disulfide in the seawater were (268 ± 58 ) , ( 1264 ± 278 ) , ( 19 ± 2 ) pmol/L, and ( 543 ± 39 ) , ( 29 ± 9 ) , ( 56 ± 20 ) ( ×10-12 , V/V) in the atmosphere, respectively.

Carbon disulfide exposure estimate and prevalence of chronic diseases after carbon disulfide poisoning-related occupational diseases

BACKGROUND: In Korea, Carbon disulfide (CS2) toxicity was an important social problem from the late 1980s to the early 1990s but there have been few large-scale studies examining the prevalence of diseases after CS2 exposure discontinuance. So we investigated past working exposure to CS2 characteristics from surviving ex-workers of a rayon manufacturing plant including cumulative CS2 exposure index. Furthermore, we studied the prevalence of their chronic diseases recently after many years. METHODS: We interviewed 633 ex-workers identified as CS2 poisoning-related occupational diseases to determine demographic and occupational characteristics and reviewed their medical records. The work environment measurement data from 1992 was used as a reference. Based on the interviews and foreign measurement documents, weights were assigned to the reference concentrations followed by calculation of individual exposure index, the sum of the portion of each time period multiplied by the concentrations of CS2 during that period. RESULTS: The cumulative exposure index was 128.2 ppm on average. Workers from the spinning, electrical equipment repair, and motor repair departments were exposed to high concentrations of ≥10 ppm. Workers from the maintenance of the ejector, manufacturing of CS2, post-process, refining, maintenance and manufacturing of viscose departments were exposed to low concentrations below 10 ppm. The prevalence for hypertension, coronary artery disease, cerebrovascular disease, diabetes, arrhythmia, psychoneurotic disorder, disorders of the nervous system and sensory organ were 69.2%, 13.9%, 24.8%, 24.5%, 1.3%, 65.7%, 72.4% respectively. CONCLUSIONS: We estimated the individual cumulative CS2 exposure based on interviews and foreign measurement documents, and work environment measurement data. Comparing the work environment measurement data from 1992, these values were similar to them. After identified as CS2 poisoning, there are subjects over 70 years of average age with disorders of the nervous system and sensory organs, hypertension, psychoneurotic disorder, cerebrovascular disease, diabetes, coronary artery disease, and arrhythmia. Because among ex-workers of the rayon manufacturing plant, only 633 survivors recognized as CS2 poisoning were studied, the others not identified as CS2 poisoning should also be investigated in the future.

Recognition and Using Status of Carbon Disulfide (CS₂) as Fumigant for Controlling Chestnut Weevil, Curculio sikkimensis among Chestnut Farmers / 農村醫學 地域保健

OBJECTIVES: We surveyed the awareness and current status of using fumigant carbon disulfide for exterminate Curculio sikkimensis among chestnut farmers in Chungnam Province to suggest directions for health education and public relations. METHODS: We designed questionnaires to evaluate recognition of fumigant carbon disulfide. We conducted a questionnaire survey to assess recognition and recognition level of fumigant carbon disulfide by the study variables. RESULTS: The recognition status for fumigant carbon disulfide was 74.5%, but the recognition level was low (know well 27.5%). The path of recognition was 45.1% and 15.7% for neighbor and rural technology center, respectively. The recognition status for warning label of fumigant carbon disulfide was 52.9%. Recognition for warning label of fumigant carbon disulfide was tended to increase with high educational attainment, bigger owning land area. Recognition on the content of warning label were 29.4%, 27.5%, 21.6%, and 21.6% for inflammability, toxicity, hazard, and explosiveness, respectively. Using personal protection equipment was tended to increase with the high status of awareness on fumigant carbon disulfide. CONCLUSIONS: Health education programs for using fumigant carbon disulfide are needed for chestnut farmers. In addition, publicity information activities about prevention and protection of carbon disulfide poisoning are needed for high risk farmers.

Occupational Neurotoxic Diseases in Taiwan

Occupational neurotoxic diseases have become increasingly common in Taiwan due to industrialization. Over the past 40 years, Taiwan has transformed from an agricultural society to an industrial society. The most common neurotoxic diseases also changed from organophosphate poisoning to heavy metal intoxication, and then to organic solvent and semiconductor agent poisoning. The nervous system is particularly vulnerable to toxic agents because of its high metabolic rate. Neurological manifestations may be transient or permanent, and may range from cognitive dysfunction, cerebellar ataxia, Parkinsonism, sensorimotor neuropathy and autonomic dysfunction to neuromuscular junction disorders. This study attempts to provide a review of the major outbreaks of occupational neurotoxins from 1968 to 2012. A total of 16 occupational neurotoxins, including organophosphates, toxic gases, heavy metals, organic solvents, and other toxic chemicals, were reviewed. Peer-reviewed articles related to the electrophysiology, neuroimaging, treatment and long-term follow up of these neurotoxic diseases were also obtained. The heavy metals involved consisted of lead, manganese, organic tin, mercury, arsenic, and thallium. The organic solvents included n-hexane, toluene, mixed solvents and carbon disulfide. Toxic gases such as carbon monoxide, and hydrogen sulfide were also included, along with toxic chemicals including polychlorinated biphenyls, tetramethylammonium hydroxide, organophosphates, and dimethylamine borane. In addition we attempted to correlate these events to the timeline of industrial development in Taiwan. By researching this topic, the hope is that it may help other developing countries to improve industrial hygiene and promote occupational safety and health care during the process of industrialization.

Occupational Neurotoxic Diseases in Taiwan

Occupational neurotoxic diseases have become increasingly common in Taiwan due to industrialization. Over the past 40 years, Taiwan has transformed from an agricultural society to an industrial society. The most common neurotoxic diseases also changed from organophosphate poisoning to heavy metal intoxication, and then to organic solvent and semiconductor agent poisoning. The nervous system is particularly vulnerable to toxic agents because of its high metabolic rate. Neurological manifestations may be transient or permanent, and may range from cognitive dysfunction, cerebellar ataxia, Parkinsonism, sensorimotor neuropathy and autonomic dysfunction to neuromuscular junction disorders. This study attempts to provide a review of the major outbreaks of occupational neurotoxins from 1968 to 2012. A total of 16 occupational neurotoxins, including organophosphates, toxic gases, heavy metals, organic solvents, and other toxic chemicals, were reviewed. Peer-reviewed articles related to the electrophysiology, neuroimaging, treatment and long-term follow up of these neurotoxic diseases were also obtained. The heavy metals involved consisted of lead, manganese, organic tin, mercury, arsenic, and thallium. The organic solvents included n-hexane, toluene, mixed solvents and carbon disulfide. Toxic gases such as carbon monoxide, and hydrogen sulfide were also included, along with toxic chemicals including polychlorinated biphenyls, tetramethylammonium hydroxide, organophosphates, and dimethylamine borane. In addition we attempted to correlate these events to the timeline of industrial development in Taiwan. By researching this topic, the hope is that it may help other developing countries to improve industrial hygiene and promote occupational safety and health care during the process of industrialization.

Work Environments and Exposure to Hazardous Substances in Korean Tire Manufacturing

OBJECTIVES: The purpose of this study is to evaluate the tire manufacturing work environments extensively and to identify workers' exposure to hazardous substances in various work processes. METHODS: Personal air sampling was conducted to measure polycyclic aromatic hydrocarbons, carbon disulfide, 1,3-butadiene, styrene, methyl isobutyl ketone, methylcyclohexane, formaldehyde, sulfur dioxide, and rubber fume in tire manufacturing plants using the National Institute for Occupational Safety Health Manual of Analytical Methods. Noise, carbon monoxide, and heat stress exposure were evaluated using direct reading instruments. Past concentrations of rubber fume were assessed using regression analysis of total particulate data from 2003 to 2007, after identifying the correlation between the concentration of total particulate and rubber fume. RESULTS: Workers were exposed to rubber fume that exceeded 0.6 mg/m3, the maximum exposure limit of the UK, in curing and production management processes. Forty-seven percent of workers were exposed to noise levels exceeding 85 dBA. Workers in the production management process were exposed to 28.1degrees C (wet bulb globe temperature value, WBGT value) even when the outdoor atmosphere was 2.7degrees C (WBGT value). Exposures to other substances were below the limit of detection or under a tenth of the threshold limit values given by the American Conference of Governmental Industrial Hygienists. CONCLUSION: To better classify exposure groups and to improve work environments, examining closely at rubber fume components and temperature as risk indicators in tire manufacturing is recommended.

Occupational Neurological Disorders in Korea

The purpose of this article was to provide a literature review of occupational neurological disorders and related research in Korea, focusing on chemical hazards. We reviewed occupational neurological disorders investigated by the Occupational Safety and Health Research Institute of Korean Occupational Safety and Health Agency between 1992 and 2009, categorizing them as neurological disorders of the central nervous system (CNS), of the peripheral nervous system (PNS) or as neurodegenerative disorders. We also examined peer-reviewed journal articles related to neurotoxicology, published from 1984 to 2009. Outbreaks of occupational neurological disorder of the CNS due to inorganic mercury and carbon disulfide poisoning had helped prompt the development of the occupational safety and health system of Korea. Other major neurological disorders of the CNS included methyl bromide intoxication and chronic toxic encephalopathy. Most of the PNS disorders were n-hexane-induced peripheral neuritis, reported from the electronics industry. Reports of manganese-induced Parkinsonism resulted in the introduction of neuroimaging techniques to occupational medicine. Since the late 1990s, the direction of research has been moving toward degenerative disorder and early effect of neurotoxicity. To understand the early effects of neurotoxic chemicals in the preclinical stage, more follow-up studies of a longer duration are necessary.

Heart Rate Variability of Carbon Disulfide Poisoned Subjects after Exposure Cessation / 대한산업의학회지

OBJECTIVES: A previous study conducted in 2000 measuring the heart rate variability (HRV) of carbon disulfide (CS2)-poisoned subjects suggested that their HRV was reduced after exposure cessation. However, the study was limited by the following procedural limitations: (1) only 71 CS2-poisoned subjects participated, (2) no females participated, and (3) the CS2-poisoned subjects were older than the controls. This study was therefore conducted to overcome these limitations of the earlier study. METHODS: The study subjects comprised 122 retired workers with CS2 poisoning and the same number of age- and sex-matched controls. Information on individual age, sex, height, weight, smoking history, alcohol drinking, regular exercise, medical and occupational history, chest x-ray, and ECG recording of the two groups was collected though a self-administered questionnaire and a medical examination. Standard Deviation of NN intervals (SDNN), Root-Mean-Square of Successive Differences (RMSSD), Total Power (TP), Low Frequency (LF), High Frequency (HF), and LF/HF ratio were measured as HRV indices for 5 minutes in the sitting position. RESULTS: Univariate analysis revealed that all HRV indices of CS2-poisoned subjects were lower than those of the controls. Multiple linear regression analysis showed that CS2 poisoning had negative association with all HRV indices and that its association with RMSSD was statistically significant (P<0.05). CONCLUSIONS: This study suggests that CS2-poisoned subjects continue to have reduced HRV, even though the exposure has ceased.

The Association of Carbon Disulfide Poisoning with Heart Rate Variability / 대한산업의학회지

OBJECTIVES: Mass poisoning by carbon disulfide (CS2) occurred in a viscose rayon factory in Korea. Up until 1998, 830 employees, including 38 who had died, were diagnosed with CS2 poisoning. Among the CS2 poisoned subjects, heart rate variability (HRV) was evaluated to investigate whether the toxic effect of CS2 persists after the exposure has ceased. The dose-response relationship between carbon disulfide exposure and HRV was also evaluated. METHODS: The case group was comprised of 71 retired male workers diagnosed as being CS2 poisoned. The control group was comprised of 127 males of same age-range who had no history of CS2 exposure and cardiovascular diseases. Information on individual age, height, weight, cigarette smoking, alcohol drinking, regular exercise, medical and occupational history, chest x-ray, and ECG recording of the two groups were collected through a self-administered questionnaire and with a medical examination. Time (maximum, average, minimum RR interval) and frequency domain measures (low frequency - LF, high frequency - HF, total power spectrum TPS, and LF/HF ratio) of the two groups were analyzed. CS2 exposure indices of the case group (duration of employment, exposure level per work department, cumulative exposure index and duration of retirement) were investigated. RESULTS: Using a univariate analysis, the frequency domain measures for the case group were significantly lower than those in the control group, except for HF. In the multivariate analysis, previous history of CS2 poisoning was inversely related to all frequency domain parameters and it significantly affected the LF (p<0.05) and the LF/HF ratio (p<0.05). There was no significant dose-response relationship between CS2 exposure indices and HRV parameters in the case group. CONCLUSION: This study suggests that further studies are necessary to evaluate the residual effects of CS2 poisoning even after the CS2 exposure has ceased.

Health Evaluation of ex-workers occupationally exposed to Carbon disulfide: Subjective Symptoms and Related Factors according to compensation for CS2 poisoning / 대한산업의학회지

OBJECTIVES: To investigate the chronological subjective symptoms and related factors in ex-workers who were occupationally exposed to Carbon disulfide. METHODS: One hundred and seventy-seven subjects (147 males and 30 females) were randomly selected among ex-workers and interviewed by well trained doctors, who filled out a structured questionnaire developed by authors on the subjective symptoms. The questionnaire was composed of symptoms in the head and neck, and those of the neuro-psychological, respiratory, endocrine, musculoskeletal, and reproductive systems. Other factors such as general and occupational characteristics including work department, work duration, duration since cessation of exposure, and compensation for occupational disease were also investigated. RESULTS: The mean subject age was 55.4 years. The mean cumulative exposure index (CEI) was 38.96 +/- 31.18. CEI was significantly higher in the compensated group (47.61 +/- 32.51) than in the non-compensated group (26.81 +/- 24.75)(p=0.000). Symptom complaints were significantly higher in the compensated group in all organ systems, and their incidence increased gradually until 10 years after cessation of work, and then decreased. The mean duration for cessation of exposure at the time of compensation was 10.97 years. The significantly different factors between the compensated group and the non-compensated group were total cumulative exposure index and the time interval between the cessation of work and the time of compensation. CONCLUSION: Our findings suggest that total cumulative exposure index and the time interval between the cessation of work and the time of compensation may be important factors affecting the compensation for occupational disease. Therefore, further studies will be necessary.

Cerebrovascular, and Other Health Effects, Due to the Exposure of Ex-Workers to Carbon Disulfide in the Maunfacture of Rayon / 대한산업의학회지

OBJECTIVE: The purpose of this study was to evaluate the cerebrovascular and other related health effcets, due to the exposure of ex-workers to carbon disulfide in the manufacture of rayon. METHODS: The study subjects comprised of 453 workers from the rayon manufacturing industry (387 males, 66 females). They were examined with a brain MRI and for other risk factors related to their occupation, such as age, work department, work duration, duration of work cessation, and blood pressure. Laboratory tests were also performed such as blood sugar, hemoglobin, cholesterol, etc. The cumulative exposure levels were calculated as the mean exposure level, per work department, multiplied by the total work duration in months. RESULTS: 75.1% of the subjects were between the ages of 40 and 59 years. 76.0% of the subjects had worked in high exposure departments (e.g., department of spinning and refining etc). 52.5% of the subjects had worked for more than 10 years, and 63.3% of the subjects had ginven up the work (exposure) more than 10 years earlier. The brain MRI findings were normal, a single lacunar infarct, multiple lacunar infarcts (mostly, on subcortex and white matter), and a hemorrhage in 52.5, 8.6, 36.2 and 2.7% respectively. Multiple lacunar infarcts were not related to the cumulative exposure level but in the female workers only, were significantly related to the increasing level of work duration (p<0.05), and in the male workers only, were related to the increased duration of work cessation and age (p<0.01). Abnormal rates of laboratory tests were higher in the multiple lacunar infarcts subjects with hypertension compared to theose with normal brain MRI findings (p<0.01). CONCLUSIONS: The multiple lacunar infarcts of the brain seemed not to be related to the cumulative exposure level but to the low exposure departments, duration of work, duration of work cessation, age and hypertension. This was conducted as a health evaluation on workers from the rayon manufacturing industry who had terminated their exposure to carbon disulfide many years earlier.

Simultaneous analysis of urinary 2-thiothiazolidine-4-carboxylic acid and thiocarbamide as a biological exposure index for carbon disulfide exposure

The objectives of this study were to develop optimal analytic methods for detecting urinary 2-thiothiazolidine-4-carboxylic acid (TTCA) and thiocarbamide simultaneously and to evaluate the usefulness of these metabolites to a biological exposure index (BEI) for carbon disulfide (CS2) exposure. For this experiment, synthesized TTCA and thiocarbamide were used. The synthesized TTCA was identified by infrared spectrophotometer, nuclear magnetic resonance spectrometer and thin layer chromatography. The recovery rates of both metabolites were calculated to find the optimum analytical method. The amounts of urinary TTCA and thiocarbamide were measured by using an ultraviolet detector connected to high performance liquid chromatography (HPLC) after the administration of CS2 (350, 700 mg/kg) into Sprague-Dawley rats intraperitoneally. The maximum absorbance wave lengths for TTCA and thiocarbamide were 272 and 236 nm, respectively. Ethyl acetate extraction with NaCl as a salting-out reagent was used as a simultaneous extraction method for these metabolites. HPLC conditions for these metabolites included using a NH2 column, 50 mM KH2PO4: acetonitrile (85:15) and pH 3. Excreted amounts of urinary TTCA and thiocarbamide were increased significantly following CS2 administration. TTCA, which was already adopted as a BEI for CS2 by the American Conference of Governmental Industrial Hygienists (ACGIH), seems to be a more useful BEI for CS2 exposure than thiocarbamide. However further studies are needed to increase analytical efficiency before thiocarbamide can be adopted as a BEI and to apply this analytic method for simultaneous analysis of these metabolites in workers exposed to CS2.

Vibration Perception Threshold of Male Workers Exposed to Carbon Disulfide / 대한산업의학회지

This study was conducted on 367 male workers to evaluate the change of vibration perception threshold (VPT) according to exposure degree to carbon disulfide. VPT was measured on both metacarpal bones of index and little fingers and on fibular malleoli by Vibrometer (Rion, on 125Hz). The exposure degree was classified by the name of department. Workers in department 1 had been exposed to high concentration of carbon disulfide, those in. department 2 had been exposed to carbon disulfide moderately or intermittently, and those in department 3 had been exposed to undetectable concentration of carbon disulfide. The results were as follows: 1. The mean values of VPT of metacarpal(MC) bones showed dose-response pattern, i.e., the mean values of VPT at department 1 were highest, and those of VPT at department 3 were lowest with similar work duration or age. But the mean values of VPT of fibular malleoli (FM) showed dose-response pattern only in workers having above 5 years of work duration or whose age were above 30. 2. The mean values of VPT of MC bone of workers increased by age. 3. There were statistically significant difference in mean values of VPT of MC bone only in workers having 5-10 year work duration. And there were statistically significant difference of mean values of VPT of left 2nd and 5th MC bone in workers whose age was 30's, of right 2nd MC bone in those whose age was 40's, and of left 2nd MC bone in those whose age was 50's. 4. The variables affecting VPT significantly were department and age (or age group) both in multiple regression and general linear model. The department showed to have more effect to VPT than age in multiple regression, but age group showed to have more effect to VPT than department in general linear model. 5. The variables were transformed to indicator variable to do logistic regression analysis. Department 1, 2, 3 were classified into high exposure (spinning department) and low exposure (other department), age was classified into old (above 30) and young, and work duration was classified into long(above 10 years) and short. The exposure and age were significant variables by logistic regression analysis. Odds ratios of department and VPT on metacarpal bones or malleoli were 2.7-3.2 and those of age and VPT were 2.6 or 2.7. Odds ratio of age and abnormality of VPT on'any point was 3.3(1.59-6.;8), and that of department and VPT was 2.8(1.5-5.5). We concluded that exposure of carbon disulfied was significantly associated with reduction of VPT regardless of age; and that the test of VPT would be useful tool for screening and early detection in neuropathy by carbon disulfide or other neurotoxic chemicals,even though it is simple and cheap.

An Analytic Study on the Effect of Carbon Disulfide on the Blood Pressure / 예방의학회지

To investigate the effect of carbon disulfide on blood pressure, the BP measurements in the periodic health examination results and the medical records of factory clinic were reviewed The study subjects were composed of 1336 male and 544 female workers, who were categorized into three groups by the exposure status-highly exposed, moderately exposed and non-exposed group. The results of the study were as follows; 1. The age-adjusted mean systolic and diastolic BP of male workers were 122.35 mmHg/79.11mmHg in highly exposed, 121.57mmHg/79.05mmHg in moderately exposed and 122.67mmHg/82.27mmHg in non-exposed group. For female workers, BP were 115.13mmHg/74.49mmHg in moderately exposed and 113.48mmHg/74.30mmHg in non-exposed group. 2. In multiple regression analysis of maximum BP against Age and tenure, the slope coefficients of age and tenure on the systolic BP were 0.379, 0.667 respectively and those on the diastolic BP were 0.331, 0.405 respectively in highly exposed male workers. Tenure was a significant variable in this study. For female workers, however, the slope coefficients of tenure on BP were significant only for systolic BP of moderately- expected group. 3. In multiple regression analysis of Bp against age, cumulative exposure index(CEI), cholesterol, all the variables showed significant slope coefficients in male, but age and CEl on systolic BP were significant for female workers (P<0.05). 4. In the multiple analysis of the amount of Bp change and the velocity of Bp change among male workers, the slope coefficients of tenure tended to increase as exposure level increased. Among female workers, the slope coefficients of tenure were significant on the amount of Bp change and the velocity of Bp change in moderately exposed group.