Effect of shift work on hypertension: cross sectional study

BACKGROUND: The need of efficient resource management and full-time accessibility to resources has increased with the development of industry, resulting in the increase of shift workers. Previous researches of past decades show that there are various health effects on shift workers. However, the definition and the form of shift work have varied from each research and occupational harmful factors except for shift work have not been excluded completely in previous researches. Therefore, in this research, we tried to find out the effect of shift work focusing on the hypertension. To complement previously mentioned weakness of other researches, we performed our research on participants to whom we could minimize other risk factors excluding shift work. METHODS: This research examined 1,953 petrochemical plant male workers (shift work 1,075, day worker 878) who did medical checkup from 1st Jan. 2014 to 31th Dec. 2014 in a general hospital located in Ulsan, based on their medical records and questionnaires. With the questionnaire, we found out their basic information including age, social status, occupational history, and we took their physical measurements. RESULTS: Compared to day workers, shift workers' odds ratio of developing hypertension was 1.31 (95% CI 0.98–1.75). After adjusting confounding variables, adjusted odds ratio for entire subjects was 1.51 (95% CI 1.11–2.06). Also, for subjects who were in continuous service for over 20 years, odds ratio was 1.51 (95% CI 1.08–2.11). CONCLUSIONS: Shift workers had a higher chance of hypertension than day workers do. Particularly, the longer the workers work continuously, the risk of hypertension getting higher.

Health care strategy for ensuring work ability in an aging Korea

The rapid aging trend in South Korea will cause a growing shortage of labor and decreasing quality of the labor force. The purpose of this commentary is to recommend a health care strategy to maintain and promote the work ability of employees in an aging Korea. Strategies to promote the work ability require the collaboration of governmental agencies at the central and local levels. First, the common goal should be the reinforcement of follow-up measure in general medical examinations and the promotion of healthy lifestyles for workers. Second, collaborating activities should be performed among the Worker’s Health Center, the Health Promotion Center, and community health centers. In conclusion, health care strategies for ensuring the work ability in an aging Korea require the collaboration of governmental agencies at the central and local levels.

Nailfold capillary microscopy for evaluating hand-arm vibration syndrome

OBJECTIVES: We evaluated nailfold capillary abnormalities in patients with hand-arm vibration syndrome using nailfold capillary microscopy. METHODS: Fifty workers who underwent a special health examination because of exposure to hand-arm vibration at Ulsan University Hospital in 2012 (exposed group) and a control group of 50 white-collar employees were evaluated through a questionnaire survey regarding their present tasks, types of tools used, vibration exposure duration, use of protective wear, and medical history. Then, an occupational physician performed a physical examination for any hand deformities, skin problems, or motor and sensory dysfunctions of the upper extremities. The nailfold capillary morphologies (tortuous, crossing, bushy, meandering, branching, hemorrhage, avascular area, enlarged, and giant), capillary dimensions (afferent, top, venous, total width, and length), and specific counts (crossing and branching) on both fourth fingers were determined by a rheumatologist. Thereafter, the exposed subjects were assessed according to the Stockholm workshop classification scale. In total, 8 and 6 subjects in the exposed and control groups, respectively, were excluded from the study because of poor capillary microscopic image quality. In addition, 24 subjects in the exposed group with Stockholm vascular stage 0 were excluded. Finally, capillary morphology, dimensions, and specific counting were compared between the exposed (n = 18) and control groups (n = 44). RESULTS: The exposed group had significantly greater crossing capillaries and abnormal capillary numbers that included crossing capillaries (crossing, branching, bushy, and meandering) but smaller branching and abnormal capillary numbers that excluded crossing capillaries (branching, bushy, and meandering) than the control group did. No significant difference in capillary dimensions was observed between the two groups. Despite the adjustment for age, smoking status, and underlying diseases, the statistical significance was unchanged. In the specific counting of the type of capillaries, the exposed group had a significantly higher total crossing count but fewer total branching count than the control group did. However, no statistical significance resulted after adjustment for age, smoking status, and underlying diseases. CONCLUSIONS: In this study, the exposed group had significantly more crossing capillaries and a higher crossing count than the control group did.

Relationship of cigarette smoking and hearing loss in workers exposed to occupational noise

OBJECTIVES: To investigate the effects of smoking on hearing loss among workers exposed to occupational noise. METHODS: From the results of a special workers health examination performed in 2011, we enrolled 8,543 subjects exposed to occupational noise and reviewed the findings. Using self-reported questionnaires and health examination results, we collected data on age, smoking status, disease status, height, weight, and biochemistry and pure tone audiometry findings. We divided the workers into 3 groups according to smoking status (non-smoker, ex-smoker, current smoker). Current smokers (n = 3,593) were divided into 4 groups according to smoking amount (0.05-9.9, 10-19.9, 20-29.9, > or =30 pack-years). We analyzed the data to compare hearing thresholds between smoking statuses using analysis of covariance (ANCOVA) after controlling for confounder effects. RESULTS: According to ANCOVA, the hearing thresholds of current smokers at 2 k, 3 k, and 4 kHz were significantly higher than that of the other groups. Multiple logistic regression for smoking status (reference: non-smokers) showed that the adjusted odds ratios of current smokers were 1.291 (95% confidence interval [CI]: 1.055-1.580), 1.180 (95% CI: 1.007-1.383), 1.295 (95% CI: 1.125-1.491), and 1.321 (95% CI: 1.157-1.507) at 1 k, 2 k, 3 k, and 4 kHz, respectively. Based on smoking amount, the adjusted odds ratios were 1.562 (95% CI: 1.013-2.408) and 1.643 (95% CI: 1.023-2.640) for the 10-19.9 and > or =30 pack-years group, respectively, at 1 kHz (reference: 0.05-9.9 pack-years). At 2 kHz, the adjusted odds ratios were increased statistically significantly with smoking amount for all groups. At all frequencies tested, the hearing thresholds of noise-exposed workers were significantly influenced by current smoking, in particular, the increase of hearing loss at low frequencies according to smoking amount was more prevalent. CONCLUSIONS: Current smoking significantly influenced hearing loss at all frequencies in workers exposed to occupational noise, and heavier smoking influenced low-frequency hearing loss more greatly. There was a dose-response relationship between smoking amount and low-frequency hearing thresholds; however, this was not observed for high-frequency hearing thresholds. Therefore, well-designed prospective studies are needed to clarify the effects of smoking on the degree of hearing loss.

The General Characteristics and Results of the Cold Provocation Test in the Risk Group of HAVS / 대한산업의학회지

OBJECTIVES: The cold provocation test for diagnosing the vascular component in hand-arm vibration syndrome (HAVS) is likely to be accepted as an objective test, and a few studies have been performed. However, controversy has continued regarding the diagnostic performance of this method. Although objective methods such as plethysmography and laser doppler flowmetry have been studied, they have not received as much attention as other diagnostic methods. Therefore, our study aim was to spread the awareness of HAVS by reporting the results of the cold provocation test in a hand-transmitted vibration exposure group. METHODS: The study subjects were 549 workers who had been exposed to hand-transmitted vibrations and reported symptoms in their hands. While the subject immersed both their hands in 10degrees C water for 10 minutes, the skin temperature of 10 fingers was recorded from pre-immersion time to 20 minute postimmersion including 10 minutes immersion time. The recovery rates were calculated from the recorded skin temperatures. The 'decreased recovery rate' criteria were less than 30% at 5 minutes post-immersion and 60% at 10 minute post-immersion. RESULTS: Of the subjects, 69.1% and 30.9% had more severe symptoms in the right and left hands, respectively. The mean finger skin temperature of the right hand after cold-water immersion for 10 minutes was approximately 10degrees C, which increased gradually with time, but they did not reach the baseline temperature at 20 minutes post-immersion. The deviations of the skin temperature in the subjects were higher in the recovery phase than in the baseline and cold immersion phase. The 3rd finger of both hands showed the lowest 5-minute recovery rate among the fingers examined, and the left 4th finger and right 3rd finger showed the lowest 10-minute recovery rate. Of the subjects, 37.6% and 10.4% of subjects showed a lower recovery rate at 5 and 10 minutes in at least one finger, respectively, while 10.2% showed a lower recovery rate at both 5 and 10 minutes simultaneously in at least one finger. CONCLUSIONS: The larger deviations in the recovery phase than in the other phases indicated that interindividual differences are more prominent in the recovery phase. There might be no benefit in observing the finger skin temperature for an additional 10 minutes after 10 minutes post-immersion. Overall, approximately 10% of the subjects in the HAVS risk group had HAVS.

Effect of Hand Transmitted Vibration on the Auditory System / 대한산업의학회지

OBJECTIVES: This study was undertaken to estimate the effect of hand transmitted vibration exposure for long time period on the auditory system in shipyard grinder workers. METHODS: From 2006 to 2009, the study was carried out on 87 grinder workers for hand transmitted vibration exposure group, with 81 welders who were served as the control group. All subjects were male; at baseline, none of the participants had ear disease or diabetes mellitus. Auditory threshold at different frequencies ranged from 0.25 kHz to 8 kHz for both ear was recorded; the following were also collected from the subjects: age, exposure duration, noise exposure level of investigation year, total cholesterol, systolic/diastolic blood pressure, and smoking history. RESULTS: In comparison of two groups, mean of age, exposure duration, noise level, total cholesterol, systolic/diastolic blood pressure, smoking rate were not significantly different between the groups. Auditory thresholds of 0.25, 0.5 kHz frequencies in both ear, 1 kHz frequency in right ear, and 8 kHz frequency in left ear were higher in hand-transmitted vibration exposure group than that in the control group at a statistically significant level. After stratification by age 50 years, there were no significant differences between the two groups in less than 50-years old age group, but auditory threshold of 0.25, 0.5, 1 and 8 kHz frequency were significantly different between the two groups in above 50-years old age group. The differences between two groups ranged from 0.4 dB(HL) to 6.7 dB(HL). Multiple linear regression analysis showed that hand transmitted vibration exposure was significant only in 0.25, 0.5 kHz frequency and the regression coefficients of vibration exposure ranged from 3.826 to 5.028 in those frequencies. CONCLUSIONS: The differences of hearing threshold between two groups only in the 50-years old group were possibly owing to changed peripheral vascular system with autonomic nervous system, and significances only in low frequencies such as 0.25, 0.5 kHz probably mean that hand vibration exposure have been transmitted to auditory organ over long term. Collectively, older people can be more susceptible to hearing loss in the presence of hand transmitted vibration exposure and auditory threshold at low frequency may be more affected by the hand transmitted vibration exposure than high frequency.

Seroprevalence of Hepatitis A in a Manufacture Workplace / 대한산업의학회지

OBJECTIVES: The prevalence of hepatitis A decreases with improved hygiene and changing lifestyle. However, hepatitis A remains a global problem causing sporadic food-borne infections. Over the past 5 years, hepatitis A incidence has increased, and 15 deaths were reported in 2009 in Korea. Concerns about hepatitis A infection have increased. We checked hepatitis A virus antibody (HAV anti-IgG) in a large manufacturing company, so that the results could be a guideline for workplace preventive plan and health policy for hepatitis A. METHODS: We investigated the seroprevalence of HAV anti-IgG and the demographic characteristics of employee volunteer, in a company in Ulsan. In addition, we estimated those factors that affected seroprevalence of HAV anti-IgG. RESULTS: A total of 2,719 employee volunteers were enrolled into the study. The seropositive rate of HAV anti-IgG was 69.8% (n=1,899) and, the seronegative rate was 30.2% (n=820). There were no enrolled employees under age 24 years who tested positive for HAV anti-IgG; in this group, the seropositive rate was 0.0% (n=0); in 25~29 years the rate was 3.9% (n=12) and 26.5% (n=118) in 30~34 years olds. In the 35-39 ears, 61.1% (n=203) tested HAV anti-IgG positive and 86.8% (n=256) of 40~44 years tested positive. Other group tested as follows: 96.5% (n=335) in 45~49 year olds, 98.7% (n=593) in 50~54 year olds, and 100% (n=382) in over 55 years. There was a significantly increasing tendency to test HAV anti-IgG positive according to age group. In the 34-35 year olds, the seropositive rate exceeded the seronegative rate. CONCLUSIONS: HAV anti-IgG seropositive rate increased according to age. The result can used for guideline recommendationsand establishing hepatitis A policies.

A Case of Cerebellar Dysfunction After Acute Organotin Poisoning / 대한산업의학회지

BACKGROUND: We performed a follow-up study of an acute organotin poisoning case on the neurological sequelae that remained after 3 years since diagnosis. CASE: In the previous study, a 43-year-old male was reported for acute organotin poisoning. After 3 years, the neurological sequelae were studied using neurological examination, cognitive tests, neurobehavioral tests (by CAYSYS 2000(TM)), brain magnetic resonance imaging (MRI), and 18F-fluorodeoxyglucose (18F-FDG) PET/CT. Upon neurological examination and other tests, orientation was improved compared to that 3 years before, but cerebellar ataxia, dysmetria and dysdiadochokinesia remained the same, with little change. Brain MRI showed cerebellar atrophy. 18F-FDG PET/CT revealed mildly decreased metabolic activity in the pons and in both cerebellar hemispheres. DISCUSSION: This is the first brain MRI study on cerebellar atrophy caused by organotin poisoning. Cerebellar ataxia was confirmed by decreased metabolic activity in 18F-FDG PET/CT.

Early Objectified Detection Method of Sensorineural Component in Hand Arm Vibration Syndrome / 대한산업의학회지

OBJECTIVES: In order to determine find out the best methods for a more objective detection of neurologic abnormality in early hand arm vibration syndrome(HAVS), early with analyzing the validity of each of the detection methods was analyzed. We evaluated the relationships between the sensorineural stage of Stockholm-revised vibration syndrome classification and the results of several tests. METHODS: 497 workers were investigated for symptom, exposure duration, the types of tools used, and medical history from January 2000 to December 2007. Pain sense threshold, vibrotactile threshold, hand grasp force, finger grasp force, and a finger tapping frequency test were performed by the workers. RESULTS: The grinder(67.3%) was the most commonly used tool and the mean exposure duration was 14.8 years. Although the pain sense and vibrotactile threshold level tended to increase according to sensorineural stage of the Stockholm classification, there was statistically significant difference in the vibrotactile threshold of 125, 250 Hz (p=0.006~0.038) but not in the pain sense threshold. Hand and finger grasp force tended to decrease according to the sensorineural stage of Stockholm classification and there was statistically significant difference(p=0.041,<0.001, 0.034) only on the right hand side. The tapping frequency also generally decreased according to the sensorineural stage of the Stockholm classification and there was statistically significant difference (p=0.002~0.019) only on the left hand side. CONCLUSIONS: Although there is no single standardized method that can objectively diagnose the sensorineural component of early HAVS early, the combination of subjective symptoms, the sensorineural stage of Stockholm classification, the pain and vibrotactile threshold test, the hand and finger grasp force, and the finger agility (tapping) test can objectively detect sensorineural component of HAVS early.

Early Objectified Detection Method of Sensorineural Component in Hand Arm Vibration Syndrome / 대한산업의학회지

OBJECTIVES: In order to determine find out the best methods for a more objective detection of neurologic abnormality in early hand arm vibration syndrome(HAVS), early with analyzing the validity of each of the detection methods was analyzed. We evaluated the relationships between the sensorineural stage of Stockholm-revised vibration syndrome classification and the results of several tests. METHODS: 497 workers were investigated for symptom, exposure duration, the types of tools used, and medical history from January 2000 to December 2007. Pain sense threshold, vibrotactile threshold, hand grasp force, finger grasp force, and a finger tapping frequency test were performed by the workers. RESULTS: The grinder(67.3%) was the most commonly used tool and the mean exposure duration was 14.8 years. Although the pain sense and vibrotactile threshold level tended to increase according to sensorineural stage of the Stockholm classification, there was statistically significant difference in the vibrotactile threshold of 125, 250 Hz (p=0.006~0.038) but not in the pain sense threshold. Hand and finger grasp force tended to decrease according to the sensorineural stage of Stockholm classification and there was statistically significant difference(p=0.041,<0.001, 0.034) only on the right hand side. The tapping frequency also generally decreased according to the sensorineural stage of the Stockholm classification and there was statistically significant difference (p=0.002~0.019) only on the left hand side. CONCLUSIONS: Although there is no single standardized method that can objectively diagnose the sensorineural component of early HAVS early, the combination of subjective symptoms, the sensorineural stage of Stockholm classification, the pain and vibrotactile threshold test, the hand and finger grasp force, and the finger agility (tapping) test can objectively detect sensorineural component of HAVS early.

Nationwide Cancer Incidence in Korea, 2003-2005 / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: To estimate the current cancer burden in Korea, newly diagnosed cancer cases and cancer incidence rates were calculated for the years 2003~2005. MATERIALS AND METHODS: The cancer incidence cases and rates were calculated from the Korea National Cancer Incidence Database. Crude and age-standardized incidence rates were calculated by gender for specified cancer sites in 5-year age groups. RESULTS: From 2003 to 2005, 398,824 cases of cancer were newly diagnosed in Korea (218,856 in men and 179,968 in women). For all sites combined, the crude incidence rate (CR) was 300.0 and 248.2 for men and women and the age-standardized incidence rate (ASR) was 297.0 and 191.2 per 100,000, respectively. Among men, five leading cancers were stomach (CR 66.0, ASR 64.2), lung (CR 48.5, ASR 50.3), liver (CR 44.9, ASR 42.1), colon and rectum (CR 37.9, ASR 37.2), and prostate cancer (CR 12.7, ASR 13.8). Among women, five leading cancers were breast (CR 37.3, ASR 29.0), thyroid (CR 36.2, ASR 28.8), stomach (CR 34.1, ASR 25.4), colon and rectum (CR 28.0, ASR 21.1), and lung cancer (CR 17.9, ASR 12.8). In the 0~14-year-old group, leukemia was the most common in both sexes; in the 15~34 group, the most common cancer was stomach cancer for men and thyroid cancer for women; in the 35~64 group, stomach cancer for men and breast cancer for women; among those 65 and over, lung cancer for men and stomach cancer, for women, respectively. CONCLUSION: The cancer incidence rates have increased in recent years, and more cancers are expected to develop as Korea is quickly becoming an aged society. The cancer incidence statistics in this report can be used as an important source to effectively plan and evaluate the cancer control program in Korea.

A Case of Raynaud's Phenomenon of both Feet in a Rock Drill Operator with Hand-arm Vibration Syndrome / 대한산업의학회지

BACKGROUND: There have been many studies on hand-arm vibration syndrome (HAVS) for almost a century. The Stockholm Workshop scale has been accepted as a useful tool in diagnosing HAVS. Although they are not standard tests for diagnosis, cold provocation test and plethysmography of the fingers are commonly used as objective measurements to confirm the vascular component of HAVS. However, there are only a handful of case reports and studies worldwide on Raynaud's phenomenon in the toes. We report the case of a patient with HAVS who developed Raynaud's phenomenon in the toes after the vibration exposure had ceased. To our knowledge, this is the first report of this entity in Korea. CASE REPORT: A 58-year-old male, who had been diagnosed with HAVS in 2003, first noticed white toes in the summer of 2006 after immersing his feet in cold water. He had been working as a rock drill operator since 1976 for almost 30 years and had symptoms on his fingers since 1992. He underwent the cold provocation test, photoplethysmography, Nerve conduction velocity, and basic laboratory tests to rule out other causes of secondary Raynaud's phenomenon. To describe the severity of his feet, it could be classified as vascular stage 2 and sensorineural stage 1 if we were to apply the Stockholm Workshop scale. CONCLUSIONS: The patient showed vibration-induced white toes, and we would like to share the results of objective findings related to his condition. When diagnosing HAVS, symptoms of the feet should be assessed by the occupational and environmental medicine physicians. Further studies are needed to standardize test methods to diagnose "vibration-induced white toes."

National Cancer Incidence for the Year 2002 in Korea / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Since the revised Cancer Act of October 2006, cancer registration was reactivated, based on the Statistics Law. MATERIALS AND METHODS: The incidence of cancer during 2002 was calculated on the basis of the information available from the National Cancer Incidence Database. Crude and age-standardized rates were calculated by gender for 18 age groups (0~4, 5~9, 10~14, every five years, 85 years and over). RESULTS: The overall crude incidence rates (CRs) were 269.2 and 212.8 per 100,000 for males and females, and the overall age-standardized incidence rates (ASRs) were 287.8 and 172.9 per 100,000, respectively. Among males, the five leading primary cancer sites were stomach (CR 62.4, ASR 65.7), lung (CR 45.4, ASR 51.0), liver (CR 43.2, ASR 43.7), colon and rectum (CR 30.7, ASR 32.7), and prostate (CR 8.0, ASR 9.6). Among females, the most common cancer sites were breast (CR 33.1, ASR 26.9), followed by stomach (CR 32.8, ASR 26.0), colon and rectum (CR 23.1, ASR 18.5), thyroid (CR 19.1, ASR 15.7), and uterine cervix (CR 18.2, ASR 14.7). In the 0~14 age group, leukemia was the most common cancer for both genders. For males, stomach cancer was the most common cancer in the 15~64 age-group, but lung cancer was more frequent in men 65 or older. For females, thyroid cancer among the 15~34 age-group, breast cancer among 35~64 age-group and stomach cancer in women 65 years or older were the most common forms of cancer for each age group. The quality indices for the percentage of deaths, by death certificate only, were 4.7% for males and 4.5% for females. CONCLUSIONS: Since the National Cancer Incidence Database was started, the annual percent change of cancer cases increased by 4.8% (4.1% for males, 5.7% for females) during 1999~2002. This value reflects the increase in prostate cancer for males and breast and thyroid cancer in females during 2002. The timely reporting of improved quality of cancer registration is needed for evidence-based decisions regarding cancer control in Korea.

A Case of Acute Organotin Poisoning / 대한산업의학회지

BACKGROUND: Although organotin compounds are widely used as PVC stabilizers, catalysts and biocides, their effects on humans are not well known. However, their acute intoxication is known to cause neurotoxicity in the central nervous system, renal toxicity, and hepatotoxicity. As there has been no previously published case of organotin intoxication in Korea, we report here the first Korean case of acute exposure to organotin. CASE REPORT: A 43-year-old male with disorientation and behavioral change was admitted to a hospital. He had been working as a tank cleaner for several different companies in the previous 8 years and a week before admission, he had cleaned a tank containing dimethyltin (DMT) for 4 days. A day after finishing the job, he suffered decreased memory, behavioral change and progressive mental deterioration when he arrived at the emergency room. The result of spinal tapping was negative but on the 4th day of admission he deteriorated into a state of coma along with metabolic acidosis and severe hypokalemia. High levels of DMT and trimethyltin (TMT) were detected in a highly sensitive urine analysis. After conservative treatment and chelation therapy, the patient showed some clinical improvement but the neurological defects persisted. CONCLUSION: The patient appeared to have been intoxicated from the acute exposure to a high level of organotin while cleaning the tank.

Nationwide Cancer Incidence in Korea, 1999~2001; First Result Using the National Cancer Incidence Database / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The first Korean national population- based cancer registry using nationwide hospital-based recording system and the regional cancer registries provided the source to obtain national cancer incidences for the period 1999~2001. MATERIALS AND METHODS: The incidence of cancer in Korea was calculated based on the Korea Central Cancer Registry database, data from additional medical record review survey, the Regional Cancer Registry databases, site-specific cancer registry databases, and cancer mortality data from the Korea National Statistical Office. Crude and age-standardized rates were calculated by sex for 18 age groups. RESULTS: The overall crude incidence rates (CR) were 247.3 and 188.3 per 100, 000 for men and women and the overall age-standardized incidence rates (ASR) were 281.2 and 160.3 per 100, 000, respectively. Among men, five leading primary cancer sites were stomach (CR 58.6, ASR 65.6), lung (CR 42.1, ASR 50.9), liver (CR 41.9, ASR 44.9), colon and rectum (CR 24.2, ASR 27.3) and bladder (CR 7.7, ASR 9.2). Among women, the most common cancers were stomach (CR 30.8, ASR 25.8), breast (CR 25.7, ASR 21.7), colon and rectum (CR 19.6, ASR 16.7), uterine cervix (CR 18.4, ASR 15.5), and lung cancer (CR 15.1, ASR 12.4). In 0~14 age group, leukemia was most common for both sexes. For men, stomach cancer was most common in 15~64 age group, but lung cancer was more frequent for over 65 age group. For women, thyroid cancer in 15~34 age group, breast cancer in 35~64 age group, and stomach cancer in over 65 age group were most common for each age group. The proportions of death certificate only were 7.5% for men and 7.4% for women. CONCLUSION: This is the first attempt to determine the national cancer incidence and this data will be useful to plan for research and national cancer control in Korea.

Evaluation of Ototoxicity by Mixed Organic Solvents Using the Upper Limit of Hearing / 대한산업의학회지

OBJECTIVES: This study evaluated the ototoxicity by mixed organic solvents on workers'hearing using the upper limit of hearing(ULH). METHODS: Seven hundred ninety-seven male workers in the ship building industry who were evaluated by interview with an upper limit of hearing from August 2000 to July 2002 were enrolled in the study. The subjects were divided into 3 groups according to exposure profile and job: officers, field supporters, and painters. To assess the ototoxicity of mixed organic solvent exposure on hearing, with regard to confounders, the general liner model was used. RESULTS: After controlling for the possible confounders, such as age, career, noise exposure level, tinnitus, alcohol intake, and smoking, the estimated mean for ULH of the painter group was higher than that of the officer and the field supporter groups. These differences of mean ULH were at the borderline of statistically significance(p=0.069). CONCLUSIONS: The results of this study suggest that a relatively lower level of mixed organic solvent chronically affected the hearing organ or auditory pathway. ULH seems to be a useful method for early detection of the ototoxicity of organic solvents.

Relationship of Biological Indices of Manganese with Pallidal Index on MRI in Liver Cirrhotics / 대한산업의학회지

OBJECTIVES: The objectives of this study were to clarify which biological manganese exposure indices reflect the pallidal signal intensities in magnetic resonance imaging (MRI) in liver cirrhotics. METHODS: We examined whole blood, plasma, RBC and urinary manganese concentrations, as well as, brain MRI in 22 cirrhotic patients and 10 healthy controls. From MRI scans we calculated the signal intensity of the globus pallidus using the pallidal index (PI), the ratio of the globus pallidus to subcortical frontal white-matter signal intensity in axial T1-weighted MRI planes multiplied by 100. In addition, we studied the relationships between PI and other measurements. RESULTS: The high signal intensity in the globus pallidus on T1-weighted MRI was observed in 18 (81.8%) patients. There was a significant correlation between whole blood and RBC manganese concentration, and PI on MRI. According to multiple linear regression, whole blood and RBC manganese concentration reflected PI on MRI better the other indices did. CONCLUSIONS: Whole blood and RBC manganese concentrations could be useful as biological manganese exposure indices that reflect PI on MRI.

Occupational disease surveillance system in Busan, Ulsan, Kyung-Nam area / 대한산업의학회지

OBJECTIVE: Occupational medicine specialists in the Busan, Ulsan and Kyung-Nam areas established an area-based occupational disease surveillance system and used this system to collected case information for the purpose of preventing occupational diseases METHODS: 11 hospitals participated in this system. The authors selected five main diseases, which were hand-arm vibration syndrome (HAVS), work-related musculoskeletal disorder (WRMSD), occupational asthma, occupational skin disease and occupational lung cancer and established their case definitions. All cases were reported on the web, and real time analysis was conducted. RESULTS: Between Apri1 2001 and April 2003, 192 cases of HAVS, 118 cases of WRMSD, 33 cases of occupational asthma, 17 cases of occupational skin disease and 17 cases of occupational lung cancer (for a total of 377 cases of these five main diseases) were reported. Most of the HAVS cases came from shipbuilding, and 172 of them (92.7 %) were associated with grinding. Of the four main types of WRMSD, carpal tunnel syndrome (CTS) was the most prevalent with 46 cases and shipbuilding was also the main industry involved (83.9 %). The ergonomic risk factors involved mainly associated with the hand. In 19 (57.6 %) and 4 (12.1 %) cases of occupational asthma, the agents included isocyanate and welding fume, respectively. 64.7 % of the cases of occupational skin diseases were contact dermatitis, and organic solvents and welding fume were the main agents involved. The causative agents of occupational lung cancer included Cr, welding fume, PAH, Ni, etc. 10 (58.8 %) of the cases were diagnosed as squamous cell carcinoma and 5 (29.4 %) as adenoma. CONCLUSION: This result showed that an area-based occupational disease surveillance system might provide an effective method of evaluating the prevalence of such diseases, however the Busan, Ulsan and Kyung-Nam provinces are too large to be treated as individual areas. Therefore, the authors suggest that each province should establish its own surveillance system.

Mental Disorders and Fitness for Work in Korea / 대한산업의학회지

OBJECTIVES: This study investigated the actual state of people with mental disorders in Korea, in order to present an alternative proposal for their work fitness and vocational rehabilitation. METHODS: The authors conducted this study through a review of statistics on the prevalence of mental disorder, labor laws, and the literatures related with work fitness and vocational rehabilitation of people with mental disorders. RESULTS: According to recent surveys, about 3 million people in Korea are likely to have mental disorders which could lead to discrimination in social life and dishonor in occupational career, either in the present or near future. Therefore, evaluation of work fitness and vocational rehabilitation for persons with mental disorders are important. At present, work fitness for psychiatric patients is evaluated without suitable guidelines regarding the kinds and severity of mental disorders that impede work capacity. Furthermore, mental disorder-specific fitness for work is not under consideration. CONCLUSION: It is true that most psychiatric patients have some limitation in performing their job. However, judging from the results of some research, proper displacement, apprehension of co-workers, and adjusted workplace could help them complete their tasks properly despite their troublesome psychiatric symptomatology. The government must help all citizens to do their best in their social life, and show a deep interest in the employment of all disabled people including those with psychiatric disorders. Above all we have to change our attitudes and preconceptions against people with mental disorders. Some labor laws, which presently impede employment of people with psychiatric disorders, need to be revised in their favor. Future work capacity evaluation should be done on the basis of ability to function in the workplace rather than symptomatology.

Epidemiologic Characteristics of Hand-Arm Vibration Syndrome through Occupational Disease Surveillance System in Busan, Ulsan, Kyungnam Province / 대한산업의학회지

OBJECTIVES: The objectives of this study were to estimate the epidemiologic characteristics of hand-arm vibration syndrome (HAVS) due to occupational exposure of hand transmitted vibration and to identify the occupations and industries where such exposures arises, and the main sources of exposure. METHODS: In April 2001 the Busan, Ulsan, and Kyung-Nam Province occupational disease surveillance system was established to measure the incidence and prevalence of work-related HAVS and other occupational diseases in these Korean provinces. Occupational physicians of nine hospitals in Busan, Ulsan, and Kyung-nam Province were involved in this project between April 2001 and November 2002. Physicians collected information through questionnaires and interviews. Information gathered included age, occupation, types of vibration tools used and presence of subjective symptoms such as vibration-induced white finger (VWF), numbness and tingling. RESULTS: A total 192 cases were reported with 188 males and 4 females. The shipbuilding industry was the most common type of industry and grinders were the most common source of exposure. Symptoms of neurological disorder were more common than those of vascular disorder. CONCLUSIONS: The authors concluded that exposure to hand transmitted vibration is common and that HAVS is one of the most common occupational diseases in Korea. However, the range and extent of hand transmitted vibration and the overall prevalence of HAVS in Korea is still unknown. More extensive research on this syndrome in order to priorite necessary preventive measures is required.