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

The purpose of this study was to review occupational reproductive abnormalities and occupational bladder cancer in Korea and to discuss their toxicological implications. Reproductive dysfunction as a result of 2-bromopropane poisoning was first reported in Korean workers. In 1995, 23 of the 33 workers (25 female and 8 male workers) who were exposed to 2-bromopropane during the assembly of tactile switch parts developed reproductive and/or hematopoietic disorders. A total of 17 (68%) workers were diagnosed with ovarian failure. Two of the eight male workers experienced azoospermia and four workers experienced some degree of oligospermia or reduced sperm motility. In summary, 2-bromopropane poisoning caused severe reproductive effects in Korean workers. The prognosis was poor for reproductive dysfunction. A few cases of occupational bladder cancer have been reported in Korea, whereas other cancers of the urinary tract have not been reported after occupational exposure. A few cases of benzidine-induced cancer have been reported in Korea and 592 workers in Japan have received compensation for benzidine and beta-naphthylamine-induced cancer. In conclusion, a few cases of benzidine-induced occupational bladder cancer have been reported in Korea. However, benzidine-induced bladder cancer will likely be an important occupational health issue in Korea in the coming years.
2-Naphthylamine/toxicity ; Azoospermia/chemically induced/epidemiology ; Benzidines/toxicity ; Female ; Humans ; Hydrocarbons, Brominated/toxicity ; Infertility/*chemically induced/*epidemiology ; Male ; Occupational Diseases/*chemically induced/*epidemiology ; Occupational Exposure/adverse effects ; Oligospermia/chemically induced/epidemiology ; Primary Ovarian Insufficiency/chemically induced/epidemiology ; Republic of Korea ; Sperm Motility/drug effects ; Urinary Bladder Neoplasms/*chemically induced/*epidemiology

In this article, current status of noise exposure in workplaces, trend of workers with noise-induced hearing loss (NIHL), and prevalence of NIHL in workers by industry and job category in Korea were reviewed. In addition, trends of research on the audiological effects such as hearing loss from noise and occupational hearing loss from non-noise in Korea were addressed through reports in industrial audiology. Though noise exposure level has improved, noise still shows the highest rate of cases exceeding exposure limit among workplace hazards. NIHL is the most common occupational disease except work-related disease such as musculoskeletal disorders and cerebrovascular diseases, and NIHL prevalence is thought to be much higher than reported in official publications. Noise affecting hearing comes from various sources such as workplaces, military settings, areas with exposure to high noise, and specific noise sources. There is also occupational hearing loss by non-noise including chemicals such as organic solvents and heavy metals, barotrauma, and trauma due to welding spark. Noise affects daily life through audiological effects such as hearing loss and tinnitus, non-audiological physical effects (e.g., cardiovascular), and psychosocial and behavioral effects. Development of systematic and comprehensive hearing conservation programs for lowering the noise level in workplaces and preventing the NIHL, and preparation of technological, administrative system for its settlement at workplace are urgently needed.
Hearing Loss/*chemically induced ; Hearing Loss, Noise-Induced/*epidemiology ; Humans ; Noise, Occupational/*adverse effects ; Occupational Diseases/chemically induced/*epidemiology/*etiology ; Occupational Exposure/adverse effects ; Prevalence ; Republic of Korea/epidemiology ; Tinnitus/epidemiology

China ; epidemiology ; Data Collection ; standards ; Humans ; Occupational Diseases ; chemically induced ; epidemiology ; Occupational Exposure ; statistics & numerical data ; Occupational Health ; statistics & numerical data ; Occupational Medicine ; legislation & jurisprudence

Malignant mesothelioma and lung cancer are representative examples of occupational cancer. Lung cancer is the leading cause of cancer death, and the incidence of malignant mesothelioma is expected to increase sharply in the near future. Although information about lung carcinogen exposure is limited, it is estimated that the number of workers exposed to carcinogens has declined. The first official case of occupational cancer was malignant mesothelioma caused by asbestos exposure in the asbestos textile industry in 1992. Since then, compensation for occupational respiratory cancer has increased. The majority of compensated lung cancer was due to underlying pneumoconiosis. Other main causative agents of occupational lung cancer included asbestos, hexavalent chromium, and crystalline silica. Related jobs included welders, foundry workers, platers, plumbers, and vehicle maintenance workers. Compensated malignant mesotheliomas were associated with asbestos exposure. Epidemiologic studies conducted in Korea have indicated an elevated risk of lung cancer in pneumoconiosis patients, foundry workers, and asbestos textile workers. Occupational respiratory cancer has increased during the last 10 to 20 yr though carcinogen-exposed population has declined in the same period. More efforts to advance the systems for the investigation, prevention and management of occupational respiratory cancer are needed.
Asbestos/toxicity ; Carcinogens/toxicity ; Chromium/toxicity ; Female ; Humans ; Lung Neoplasms/chemically induced/*epidemiology/*etiology ; Male ; Mesothelioma/epidemiology/*etiology ; Occupational Diseases/chemically induced/*epidemiology/etiology ; Occupational Exposure/*adverse effects ; Pneumoconiosis/complications ; Republic of Korea/epidemiology ; Silicon Dioxide/toxicity ; Workers' Compensation

OBJECTIVETo understand the toxic effects of manganese exposure on health by measurement of manganese concentration and occupational health inspection among workers in an enterprise exposed to manganese, and to provide a basis for occupational disease control.

METHODSThe air concentrations of manganese in 12 workplaces where workers often stayed were measured by typical sampling; occupational health inspection was performed among a total of 538 workers in the enterprise by cluster sampling.

RESULTSThe average concentrations of manganese in the workplace from 2011 to 2013 were 0.179 mg/m(3), 0.122 mg/m(3), and 0.082 5 mg/m(3), respectively, indicating a significant decrease in manganese level within the three years by rank-sum test (P < 0.05). The results of health inspection showed that 165 (30.7%) out of 538 workers had abnormal indices, and the incidence of autonomic nervous system abnormalities reached 32.7% (176/538). There was no correlation between manganese concentration in the workplace and the incidence of abnormal indices in health inspection, while the manganese concentration in the workplace was positively correlated with the incidence of autonomic nervous system symptoms (r = 0.718, P < 0.05).

CONCLUSIONThe manganese concentration in the workplace is positively correlated with the incidence of autonomic nervous system symptoms. Early exposure to a low level of manganese can induce functional changes and potential damages in the nervous system.

Humans ; Incidence ; Manganese ; analysis ; Nervous System ; drug effects ; physiopathology ; Occupational Diseases ; chemically induced ; epidemiology ; Occupational Exposure ; analysis ; Occupational Health ; standards ; Workplace

OBJECTIVETo investigate whether asbestosis is a risk factor for mortality of lung cancer.

METHODSA fixed cohort study was established in an asbestos plant in Chongqing, China, and followed up for 30 years from the beginning of 1972. Basic personal information on life state, cause of death, and diagnosis of asbestosis was collected. Multiple logistic regressions were applied to analyze risk factors.

RESULTSDuring the 30-year follow-up, 584 male workers constituting a total of 14,664 person-years were monitored and data were analyzed. Among them, 203 (34.8%) died and the mortality rate was 13.8 per 1000 person-years, cancer accounting for 37.4%. Excess risks were observed for lung cancer (OR = 3.72) and nonmalignant respiratory diseases (OR = 2.73) among workers with asbestosis. High-exposure level was another risk factor for lung cancer (OR = 3.20). Workers with category II of asbestosis demonstrated a higher OR of both lung cancer and nonmalignant respiratory diseases than those with category I of asbestosis.

CONCLUSIONHigh asbestos exposure level and asbestosis were the risk factors for death of lung cancer and nonmalignant respiratory diseases. Asbestosis is an independent risk factor for lung cancer among Chinese workers exposed to chrysotile, the risk increases with the increasing profusion of opacities of lung.

Adult ; Air Pollutants, Occupational ; toxicity ; Asbestos, Serpentine ; toxicity ; Asbestosis ; complications ; mortality ; Chemical Industry ; China ; epidemiology ; Humans ; Lung Neoplasms ; chemically induced ; mortality ; Male ; Occupational Diseases ; chemically induced ; mortality ; Occupational Exposure ; adverse effects ; Odds Ratio ; Risk Factors

The purpose of this study was to review the existing studies on lymphohematopoietic (LHP) cancer in Korea, estimate the prevalence of workers exposed to carcinogens, and determine the population attributable fraction (PAF) of leukemia. Two case series and 4 case reports were reviewed. Using official statistics, the prevalence of benzene exposure and ionizing radiation exposure was estimated. Based on the prevalence of exposure and the relative risk, The PAF of leukemia was calculated. Between 1996 and 2005, 51 cases of LHP cancer were reported from the compensation system. Greater than 50% of occupational LHP cancer was leukemia, and the most important cause was benzene. In a cohort study, the standardized incidence ratio was 2.71 (95% CI, 0.56-7.91). The prevalence of exposure was 2.5% and 2.2% in 1995 and 2000, respectively. Using the 1995 prevalence, 3.6-4.8% and 0.1% of cases with leukemia were attributable to benzene and ionizing radiation exposure, respectively, which resulted in 39.7-51.4 cases per year. Benzene is the most important cause of occupational leukemia in Korea. Considering the estimated PAF in this study, the annual number of occupational LHP cancer (51 cases during 10-yr period), might be underreported within the compensation system.
Adult ; Benzene/toxicity ; Cohort Studies ; Female ; Humans ; Incidence ; Leukemia/*chemically induced/*epidemiology ; Leukemia, Radiation-Induced/*epidemiology ; Male ; Middle Aged ; Occupational Diseases/*epidemiology/etiology ; Occupational Exposure/*adverse effects ; Prevalence ; Radiation, Ionizing ; Republic of Korea/epidemiology ; Workers' Compensation

Occupational hepatic disorders are classified into toxic hepatitis, viral hepatitis, and chemical-induced malignancy in Korea. Toxic hepatitis cases were reported in workers who were exposed to dimethylformamide, dimethylacetamide, or trichloroethylene. Pre-placement medical examination and regular follow-up are necessary to prevent the development of toxic hepatitis. Viral hepatitis was chiefly reported among health care workers such as doctors, nurses and clinical pathology technicians who could easily be exposed to blood. Preventive measures for these groups therefore include vaccination and serum monitoring programs. Hepatic angiosarcoma caused by vinyl chloride monomer (VCM) exposure is a very well known occupational disease and it has not been officially reported in Korea yet. Some cases of hepatocellular carcinoma were legally approved for compensation as an occupational disease largely by overwork and stress, but not supported by enough scientific evidence. Effort to find the evidence of its causal relationship is needed.
Adult ; Drug-Induced Liver Injury/epidemiology ; Female ; Health Personnel ; Hepatitis, Viral, Human/epidemiology/prevention & control ; Humans ; Liver Diseases/*epidemiology/prevention & control ; Liver Neoplasms/chemically induced/epidemiology ; Male ; Middle Aged ; Occupational Diseases/*chemically induced/*epidemiology/prevention & control ; Occupational Exposure/adverse effects ; Republic of Korea/epidemiology ; Young Adult

Skin disease is the most common occupational disease, but the reported number is small in Korea due to a difficulty of detection and diagnosis in time. We described various official statistics and data from occupational skin disease surveillance system, epidemiological surveys and cases published in scientific journals. Until 1981, 2,222 cases of occupational skin disease were reported by Korean employee's regular medical check-up, accounting for 4.9% of the total occupational diseases. There was no subsequent official statistics to figure out occupational skin diseases till 1998. From 1999, the Korea Occupational Safety and Health Agency (KOSHA) published the number of occupational skin diseases through the statistics of Cause Investigation for Industrial Accidents. A total of 301 cases were reported from 1999 to 2007. Recent one study showed the figures of compensated occupational skin diseases. Many of them belonged to daily-paid workers in the public service, especially forestry workers. Also, it described the interesting cases such as vitiligo and trichloroethylene-induced Stevens-Johnson Syndrome. Skin diseases are still important though the number of cases has decreased, and therefore it is recommended to grasp the status of occupational skin diseases through continuous surveillance system and to make policy protecting high-risk group.
Adult ; Aged ; Aged, 80 and over ; Female ; Humans ; Male ; Middle Aged ; Occupational Diseases/*epidemiology ; Occupational Exposure ; Republic of Korea/epidemiology ; Safety Management ; Skin Diseases/*epidemiology ; Stevens-Johnson Syndrome/chemically induced/epidemiology ; Trichloroethylene/toxicity