This study investigated the human health risks of trichloroethylene from Industrial Complex A. The excessive carcinogenic risks for central tendency exposure were 1.40 x 10(-5) for male and female residents in the vicinity of Industrial Complex A. The excessive cancers risk for reasonable maximum exposure were 2.88 x 10(-5) and 1.97 x 10(-5) for males and females, respectively. These values indicate that there are potential cancer risks for exposure to these concentrations. The hazard index for central tendency exposure to trichloroethylene was 1.71 for male and female residents. The hazard indexes for reasonable maximum exposure were 3.27 and 2.41 for males and females, respectively. These values were over one, which is equivalent to the threshold value. This result showed that adverse cancer and non-cancer health effects may occur and that some risk management of trichloroethylene from Industrial Complex A was needed.
Female ; Humans ; Male ; Risk Assessment ; Risk Management ; Trichloroethylene ; Volatile Organic Compounds

Hazardous area classification design is required to reduce the explosion risk in process plants. Among the international design guidelines, only IEC 60079-10-1 proposes a new type of zone, namely zone 2 NE, to prevent explosion hazards. We studied how to meet the zone 2 NE grade for a facility handling hydrogen gas, which is considered as most dangerous among explosive gases. Zone 2 NE can be achieved considering the grade of release, as well as the availability and effectiveness of ventilation, which are factors indicative of the facility condition and its surroundings. In the present study, we demonstrate that zone 2 NE can be achieved when the degree of ventilation is high by accessing temperature, pressure, and size of leak hole. The release characteristic can be derived by substituting the process condition of the hydrogen gas facility. The equations are summarized considering relation of the operating temperature, operating pressure, and size of leak hole. Through this relationship, the non-hazardous condition can be realized from the perspective of inherent safety by the combination of each parameter before the initial design of the hydrogen gas facility.

Hazardous area classification design is required to reduce the explosion risk in process plants. Among the international design guidelines, only IEC 60079-10-1 proposes a new type of zone, namely zone 2 NE, to prevent explosion hazards. We studied how to meet the zone 2 NE grade for a facility handling hydrogen gas, which is considered as most dangerous among explosive gases. Zone 2 NE can be achieved considering the grade of release, as well as the availability and effectiveness of ventilation, which are factors indicative of the facility condition and its surroundings. In the present study, we demonstrate that zone 2 NE can be achieved when the degree of ventilation is high by accessing temperature, pressure, and size of leak hole. The release characteristic can be derived by substituting the process condition of the hydrogen gas facility. The equations are summarized considering relation of the operating temperature, operating pressure, and size of leak hole. Through this relationship, the non-hazardous condition can be realized from the perspective of inherent safety by the combination of each parameter before the initial design of the hydrogen gas facility.

Background: According to the previous studies, the work-related accident rate decreased in Korea after the introduction of occupational health and safety management system (OHSMS), but there were several disasters in Korea such as subway worker's death at Guui station in 2016 and the Taean thermal power plant accident in 2018, which escalated the social demand for safety. In 2018, OHSMS became an international standard, as ISO45001 was announced. Methods: A survey was conducted to research the implementation status of OHSMS and changes in people's perception, and the results were compared with those of a past survey. Results: Enhanced social demand and various stakeholders' (not only buyer) needs, and social responsibility are perceived as the motivation for the introduction of OHSMS rather than legal compliance or customer demand. In the questionnaire about problems with the implementation of OHSMS, the factors with higher response rate in 2018 than 2004 were “excessive cost” and “complicated documentation management.” In the questionnaire about how to promote OHSMS in organizations, most people answered “reduction of workers' compensation insurance rate” in 2004, but most people answered “exemption from health and safety supervision” in 2018. Conclusion For the effective implementation of ISO45001, emphasis is placed on social demand, training to recognize health and safety as a part of management, and the reduction of certification and consulting costs to promote the introduction of OHSMS. Incentives such as insurance premium cuts and exemptions from health and safety supervision are needed.

Background: According to the previous studies, the work-related accident rate decreased in Korea after the introduction of occupational health and safety management system (OHSMS), but there were several disasters in Korea such as subway worker's death at Guui station in 2016 and the Taean thermal power plant accident in 2018, which escalated the social demand for safety. In 2018, OHSMS became an international standard, as ISO45001 was announced. Methods: A survey was conducted to research the implementation status of OHSMS and changes in people's perception, and the results were compared with those of a past survey. Results: Enhanced social demand and various stakeholders' (not only buyer) needs, and social responsibility are perceived as the motivation for the introduction of OHSMS rather than legal compliance or customer demand. In the questionnaire about problems with the implementation of OHSMS, the factors with higher response rate in 2018 than 2004 were “excessive cost” and “complicated documentation management.” In the questionnaire about how to promote OHSMS in organizations, most people answered “reduction of workers' compensation insurance rate” in 2004, but most people answered “exemption from health and safety supervision” in 2018. Conclusion For the effective implementation of ISO45001, emphasis is placed on social demand, training to recognize health and safety as a part of management, and the reduction of certification and consulting costs to promote the introduction of OHSMS. Incentives such as insurance premium cuts and exemptions from health and safety supervision are needed.

OBJECTIVE: The authors undertook a study to compare three intraoperative guidance systems, which are intraoperative ultrasonography, stereotaxy and computer-assisted image-guided surgery (neuronavigation) in terms of time consuming during the preparation of these procedures. In this operative case-based study, we have investigated the ability and benefits of intraoperative grey-scale sonographic examination in the localizing of intracranial hemorrhage (ICH) in the brain. METHODS: We used B-mode ultrasonography (5-MHz, 1.2x2.5 mm sized probe) during 23 procedures (craniotomy or craniectomy ; 17, hematoma aspiration : 6) performed in the acute stage after head injury, hypertensive ICH, ruptured cerebral aneurysm. Seventeen patients who suffered from spontaneous ICH underwent stereotactic hematoma aspiration and fourteen patients underwent hematoma removal using neuronavigation system (spontaneous ICH ; 11, Arteriovenous malformation and aneurysm ; 3). We compared intraoperative ultrasonography-assisted hematoma removal with procedures with stererotaxy or neuronavigation system in respect of detection of the pathology and time consuming for preparation. RESULTS: Mean preparation time for stereotactic hematoma aspiration was 71.2 minutes (50-90 minutes), and mean preparation time for neuronavigation-guided surgery was 52.5 minutes (30-70 minutes). However, only 7.4 minutes (4-20 minutes) were needed for the preparation time of intraoperative ultrasonography. Moreover, intraoperative ultrasonography-guided surgery had many advantages compared to other image-guide surgery, such as capability of real-time monitoring and independency of brain shifting. However, there were several limitations too, which were relatively low resolution, artifact by air bubble during the procedure, and the lower echogenecity of liquified hematomas when a delay of several days was needed. Nevertheless, ultrasound-guided hematoma surgery could serve as minimally invasive treatment whenever hematoma evacuation seems to be advisable, at least as a first attempt. CONCLUSION: Based on this preliminary result, we concluded that intraoperative ultrasonographic examination during the surgical treatment of ICH was a non-invasive, useful, and simple diagnostic tool in the detection of the components and accompanying parts of the lesion. It was more useful than stereotaxy or neuronavigation system in the situation of emergent case such as an impending brain herniation.
Aneurysm ; Arteriovenous Malformations ; Artifacts ; Brain ; Cerebral Hemorrhage* ; Craniocerebral Trauma ; Hematoma ; Humans ; Intracranial Aneurysm ; Intracranial Hemorrhages ; Neuronavigation ; Pathology ; Surgery, Computer-Assisted* ; Ultrasonography*

BACKGROUND: Infusion methods during regional analgesia using perineural catheters may influence the quality of postoperative analgesia. This study was conducted to compare the effects of combined or bolus-only infusion of 0.2% ropivacaine on the postoperative analgesia in interscalene brachial plexus block (ISBPB) with perineural catheterization. METHODS: Patients scheduled for arthroscopic rotator cuff repair were divided into two groups, one that would receive a combined infusion (group C, n = 32), and one that would receive intermittent infusion (group I, n = 32). A perineural catheter was inserted into the interscalene brachial plexus (ISBP) using ultrasound (US) and nerve stimulation, and 10 ml of 0.2% ropivacaine was administered. After the operation, group C received a continuous infusion of 4 ml/h, and a 4 ml bolus with a lockout interval of 60 min. Group I received only a 4 ml bolus, and the lockout interval was 30 min. Postoperative pain by the numeric rating scale (NRS) and the forearm muscle tone by the manual muscle test (MMT) were checked and evaluated at the following timepoints: preoperative, and postoperative 1, 4, 12, 24, 36, and 48 h. Supplemental opioid requirements, total consumed dose of local anesthetic, and adverse effects were compared between the two groups. RESULTS: Sixty-four patients completed the study and the postoperative values such as operation time, time to discharge, and operation site were comparable. There were no differences in NRS scores and supplemental opioid requirements between the two groups. The MMT scores of group I at 4 and 12 h after surgery were significantly higher than those of group C (P < 0.05). The total consumed dose of local anesthetic was significantly lower in group I than in group C (P < 0.05). The adverse effects were not different between the groups. CONCLUSIONS: The bolus-only administration of 0.2% ropivacaine provided a similar analgesic effect with a lower total volume of local anesthetic and decreased motor weakness compared to combined infusion. Therefore, bolus-only administration is an effective postoperative analgesic method in ISBPB with perineural catheterization after rotator cuff repair.
Analgesia ; Analgesia, Patient-Controlled ; Arthroscopy ; Brachial Plexus* ; Catheterization ; Catheters ; Forearm ; Humans ; Pain, Postoperative* ; Rotator Cuff* ; Ultrasonography

Patients with altered anatomy such as a Roux-en-Y anastomosis often present with various pancreaticobiliary problems requiring therapeutic intervention. However, a conventional endoscopic approach to the papilla is very difficult owing to the long afferent limb and acute angle of a Roux-en-Y anastomosis. Balloon-assisted enteroscopy can be used for endoscopic retrograde cholangiopancreatography (ERCP) in patients with altered anatomy. We experienced six cases of Roux-en-Y anastomosis with biliary problems, and attempted ERCP using single balloon enteroscopy (SBE). SBE insertion followed by replacement with a conventional endoscope was attempted in five of six patients. The papilla was successfully approached using SBE in all cases. However, therapeutic intervention was completed in only three cases because of poor maneuverability caused by postoperative adhesion. We conclude that in patients with Roux-en-Y anastomosis, the ampulla can be readily accessed with SBE, but longer dedicated accessories are necessary to improve this therapeutic intervention.
Anastomosis, Roux-en-Y* ; Cholangiopancreatography, Endoscopic Retrograde* ; Endoscopes ; Extremities ; Gastrectomy* ; Humans

BACKGROUND/AIMS: Endoscopic mucosal resection with circumferential mucosal incision (CMI-EMR) may offer benefits comparable to those of endoscopic submucosal dissection (ESD), while requiring less technical proficiency than ESD. METHODS: We retrospectively compared the outcomes of CMI-EMR (n=34) and size-matched ESD (n=102), which were performed by a Korean endoscopist for colorectal epithelial lesions of 20–35 mm. Procedural parameters of CMI-EMRs performed by an American ESD novice (n=30) were compared with those performed by the Korean endoscopist. RESULTS: The lesion size was 22.3±3.9 mm and 22.9±2.4 mm in the CMI-EMR and size-matched ESD groups, respectively (p=0.730). The resection time was 12.7±7.0 minutes in the CMI-EMR group and 45.6±30.1 minutes in the ESD group (p<0.001). The en bloc resection rate was 94.1% in the CMI-EMR group and 100% in the ESD group (p=0.061). There were no differences in the en bloc resection and complication rates of CMI-EMRs between a Korean and an American endoscopist. CONCLUSIONS: For the treatment of moderate-size colorectal lesions, CMI-EMR showed a trend toward lower en bloc resection rate, but required shorter procedure time than ESD. CMI-EMR outcomes were similar when performed by a Korean ESD expert and an American ESD novice.
Colon ; Colorectal Neoplasms* ; Rectum ; Retrospective Studies

Intramucosal colorectal cancer (CRC) is thought not to metastasize because the colonic lamina propria lacks lymphatics. Only a few recent case reports have suggested lymph node metastasis from intramucosal CRC, but there is no clear evidence supporting the metastatic potential of intramucosal CRC. Hence, endoscopic resection is regarded as curative treatment for intramucosal CRC. This report describes two cases of unusual local recurrence with distant metastasis in patients who had previously undergone successful endoscopic submucosal dissection for intramucosal CRC. The recurrent colorectal lesions developed at the site of the previous endoscopic submucosal dissection scars in a relatively short-term period, and the pathologic findings showed an “undermining” invasion pattern without surrounding mucosal change. Based on the clinical course and pathological findings, we concluded that the second colorectal lesions were recurrences rather than de novo cancers.
Cicatrix ; Colon ; Colorectal Neoplasms ; Humans ; Lymph Nodes ; Mucous Membrane ; Neoplasm Metastasis* ; Recurrence*