Insomnia and hearing impairment among occupational noise exposed male workers

BACKGROUND: The aim of this study was to investigate the association between insomnia and hearing impairment among workers exposed to occupational noise. METHODS: This study included 809 male workers exposed to occupational noise. The participants underwent audiometric testing, and their insomnia was examined based on the Insomnia Severity Index test. Hearing impairment was defined as hearing threshold >25 dB hearing level in the range of 1–4 kHz. RESULTS: According to analysis of covariance, it was observed that pure tone audiometry thresholds at 1–2 kHz in the right ear and at 1 kHz in the left ear were significantly higher among workers with insomnia compared to those with no insomnia. Multiple logistic regression analysis of insomnia for hearing impairments was performed, which showed the odds ratio was 1.806 (95% confidence intervals: 1.022–3.188, p = 0.042) after adjustment for age, working period, noise level, snoring, use of protection devices, diabetes mellitus, hypertension, smoking, alcohol consumption, regular exercise, waist circumference, total cholesterol, triglyceride and high density lipoprotein cholesterol. CONCLUSION: Insomnia could be associated with hearing impairment in workers who are exposed to occupational noise. Additionally, insomnia may be associated with decreased hearing at low frequencies. Especially, more efforts are required to improve the quality of sleep for workers who are exposed to loud occupational noise. Further well- designed prospective studies are needed to clarify the relationship between insomnia and hearing impairment.

Comparison of anxiety and depression status between office and manufacturing job employees in a large manufacturing company: a cross sectional study

BACKGROUND: The aim of this study was to investigate whether type of work is associated with anxiety and depression using the Hospital Anxiety and Depression Scale (HADS). Additionally, we investigated the impact of number of working hours on anxiety and depression. METHODS: A total of 1774 workers participated and completed the HADS to determine their levels of anxiety and depression. All subjects were employed at one of two manufacturing plants for the same company. Of all participants, 222 were employed in office jobs and 1552 in manufacturing jobs. RESULTS: Results of multivariate logistic regression analysis including age, sex, body mass index, smoking status, alcohol consumption, regular exercise, factory region, and working hours, indicated that employment in an office job was associated with a 2.17-fold increase in the odds of anxiety compared to a manufacturing job (odds ratio [OR] = 2.17; 95 % confidence interval [CI], 1.24–3.80). Office jobs were also associated with a 1.94-fold increase in the odds of depression (OR = 1.94; 95 % CI, 1.34–2.82). In addition, number of hours worked was significantly associated with depression, and working hours significantly modified the effect of office job employment on the risk of depression. CONCLUSIONS: Office job workers had higher levels of anxiety and depression than those working in manufacturing jobs. Our findings suggest that occupational physicians should consider the organizational risks faced by office job employees, and consider the differences in psychological health between office and manufacturing job workers when implementing interventions.

Respiratory Syncytial Virus Outbreak in the Basic Military Training Camp of the Republic of Korea Air Force / 예방의학회지

OBJECTIVES: An outbreak of acute febrile illness occurred in the Republic of Korea Air Force boot camp from May to July 2011. An epidemiological investigation of the causative agent, which was of a highly infective nature, was conducted. METHODS: Throat swabs were carried out and a multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) assay was performed to identify possible causative factors. RESULTS: The mean age of patients who had febrile illness during the study period was 20.24 years. The multiplex RT-PCR assay identified respiratory syncytial virus (RSV) as the causative agent. The main symptoms were sore throat (76.0%), sputum (72.8%), cough (72.1%), tonsillar hypertrophy (67.9%), and rhinorrhea (55.9%). The mean temperature was 38.75degreesC and the attack rate among the recruits was 15.7% (588 out of 3750 recruits), while the mean duration of fever was 2.3 days. The prognosis was generally favorable with supportive care but recurrent fever occurred in 10.1% of the patients within a month. CONCLUSIONS: This is the first epidemiological study of an RSV outbreak that developed in a healthy young adult group. In the event of an outbreak of an acute febrile illness of a highly infective nature in facilities used by a young adult group, RSV should be considered among the possible causative agents.

Serum prostate-specific antigen levels and type of work in tire manufacturing workers

OBJECTIVES: This study measures serum prostate-specific antigen (PSA) levels in tire-manufacturing workers, and attempts to find occupational or non-occupational factors that related to their PSA levels. METHODS: A total of 1,958 healthy male workers (1,699 were production workers and 259 were office workers) took PSA measurement for analysis. RESULTS: After adjusting for age, body mass index, hypertension, regular exercise, alcohol drinking and smoking, which were significantly related to serum PSA levels or known related factors of serum PSA levels, the geometric mean PSA levels were significantly high in the office workers (p = 0.017), the older age group (p or =4.0 (OR 7.73, 95% CI: 2.78-21.46) or 2.5 ng/mL (OR 2.74, 95% CI: 1.49-5.08). After stratifying by age and adjusting aforementioned covariates, office workers 50 years of age and older had the significantly higher geometric mean PSA levels (p = 0.017) and were more likely to have a serum PSA level of > or =4.0 ng/mL (OR 12.90, 95% CI: 3.65-45.64) or 2.5 ng/mL (OR 3.90, 95% CI: 1.64-9.25) than production workers 50 years of age and older. CONCLUSIONS: This study showed that serum PSA levels were significantly higher among the group with hypertension or the group of individuals that did not exercise regularly or group of office workers who were considered to have lesser physical activities.

Two Cases of Methemoglobinemia Induced by the Exposure to Nitrobenzene and Aniline

OBJECTIVE: To report two cases of methemoglobinemia induced by inhaled nitrobenzene and dermally absorbed aniline. METHODS: We have evaluated a 37-year-old male worker exposed to nitrobenzene by inhalation while conducting maintenance job of mononitrobenzene pump and a 25-year-old male worker exposed dermally to aniline while unloading. RESULTS: The first case is a 37-year-old male exposed to nitrobenzene. His blood methemoglobin concentration level was initially 19.8%, and chest X-ray was normal. After oxygen therapy, the blood methemoglobin concentration level decreased to 2.1%, and the symptoms were alleviated. The second case is a 25-year-old male exposed dermally to aniline. His chest X-ray was normal, but blood methemoglobin concentration level reached maximally 46.8%. He was treated with methylene blue due to relatively high blood methemoglobin level. Gradually after the treatment, his methemoglobin concentration level was normalized to 0.8% and simultaneously symptoms were resolved. CONCLUSIONS: After the thorough exposure investigations and medical evaluations, we have concluded that these cases were methemoglobinemia induced by occupational exposure to nitrobenzene and aniline. We suggest that businesses which handle methemoglobinemia-causing substances control the engineering process strictly, implement periodic screening, and establish emergency patient management system.

A Suspicious Case of Chloroform Induced Acute Toxic Hepatitis in Laboratory Worker / 대한산업의학회지

OBJECTIVES: To report upon a case of toxic hepatitis in a worker exposed to chloroform. METHODS: A 28-year-old female who had worked as chemical analysis engineer in a laboratory using chloroform was hospitalized due to nausea, vomiting and generalized weakness. The authors evaluated her using blood tests, abdominal CT scan and her occupational history. RESULTS: The blood tests revealed acute toxic hepatitis. Other causes of hepatitis such as viral, drug induced or alcoholic hepatitis could be excluded. But autoimmune hepatitis couldn't be totally ruled out(ANA (++), IgG(serum) 1780 mg/dL). After admission, her symptoms improved and her liver enzyme levels(AST and ALT) were markedly reduced. She returned to her workplace after discharge. Afterwards, however, her liver enzyme levels increased again one week after returning to her workplace. Subsequent to a job change, her liver enzyme levels reduced and normalized after eight weeks. The airbone laboratory chloroform ranged from 3.155 to 9.037 ppm. CONCLUSIONS: The authors presume that this patient's liver injury was related to an interaction of chloroform toxicity and a predisposition to autoimmune hepatitis. The rapid improvement of the clinical symptoms and the progressive normalization of the liver function tests once the chloroform exposure eliminated supports the diagnosis.

Comparison of Cardiovascular Disease Status Between Large Scale Industry Office and Self Employed Male Workers / 대한산업의학회지

OBJECTIVES: The aim of this study is to compare the cardiovascular disease status between large scale industry office and self employed male workers who have gaps in their intensive health management. METHODS: The cross sectional study was carried out with subjects composed of 244 shipyard office male workers and 381 self employed male workers, aged 30 to 55 years. They were given a health exam in a general hospital from January 2007 to June 2009. Information was based on data from self-administered questionnaires, physical examination and laboratory results on blood samples. The degree of coronary artery calcification and stenosis was evaluated by a 64 channel multi-detector computed tomography angiography. RESULTS: The prevalence of hypertension(p<0.01) and diabetes mellitus(p=0.02) and waist circumference(p<0.01) was significantly lower in the shipyard office workers than in self employed workers. Proper drinking(p<0.01) was more commmon in shipyard office workers. The rates of coronary artery calcification and stenosis were estimated to be 18.4% and 11.5% respectively for shipyard office workers and were significantly lower than the 26.5% and 21.5% for self employed workers. After adjustment for age, the probability of coronary artery stenosis in shipyard office workers was lower than in self employed workers (OR=0.56, 95% CI=0.35~0.90). CONCLUSIONS: The study results verified the benefits of a health promotion and intervention program and the healthy worker effect for cardiovascular diseases. More specifically, it verified the benefits regarding coronary artery stenosis in large scale industry office workers. This result should encourage the establishment of health promotion programs and the study of occupational epidemiology.

Comparison of Cardiovascular Disease Risk Assessment Tools by Using Coronary CT Angiography / 대한산업의학회지

OBJECTIVE: The prevalence and mortality rate of cardiovascular disease (CVD) have increased among Koreans over the past 20 years. To manage and control this disease, various CVD risk assessment tools such as KOSHA (Korean Occupational Safety and Health Agent) CVD risk assessment, the presence of metabolic syndrome and the Framingham risk score (FRS) have been developed and applied to employees at the workplace. This study was designed to compare the validity of the CVD risk assessment tools mentioned above with the findings of coronary CT angiography (CCTA). METHODS: The subjects of this study who were 490 male-workers aged between 31 and 70, and these subjects were selected among those who had visited a University Hospital for a general health examination and who underwent CCTA from January 2007 to June 2009. Chi-square tests and logistic regression analysis were used to compare and analyze the associations between the CVD risk assessment tools and the coronary artery changes such as calcification and stenosis. RESULTS: Metabolic syndrome (OR=1.90, 95% CI 1.23-2.95) and the Framingham risk score (OR=2.71, 95% CI 1.83-4.01) were the significant and meaningful predictors of coronary artery calcification. On the analysis of the association with coronary artery stenosis, only the Framingham risk score (OR=2.21, 95% CI 1.46-3.36) turned out to be a significant and meaningful predictor. CONCLUSION: The results suggest that the Framingham risk score is a relatively valid CVD risk assessment tool. Henceforth, to effectively manage cardiovascular diseases in the workplace, advanced tools and indicators for management should be considered and provided based on meaningful study results.

The Relationship of Serum CEA Levels and Type of Work in Shipyard Workers / 대한산업의학회지

OBJECTIVES: Benign conditions have been known to cause an increase in the levels of serum carcinoembryonic antigen, a level change that is often associated with an increase in the occurrence of malignancy. The purpose of this study was to elucidate the relationship between serum CEA levels and type of work in shipyard workers. METHODS: From July-August 2007, 637 study subjects were enrolled into the study with the following characteristics: age 37~58 years, healthy shipyard workers, and who undergone an examination in a general hospital. Data on general characteristics was gathered from self-administered questionnaires. Information on job factors was collected from company personnel data. Serum CEA levels were measured after 10 hours'fasting. RESULTS: The level of mean serum CEA was 1.83+/-1.20 ng/mL. On univariate analysis, the mean CEA level was significantly higher in older age groups (P<0.05), current smokers, lower education, and in production workers (P<0.01). After adjusting for age, BMI, cigarette smoking, job pattern, and educational level, the serum CEA level was higher in production workers than in office workers(P<0.01). This is particularly true in the shipyard painters, who had the highest level of CEA across job groups. CONCLUSIONS: The goal of this was to determine if there were differences in serum CEA levels according to occupational role in shipyard workers. Production shipyard workers had relatively higher level of serum CEA than office workers, most likely due to occupational exposure. This serum CEA level is influenced by occupation role. Serum CEA level could be a parameter for evaluating pollutant effects.