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This study aimed to investigate the association between obstructive sleep apnea (OSA) risk and hearing impairment among workers exposed to occupational noise. A cross-sectional study was conducted among 607 healthy male workers at a tire-manufacturing factory. The subjects underwent audiometric testing, and their OSA risk was examined based on the STOP-Bang questionnaire. Hearing impairment was defined as a hearing threshold25 dB hearing level (HL) in any frequency of 1, 2, 3 and 4 kHz in either ear. High OSA risk was defined as a STOP-bang score of ≥3. Hearing thresholds at 1, 2, 3 and 4 kHz in both ears were significantly higher among workers with high OSA risk than among those with low OSA risk after adjusting for confounders. Multiple logistic regression analysis examining the association of OSA risk and STOP-Bang score with hearing impairment revealed an odds ratio of 1.738 (95% confidence interval [CI] 1.113-2.713

The aim of this study was to investigate whether elevated blood lead level (BLL) is a risk factor for Helicobacter pylori infection. Upper gastrointestinal endoscopy was performed on 2,625 subjects...

Background For health care workers, immune management plays an important role in the protection against infectious diseases. This study investigated the seroprevalence of measles, mumps, rubella, and varicella-zoster in newly employed female nurses. Methods We conducted a survey on the seroprevalence of measles, mumps, rubella, and varicella-zoster in newly employed female nurses at a university hospital from 2011 to 2019, before the nurses were given their department placements and duty start. Enzyme-linked immunosorbent and chemiluminescence immunoassays were used to detect immunoglobulin G antibodies. We analyzed whether there was a significant difference in seroprevalence depending on the age, birth year, birth season, and region of residence (metropolitan residency: yes or no). Results The arithmetic mean ages of the participants were 28.6 ± 4.8, 23.5 ± 3.2, 23.6 ± 3.0, and 26.1 ± 4.5 years for measles, mumps, rubella, and varicella-zoster, respectively. The seropositivity rates were 93.9% (551/587), 60.2% (50/83), 83.3% (3,093/3,711), and 89.5% (978/1,093) for measles, mumps, rubella, and varicella-zoster, respectively. Significant differences in the seroprevalence when assessed according to the age and birth year were noted with measles, while significant differences in the seroprevalence were only noted with rubella and varicella-zoster when assessed according to birth year and age, respectively. Conclusions In this study, we identified the levels of antibody prevalence in new female nurses. Considering the seropositivity levels, cost-effectiveness, and convenience for the participants, we recommend that the measles-mumps-rubella vaccination be provided without serologic testing for all new female nurses and the varicella-zoster vaccination only be performed for persons who are negative after serologic testing. And it would be useful if the vaccinations were combined with compulsory worker health examinations, such as the pre-placement health examinations.

Background: Lead exposure is a risk factor for increased blood pressure and cardiovascular disease, even when blood lead levels (BLLs) are within the normal range. Objective: This study aimed to investigate the association between BLL and coronary artery stenosis (CAS) in asymptomatic adults using 128-slice dual-source coronary computed tomography (CT) angiography. Methods: We analyzed medical records data from 2,193 adults (1,461 men and 732 women) who elected to complete a screening health examination, coronary CT angiography, and BLL measurement during 2011–2018 and had no history of CAS symptoms, cardiovascular disease, or occupational exposure to lead. Logistic regression models were used to estimate associations between moderate-to-severe CAS (≥25% stenosis) and a 1-μg/dL increase in blood lead, with and without adjustment for age, sex, hypertension, diabetes mellitus, dyslipidemia, body mass index, regular exercise, smoking status, and alcohol drinking. Results: BLLs ranged from 0.12 to 10.14μg/dL, with an arithmetic mean of 2.71±1.26μg/dL. The arithmetic mean was higher for men than for women (2.98±1.26μg/dL vs. 2.18±1.08μg/dL, p

Background Previous studies have shown that morning types are less sensitive to pain. This study aimed to examine the relationship between chronotypes and musculoskeletal problems in workers with musculoskeletal burdens at work. Methods This cross-sectional study included 119 male production workers from a large automobile manufacturing plant. All the participants worked 2 shifts and worked on the automobile assembly line. Data were obtained using structured questionnaires, including the reduced Morningness-Eveningness Questionnaire (rMEQ), and musculoskeletal symptom questionnaire. Participants with an rMEQ score of 18 points or more were defined as morning-type workers (MTWs). Participants whose scores were less than 18 points were defined as neither-type workers (NTWs). Results The arithmetic mean age was 51.8 ± 5.3 years. MTWs and NTWs accounted for 35.3% and 64.7% of the total participants, respectively. Evening- and intermediate-type workers accounted form 6.7% and 58.0% of the participants, respectively. There was no significant difference in the health indicators when the MTW and NTW groups were compared. However, the musculoskeletal symptom questionnaire demonstrated a significant difference between the MTW and NTW groups. In the preceding year, the MTW group had significantly lower musculoskeletal pain and treatment ratios compared to the NTW group (35.7% vs. 62.3%, p = 0.005 and 14.3% vs. 32.5%, p = 0.031, respectively). After adjusting for variables, the odds ratio (OR) for musculoskeletal pain was significantly higher in the NTW group than in the MTW group (OR, 3.112; 95% confidence interval, 1.285-7.535; p = 0.012). Conclusions In this study, the musculoskeletal pain ratio was significantly lower for MTWs when compared to NTWs. Chronotypes could play an important role in work-related musculoskeletal disorders. Further, larger-scale, follow-up studies on chronotypes are required to assist in the prevention of musculoskeletal disorders in future.

Objective To report the case of a fisherman who developed chronic mercury poisoning due to excessive consumption of tuna while working on a pelagic fishing vessel. Case report A 48-year-old male deep-sea fisherman developed paresthesia and pain in both legs while working at sea. He continued working for over 4 months on a pelagic fishing vessel but was eventually unable to function normally as his condition deteriorated. Upon arrival on land, he received specialist treatment, including imaging studies, for 2 months; however, the cause of the symptoms was not identified. An examination of his occupational history revealed that he had worked as a crew member on a pelagic fishing vessel catching tuna for the last 2 years and consumed tuna for two or more meals per day, every day. Two months after discontinuation of tuna consumption, he was tested for mercury. The result showed an elevated blood mercury level (BML) of 21.79 μg/l. Based on the half-life of mercury, the BML was evaluated as 38.70-53.20 μg/l when he was on board. Four months after discontinuing tuna consumption, his BML decreased to 14.18 μg/l, and the symptoms were almost ameliorated. The person responsible for preparing meals on a pelagic fishing ship should be aware that fish may contain high levels of heavy metals and should prepare meals for crew members according to the recommended levels. Crew members should also be aware that fish and shellfish may contain mercury, and hence, they should consume only an appropriate amount.

The aim of this study was to investigate whether elevated blood lead level (BLL) is a risk factor for

Background Recent studies suggest that night shiftwork may increase the risk of prostate cancer and elevated serum prostate-specific antigen (PSA) level. The purpose of this study was to verify whether rotating night shiftwork affects serum PSA level. Methods This study included 3,195 male production workers who work in a large tire manufacturing factory. Serum PSA levels were measured and the data on related factors were obtained. Results The mean serum PSA level was 0.98 ± 0.79 ng/mL. PSA levels were significantly lower in the younger age group, the obese group, and regular exercise group. PSA levels were lower in night shift workers (n = 2,832) compared to day workers (n = 363), but the difference was not statistically significant. Conclusions Unlike previous studies, we did not find any evidence that night shiftwork results in an increase in serum PSA levels. Further research and consistent results are needed to elucidate the association between night shiftwork and the effect on the prostate.

Background Dehydroepiandrosterone sulfate (DHEAS) is an endogenous steroid hormone produced by the adrenal gland. DHEAS has been suggested to play a protective role against psychosocial stress. The aim of this study was to investigate the association between job-related stress and blood concentrations of DHEAS according to occupational stress factors among female nurses. Methods A cross-sectional study was conducted among 118 premenopausal nurses from 4 departments (operating room, emergency room [ER], intensive care unit, and ward) of a university hospital. Participants were all rotating night shift workers who have worked for over a year and mean age of 33.5 ± 4.8 years. Data from structured questionnaires including the Korean Occupational Stress Score, Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), and Pittsburgh Sleep Quality Index (PSQI) were used. Results In the high job-related stressor group, scores of BDI, BAI, and PSQI were significantly higher than low-stressor group. ER nurses had relatively more work-burden related stressors, but they had significantly lower levels of anxiety and depression than other groups. And, ER nurses showed higher levels of DHEAS than the other department nurses. The differences were significant (p = 0.003). Additionally, there was a statistically significant difference even after adjusting for factors that could affect level of DHEAS, such as age, body mass index, drinking, and physical activity (p = 0.039). Conclusions This result suggests the possibility that DHEAS may play a role as a marker of proper stress management. The capacity to secrete DHEAS is not simply due to workload or job stressor but could be determined depending on how individuals and groups deal with and resolve stress. Proper resolution of stress may affect positive hormone secretion.

Background In Asian countries, including Korea, lead poisoning caused by traditional herbal medicines is often observed in the clinic. However, there have been no reports thus far of lead poisoning caused by drugs that were approved by the Korea Food and Drug Administration (KFDA). Here, we describe seven patients who ingested a problematic natural product-derived drug (NPD). Case presentation In July 2018, seven patients visited a university hospital after ingesting an NPD, S. capsules. These patients complained of various symptoms, and their blood lead levels (BLLs) were elevated relative to those of the general population (arithmetic mean: 19.5 ± 11.6 µg/dL, range: 6.28–35.25 µg/dL). The total doses and BLLs were directly proportional to each other among the patients (r = 0.943, p = 0.001). After the patients discontinued drug intake, their BLLs decreased gradually. The capsule was confirmed to contain lead above the standard value (arithmetic mean: 2,547 ± 1,821.9 ppm). Conclusion This incident highlights the need to strengthen standards for the management of NPD ingredients in Korea. NPDs are more likely to be contaminated than other drugs. Thorough management by the KFDA is essential to prevent a recurrence. Moreover, systematic health care is needed for many patients who have taken problematic NPDs.

Objectives The aim of this study was to investigate whether shift work is related to elevated risk of coronary artery disease (CAD) by determining the coronary artery calcium (CAC) score and the presence of coronary artery stenosis by using coronary artery CT angiography (CCTA). Methods In this study, 110 male workers participated and underwent a CCTA examination for CAC scoring, which represents coronary artery plaque, and were evaluated for luminal stenosis. All of the participants were working in the same chemical plant, of whom 70 worked day shifts and 40 worked rotating shifts. Results In a multivariate logistic regression analysis, including age, smoking status, alcohol consumption, regular exercise and waist circumference, shift work was associated with a 2.89-fold increase in the odds of developing coronary plaque compared with day work (OR, 2.89; 95% CI 1.07 to 7.82). The association between shift work and coronary plaque was strong after adjustment for age, low-density lipoprotein cholesterol, hypertension and diabetes mellitus (OR, 2.92; 95% CI 1.02 to 8.33). In addition, the number of years of shift work employment was associated with coronary plaque. However, no association was found between shift work and coronary artery stenosis. Conclusions Shift work could induce CAD onset via the atherosclerotic process, and shift work employment duration was associated with an increased risk of atherosclerosis in male workers.

Aircraft maintenance crews are constantly exposed to severe aircraft noise. The purpose of this study was to verify whether noise from aircraft adversely affects the hearing threshold levels (HTLs) of aircraft maintenance conscripts during their 2 years of mandatory military service. This study included 3,000 male aircraft maintenance conscripts who work in the military runway area. We measured and analyzed HTLs at 2-4 kHz. The duration of exposure to noise increased with an increase in rank; however, HTLs showed a tendency to decrease. We attributed such contradicting results to the learning effect and adaptation to military service. However, we suspected that sudden deafness in 6 conscripts (0.2%) was due to loud noise in the runway area during military service. The effectiveness of the hearing conservation program for short-term military service personnel could be increased by focusing on preventing sudden deafness and preenlistment baseline audiogram tests.

Background In Korea, there were repeated radiation exposure accidents among non-destructive testing workers. Most of the cases involved local injury, such as radiation burns or hematopoietic cancer. Herein, we report a case of acute radiation syndrome caused by short periods of high exposure to ionizing radiation. Case presentation In January 2017, Korea Information System on Occupational Exposure (KISOE) found that a 31-year-old man who had worked in a non-destructive testing company had been overexposed to radiation. The patient complained of symptoms of anorexia, general weakness, prostration, and mild dizziness for several days. He was anemic. The venous injection areas had bruises and bleeding tendency. Blood and bone marrow testing showed pancytopenia and the patient was diagnosed with acute radiation syndrome (white blood cells: 1400/cubic mm, hemoglobin: 7.1 g/dL, platelets: 14000/cubic mm). He was immediately prohibited from working and blood transfusion was commenced. The patient’s radiation exposure dose was over 1.4 Gy (95% confidence limits: 1.1–1.6) in lymphocyte depletion kinetics. It was revealed that the patient had been performing non-destructive tests without radiation shielding when working in high places of the large pipe surface. Conclusions Exposure prevention is clearly possible in radiation-exposed workers. Strict legal amendments to safety procedures are essential to prevent repeated radiation exposure accidents.

We analyzed national data on blood lead levels (BLL) and blood cadmium levels (BCL) in residents living near 38 abandoned metal mining areas (n = 5,682, 18–96 years old) in Korea that were collected by the first Health Effect Surveillance for Residents in Abandoned Metal mines (HESRAM) from 2008 to 2011. The geometric mean BCL and BLL were 1.60 μg/L (95 % CI = 1.57–1.62 μg/L) and 2.87 μg/dL (95 % CI = 2.84–2.90 μg/dL), respectively, notably higher than levels in the general population in Korea and other countries. We found significantly higher BLL and BCL levels in people living within 2 km of an abandoned metal mine (n = 3,165, BCL = 1.87 μg/L, BLL = 2.91 μg/dL) compared to people living more than 2 km away (n = 2,517, BCL = 1.31 μg/L, BLL = 2.82 μg/dL; P

Background The National Lung Screening Trial revealed that low dose computed tomography (CT) screening reduced lung cancer mortality by 20%. However, nearly all (96.4%) of the positive screening results were false-positive. A higher false-positive rate (FPR) is expected in Korea, where the prevalence of tuberculosis and parasitic diseases are high. Material and methods We retrospectively reviewed the records of 1587 cases (906 males, 57.1%; 495 females, 31.2%) in which chest CT was used for health screening from 2006 to 2011 in one institution. The mean ± standard deviation age of the subjects was 62.7 ± 5.7 years and 495 (31.2%) subjects had a smoking history. Results Three hundred and thirty six subjects (21.2%) had non-calcified pulmonary nodules (NCPNs) described as solid nodules (n = 319), masses (n = 15) or pure or mixed ground glass opacities (n = 36). The incidence of NCPNs was 23.8% in smokers and 20.0% in non-smokers (P = 0.08). During a median follow up duration of 37 months (range, 0–67 months), eight subjects were confirmed to have lung cancer. Positive predictive value (PPV) of positive CT screening was 2.4% and FPR was 97.6%. Among 495 subjects who had a smoking history, 118 subjects displayed NCPNs (23.8%) and four patients were diagnosed with lung cancer, with a PPV and FPR of 3.4% and 96.6%, respectively. Conclusion CT screening has low PPV and high FPR, even in subjects with a high risk of lung cancer.

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.

We deeply appreciate the comments and suggestions from Rahman Shiri, MD, PhD. In South Korea, general health check-ups are performed by companies according to their labour management agreement. In this study, coronary artery CT angiography (CCTA) was the investigation specified by the labour management agreement. Prior to the test, the participants in this study were interviewed by a clinician. If the participants had any cardiovascular symptoms or a history of cardiovascular disease, they were transferred to specialist cardiology care and excluded from CCTA. Furthermore, the general population in South Korea can undergo self-referred CCTA evaluation as a general health examination regardless of having a clinical …

Background An outbreak of eye diseases occurred among workers at a poultry abattoir in South Korea from December 2012 to June 2013. An epidemiological investigation of the causative agent was conducted. The workers were given a special health examination and workplace environmental monitoring was performed. Workers with ocular symptoms subsequently underwent an ophthalmic examination. Case Presentaion From a total of 41 workers, 26 (63.4 %) were diagnosed with keratoepitheliopathy by ophthalmic examination. Environmental monitoring of the workplace revealed that the ultraviolet (UV) apron-disinfection lamp had not been turning off at the set times, and so the workers’ faces had been exposed to UV radiation. Effective radiation dose measurement showed a UV-B exposure of 7-30 μW/cm2, and a UV-C exposure of 40-200 μW/cm2; both values exceed the occupational exposure limits. The outbreak ceased after the lamp was repaired. Conclusions This case shows that inappropriate use of the UV disinfection lamp can cause mass photokeratitis. In order to prevent this, the UV disinfection lamp must be checked regularly, workers must be educated on the health effects of UV radiation, and appropriate eye protection must be worn.

Even though exposure to benzene has been linked to a variety of cancers including leukemia, the detailed molecular mechanisms relevant to benzene-induced carcinogenesis remain to be clearly elucidated. In this study, we evaluated the effects of benzene on differential gene expression in a leukemia cell line. The K562 leukemia cell line used in this study was cultured for 3 h with 10 mM benzene and RNA was extracted. To analyze the gene expression profiles, a 41,000 human whole genome chip was employed for cDNA microarray analysis. We initially identified 6,562 genes whose expression was altered by benzene treatment. Among these, 3,395 genes were upregulated and 3,167 genes were downregulated by more than 2-fold, respectively. The results of functional classification showed that the identified genes were involved in biological pathways including transcription, cell proliferation, the cell cycle, and apoptosis. These gene expression profiles should provide us with further insights into the molecular mechanisms underlying benzene-induced carcinogenesis, including leukemia.

Objective The aim of this study was to determine the association between urinary cadmium (U-cd) concentration and diabetes in middle-aged Korean residents of abandoned mines using the first Health Effect Surveillance for Residents in Abandoned Metal mines (HESRAM). Methods This study was cross-sectional study conducted on 719 residents between 40–70 years in 38 abandoned metal mines in Korea. Data was collected by HESRAM from 2008 to 2011. The correlation coefficient of U-cd and fasting blood glucose, odds ratio in urinary cadmium tertiles and diabetes prevalence was analyzed according to the sex category. Results The correlation coefficient U-cd concentration and fasting blood glucose was 0.182 in male. Logistic regression analysis in male revealed a third tertile odds ratio of U-cd (2 μg/g creatinine

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 38.75°C 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.

A selective and sensitive reversed-phase HPLC method for the determination of pentoxifylline in human serum was developed, validated, and applied to the pharmacokinetic study of pentoxifylline. Pentoxifylline and internal standard, chloramphenicol, were extracted from the serum by liquid-liquid extraction with dichloromethane and analyzed on a Luna CI8(2) column with the mobile phase of acetonitrile-0.034 M phosphoric acid (25:75, v/v, adjusted to pH 4.0 with 10 M NaOH). Detection wavelength of 273 nm and flow rate of 0.8 mL/min were used. This method showed linear response over the concentration range of 10-500 ng/mL with correlation coefficients greater than 0.999. The lower limit of quantification using 0.5 mL of the serum was 10 ng/mL, which was sensitive enough for pharmacokinetic studies of pentoxifylline. The overall accuracy of the quality control samples ranged from 89.3 to 92.7% for pentoxifylline with overall precision (% C.V.) being 4.1-9.2%. The relative mean recovery of pentoxifylline for human serum was 105.8%. Stability (stock solution, short and long-term) studies showed that pentoxifylline was not stable during storage. But three freeze-thaw cycles and extracted serum samples were stable. This method showed good ruggedness (within 15% C.V.) and was successfully applied for the analysis of pentoxifylline in human serum samples for the pharmacokinetic studies of orally administered tablet (400 mg pentoxifylline), demonstrating the suitability of the method.

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

A rapid, selective and sensitive reversed-phase HPLC method for the determination of etodolac in human serum was developed, validated, and applied to the pharmacokinetic study of etodolac. Etodolac and internal standard, ibuprofen were extracted from human serum by liquid-liquid extraction with hexane/isopropanol (95:5, v/v) and analyzed on a Luna C18(2) column with the mobile phase of 1% aqueous acetic acid-acetonitrile (4:6, v/v). Detection wavelength of 227 nm and flow rate of 1.0 mL/min were fixed for the study. The assay robustness for the changes of mobile phase pH, organic solvent content, and flow rate was confirmed by factorial design using a fixed etodolac concentration with respect to its peak area and retention time. And also, the ruggedness of this method was investigated at three different laboratories using same quality control (QC) samples. This method showed linear response over the concentration range of with correlation coefficients greater than 0.999. The lower limit of quantification using 0.5 mL of serum was 0.05 , which was sensitive enough for pharmacokinetic studies. The overall accuracy of the quality control samples ranged from 92.00 to 110.00% for etodolac with overall precision (% C.V.) being 1.08-10.11%. The percent recovery for human serum was in the range of 76.73-115.30%. Stability studies showed that etodolac was stable during storage, or during the assay procedure in human serum. The peak area and retention time of etodolac were not significantly affected by the changes of mobile phase pH, organic solvent content, and flow rate under the conditions studied. This method showed good ruggedness (within 15% C.V.) and was successfully used for the analysis of etodolac in human serum samples for the pharmacokinetic studies of orally administered Lodin XL tablet (400 mg as etodolac) at three different laboratories, demonstrating the suitability of the method.

Gabapentin is an antiepileptic drug that is structurally similar to acid (GABA), but does not interact with the GABA receptor. It does not bind significantly to plasma proteins, and is excreted to unchanged form in the urine. The purpose of the present study was to evaluate the bioequivalence of two gabapentin capsules, capsule 300 mg (Pfizer Pharm. Co., Ltd.) and Kuhnil capsule 300 mg (Kuhnil Pharm. Co., Ltd), according to the guidelines of the Korea Food and Drug Administration (KFDA). The release of gabapentin from the two gabapentin formulations in vitro was tested using KP VIII Apparatus II method with various dissolution media (pH 1.2, 4.0, 6.8 buffer solution and water). Twenty six healthy male subjects, years in age and kg in body weight, were divided into two groups and a randomized cross-over study was employed. After a single capsule containing 300 mg as gabapentin was orally administered, blood samples were taken at predetermined time intervals and the concentrations of gabapentin in serum were determined using HPLC with fluorescence detector. The dissolution profiles of two formulations were similar at all dissolution media. In addition, the pharmacokinetic parameters such as , and were calculated and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed , and untransformed . The results showed that the differences between two formulations based on the reference drug, capsule 300 mg, were -2.03, -0.43 and 4.29% for , and , respectively. There were no sequence effects between two formulations in these parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log 0.8 to log 1.25 for and , respectively). Thus, the criteria of the KFDA bioequivalence guideline were satisfied, indicating Kuhnil capsule 300 mg was bioequivalent to capsule 300 mg.

The purpose of the present study was to evaluate the bioequivalence of two cefaclor capsules, Ceclor (Lilly Korea Co., Ltd.) and Kyongbocefaclor (Kyongbo Pharm. Co., Ltd.), according to the guidelines of the Korea Food and Drug Administration (KFDA). The release of cefaclor from the two cefaclor formulations in vitro was tested using KP VIII Apparatus II method with various dissolution media (pH 1.2, 4.0, 6.8 buffer solution and water). Twenty four healthy male subjects, years in age and kg in body weight, were divided into two groups and a randomized crossover study was employed. After one capsule containing 250 mg of cefaclor was orally administered, blood was taken at predetermined time intervals and the concentrations of cefaclor in serum were determined using HPLC method with UV detector. The dissolution profiles of two formulations were similar at all dissolution media. In addition, the pharmacokinetic parameters such as , and were calculated and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed , and untransformed . The results showed that the differences between two formulations based on the reference drug, Ceclor, were -1.90%, 2.68% and -7.60% for , and , respectively. There were no sequence effects between two formulations in these parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log 0.8 to log 1.25 , respectively). Thus, the criteria of the KFDA bioequivalence guideline were satisfied, indicating Kyongbocefaclor capsule was bioequivalent to Ceclor capsule.

The purpose of the present study was to evaluate the bioequivalence of two propiverine hydrochloride tablets, BUP-4 (Jeil Pharm. Co., Ltd.) and Kuhnil Propiverine Hydrochloride (Kuhnil Pharm. Co., Ltd.), according to the guidelines of the Korea Food and Drug Administration (KFDA). The propiverine release from the two propiverine hydrochloride formulations in vitro was tested using KP VIII Apparatus II method with a variety of dissolution media (pH 1.2, 4.0, 6.8 buffer solutions, water and blend of polysorbate 80 into pH 6.8). Twenty six healthy male subjects, years in age and in body weight, were divided into two groups and a randomized cross-over study was employed. After one tablet containing 20 mg as propiverine hydrochloride was orally administered, blood was taken at predetermined time intervals and the concentrations of propiverine in serum were determined using HPLC method with UV detector. The dissolution profiles of two formulations were similar at all dissolution media. Besides, the pharmacokinetic parameters such as were calculated and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed and untransformed . The results showed that the differences between two formulations based on the BUP-4 were 0.17%, 7.98% and 4.55% for . respectively. There were no sequence effects between two formulations in these parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log(0.8) to log(1.25) . Thus, the criteria of the KFDA bioequivalence guideline were satisfied, indicating Kuhnil Propiverine Hydrochloride tablet was bioequivalent to BUP-4 tablet.

The purpose of the present study was to evaluate the bioequivalence of two glimepiride tablets, (Handok/Aventis Pharm. Co., Ltd.) and Glimed (Kuhn II Pharm. Co., Ltd.), according to the guidelines of Korea Food and Drug Administration (KFDA). The glimepiride release from the two glimepiride formulations in vitro was tested using KP VIII Apparatus II method with a variety of dissolution media (pH 1.2, 4.0, 6.8 buffer solution, water and blend of PSB 80 into each dissolution medium). Twenty six healthy male subjects, years in age and kg in body weight, were divided into two groups and a randomized cross-over study was employed. After one tablet containing 2 mg as glimepiride was orally administered, blood was taken at predetermined time intervals and the concentrations of glimepiride in serum were determined using HPLC method with UV detector. The dissolution profiles of two formulations were similar at all dissolution media. Besides, the pharmacokinetic parameters such as , and were calculated and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed , and untransformed . The results showed that the differences between two formulations based on the Amaryl were -3.70, -8.28 and 0.61% for , and , respectively. There were no sequence effects between two formulations in these parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log(0.8) to log(1.25) (e.g., for for and , respectively). Thus, the criteria of the KFDA guideline for the bioequivalence were satisfied, indicating Glimed tablet and Amaryl tablet were bioequivalent.

The purpose of the present study was to evaluate the bioequivalence of two risperidone tablets, Risperdal (Janssen Korea Co., Ltd.) and Rispen (Myung In Pharm. Co., Ltd), according to the guidelines of Korea Food and Drug Administration (KFDA). The risperidone release from the two risperidone formulations in vitro was tested using KP VIII Apparatus II method with various of dissolution media (pH 1.2, 4.0, 6.8 buffer solution and water). Twenty four healthy male subjects, years in age and kg in body weight, were divided into two groups and a randomized cross over study was employed. After one tablet containing 2 mg as risperidone was orally administered, blood was taken at predetermined time intervals and the concentrations of risperidone in serum were determined using HPLC method with UV detector. The dissolution profiles of two formulations were similar at all dissolution media. Besides, the pharmacokinetic parameters such as , were calculated and ANOVA test was utilized for the analysis of the parameters using logarithmically transformed , and untransformed . The results showed that the differences between two formulations based on the Risperdal were 0.20, -1.29 and -11-09% for ,, respectively There were no sequence effects two formulations in parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log(0.8) to log(1.25) (e.g., and for and , respectively). Thus, the criteria of the KFDA guideline for the bioequivalence were satisfied, indicating Rispen tablet and Risperdal tablet were bioequivalent.

Felodipine is a calcium antagonist that lowers blood pressure by reducing peripheral resistance by meas of a direct, selective action on smooth muscle in arterial resistance vessels. Futhermore, it have been approved for the effective in angina pectoris and cardiac failure. The purpose of the present study was to evaluate the bioequivalence of two felodipine extended release (ER) tablets, Splendil (YuHan Corporation) and Stapin (Hana Pharmaceutial Co., Ltd.), according to the guidelines of Korea Food and Drug Administration (KFDA). The felodipine release from the two felodipine formulations in vitro was tested using KP VIII Apparatus II method at pH 6.5 buffer solution. Twenty six healthy male subjects, years in age and in body weight, were divided into two groups and a radomized cross-over study was employed. After two tablets containing 5 mg as felodipine were orally administered, blood sample was taken at predetermined time intervals and the concentrations of felodipine in serum were determined using column-switching HPLC method with UV detector. The dissolution profiles of two formulations were similar at pH 6.5 buffer solution. Besides, the pharmacokinetic parameters such as were calculated and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed and untransformed . The results showed that the differences between two formulations based on the Splendil were 2.53%, 1.32% and 18.32% for , respectively. There were no sequence effects between two formulations in these parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance rage of log(0.86) to log(1.25) . Thus, the criteria of the KFDA guidelines for the bioequivalence was satisfied, indicating Stapin ER tablet and Splendil ER tablet are bioequivalent.

Erdosteine, the thiol derivatives chemically related to cysteine, is a mucolytic and mucoregulator agent which modulates mucus production and viscosity and increases mucociliary transport. The purpose of the present study was to evaluate the bioequivalence of two erdosteine capsules, Erdos (Dae Woong Pharmaceutical Co., Korea) and Erblon (Kuhn Il Pharmaceutical Co., Korea), according to the guidelines of Korea Food and Drug Administration (KFDA). The erdosteine release from the two erdosteine capsules in vitro was tested using KP VII Apparatus II method with various different kinds of dissolution media (pH 1.2, 4.0, 6.8 buffer solution and water). Twenty four healthy male subjects, years in age and in body weight, were divided into two groups and a randomized cross-over study was employed. After three capsules containing 300 mg as erdosteine were orally administered, blood was taken at predetermined time intervals and the concentations of erdosteine in serum were determined using HPLC method with UV detector. The dissolution profiles of two formulations were similar at all dissolution media. Besides, the pharmacokinetic parameters such as were calculated and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed and untransformed . The results showed that the differences between two formulations based on the Erdos were 0.20%, 1.10% and -9.44% for , respectively. There were no sequence effects between two formulations in these parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log(0.8) to log(1.25) . Thus, the criteria of the KFDA guidelines for the bioequivalence was satisfied, indicating Erblon capsule and Erdos capsule are bioequivalent.

Fluconazole is an orally active bis-triazole antifungal agent, which is used in the treatment of superficial and systemic candidiasis and in the treatment of cryptococcal infections in patients with the acquired immuno deficiency syndrome (AIDS). The purpose of the present study was to evaluate the bioequivalence of two fluconazole capsules, Diflucan (Pfizer Pharmaceuticals Korea Inc.) and Flucona (Korean Drug Pharmaceuticals Co., Ltd.), according to the guidelines of Korea Food and Drug Administration (KFDA). The fluconazole release from the two fluconazole capsules in vitro was tested using KP VII Apparatus II method at 0.1 M hydrochloride dissolution media. Twenty normal male volunteers, years in age and in body weight, were divided into two groups and a randomized cross-over study was employed. After three capsules containing 50 mg as fluconazole was orally administered, blood was taken at predetermined time intervals and the concentrations of fluconazole in serum were determined using HPLC method with UV detector. The dissolution profiles of two fluconazole capsules were very similar at 0.1 M hydrochloride dissolution media. Besides, the pharmacokinetic parameters such as were calculated and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed and and untransformed . The results showed that the differences in between two capsules based on the Diflucan were 4.96%, 5.65% and -13.76%, respectively. There were no sequence effects between two capsules in these parameter. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log(0.8) to log(1.25) , indicating that Flucona capsule is bioequivalent to Diflucan capsule.

To assess trends of public attitudes toward epilepsy in Korea, two surveys were performed in the same village using a common questionnaire before and after the schedule of public education on epilepsy. Cross-sectional studies were conducted by means of a door-to-door interview, in which all residents over 19 yr of age living in the survey area were targeted. Vehicles for the educational campaign took the form of lectures and small group discussions. The understanding of epilepsy among Korean respondents appeared to be not only based more on supernatural or superstitious thinking, but was also less comparable to that of other studies. The attitudes toward epilepsy also were far more negative in Korean rural areas than in other countries. The false belief that "epilepsy can not be treated" was the factor that contributed most to negative attitudes. Although a positive trend was obvious not only in understanding the cause of epilepsy but also in attitudes toward epilepsy, the majority of respondents still remain unchanged in their misunderstanding of and negative attitudes toward epilepsy. To ameliorate the social stigma against epilepsy in Korea, continuous and repetitive educational efforts as well as the sympathy of the lay societies regarding epilepsy would be needed.

Metformin is an oral antihyperglycemic agent used in the therapy of noninsulin-dependent diabetes mellitus and does not cause hypoglycemia at the therapeutic dose. Its mechanism of action may involve an increased binding of insulin to its receptors and glucose uptake at the post-receptor level. The purpose of the present study was to evaluate the bioequivalence of two metformin tablets, Glucophage (Daewoong Pharmaceutical Co., Ltd.) and Glycomin (Ilsung Pharmaceuticals Co., Ltd.), according to the guidelines of Korea Food and Drug Administration (KFDA). The metformin release from the two metformin tablets in vitro was tested using KP VII Apparatus II method with various dissolution media (pH 1.2, 4.0, 6.8 buffer solution and water). Twenty four normal male volunteers, years in age and in body weight, were divided into two groups with a randomized cross-over study. After one tablet containing 500 mg as metformin was orally administered, blood was taken at predetermined time intervals and the concentrations of metformin in serum were determined using HPLC with UV detector. Besides, the dissolution profiles of two metformin tablets were very similar at 떠1 dissolution media. The pharmacokinetic parameters such as were calculated. The ANOVA test was performed for the statistical analysis of the logarithmically transformed , untransformed . The results showed that the differences in between two tablets based on the Glucophage were 0.09%, 6.09% and -8.22%, respectively. There were no sequence effects between two tablets in these parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log(0.8) to log(1.25) , indicating that Glycomin tablet is bioequivalent to Glucophage tablet.

Cefadroxil is a semi-synthetic cephalosporin active against many Gram-positive and Gram-negative bacteria. The drug has been used for the treatment of the urinary and respiratory tract infections when caused by susceptible strains of the designated microorganism. The purpose of the present study was to evaluate the bioequivalence of two cefadroxil capsules, Duricef (Bo Ryung Pharmaceutical Co. Ltd.) and Hanacef (Korean Pharmaceutical Co. Ltd.), according to the guidelines of Korea Food and Drug Administration (KFDA). The cefadroxil release from the two cefadroxil capsules in vitro was tested using KP VII Apparatus II method with various different kinds of dissolution media (pH 1.2, 4.0, 6.8 buffer solution and water). Twenty four normal male volunteers, years in age and kg in body weight, were divided into two groups and a randomized cross-over study was employed. After one capsule containing 500 mg as cefadroxil was orally administered, blood was taken at predetermined time intervals and the concentrations of cefadroxil in serum were determined using HPLC with UV detector. The dissolution profiles of two cefadroxil capsules were very similar at all dissolution media. The pharmacokinetic parameters such as were calculated and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed and untransformed . The results showed that the differences in between two capsules based on the Duricef were 0.05%, -5.29% and 4.53%. There were no sequence effects between two capsules in these parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log(0.8) to log(1.25) for , respectively). The 90% confidence interval using untransformed data was within . All parameters met the criteria of KFDA guideline for bioequivalence, indicating that Hanacef capsule is bioequivalent to Duricef capsule.

We investigated whether sildenafil citrate (Viagra) may reduce the dose of nitrovasodilators to induce deliberate hypotension. Ten mongrel dogs were acutely instrumented with a femoral artery catheter and a pulmonary artery catheter. Sodium nitroprusside (SNP; 1-16 microg. kg(-1). min(-1)) or nitroglycerin (NTG; 2-32 microg. kg(-1). min(-1)) was IV given to induce hypotension. The study consisted of two occasions, in a random order, in each animal: one with sildenafil pretreatment (1 mg/kg IV followed by 0.3 mg. kg(-1). h(-1)) and the other without to serve as a control. Hemodynamic variables were continuously monitored. Plasma cyclic guanosine monophosphate (cGMP) concentrations were measured by radioimmunoassay. Both SNP and NTG produced dose-dependent decreases in mean arterial blood pressure without affecting the heart rate in the presence as well as in the absence of sildenafil. Systemic vascular resistance index and mean pulmonary arterial pressure were also decreased. The magnitude of mean arterial blood pressure and systemic vascular resistance index reductions caused by SNP was augmented by sildenafil, whereas that caused by NTG was not affected. Neither SNP nor NTG alone altered the plasma cGMP concentrations. Sildenafil increased the plasma cGMP concentration, which was further increased by SNP but not affected by NTG. These results indicate that sildenafil may reduce the dose of SNP in producing deliberate hypotension in the dog. The potentiation of SNP-induced hypotension by sildenafil may be related to an augmented accumulation of cGMP.Sildenafil may reduce the dose of sodium nitroprusside required to induce deliberate hypotension and hence the potential for cyanide toxicity.

Cimetropium bromide, a quaternary ammonium compound which is chemically related to scopolamine, exhibits its antispasmodic activity by competing with acetylcholine for the muscarinic receptors of the smooth muscle of gastrointestinal tract. The drug has been used for the treatment of various disorders involving spasms of the musculature of the gastrointestinal, biliary and genitourinary tracts. The purpose of the present study was to evaluate the bioequivalence of two cimetropium bromide tablets, (Boehringer Ingelheim Korea Ltd.) and (Hana Pharmaceutical Co., Ltd.), according to the prior and revised guidelines of Korea Food and Drug Administration (KFDA). The cimetropium bromide release from the two cimetropium bromide tablets in vitro was tested using KP VII Apparatus II method with various different kinds of dissolution media (pH 1.2, 4.0, 6.8 buffer solution and water). Twenty normal male volunteers, years in age and kg in body weight, were divided into two groups and a randomized cross-over study was employed. After three tablets containing 50 mg of cimetropium bromide per tablet were orally administered, blood was taken at predetermined time intervals and the concentrations of cimetropium bromide in serum were determined using HPLC method with UV detector. The dissolution profiles of two cimetropium bromide tablets were very similar at all dissolution media. Besides, the pharmacokinetic parameters such as were calculated and ANOVA test was utilized for the statistical analysis of the parameters using non-transformed and logarithmically transformed . The results showed that the differences in between two tablets based on the were 2.19%, -5.97% and 3.49%, respectively. Minimum detectable differences were less than 20% (e.g., 13.71 %, 19.05% and 15.11% for , respectively). The powers , were 97.79%, 83.22% and 95.60%, respectively. The 90% confidence intervals were within (e.g., , respectively). There were no sequence effect between two tablets in logarithmically transformed . The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log(0.8) to log(1.25) (e.g., , respectively). Two parameters met the criteria of prior and revised KFDA guideline for bioequivalence, indicating that tablet is bioequivalent to tablet.

Organophosphate poisoning has been associated with chronic neurobehavioral dysfunction, but no epidemiologic data exist with regard to long-term consequences from carbamate poisoning. This cross-sectional study evaluated the neurobehavioral performances of 81 banana workers who, on average 27 months earlier, had received medical attention not requiring hospitalization for mild occupational poisoning by either an organophosphate or a carbamate pesticide. These performances were compared with those of 130 banana workers who had never sought medical attention for pesticide poisoning. Poisoned subjects did less well than controls on tests measuring psychomotor and visuomotor skills, language function, and affect, the differences being significant for coding skills on the Digit-Symbol test and two tests of neuropsychiatric symptoms. These deficits, in particular a marked increase of neuropsychiatric symptoms, occurred among the organophosphate-poisoned subjects, but small deficits in performance were also seen in the carbamate-poisoned subjects. The performances of the previously poisoned subjects who had had contact with cholinesterase inhibitors within three months before testing were particularly poor. These findings in workers with mild poisoning are consistent with previous findings of persistent damage to the central nervous system from organophosphate poisoning. The possibility of persistent neurobehavioral effects associated with poisonings by nmethyl carbamate insecticides cannot be excluded. Workers with histories of poisoning may be more susceptible to neurobehavioral effects with subsequent exposures.

OBJECTIVE—To determine whether hepatic biochemical changes, as measured by routinely available tests indicative of hepatocellular necrosis, cholestasis, or altered hepatic clearance of bilirubin, occur in association with low to moderate exposure to styrene commonly experienced in industrial production. METHODS—Two independent cross sectional studies were performed comparing serum hepatic transaminases (alanine aminotransferase (ALT) and aspartate aminotransferase (AST)), cholestatic enzymes (alkaline phosphatase (AP) and γ glutamyl transpeptidase (GGT)), and bilirubin in (a) 47 workers of fibreglass reinforced plastics who were exposed to styrene and (b) 21 boat and tank fabricators, with separate referent groups of unexposed workers. Exposure to styrene was assessed in air by dosimetry, and in venous blood by headspace analysis. Hepatic biochemical variables were assessed across strata of exposure to styrene defined as 25 ppm in air, or 0.275 mg/l in blood, adjusting for age, sex, body mass index, and ethanol consumption. RESULTS—A consistent and significant linear trend for increasing direct bilirubin and direct/total bilirubin ratio was found in association with increasing exposure to styrene, by both air and blood monitoring, in both studies. Mean direct bilirubin concentrations increased from 0.05-0.08 mg% in referents to 0.12-0.19 in workers exposed above 25 ppm, with a significant exposure-response trend (p

Background The purpose of this study was to investigate the prevalence of airway hyperresponsiveness induced by methylene diphenyldiisocyanate (MDI) and toluene diisocyanate (TDI) at a petrochemical industry complex in Korea. Methods Questionnaires, allergic skin test, and nonspecific airway hyperresponsiveness (AHR) were studied in 64 exposed workers and 27 control subjects. Questionnaires included questions about symptoms of cough, wheezing, chest tightness, dyspnea, rhinorrhea, sneezing, itching, stuffiness, tearing, urticaria, sore throat, and exacerbating time. Methacholine challenge tests were done. Bronchial responsiveness (BRindex) defined as log (% fall in FEV1)/log (last concentration of methacholine +10). Results Prevalence of AHR (PC20 FEV1

Both benign prostatic hyperplasia (BPH) and male pattern baldness (androgenic alopecia) share the pathogenesis of an androgen-dependent disorder and afflict a large population of elderly men with chronobiologic progress. However, it is unclear whether these diseases are related epidemiologically. We evaluated the association of frequency and severity of male pattern baldness between patients with BPH and a control group.A total of 225 patients with BPH (mean age 69.3 +/- 6.5 years) and 1 60 controls (mean age 68.5 +/- 6.4 years), all over 60 years of age, were included in this study. The estimation of baldness severity was based on Norwood's classification (grade I to VII). The International Prostate Symptom Score (IPSS) and genetic tendency for baldness were also evaluated. The difference between IPSS and grade of baldness between the two groups was analyzed by the Mann-Whitney test and the frequency of inherited baldness was compared by the chi-square test. Correlation between severity of baldness and IPSS in each group was estimated by Spearman's rank correlation method.The patients with BPH had an apparently higher grade of male pattern baldness in comparison with that of controls (median value of grade IV versus III, P0.001). The proportion of men with male pattern baldness of grade IV or higher in the BPH group was significantly larger than that of controls (53.8% versus 36.9%, P0.01). There was a greater frequency of inherited baldness in the BPH group than in the controls (31.6% versus 12.5%, P0.001). No significant correlation was noted between baldness severity and IPSS in either group.This study demonstrates a strong association of BPH with male pattern baldness.

Superoxide dismutases (SODs) are metalloenzymes that detoxify superoxide radicals, and occur in cytosolic (Cu,Zn-SOD) and mitochondrial (Mn-SOD) forms in multiple tissues, including brain. A neuroprotective effect against oxide stressor exposures may be provided by SOD, although excessive enzyme activity can produce cell injury by formation of hydroxyl radical from hydrogen peroxide. We measured Cu,Zn-SOD and Mn-SOD activities in peripheral lymphocytes of 43 newly diagnosed idiopathic Parkinson's disease (PD) cases and 62 age- and sex-matched controls free of neurodegenerative disorders. Significant excesses of both SOD forms were found among PD cases compared with controls; however, the excesses were found exclusively among PD patients treated with the monoamine oxidase inhibitor selegiline (L-deprenyl). Enzyme-linked immunosorbent assays (ELISAs) confirmed that the activity excesses were due to increased protein rather than more highly reactive enzymes in lymphocytes of PD cases. Our findings clearly indicate the importance of selegiline on measured Cu,Zn-SOD and Mn-SOD activity in peripheral lymphocytes. Characterizing a possible therapeutic value of SOD will require longitudinal assessments of SOD in relation to PD progression.

A cross-sectional study was conducted to evaluate monoamine oxidase type B (MAO-B) activity in platelets as a biomarker of effect of styrene and perchloroethylene exposures. MAO-B is an enzyme system involved in dopamine catabolism, the impairment of which has been postulated as a mechanism of styrene-induced neurotoxicity. We previously observed an inverse association between blood styrene and MAO-B among reinforced plastics manufacturing workers. The present study included 59 male boat plant workers exposed to styrene (exposure range < 1–144 ppm, 8-h TWA). Two comparison groups comprised six male dry cleaning workers exposed to perchloroethylene (PCE; exposure range < 2-37 ppm) and 14 male laundry workers not exposed to either agent. Respiratory protection was not used by any of the styrene- or PCE-exposed workers; thus, air concentrations were regarded as valid exposure indicators. MAO-B activity (pmol/108 cells/h) was measured in peripheral blood platelets, using phenylethylamine as substrate. Only small overall mean differences in MAO-B were observed among the three groups; mean values were 4.21, 4.51, and 4.12 for the styrene-exposed, PCE-exposed, and laundry workers, respectively. Despite the absence of gross differences among the groups, styrene exposure was inversely related to MAO-B. Mean values for four increasing exposure group quartiles were: 5.60, 4.13, 3.69, and 3.44. The Spearman rank correlation coefficient for styrene with MAO-B was −0.41. Adjustment for age, medication use, smoking, and alcohol consumption had only a minimal effect on this trend. Duration of exposure to styrene bore a weak positive relation to MAO-B (Spearman r = + 0.29), which was nearly entirely explained by collinearity with age. The results from this study are in close quantitative agreement with previous findings of an inverse association between styrene exposure and MAO-B. More agents need to be evaluated to establish specificity, and longitudinal analyses of styrene-exposed workers will be required before confident conclusions can be reached about the predictive value of MAO-B as a biomarker of styrene-related neurotoxicity.

The present study was performed to identify biomarkers for exposure of benzene in blood cells and hematopoietic tissues. Peripheral mononuclear cells, hematopoietic stem cells, and leukemia cell lines were cultured in RPMI 1640 media with the addition of 0, 1, and 10 mM of benzene. Hydrogen peroxide was measured using an enzyme immunoassay. Mitochondrial mass, membrane potential, and mitochondrial DNA (mtDNA) copy number were measured using MitoTracker Green/Red probes, and real-time polymerase chain reaction. In addition, two-dimensional gel electrophoresis and mass spectrometry matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) technology were performed to identify protein markers. The mitochondrial contents and membrane potentials were dramatically increased after three weeks of direct benzene exposure. The hydrogen peroxide level increased significantly after two weeks of treatment with benzene (4.4 ± 1.9 µM/mg protein) compared to the non-benzene treatment group (1.2 ± 1.0; p = 0.001). The mtDNA copy number gradually increased after exposure to benzene. Numerous protein markers showed significant aberrant expression after exposure to benzene. Among them, the heterogeneous nuclear ribonucleoprotein (hnRNP) A2/B1 was markedly decreased after exposure to benzene. Thus, increased mitochondrial mass, mtDNA copy number, and the hnRNP A2/B1 protein were biomarkers for benzene-related toxicity and hematotoxicity.

In 2007, as part of the control and prevention of environmental contamination threatening public health, the Korean Ministry of Environment planned to implement a national biomonitoring survey of three metals: lead, cadmium, and mercury in the blood of residents living near 350 abandoned metal mines known to be contaminated and as possible threats to the health of inhabitants. Thus, we investigated demographic and lifestyle variables and blood lead levels in residents living around the mines and compared them against those of control subjects. We measured the blood lead concentrations in 14,849 subjects (14,132 from nearby the 350 abandoned metal mines and 717 subjects from eight control areas). A questionnaire was provided to all subjects to determine gender, age, mining experience, period of time living in the vicinity of mines, smoking status, and personal perception of abandoned mines as a health risk. The geometric means (95% confidence intervals) of the blood lead levels of residents living around the abandoned metal mines and control areas were 3.017 (2.996–3.037 μg/dL) [female, 2.797 μg/dL (2.771–2.822 μg/dL); male, 3.330 μg/dL (3.298–3.363 μg/dL)] and 2.757 (2.677–2.837 μg/dL) [female, 2.604 μg/dL (2.506–2.700 μg/dL); male, 2.993 μg/dL (2.859–3.126 μg/dL)], respectively. Among residents of the mining areas, nonsmokers and residents who had no mining experience showed significantly lower mean blood lead levels than did smokers, past smokers, and those with mining experience. The mean blood lead concentrations of residents who expressed some concern about the abandoned mines were significantly higher than those of residents without concerns. The mean blood lead concentration of residents living around the abandoned mines was significantly higher than that of residents living in control areas as well as that of the general adult Korean population. We also confirmed that smoking is an important variable to consider, as it increases blood lead concentration.

Objectives: The lung cancer mortality in Korea has increased remarkably during the last 20 years, and has been the first leading cause of cancer-related deaths since 2000. The aim of the current study was to examine the time trends of occupational lung cancer and carcinogens exposure during the period 2006-2009 in South Korea, by assessing the proportion of occupational burden. Methods: We defined occupational lung cancer for surveillance, and developed a reporting protocol and reporting website for the surveillance of occupational lung cancer. The study patients were chosen from 9 participating university hospitals in the following 7 areas: Seoul, Incheon, Wonju, Daejeon, Daegu, Busan, and Gwangju. Results: The combined proportion of definite and probable occupational lung cancer among all lung cancers investigated in this study was 10.0%, 8.6%, 10.7%, and 15.8% in the years 2006 to 2009, respectively, with an average of 11.7% over the four-year study period. The main carcinogens were asbestos, crystalline silica, radon, polyaromatic hydrocarbons (PAHs), diesel exhaust particles, chromium, and nickel. Conclusion: We estimated that about 11.7% of the incident lung cancer was preventable. This reveals the potential to considerably reduce lung cancer by intervention in occupational fields.