Evaluation of Temporal Trends of Lead Exposure in Korean Workers Using Workplace Monitoring Data

Background@#Lead, which is widely used in various industrial settings, is a major health hazard for manufacturing workers. Therefore, control of lead exposure has been implemented in an effort to prevent lead-related health problems. In this study, our aim was to evaluate temporal trends in occupational lead exposure in Korean lead workers using data from monitoring of workplace exposure. @*Methods@#A nationwide work environment monitoring database, data from a work environment monitoring institution, and data extracted from a review paper were utilized. Different versions of standard industrial classification codes were aligned with the 10th Korean Standard Industrial Classification, which is generally consistent with the 4th revision of the International Standard Industrial Classification. The multiple data sources were combined and temporal trends over the period from 1994–2021 were estimated. In addition, separate estimation of temporal trends in the storage battery manufacturing industry over the period from 1987–2021 was also performed. @*Results@#A total of 444,296 personal airborne lead measurements were used for the estimation process. The temporal trends in occupational exposure to lead declined by −6% annually over the study period. In particular, levels of lead exposure in the storage battery manufacturing industry showed a steeper decline of −12% annually. @*Conclusions@#Findings of our study showed that occupational exposure to lead declined over the period from 1994 to 2021 in Korea. However, adverse effects of exposure to lead on health should be regarded with caution. The results will be useful in conduct of epidemiological studies examining lead-related effects on health.

Review of Inhalation Health Risks Involving Chloromethylisothiazolinone (CMIT) and Methylisothiazolinone (MIT) Used as Disinfectants in Household Humidifiers

The association between lung injury and exposure to humidifier disinfectant (HD) containing a mixture of chloromethylisothiazolinone (CMIT) and methylisothiazolinone (MIT) has been controversial in South Korea. This study conducts a literature review in order to evaluate the likelihood of CMIT/MIT reaching the lower part of the respiratory tract and causing lung injury. A literature review focused on the inhalation risk of HD containing a mixture of CMIT and MIT. The major contents included the physicochemical properties of CMIT and MIT contained in HDs and methodological reviews on substance analysis, toxicity tests and clinical cases. HD products marketed in South Korea have been reported to contain approximately 1–2% CMIT and 0.2–0.6% MIT along with magnesium nitrate (20–25%), magnesium chloride (0.2–1.0%), and water (70–75%). The types of CMIT and MIT dispersed into the air and deposited in the respiratory tract are assumed to be either gaseous substances or nanoparticles mixed with magnesium salts. The result of the literature review including clinical cases of lung injury among CMIT/MIT HD product users, demonstrated that these chemicals likely reach the lower respiratory tract and accordingly cause lung injury.A number of humidifier disinfectant-associated lung injury cases with clinical evidence should be prioritized in risk assessment of HD containing CMIT and MIT, even though there might be insufficient evidence in all related areas, including inhalation exposure assessment studies, animal testing, and epidemiological studies.

Overview of Legal Measures for Managing Workplace COVID-19 Infection Risk in Several Asia-Pacific Countries

Background@#Despite the lack of official COVID-19 statistics, various workplaces and occupations have been at the center of COVID-19 outbreaks. We aimed to compare legal measures and governance established for managing COVID-19 infection risks at workplaces in nine Asia and Pacific countries and to recommend key administrative measures. @*Methods@#We collected information on legal measures and governance from both general citizens and workers regarding infection risks such as COVID-19 from industrial hygiene professionals in nine countries (Indonesia, India, Japan, Malaysia, New Zealand, Republic of the Philippines, Republic of Korea, Taiwan, and Thailand) using a structured questionnaire. @*Results@#A governmental body overseeing public health and welfare was in charge of containing the spread and occurrence of infectious diseases under an infectious disease control and prevention act or another special act, although the name of the pertinent organizations and legislation vary among countries. Unlike in the case of other traditional hazards, there have been no specific articles or clauses describing the means of mitigating virus risk in the workplace that are legally required of employers, making it difficult to define the responsibilities of the employer. Each country maintains own legal systems regarding access to the duration, administration, and financing of paid sick leave. Many workers may not have access to paid sick leave even if it is legally guaranteed. @*Conclusion@#Specific legal measures to manage infectious disease risks, such as providing proper personal protective equipment, education, engineering control measures, and paid sick leave are recommended to be stipulated in Industrial safety and health-related acts.

The Pathological Findings of Chloromethylisothiazolinone and Methylisothiazolinone-associated Lung Injury

No abstract available.

Occupational Characteristics of Semiconductor Workers with Cancer and Rare Diseases Registered with a Workers' Compensation Program in Korea

BACKGROUND: The aim of this study was to describe the types of diseases that developed in semiconductor workers who have registered with the Korea Workers' Compensation and Welfare Service (KWCWS) and to identify potential common occupational characteristics by the type of claimed disease. METHODS: A total of 55 semiconductor workers with cancer or rare diseases who claimed to the KWCWS were compared based on their work characteristics and types of claimed diseases. Leukemia, non-Hodgkin lymphoma, and aplastic anemia were grouped into lymphohematopoietic (LHP) disorder. RESULTS: Leukemia (n = 14) and breast cancer (n = 10) were the most common complaints, followed by brain cancer (n = 6), aplastic anemia (n = 6), and non-Hodgkin lymphoma (n = 4). LHP disorders (n = 24) accounted for 43%. Sixty percent (n = 33) of registered workers (n = 55) were found to have been employed before 2000. Seventy-six percent (n = 42) of registered workers and 79% (n = 19) among the registered workers with LHP (n = 24) were found to be diagnosed at a relatively young age, ≤40 years. A total of 18 workers among the registered semiconductor workers were finally determined to deserve compensation for occupational disease by either the KWCWS (n = 10) or the administrative court (n = 8). Eleven fabrication workers who were compensated responded as having handled wafers smaller than eight inches in size. Eight among the 18 workers compensated (44 %) were found to have ever worked at etching operations. CONCLUSION: The distribution of cancer and rare diseases among registered semiconductor workers was closely related to the manufacturing era before 2005, ≤8 inches of wafer size handled, exposure to clean rooms of fabrication and chip assembly operations, and etching operations.

Two Cases of Chloromethylisothiazolinone and Methylisothiazolinone-associated Toxic Lung Injury

Previous animal studies have not conclusively determined the association between exposure to humidifier disinfectants (HDs) containing 5-chloro-2-methyl-4-isothiazolin-3-one (CMIT) and/or 2-methyl-4-isothiazolin-3-one (MIT) and development of HD-associated lung injuries. Nonetheless, patients exposed to HDs containing only CMIT and/or MIT showed clinically similar lung injuries to those exposed to HDs containing polyhexamethylene guanidine (PHMG) or oligo (2-[2-ethoxy]ethoxyethyl) guanidinium chloride (PGH). Here, we report twin sisters with lung injuries associated with exposure to CMIT/MIT-containing HDs. At 6 months of age, a younger twin sister presented with the 3-day history of cough, sputum, and respiratory difficulty. Chest radiography revealed multiple patchy consolidation and ground-glass opacities with pneumothorax and pneumomediastinum. Thoracostomy was performed due to pneumothorax at admission and she was discharged at 11 days of hospitalization. At 5 years of age, multiple tiny nodules and faint centrilobular ground-glass opacities were observed with the small pneumatocele. The elder sister visited a tertiary hospital due to dyspnea at 12 months of age. Chest radiography showed consolidation, pneumomediastinum, and pulmonary interstitial emphysema. There was no response to the administration of immunosuppressant drugs and antifibrotic agents. At 5 years of age, chest CT revealed ground-glass opacity and multiple tiny centrilobular ground-glass opacities nodules in both lungs with exercise intolerance.

Inhalation Lung Injury Associated with Humidifier Disinfectants in Adults

We recently established a novel disease entity presented as progressive respiratory failure associated with the inhalation of humidifier disinfectants. In April 2011, we encountered a series of peripartum patients with complaints of respiratory distress of unknown etiology, which was an uncommon phenomenon. Accordingly, we created a multidisciplinary team comprising intensivists, radiologists, pathologists, epidemiologists, and the Korea Centers for Disease Control and Prevention (KCDC). Further, we defined the disease entity and performed a case-control study, epidemiologic investigation, and animal study to determine the etiology. The study findings indicated that the lung injury outbreak was related to the inhalation of humidifier disinfectants and showed that household chemical inhalation can cause severe respiratory failure. Following the withdrawal of humidifier disinfectants from the Korean market in 2012, no such cases were reported. This tragic event is a warning that appropriate safety regulations and monitoring for potential toxic household chemicals are critical to protect public health.

Association of cadmium with diabetes in middle-aged residents of abandoned metal mines: the first health effect surveillance for residents in abandoned metal mines

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 mug/g creatinine < U-cd) while diabetes prevalence was 1.81 (95 % CI 1.05-3.12) with adjusted age, BMI, smoking and alcohol consumption, region, family income. On the other hand, the odds ratio for third tertile of U-cd (3 mug/g creatinine < U-cd) between diabetes prevalence in female was 1.39 (95 % CI 0.52-3.72) in addition to adjusted menopausal status. CONCLUSIONS: Environmental exposure to cadmium in abandoned mine residents was associated with diabetes in male. Closed monitoring and periodic evaluation of the health effects of chronic environmental exposure on abandoned mines residents will be needed.

A Case of Carcinosarcoma of the Parotid Gland / 대한이비인후과학회지

Carcinosarcoma is an extremely rare tumor, composed of a mixture of both carcinomatous and sarcomatous elements. The two-thirds are derived from the parotid gland. Because carcinosarcoma is highly aggressive malignant tumor with high local recurrence and poor survival rates, the combination of radical surgical excision and chemotherapy or radiotherapy is regarded as treatment of choice. However, treatment protocol has not been established. A 73-year-old man presented with a painful mass in the left parotid gland that had been rapidly enlarging for 2 weeks. Fine-needle aspiration biopsy was performed and it showed atypical epithelium. Superficial parotidectomy and modified radical neck dissection were performed for the left parotid gland cancer. The pathological diagnosis was carcinosarcoma and sequential chemoradiotherapy was performed. After a clinical follow-up of 30 months, he has remained free of disease. Based on our experience, we suggest that conservative surgical procedure could be one of the effective therapies.

A Case of Post-Traumatic Olfactory Disorder Presenting Negative Results of Schneider Test due to Trigeminal Nerve Injury / 대한이비인후과학회지

There has been a considerable increase in the number of patients with olfactory disorder due to head and facial injuries. Conventional olfactory function evaluation methods, such as T&T olfactometer, the Schneider test and the Alinamin test have been widely used in clinical practice. Among these, the Schneider test can determine whether the patient is a malingerer. A woman who sustained head and facial injuries visited our department with the chief complaint of anosmia. The patient underwent conventional olfactory function tests, including T&T olfactometer and the Schneider test. T&T olfactometer revealed olfactory loss, but the Schneider test did not. Thus, she was diagnosed with malingering. However, her diagnosis of olfactory disorder and concurrent trigeminal nerve injury was made definite during the follow-up period. We herein report a 30-year-old female patient with olfactory disorder who was misdiagnosed with olfactory malingering based on the negative result of the Schneider test. A brief review of the literature has been included.

Review on Potential Risk Factors in Wafer Fabrication Process of Semiconductor Industry / 대한산업의학회지

OBJECTIVES: To associate work in the semiconductor industry, including silicon wafer fabrication, with cancer risks or mortality and other adverse health effects, the operation of wafer fabrication should initially be understood. A detailed study on the fabrication operation allows retrospective exposure to be assessed and wafer fabrication workers to be classified into similar exposure groups. Therefore, the objective of this study was to comprehensively review silicon wafer fabrication operations and related hazardous materials and agents. METHODS: The literatures related to semiconductor industry processes were reviewed from an occupational health viewpoint based on wafer manufacturing, wafer fabrication and packaging. The focus was especially related to the hazardous materials used in wafer fabrication industries. RESULTS: During the fabrication of silicon wafers, many toxic chemicals, a strong electric field and hazardous equipment are used. The process allows the integration of a three-dimensional array of electric circuits onto a silicon wafer substrate. Wafers are sliced from single crystal silicon and subject to a series of steps during the fabrication process, which alternatively adds and then selectively removes materials in layers from the surface of the wafer to create different parts of the completed integrated circuit. There are four major steps in this process; patterning, junction formation, thin film and metallization. CONCLUSIONS: In order to associate exposure to the hazard agents generated during wafer fabrication operations with adverse health effects the details of the operation should be completely studied, which will be helpful in both exposure assessments and epidemiological studies.

A Case of Hypersensitivity Pneumonitis in a Worker Exposed to Metal Working Fluid / 대한산업의학회지

INTRODUCTION: There have been no reports of hypersensitivity pneumonitis caused by metal working fluids in Korea, despite their existence in other countries. Here, we report the first such case, along with an assessment of work-relatedness through exposure assessment. CASE REPORT: A 64-year old male patient visited the hospital with dyspnea after metal pipe cutting for about a year. He was diagnosed with hypersensitivity pneumonitis from the evidence of specific exposure history, clinical symptoms, and radiologic findings. The air exposure levels of the oil mist, endotoxin, total bacteria and fungus in the work environment was TWA(8-hr) 0.531 mg/m3, 6.33 EU/m3, 100 CFU/m3 and 75 CFU/m3, respectively. The concentrations of the endotoxin, total bacteria and fungus within the metal working fluid was 1.5x10(4) EU/mL, 4.6x10(5) CFU/mL and 1.8x10(5) CFU/mL, respectively. DISCUSSION: Although the patient did not receive a specific precipitating antibody test, the microbial concentration within the metal working fluid was higher than normal and similar to previous case reports, The oil mist level in the air exceeded the NIOSH REL and ACGIH NIC, and were similar or higher than previous cases. By excluding other causes of hypersensitivity pneumonitis, we concluded that the disease developed from exposure to microbial antigens in the metal working fluid.

A Case of Hypersensitivity Pneumonitis in a Worker Exposed to Metal Working Fluid / 대한산업의학회지

INTRODUCTION: There have been no reports of hypersensitivity pneumonitis caused by metal working fluids in Korea, despite their existence in other countries. Here, we report the first such case, along with an assessment of work-relatedness through exposure assessment. CASE REPORT: A 64-year old male patient visited the hospital with dyspnea after metal pipe cutting for about a year. He was diagnosed with hypersensitivity pneumonitis from the evidence of specific exposure history, clinical symptoms, and radiologic findings. The air exposure levels of the oil mist, endotoxin, total bacteria and fungus in the work environment was TWA(8-hr) 0.531 mg/m3, 6.33 EU/m3, 100 CFU/m3 and 75 CFU/m3, respectively. The concentrations of the endotoxin, total bacteria and fungus within the metal working fluid was 1.5x10(4) EU/mL, 4.6x10(5) CFU/mL and 1.8x10(5) CFU/mL, respectively. DISCUSSION: Although the patient did not receive a specific precipitating antibody test, the microbial concentration within the metal working fluid was higher than normal and similar to previous case reports, The oil mist level in the air exceeded the NIOSH REL and ACGIH NIC, and were similar or higher than previous cases. By excluding other causes of hypersensitivity pneumonitis, we concluded that the disease developed from exposure to microbial antigens in the metal working fluid.

First year report of analytical proficiency testing program for industrial hygiene laboratories / 대한산업의학회지

No abstract available.