Incidence of Dimethylacetamide Induced Toxic Liver Injury among Workers in a Synthetic Fiber Manufacturing Company / 대한산업의학회지

OBJECTIVES: The main goal of this study was to find the incidence of the dimethylacetamide (DMAc) induced toxic liver injury among workers who were exposed to DMAc for about 5 years in a synthetic fiber factory. METHODS: In our investigation, total 1,021 workers had been exposed to DMAc from 1st February, 2000 to 30th June, 2004. Among them, 24 workers who had initial abnormal hepatic enzyme level or was viral hepatitis B carrier were excluded. Finally, 997 DMAc exposed workers were followed up for their incidence of toxic liver injury. To find out DMAc induced toxic liver injury case, we carried out regular examinations including liver enzyme tests such as AST and ALT. RESULTS: We followed up 997 workers and among them 72 cases coincided with our case definition. Incidence density method was 6.05 per 100 person-year. and, a cumulative incidence by life table method was 0.0965 within a year. The incidence of the DMAc-induced toxic liver injury peaked at 4 to 5 in weeks after employment. There was no toxic liver injury case within second week after exposure to DMAc. Five new cases developed in 2th to 3th week, 25 cases in 4th to 5th week, 14 cases in 6th to 7th week, 12 cases in 8th to 9th week, 5 cases in 10th to 11th week, 4 cases in 12th to 13th week, 4 cases in 14th to 15th week, 1 case in 16th to 17th week, 1 case in 30th to 31th week, and there was one case in 48th to 49th week. CONCLUSIONS: The incidence rate of toxic liver injury was considerably high during the 1st year after a worker is placed. So it is needed to take careful monitoring of hepatic enzyme level for newly exposed worker.

Inadvertent Epidural Administration of Atracurium and Lidocaine Mixture: A case report / 대한마취과학회지

Epidural administration of opioid and/or local anesthetics during general anesthesia is widespread method for postoperative pain control. Despite of its availability, inadvertent administration of non-epidural medications into epidural space can be associated with serious neurologic sequelae. We report a case of accidental epidural atracurium injection.

No Difference in the pH of Gastric Contents between Moderate Obese and Lean Gynecological Patients / 대한마취과학회지

BACKGROUND: Two results have been conflict regarding the pH of gastric contents in obese and lean surgical patients. Obese patients have been considered to have lower pH of gastric contents than lean surgical patients since the study by Vaughan, whereas Harter reported no significant difference in the pH's of obese and lean surgical patients. The author wanted to investigate whether gastric content pH differs or not between obese and lean surgical patients aged from 20 to 60 years. METHODS: Forty patients scheduled for elective abdominal hysterectomy under general endotracheal anesthesia were studied. Group I (n = 20) was composed of lean patients whose body mass indices (BMIs) were between 20 and 25, whereas Group II (n = 20) was composed of obese patients whose BMIs were above 30. Every patient was fasted between 8 and 14 hours preoperatively. Within 10 minutes of endotracheal intubation, gastric contents were withdrawn with a 20 cc syringe connected to a 16F nasogastric tube placed in the stomach. pH and the incidences of pH <2.5, and pH <1.8 were compared. RESULTS: No significant difference in pH (P = 0.199) or in the incidences of pH less than 2.5 (P = 0.23) or 1.8 (P = 0.52) were observed between obese and lean patients. CONCLUSIONS: Obese and lean patients have similar fasting gastric pH's, as long as the obesity is not too severe (BMI under 40).

Spinal Symptoms in Aviators and Their Relationship to Aircraft Types / 항공우주의학회지

BACKGROUND: By frequent G-exposures cervical and lumbar spinal symptoms may be the factors to limit their flying performance and causes of acute and chronic spinal diseases. We examined not only the frequency and degree of spinal symptoms but inter-relationship between these symptoms and several factors according to aircraft type. METHODS: We surveyed 244 ROKAF aviators by questionnaires attending aerospace-medical aviator physiology class of aeromedical center. RESULTS: Exposured gravities are 8.23, 6.02, 5.89 and 5.38 +Gz in pilots of F-16, F-5, F-4 and trainer aircraft respectively. Pilots of trainer aircraft were most frequently exposured to a gravity in a month. 72.5% of F-16 aviators had neck pain and 82.6% of trainer aircraft low back pain. Spinal symptoms limited checking 6 in about 55% of aviators and air combat maneuver in over 30% of aviators. CONCLUSION: To improve combat performance by alleviation of spinal symptoms aircraft aviators may rest sufficiently and had better keep a correct posture while +Gz exposures. We need to invent stretching exercises for relaxing muscle stress and correct seating frame of aircraft. Skilled medical team and instruments for physiotherapy also needed in airbases.

Effects of Flight Training on Vestibuloocular Reflex in Student-pilots

The aim of this study was to investigate the effect of flight training on vestibuloocular reflex (VOR) induced by rotational chair test in student-pilots. The study group was divided into followings; control, prepilot (student-pilots before flight training), and student-pilot (after training). Gain, phase and symmetry of eye movement induced by sinusoidal harmonic acceleration with frequencies of 0.01, 0.02, 0.04, 0.08, 0.16, 0.32 Hz. Gain and phase did not show any significant differences between control and student-pilots before flight training in all frequencies. But there were significant gain differences between control and student-pilots after flight training in 0.01, 0.04, 0.08 frequencies. And phase showed significant differences between before and after flight training in student-pilots in 0.01, 0.04 Hz. These results suggest that the flight training would be attributable to modulate the vestibular function in the student-pilots.

Surveillance of Work-related Diseases in Kumi / 대한산업의학회지

OBJECTIVES: Area-based occupational disease surveillance in Kumi (KODS) was used to collect data on occupational diseases. The data was used to estimate the magnitude of the diseases, to analyze for their characteristics, and to find links for their intervention and prevention. METHODS: Since January 2001, occupational physicians and nurses in Occupational Health Service (OHS)have reported six major occupational diseases; occupational musculoskeletal disorders of the upper extremities(MSDUE), occupational dermatoses, toxic hepatitis, occupational asthma (OA), hand-arm vibration syndrome(HAVS), and occupational cancer. For the respective diseases, a reporting sheet and operational diagnostic criteria were developed by the KODS. An analysis of the KODS data, collected over a certain period, was compared with data from the Korea Labor Workers Corporation (KLWC) and the Specific Health Examination (SHE), and the incidence rates of the diseases estimated. RESULTS: Between Jan 2001 and Apr 2002, 287 cases of the six major occupational disease were reported. Of these, there were 132 (46.0%), 100 (34.8%), 34 (11.8%), 16 (5.6%), and 5 (1.7%), cases of MSDUE, occupational dermatoses, toxic hepatitis, OA, and HAVS, respectively. But, there were no cases of occupational cancer. 33 (11.5%) of the incidence were reported via the OHS, 206 (71.7%) from health checkups, and the other 48(16.8%) from other routes. The synthetic fibers and electronic components manufacturing industries accounted for the greatest number of reported cases. With respect to occupation, the greatest numbers of incidence were reported from the elementary occupations, textile workers, assemblers, and cooks and food services worker, in that order. Of the MSDUE cases, carpal tunnel syndrome and epicondylitis were the two most common diseases. Most of the occupational dermatoses were due to contact dermatitis, with organic solvents (59%), nickel (6%), and epoxy resin (5%) accounting for the majority of these cases. All cases of toxic hepatitis were induced by dimethylformamide or dimethylacetamide, which were reported by a unique monitoring system. During same period, there were no cases claimed by workers to the KLWC, and only three cases from SHE, were identified. Using data from workers' number and surveillance, the annual incidences of MSDUE, dermatoses, hepatitis, OA, and HAVS, per 100,000 workers were 63.6, 48.2, 17.9, 7.7, and 2.4, respectively. CONCLUSIONS: These results show that an area-based surveillance system can be very effective for the collection of data on work-related diseases, at least in Kumi.

A Survey of Hepatitis B Surface Antigen and Hepatitis B Surface Antibody Positivity in ROK Air Force Pilots

OBJECTIVE: The aim of this study was to detect the prevalence of hepatitis B surface antigen (HBsAg) and hepatitis B surface antibody (anti-HBs) in The Republic of Korea Air Force (ROKAF) pilots, and to investigate the factors related to occupational exposure. METHODS: For 720 pilots who visited aeromedical center, ROKAF for general health screening from January, 2001 to August, 2002, HBsAg and anti-HBs were tested using passive hemagglutination and passive hemagglutination, respectively. If HBsAg results had been positive or vague, we performed confirmation test by ASAN Easy Test(R) HBs kit. RESULTS: The overall prevalence of HBsAg and Anti-HBs was 1.8% and 49.4%, respectively. HBsAg positivity was 0.0% in 20-24 years, 0.8% in 25-29 years, 1.1% in 30-34 years, 4.4% in 35-39 years, 1.5% in 40-44 years, 5.4% in 45-49 years, 5.3% in 50-54 years and significantly different below and above thirties (P=0.024). The prevalence of HBsAg in pilots was not different with general adults. Anti-HBs positivity was 100.0% in 20-24 years, 43.9% in 25-29 years, 57.1% in 30-34 years, 50.0% in 35-39 years, 62.1% in 40-44 years, 50.0% in 45-49 years, 73.7% in 50-54 years and significantly increased with age (44.2% in twenties, 53.6% in thirties, 58.9% in more than 40) (P=0.005). The pilots susceptible to HBV infection who were negative in both HBsAg and anti-HBs were found in 49.0% of entire subjects. CONCLUSION: The prevalence of HBsAg and anti-HBs in pilots was lower than in general adults. The pilots tendered to be more susceptible to HBV infection than general adults. Hepatitis B vaccine should be integrated into pilot health programmes.

The Needle Stick Injuries of Interns and Residents Working in Hospitals in a City / 대한산업의학회지

OBJECTIVES: This study was conducted in order to assess the experience of needle stick injury among interns and residents working in hospitals during the previous 4 months. METHODS: We conducted a questionnaire survey of 695 interns and residents working in two university hospitals and one general hospital in Tague city. Four hundred and forty three of those questioned(63.7 %) fully responded. RESULTS: Two hundred of the respondents(45.1 %) suffered at least one injury. Respondents suffered an average of 1.8 injuries. 96.5 % of interns, 40.6 % of surgical residents and 34.4 % of non-surgical residents suffered at least one injury. According to multiple logistic regression, Intern status and an increased amount of working time is associated with high risk of needle stick injury. CONCLUSIONS: This study demonstrates that interns and residents suffer a high rate of needle stick injury.

Toxic Hepatitis Induced by Occupational Dimethylacetamide Exposure / 대한산업의학회지

Dimethylacetamide is widely used in the production of plastics, resins, synthetic fibers, and gums and in purification and crystallization processes. Inhalation of the vapor or skin absorption of the liquid of dimethylacetamide(DMAC) can cause liver damage. Toxic hepatitis possibly attributable to DMAC exposure occurred in seven works among 178 employees who had worked on a new spandex-fiber production line. A large amount of DMAC is used as a spinning solvent for synthetic fibers in the factory. The patients were aged 23-47 years old and composed of five males and two females. They were involved in the process of polymerization(1 patient), spinning(1), take-up(4) and packaging(1). The mean duration of exposure was 10 weeks. They experienced fatigue, dizziness and jaundice. The patients showed elavated total bilirubin, alanine aminotransferase(ALT), and aspartate aminotransferase(AST) levels. The serologic test for viral hepatitis A, B and C were negative, as were the abdominal ultrasonographic scans. Based on the presumptive diagnosis of DMAC-induced toxic hepatitis, they were removed from the workplaces. One or two months after removal from the work, the transaminase levels returned to normal. The patients had no history of significant alcohol use, blood transfusion, recent medication, and drug abuse. As a result, authors could not find any attributable cause of toxic hepatitis but the toxicity by DMAC exposure.

Ocular, Respiratory and Skin Symptoms Among Solderers Employed in Printed Circuit Board Assembly Units / 대한산업의학회지

OBJECTIVES: This study was conducted to evaluate the prevalence of ocular, respiratory and skin symptoms among solderers and to investigate the relationship between symptom prevalence and exposure intensity. METHODS: We analyzed 126 eligible participants out of a population of 146 male solderers who completed the symptom questionnaires. Fourteen symptoms including 'itchy and red eyes', 'itchy or prickly nose', 'sneezing', 'rhinorrhea', 'blocked nose', 'pricklythroat', 'foreign body sensation in throat', 'sudden bouts of coughing', 'exertional breathlessness ', 'wheezing', 'sputum production', 'itchy face or hands', 'acneiform eruptions on the face'and 'red spots on the face or hands'were contained. Blood lead levels of all the 126 participants were tested and the participants'own assessments of the health risk of soldering were collected. RESULTS: Of the 14 investigated symptoms, 'sudden bouts of coughing'was significantly more prevalent in solderers who worked 4 hours or more a day than those who worked less than 4 hours a day, as for the other symptoms, there were no significant differences in the preva1ences related to daily soldering hours. 2.8% of the solderers considered the risk of flux exposure to be serious. The mean blood lead level was 6.05 microgram/dL (maximum 15.50 microgram /dL). CONCLUSIONS: Soldering may increase the risk of respiratory symptoms. Further investigations on the hazards of soldering processes are warranted and solderers should be educated on these hazards.

Related factors of high frequency hearing loss in the noise-exposed male workers / 대한산업의학회지

OBJECTIVES: The purpose of the study was to assess the risk factors assumed to be related to the high frequency hearing loss in the noise-exposed male workers. METHODS: 712 occupationally noise-exposed male workers were included in this cross sectional study. The subjects filled out a questionnaire on the history of noise exposure, hearing protection, otologic diseases, tobacco smoking, and were tested on height, weight, hematocrit, serum total cholesterol level, fasting plasma glucose level and arterial blood pressure level. Pure tone audiometry and otoscopy were conducted and the subjects were allocated into two groups according to whether they had 4000 Hi hearing loss or not. RESULTS: The multiple logistic regression analysis showed that military noise exposure, poor wearing status of the hearing protection devices, increased age, long noise exposure duration, mean arterial pressure less than 80mmHg, high fasting plasma sugar are the factors significantly related to high frequency hearing loss (P<0.05). On the contrary, there was no significant relationship between noise intensity, body mass index, serum total cholesterol level, smoking and high frequency hearing loss. Low hematocrit was shown to be a significant factor with a p-value less than 0.1. CONCLUSIONS: High frequency hearing loss in the noise-exposed male workers is related to military noise exposure, use of hearing protection devices, age, noise exposure length, fasting glucose level and mean arterial pressure, in this order. Appropriate use of the hearing protection devices has a great impact on the prevention of the noise-induced hearing loss.

The Association of the Serum Magnesium with Hearing Loss Among Noise Exposed Male Workers / 대한산업의학회지

OBJECTIVES: This study was conducted to investigate that the chronic noise exposure is associated with decreased serum magnesium concentrations and evaluate whether decreased serum magnesium is associated with noise induced hearing loss. METHODS: One hundred seventy-eight male workers exposed to noise were selected and classified three groups by the degree of hearing loss. Hearing threshold levels were less than 30 dB at 1,000 Hz or less than 40 dB at 4,000 Hz in group I, more than 30 dB at 1,000 Hz or more than 40 dB at 4,000 Hz and 15 dB and less of pure tone average(PTA: (500 Hz+1,000 Hz+2,000 Hz)/3) in group II, more than 30 dB at 1,000 Hz or more than 40 dB at 4, 000 Hz and over 15 dB of PTA in group III. RESULTS: Serum magnesium concentrations were 2. 42+/-0. 26 nc/dt in group I, 2. 35+/-0.23 mg(dl in group II, 2.26+/-0.24 ne/dl in group III, respectively and significantly different between group I and group III (p<0. 01). It was negatively correlated with duration of the noise exposure as correlation coefficient(r) of -0.194 (p<0.05). Analysis of the multiple regression on hearing threshold levels showed that serum magnesium, diastolic blood pressure, duration of the noise exposure were statistically significant at 4,000 Hz(p<0.05). While only age was statistically significant at 1,000 Hz(p<0.05). CONCLUSIONS: These results suggest that chronic noise exposure may induces decrease in serum magnesium concentrations and that its decreased concentration is related with noise induced hearing loss.