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.

Revised Clinical Practice Guideline of Korean Pancreatobiliary Association for Acute Pancreatitis: Diagnosis / 대한췌담도학회지

There is general acceptance that a diagnosis of acute pancreatitis requires two of the following three features: 1) epigastric or upper abdominal pain characteristic of acute pancreatitis, 2) serum amylase and/or lipase ≥3 times the upper limit of normal, and 3) characteristic findings of acute pancreatitis on abdominal images such as ultrasonography, computed tomography (CT) or magnetic resonance imaging. Other pancreatic diseases and acute abdomen have been ruled out before making a diagnosis of acute pancreatitis. Serum lipase may be more useful than serum amylase because serum lipase is thought to be more sensitive and specific than serum amylase in the diagnosis of acute pancreatitis. Contrast-enhanced CT scan is the best imaging technique to rule out the conditions that masquerade as acute pancreatitis, to diagnose the severity of acute pancreatitis, and to identify complications of pancreatitis. The etiology of acute pancreatitis should be made clear as soon as possible to decide treatment policy of acute pancreatitis or to prevent the recurrence of pancreatitis. The etiology of acute pancreatitis in an emergency situation should be assessed by clinical history, laboratory tests such as serum liver function tests, measurement of serum calcium and serum triglycerides and ultrasonography. A differentiation of gallstone-induced acute pancreatitis should be given top priority in its etiologic diagnosis because early endoscopic retrograde cholangiopancreatography should be considered if a complication of cholangitis and a prolonged passage disorder of the biliary tract are suspected.

A Pilot Establishment of the Job-Exposure Matrix of Lead Using the Standard Process Code of Nationwide Exposure Databases in Korea

Background@#The purpose of this study is to construct a job-exposure matrix for lead that accounts for industry and work processes within industries using a nationwide exposure database. @*Methods@#We used the work environment measurement data (WEMD) of lead monitored nationwide from 2015 to 2016. Industrial hygienists standardized the work process codes in the database to 37 standard process and extracted key index words for each process. A total of 37 standardized process codes were allocated to each measurement based on an automated key word search based on the degree of agreement between the measurement information and the standard process index. Summary statistics, including the arithmetic mean, geometric mean, and 95th percentile level (X95), was calculated according to industry, process, and industry process. Using statistical parameters of contrast and precision, we compared the similarity of exposure groups by industry, process, and industry process. @*Results@#The exposure intensity of lead was estimated for 583 exposure groups combined with 128 industry and 35 process. The X95 value of the “casting” process of the “manufacture of basic precious and non-ferrous metals” industry was 53.29 μg/m3, exceeding the occupational exposure limit of 50 μg/m3. Regardless of the limitation of the minimum number of samples in the exposure group, higher contrast was observed when the exposure groups were by industry process than by industry or process. @*Conclusion@#We evaluated the exposure intensities of lead by combination of industry and process. The results will be helpful in determining more accurate information regarding exposure in lead-related epidemiological studies.

Atorvastatin Induces FXR and CYP7A1 Activation as a Result of the Sequential Action of PPARγ/PGC-1α/HNF-4α in Hep3B Cells / 대한소화기학회지

Background/Aims@#PPARγ, farnesoid X receptor (FXR) and CYP7A1 are associated with solubility of bile. This study was performed to understand a mechanism and interactions of statin-induced PPARγ, PGC-1α and HNF-4α related to the statin-induced activation of FXR and CYP7A1, and verify whether the mevalonate pathway is involved in the mechanism. @*Methods@#MTT assays were performed using cultured human Hep3B cells to determine the effect of atorvastatin on the cell proliferation. Expression levels of indicated proteins were measured using Western blotting assays by inhibiting the protein expression or not. @*Results@#Atorvastatin increased expression of PPARγ, PGC-1α, HNF-4α, FXR, and CYP7A1 in Hep3B cells. PPARγ ligand of troglitazone upregulated the expression of PGC-1α, HNF-4α, FXR, and CYP7A1 in Hep3B cells. Silencing of PPARγ, PGC1α, and HNF4α using respective siRNA demonstrated that atorvastatin-induced FXR and CYP7A1 activation required sequential action of PPARγ /PGC-1α/HNF-4α. The silencing of PPARγ completely inhibited atorvastatin-induced PGC-1α expression, and the PGC1α silencing partially inhibited atorvastatin-induced PPARγ expression. The inhibition of HNF4α did not affect atorvastatin-induced PPARγ expression, but partially inhibited atorvastatin-induced PGC-1α expression. Besides, mevalonate completely reversed the effect of atorvastatin on PPARγ, PGC-1α, HNF-4α, FXR, and CYP7A1. @*Conclusions@#Atorvastatin induces FXR and CYP7A1 activation as a result of sequential action of PPARγ/PGC-1α/HNF-4α in human hepatocytes. We propose that atorvastatin enhances solubility of cholesterol in bile by simultaneously activating of FXR and CYP7A1.

Relationship Between Shift Intensity and Insomnia Among Hospital Nurses in Korea: A Cross-sectional Study / 예방의학회지

Objectives@#This study explored the relationship between shift intensity and insomnia among hospital nurses. @*Methods@#The participants were 386 female hospital nurses who underwent a special health examination for night workers in 2015. The Korean Insomnia Severity Index (ISI), indices of shift work intensity, and other covariates such as amount of exercise, level of alcohol consumption, employment duration, and hours worked were extracted from the health examination data. The indices for shift intensity were (1) number of 3 consecutive night shifts and (2) number of short recovery periods after a previous shift, both assessed over the prior 3 months. Multiple logistic regression analysis adjusted for the aforementioned covariates was performed to evaluate the association of shift intensity with insomnia, defined as an ISI score of ≥8. @*Results@#The nurses with insomnia tended to be younger (p=0.029), to have worked 3 consecutive night shifts more frequently (p<0.001), to have experienced a greater number of short recovery periods after the previous shift (p=0.021), and to have worked for more hours (p=0.006) than the nurses without insomnia. Among the other variables, no statistically significant differences between groups were observed. Experiences of 3 or more consecutive night shifts (odds ratio [OR], 2.33; 95% confidence interval [CI], 1.29 to 4.20) and 3 or more short recovery periods (OR, 2.01; 95% CI, 1.08 to 3.73) were associated with increased odds of insomnia. @*Conclusions@#The results suggest that decreasing the shift intensity may reduce insomnia among hospital nurses working rotating shifts.

Estimation of Lead Exposure Intensity by Industry Using Nationwide Exposure Databases in Korea

Background@#In a previous study, we estimated exposure prevalence and the number of workers exposed to carcinogens by industry in Korea. The present study aimed to evaluate the optimal exposure intensity indicators of airborne lead exposure by comparing to blood lead measurements for the future development of the carcinogen exposure intensity database. @*Methods@#Data concerning airborne lead measurements and blood lead levels were collected from nationwide occupational exposure databases, compiled between 2015 and 2016. Summary statistics, including the arithmetic mean (AM), geometric mean (GM), and 95th percentile level (X95) were calculated by industry both for airborne lead and blood lead measurements. Since many measurements were below the limits of detection (LODs), the simple replacement with half of the LOD and maximum likelihood estimation (MLE) methods were used for statistical analysis. For examining the optimal exposure indicator of airborne lead exposure, blood lead levels were used as reference data for subsequent rank correlation analyses. @*Results@#A total of 19,637 airborne lead measurements and 32,848 blood lead measurements were used. In general, simple replacement showed a higher correlation than MLE. The results showed that AM and X95 using simple replacement could be used as optimal exposure intensity indicators, while X95 showed better correlations than AM in industries with 20 or more measurements. @*Conclusion@#Our results showed that AM or X95 could be potential candidates for exposure intensity indicators in the Korean carcinogen exposure database. Especially, X95 is an optimal indicator where there are enough measurements to compute X95 values.

Obesity and Pancreatobiliary Disease / 대한소화기학회지

Obesity has become a major medical and public health problem worldwide. Recent studies have shown that obesity is a chronic disease that is associated with many diseases, such as gallstone disease, acute pancreatitis, fatty liver, and digestive cancer. Obesity is also a risk factor for the formation of cholesterol gallstones. Clinical and epidemiological studies have suggested that obesity is positively associated with the risk of gallbladder cancer. Obesity may modulate the lipid and endogenous hormones metabolism, affect gallbladder motility, increase the risk of gallstones, and increased the risk of gallbladder cancer. In addition, obesity has been considered a risk factor for pancreatic diseases, including pancreatitis and pancreatic cancer. Obese patients develop systemic and local complications of acute pancreatitis more frequently. Several epidemiologic studies have suggested an association of pancreatic cancer with high body mass and lack of physical activity. This study reviewed the literature on obesity and pancreatobiliary disease in terms of epidemiology and mechanism.

Technical Reports of Endoscopic Retrograde Cholangiopancreatography Guidewires on the Basis of Physical Properties

Background/Aims@#Using an appropriate guidewire can increase the success rate of selective cannulation in endoscopic retrograde cholangiopancreatography. The purpose of this technical study was to investigate the characteristics of each guidewire type and to evaluate its efficiency and rapidity of insertion. @*Methods@#We conducted a three-point bending test using a universal testing machine to investigate the flexibility and bending features of each guidewire. 3D-printed silicone tubes with various types of stricture and a hand-made biliary tree silicone model with six-stranded intrahepatic ducts were used to evaluate the success rate and insertion time of each guidewire. @*Results@#In the three-point bending test, the characteristics of each guidewire were classified. We found that the bending strengths and times were independent of shaft thickness. Using two in vitro biliary duct models, we determined that the success rate and total insertion time were better for guidewires with a resilient shaft and angled tip than for other types of guidewires (p<0.001). Although thickness of the guidewire affected the success rate (p<0.05), it did not affect the total insertion time (p≥0.05). @*Conclusions@#Among several types of guidewire, some factors (resilient shaft, highly flexible, and angled tip) appeared to be associated with the efficiency and rapidity of the guidewire insertion.

Review of the 2017 European Society of Gastrointestinal Endoscopy Guidelines for Endoscopic Ultrasound - Guided Sampling in Pancreaticobiliary Lesions / 대한소화기학회지

EUS currently plays an important role in the diagnosis and treatment of digestive diseases. In addition, EUS-guided sampling has been applied to pancreaticobiliary lesions for the accurate diagnosis of pancreaticobiliary lesions. Many new instruments and studies for EUS-guided sampling are being developed and attempted. This review introduces and summarizes the key recommendations made in the recent guideline for EUS-guided sampling developed by the European Society of Gastrointestinal Endoscopy.

Estimates of the Prevalence, Intensity and the Number of Workers Exposed to Cigarette Smoking across Occupations and Industries in Korea

BACKGROUND: Tobacco smoking affects the incidence of various illnesses such as lung cancer, respiratory diseases, and cardiovascular diseases. In an effort to prevent smoking-related cancers, we aimed to estimate the smoking prevalence, intensity, and number of workers exposed to smoking, which would be specific to the occupational and industrial circumstances in Korea. METHODS: We used the Korean Working Condition Survey (KWCS) and Korea's Census data. Smoking prevalence and intensity were estimated using the KWCS data. The number of smokers was estimated by multiplying smoking prevalence with the number of workers in the occupation or industry. Smoking prevalence, intensity, and number of smokers were estimated for major, sub-major, and minor groups of occupation and industry. RESULTS: Of the total labor force in 2010, 52.66% of men and 5.24% of women workers were estimated to be current smokers. Men workers smoked 15.42 cigarettes/day, and women workers 11.29 cigarettes/day. In terms of occupation, “craft and related trades workers” demonstrated the highest smoking prevalence (52.24%). “Managers” smoked the highest number of cigarettes (16.63 cigarettes/day) and “equipment, machine operating, and assembling workers” comprised the largest number of estimated smokers (1,368,726 workers). In terms of industry, “mining and quarrying” had the highest smoking prevalence (69.27%). Those in “construction” smoked the highest number of cigarettes (17.16 cigarettes/day) and those in “manufacturing” comprised the largest number of estimated smokers (1,629,893 workers). CONCLUSION: Our results may help in setting priorities for smoking prevention-related activities. In addition, these results can be used for epidemiological studies controlling for the effect of smoking by occupation or industry.

Review of the 2017 European Society of Gastrointestinal Endoscopy Guidelines for Endoscopic Ultrasound / 대한소화기병학회잡지

EUS currently plays an important role in the diagnosis and treatment of digestive diseases. In addition, EUS-guided sampling has been applied to pancreaticobiliary lesions for the accurate diagnosis of pancreaticobiliary lesions. Many new instruments and studies for EUS-guided sampling are being developed and attempted. This review introduces and summarizes the key recommendations made in the recent guideline for EUS-guided sampling developed by the European Society of Gastrointestinal Endoscopy.

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.

How to Establish the Role of the Education Board in the Korean Society of Gastroenterology / 대한소화기학회지

The Education Board of Korean Society of Gastroenterology (KSG) has three missions: 1) to meet the needs of KSG members, 2) to provide educational opportunities for future members (fellows), and 3) to train world-class experts using latest knowledge. To achieve these objectives, the ‘Education Board’: 1) updates guidelines and provides academic information to KSG members, 2) provides quality education and training for gastroenterology fellows, and 3) offers opportunities to young gastroenterologists to participate in overseas training programs, such as the American Gastroenterology Association, Clinical Observation and Research Education program.

Clinical Practice Guidelines for Acute Pancreatitis / 대한소화기학회지

Acute pancreatitis is a common gastrointestinal disease that is associated with significant morbidity and consumes enormous health care resources. As such, it requires up-to-date evidence-based diagnosis and standard treatment guidelines with broad support from the clinician. Korean Pancreatobiliary Association has developed clinical practice guidelines for the diagnosis and treatment of acute pancreatitis to provide a framework for clinicians to manage acute pancreatitis and to improve national health care. The guidelines were divided into four parts: the diagnosis of acute pancreatitis, the assessment of the severity, the initial management, and the treatment of necrotizing pancreatitis and local complications of acute pancreatitis. In this article, we summarize and present the diagnosis and treatment guidelines for acute pancreatitis established in Korea.

Ischemic Gastritis Improved by Supportive Care

Acute extensive ischemic gastritis is an extremely rare disease because the stomach has an abundant submucosal vascular plexus with a dual blood supply from the pancreaticoduodenal and gastroduodenal arteries. Smoking, hypertension, and atherosclerotic vascular diseases can be major risk factors for ischemic gastritis. Acute gastric ischemia presents as an acute abdomen with diarrhea or hematemesis that rapidly progresses to acute peritonitis, irreversible septic shock, and death if untreated. We report a case of acute extensive ischemic gastritis combined with tetraplegia due to cervical myelopathy and extensive atherosclerotic changes of the celiac trunk and abdominal aorta.

Estimates of the Number of Workers Exposed to Diesel Engine Exhaust in South Korea from 1993 to 2013

BACKGROUND: The aim of this study was to estimate the number of workers exposed to diesel engine exhaust (DEE) by industry and year in the Republic of Korea. METHOD: The estimates of workers potentially exposed to DEE in the Republic of Korea were calculated by industry on the basis of the carcinogen exposure (CAREX) surveillance system. The data on the labor force employed in DEE exposure industries were obtained from the Census on Establishments conducted by the Korea National Statistical Office from 1993 to 2013. The mean values of prevalence rates adopted by EU15 countries were used as the primary exposure prevalence rates. We also investigated the exposure prevalence rates and exposure characteristics of DEE in 359 workplaces representing 11 industries. RESULTS: The total number of workers exposed to DEE were estimated as 270,014 in 1993 and 417,034 in 2013 (2.2% of the total labor force). As of 2013, the industry categorized as “Land transport” showed the highest number of workers exposed to DEE with 174,359, followed by “Personal and household services” with 70,298, “Construction” with 45,555, “Wholesale and retail trade and restaurants and hotels” with 44,005, and “Sanitation and similar services” with 12,584. These five industries, with more than 10,000 workers exposed to DEE, accounted for 83% of the total DEE-exposed workers. Comparing primary prevalence rates used for preliminary estimation among 49 industries, “Metal ore mining” had the highest rate at 52.6%, followed by “Other mining” with 50.0%, and “Land transport” with 23.6%. CONCLUSION: The DEE prevalence rates we surveyed (1.3–19.8%) were higher than the primary prevalence rates. The most common emission sources of DEE were diesel engine vehicles such as forklifts, trucks, and vans. Our estimated numbers of workers exposed to DEE can be used to identify industries with workers requiring protection from potential exposure to DEE in the Republic of Korea.

Simvastatin Induces Apoptosis and Suppresses Insulin-Like Growth Factor 1 Receptor in Bile Duct Cancer Cells

BACKGROUND/AIMS: Statins act as antineoplastic agents through the inhibition of cell proliferation. This study sought to demonstrate the effects of statins on extrahepatic bile duct cancer cell apoptosis and to document the changes in protein expression involved in tumor growth and suppression. METHODS: Human extrahepatic bile duct cancer cells were cultured. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays were performed to determine the effect of statins on cell proliferation. Apoptosis was measured by a cell death detection enzyme-linked immunosorbent assay and caspase-3 activity assay, and flow cytometry was used to determine the percentage of cells in each phase of the cell cycle. The protein expression of Bax, Bcl-2, insulin-like growth factor 1 (IGF-1) receptor, extracellular signal-regulated kinase 1/2 (ERK1/2), and Akt was measured by Western blot analysis. RESULTS: Simvastatin suppressed cell proliferation by inducing G1 phase cell cycle arrest in bile duct cancer cells. Furthermore, it induced apoptosis via caspase-3 activation, downregulated the expression of the Bcl-2 protein, and enhanced the expression of the Bax protein. Moreover, simvastatin suppressed the expression of the IGF-1 receptor and IGF-1-induced ERK/Akt activation. CONCLUSIONS: Simvastatin induces apoptosis in bile duct cancer cells, which suggests that it could be an antineoplastic agent for bile duct cancer.

Pain Control, Nutritional and Emotional Support / 대한췌담도학회지

Pancreatic cancer is one of the most lethal malignancies. Despite the availability of newer and better antineoplastic combinations, the 5-year survival rate for all stages of pancreatic cancer remains only 6%. Palliative care represents an important aspect of care in patient with pancreatic cancer. Thus, optimal palliation of symptoms to maximize remaining quality of life is of primary importance to most patients. This review discusses highlights the most significant problems faced when caring for patients with advanced pancreatic cancer. Common problems include pain, pancreatic insufficiency, anorexia-cachexia and depression. To provide optimal and meaningful supportive care for patients with advanced pancreatic cancer is complex and requires ongoing close monitoring of the physical and emotional aspects of the patient. Prompt management of the many symptoms and problems associated with pancreatic cancer is essential to minimize distress and improve quality of life for patients with this fatal disease. Recognizing end-of-life concerns and patient preferences during the dying process helps clinicians find ways to alleviate suffering for patients and families.

Estimating Benzene Exposure Level over Time and by Industry Type through a Review of Literature on Korea

The major purpose of this study is to construct a retrospective exposure assessment for benzene through a review of literature on Korea. Airborne benzene measurements reported in 34 articles were reviewed. A total of 15,729 individual measurements were compiled. Weighted arithmetic means [AM(w)] and their variance calculated across studies were summarized according to 5-year period intervals (prior to the 1970s through the 2010s) and industry type. Industries were classified according to Korea Standard Industrial Classification (KSIC) using information provided in the literature. We estimated quantitative retrospective exposure to benzene for each cell in the matrix through a combination of time and KSIC. Analysis of the AM(w) indicated reductions in exposure levels over time, regardless of industry, with mean levels prior to the 1980e1984 period of 50.4 ppm (n = 2,289), which dropped to 2.8 ppm (n = 305) in the 1990e1994 period, and to 0.1 ppm (n = 294) in the 1995e1999 period. There has been no improvement since the 2000s, when the AM(w) of 4.3 ppm (n = 6,211) for the 2005e2009 period and 4.5 ppm (n = 3,358) for the 2010e2013 period were estimated. A comparison by industry found no consistent patterns in the measurement results. Our estimated benzene measurements can be used to determine not only the possibility of retrospective exposure to benzene, but also to estimate the level of quantitative or semiquantitative retrospective exposure to benzene.

Clinical Features and Outcomes of Endoscopic Treatment for Stones in Stemware-Shaped Common Bile Ducts: A Multicenter Data Analysis

BACKGROUND/AIMS: Various anatomical features of the biliary tree affect ability to remove difficult common bile duct (CBD) stones. In this study, we evaluated the clinical characteristics and outcomes of the endoscopic treatment of stones in stemware-shaped CBDs. METHODS: Thirty-four patients with a stone and a stemware-shaped CBD who were treated at different tertiary referral centers from January 2008 to December 2012 were studied retrospectively. When stone removal failed, percutaneous or direct peroral cholangioscopic lithotripsy, endoscopic retrograde biliary drainage, or surgery was performed as a second-line procedure. RESULTS: The overall success rate of the first-line procedure was 41.2%. Five of the 34 patients (14.7%) experienced procedure-related complications. No procedure-related mortality occurred. Mechanical lithotripsy was required to completely remove stones in 13 patients (38.2%). Conversion to a second-line procedure was required in 20 patients (58.8%). Mechanical lithotripsy was needed in 75% and 66.7% of those with a stone size of or =1 cm, respectively. Stone recurrence occurred in two patients (9.1%) after 6 months and 27 months, respectively. CONCLUSIONS: The endoscopic treatment of stones in a stemware-shaped CBD is challenging. The careful assessment of difficult CBD stones is required before endoscopic procedures.