Exposure Assessment for Toxic Hepatitis Caused by HCFC-123

This case report attempts to present a case of acute toxic hepatitis in fire extinguisher manufacturing workers exposed to 2,2-dichloro-1,1,1-trifluoro-ethane (HCFC-123) in August 2017 in Korea. Twenty-two-year-old male workers were exposed to HCFC-123 for 1.5 hours one day and for 2.5 hours the other day, after which one worker died, and the other recovered after treatment. The workers were diagnosed with acute toxicity of hepatitis. However, exposure levels of HCFC-123 were not known with no work environment measurement done. Therefore, this study was conducted to estimate the exposure concentration of HCFC-123 via a job simulation experiment. In the simulation, the HCFC-123 exposure concentration was measured with the same working practice and working time as with the workers aforementioned. As a result, the workers who infused HCFC-123 into storage tanks were estimated to be exposed to HCFC-123 at a concentration of 20.65±10.81 ppm, and a mean concentration of area samples within a working radius were estimated as 70.30±18.10ppm. Valve assembly workers working on valves of a fire extinguisher filled with HCFC-123 were exposed to HCFC-123 at concentrations of 91.65±4.03ppm and 115.55±7.28 ppm, respectively, in the simulation, and area samples simulated within the working radius were also found to be high with concentrations of 122.75±91.15 ppm and 126.80±60.25 ppm, respectively. Nitrogen gas packing workers, who did not handle HCFC-123 directly, were exposed to the agent at a concentration of 71.80±8.49 ppm. These results suggest that exposure to HCFC-123 at high concentrations for 1.5–2.5 hours caused acute toxic hepatitis in two workers.

HCFC-123-induced toxic hepatitis and death at a Korean fire extinguisher manufacturing facility: a case series

BACKGROUND: Exposure to sustained high concentrations of HCFC-123 is known to be hepatotoxic. We report two simultaneous cases of toxic hepatitis related to exposure to 2,2-dichloro-1,1,1-trifluoroethane (HCFC-123), a common refrigerant, at a Korean fire extinguisher manufacturing facility. CASE PRESENTATION: Patients A and B were men aged 21 and 22 years, respectively, with no notable medical histories. They had recently started working for a manufacturer of fire extinguishers. During the third week of their employment, they visited the emergency center of a general hospital due to fever, lack of appetite, and general weakness. At the time of their visit, they were suspected as having hepatitis due to elevated aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), and total bilirubin levels and were hospitalized. However, as their condition did not improve, they were moved to a tertiary general hospital. After conservative treatment, one patient improved but the other died from acute hepatic failure. Assessments of the work environment showed that the short-term exposure levels of HCFC-123 for valve assembly processes were as high as 193.4 ppm. A transjugular liver biopsy was performed in patient A; the results indicated drug/toxin-induced liver injury (DILI). Given the lack of a medical history and the occupational exposure to high levels of HCFC-123, a hepatotoxic agent, the toxic hepatitis of the workers was likely related to HCFC-123 exposure. CONCLUSIONS: Work environment assessments have not included this agent. To the best of our knowledge, we are the first to report a case of death related to HCFC-123-induced liver damage. Our findings suggest that exposure standards and limits for HCFC-123 must be developed in Korea; work environments will have to be improved based on such standards.

The Quality Control Program for Industrial Hygiene Laboratories in Korea

In 1992, the quality control program was introduced in Republic of Korea to improve the reliability of the work environment monitoring, which was introduced in the 1980s. The commission entrusted by the Ministry of Employment and Labor, the Occupational Safety and Health Research Institute has conducted the program for industrial hygiene laboratories including designated monitoring institutions and spontaneously participating agencies. The number of institutions that participated in the program has increased from 30 to 161. The initial conformance ratio in the participants was 43% (organic solvents) and 52% (metals). Thereafter, the conformance ratio increased rapidly and it has remained in a stable state at more than 89% since 1996. As subject materials, 13 kinds of organic solvents and 7 kinds of metals were used. To improve the capability of measurement and analysis of private institutions, educational courses were conducted annually. An assessment at the actual sites of participants was additionally introduced into the program in 2013. Thus, the program turned into a system that administrates the overall process of participants. For the future, the scope of target materials will be extended through additional items. Thus, the reliability of the results of the work environment monitoring is expected to increase accordingly.

Exposure Characteristics of Construction Painters to Organic Solvents

BACKGROUND: Construction painters have not been studied well in terms of their hazards exposure. The objective of this study was to evaluate the exposure levels of total volatile organic compounds (TVOCs) for painters in the construction industry. METHODS: Activity-specific personal air samplings were carried out in three waterproofing activities [polyurethane (PU), asphalt, and cement mortar] and three painting activities (epoxy, oil based, and water based) by using organic-vapor-monitor passive-sampling devices. Gas chromatograph with flame ionization detector could be used for identifying and quantifying individual organic chemicals. The levels of TVOCs, by summing up 15 targeted substances, were expressed in exposure-index (EI) values. RESULTS: As arithmetic means in the order of concentration levels, the EIs of TVOCs in waterproofing works were 10.77, 2.42, 1.78, 1.68, 0.47, 0.07, and none detected (ND) for indoor PU-primer task, outdoor PU-primer task, outdoor PU-resin task, indoor PU-resin task, asphalt-primer task, asphalt-adhesive task, and cement-mortar task, respectively. The highest EI for painting works was 5.61 for indoor epoxy-primer task, followed by indoor epoxy-resin task (2.03), outdoor oil-based-spray-paint task (1.65), outdoor water-based-paint task (0.66), and indoor oil-based-paint task (0.15). Assuming that the operations were carried out continuously for 8 hours without breaks and by using the arithmetic means of EIs for each of the 12 tasks in this study, 58.3% (7 out of 12) exceeded the exposure limit of 100% (EI > 1.0), while 8.3% (1 out of 12) was in 50-100% of exposure limit (0.5 > EI > 1.0), and 4 tasks out of 12 were located in less than 50% of the limit range (EI < 0.5). CONCLUSION: From this study, we recognized that construction painters are exposed to various solvents, including carcinogens and reproductive toxins, and the levels of TVOC concentration in many of the painting tasks exceeded the exposure limits. Construction workers need to be protected from chemical agents during their painting works by using personal protective devices and/or work practice measures. Additional studies should focus on the exposure assessment of other hazards for construction workers, in order to identify high-risk tasks and to improve hazardous work environments.

Exposure to Volatile Organic Compounds and Possibility of Exposure to By-product Volatile Organic Compounds in Photolithography Processes in Semiconductor Manufacturing Factories

OBJECTIVES: The purpose of this study was to measure the concentration of volatile organic compound (VOC)s originated from the chemicals used and/or derived from the original parental chemicals in the photolithography processes of semiconductor manufacturing factories. METHODS: A total of four photolithography processes in 4 Fabs at three different semiconductor manufacturing factories in Korea were selected for this study. This study investigated the types of chemicals used and generated during the photolithography process of each Fab, and the concentration levels of VOCs for each Fab. RESULTS: A variety of organic compounds such as ketone, alcohol, and acetate compounds as well as aromatic compounds were used as solvents and developing agents in the processes. Also, the generation of by-products, such as toluene and phenol, was identified through a thermal decomposition experiment performed on a photoresist. The VOC concentration levels in the processes were lower than 5% of the threshold limit value (TLV)s. However, the air contaminated with chemical substances generated during the processes was re-circulated through the ventilation system, thereby affecting the airborne VOC concentrations in the photolithography processes. CONCLUSION: Tens of organic compounds were being used in the photolithography processes, though the types of chemical used varied with the factory. Also, by-products, such as aromatic compounds, could be generated during photoresist patterning by exposure to light. Although the airborne VOC concentrations resulting from the processes were lower than 5% of the TLVs, employees still could be exposed directly or indirectly to various types of VOCs.

Endoscopic Hemoclipping in a Terminal Ileal Dieulafoy's Lesion / 대한소화기내시경학회지

Dieulafoy's lesion is an uncommon source of massive gastrointestinal hemorrhage. The lesion predominantly occurs in the proximal stomach, but may occur in all parts of the gastrointestinal tract including small bowel, colon and rectum. We herein report a case of a patient who presented with hematochezia from Dieulafoy's lesion of the terminal ileum with adherent blood clots. Bleeding was successfully controlled with endoscopic treatment by utilizing hemoclipping.

4 Cases of Duodenal Diverticular Bleeding Treated by Endoscopic Therapy / 대한소화기내시경학회지

Duodenal diverticulum appears in 6% of upper gastrointestinal examinations and up to 23% of endoscopic retrograde cholangiopancreaticographies and up to 22% at autopsy. Most of these patients are asymptomatic, but a small fraction develop complications including choledocholithiasis, cholangitis, pancreatitis, diverticulitis, perforation, fistular formation and bleeding. Among these complications, only a few documented cases of bleeding have been reported in the literature, and the experience of endoscopist to the sequence of diagnosis, endoscopic treatment, and subsequent relief of the symptoms remains limited. Aggressive but careful endoscopic examination can help diagnosis of the cases. Also, endoscopic treatment of duodenal diverticular bleeding is very effective and proved to be an effective alternative to surgery. We report 4 patients with duodenal diverticular bleeding in whom both diagnosis and definitive treatment were successful by endoscopy alone.

A Case of Hydrogen Peroxide Proctitis / 대한소화기내시경학회지

Hydrogen peroxide is a safe and useful disinfectant that has achieved widespread utility in various clinical settings. However, hydrogen peroxide may cause mucosal damage and contact injury when applied to the surface of the gut wall. Endoscopically, hydrogen peroxide colitis and proctitis can mimic acute ulcerative colitis, ischemic colitis, or pseudomembranous colitis such as mucosal whitening, erythema, frothy bubbles, granularity and ulceration. We have experienced a case of hydrogen peroxide proctitis in a 37- year-old female patient. She visited our hospital due to symptoms such as hematochezia, anal pain and pelvic pain after insertion of 15 mL of 3% hydogen peroxide. Colonscopy revealed rectal mucosal whitening, severe erythema and scattered small ulcerations up to 12 cm from the anal verge. Pathologic finding revealed neutrophil infiltration in the lamina propria and intact colonic crypt. Herein we report a case of hydrogen peroxide proctitis with reviewed literatures.

A Case of Endoscopic Treatment of Bleeding in Duodenal Dieulafoy's Lesion / 대한소화기내시경학회지

Dieulafoy's lesions are often unrecognized cause of obscure, massive gastrointestinal bleeding, reported to be 0.3~1.5% of cases of major gastrointestinal bleeding. It is characterized by severe bleeding from rupture of an exposed submucosal artery. Dieulafoy's lesion is usually occured in the lesser curvature of the stomach within 6 cm of the gastroesophageal junction. Similar lesions have also been described in the esophagus, duodenum, small intestine, colon, and rectum. The diagnosis is made by endoscopy, angiography, laparoscopy, or laparotomy. Endoscopy showed protruding and eroded artery with pulsatile bleeding or adherent thrombus. Currently, various therapeutic options are available to the endoscopist for the treatment of Dieulafoy's lesions. Therapeutic endoscopy should now become first-line therapy for Dieulafoy's lesions. We experienced a rare case of bleeding from the duodenal Dieulafoy's lesion. Endoscopic hemoclipping was performed successfully. We report this case with a review of the literature.

The rubber band ligation for bleeding hemorrhoids

No abstract available.