We have observed that the companion shadow of the upper rib may be misinterpreted as a small pnemothorax or pleural plaque associated with asbestosis. To observe the radiographic characteristics of the normal companion shadow, we analyzed, on the posteroanterior(PA) chest radiographs, the companion shadow of 50 normal cases. Factors such as occurrence on each rib, the sharpness of the margin, the relative position to the rib, the shape and the thickness were observed. Also, we analyzed the displaced pleura of 4 pneumothorax cases to differentiate their frndings from the findings of normal companion shadows. On 50 normal chest radiographs, 192 compaion shadows were observed on the first to fourth ribs. In 173 of those shadows, the visceral margin of the companion shadow on the second rib simulated pneumothorax more closely than those on any othe rivs due to its apical location and thinness. In six of 50 normal cases, the companion shadow on the first or second rib showed an inw rdly convex lower margin, mimicking pleural plaque. The compaion shadow was suggested on the plain chest radiograph by the following characteristics imultiplicity(47/50), thicker than normal pleura(3/4), persistent on serial filma with the same shape and specific location(4/4).
Asbestosis ; Friends* ; Humans ; Pleura ; Pneumothorax ; Radiography, Thoracic ; Ribs* ; Thinness

Pulmonary asbestosis is defined as bilateral diffuse interstitial fibrosis of the lungs caused by exposure to asbestos. Many occupations are at risk for asbestos exposure, particularly in the mining, milling, manufacturing, construction, shipbuilding, and automotive industries. Therefore, the prevalence of asbestosis should be fairly widespread. The diagnosis of asbestosis can be made on either clinical or pathological grounds. We recently encountered one case of asbestosis which was confirmed histologically. On HRCT, there was ground-glass opacity with irregular linear shadows, subpleural curvilinear lines and parenchymal bands. Neither plaque nor calcification were noted. The histologic findings observed on open-lung biopsy specimen were well in accord with those in HRCT. Many asbestos-coated bodies were present along with black dust.
Asbestosis/radiography* ; Asbestosis/pathology* ; Biopsy ; Case Report ; Human ; Male ; Middle Age ; Radiography, Thoracic ; Tomography, X-Ray Computed

The classification for pneumoconiosis which was developed by International Labour Office(ILO) on the basis of Radiological findings of simple chest radiography has been widely used for the study and diagnosis of pneumoconiosis. But many problems have been revealed during the pneumoconiosis study using this classification. Those problems come from simple radiography itself or classification systems. Among those, inter-reader and intra-reader variability are the severest problems, even though many efforts have been devoted to lessen the variability. With introduction of computed tomography (conventional CT and HRCT), we are learning many new aspects about the occupational lung diseases, especially pneumoconiosis. So the studies for pneumoconiosis using tomography are reviewed, focusing on silicosis, coalworkers' pneumoconiosis, and asbestosis. But in our country, the studies of that kind are very scant. It is necessary to study and diagnose pneumoconiosis by CT, because that is the need of workers and the responsibility of physicians working in the field of occupational medicine. CT is superior to simple radiography in early detection, determination of severity, and follow-up of pneumoconiosis. But simple radiography is and should be the main method for the study and diagnosis of pneumoconiosis. Although, because of radiation hazard, cost, time, and geographical availability, the method can not and should not be used on the routine basis, we have to consider the use of CT, if possible and if necessary. Before using CT widely, we should develop the standardized criteria regarding to scanning methods and reading criteria. If not, the same problems as those of simple radiography will be occurred, and then there will be no progress in occupational medicine and workers' health.
Asbestosis ; Classification ; Diagnosis* ; Follow-Up Studies ; Learning ; Lung Diseases ; Occupational Medicine ; Pneumoconiosis* ; Radiography* ; Silicosis ; Thorax

PURPOSE: To determine imaging findings among retired workers who were long-term exposed to asbestos. Lung and pleural diseases prevalence were studied on chest radiograph and HRCT. MATERIALS AND METHODS: Eighteen workers who were long-term exposedto asbestos occupationally in shipyards were examined by chest radiographs (PA and lateral view) and HRCT (high-resolution computed tomography). RESULTS: In 12 of 18 subjects (66.7%), asbestos-related pleural abnormalities were evident in diaphragmatic, lateral chest wall and costophrenic angle of the pleura on chest radiographs. The thickness of pleural plaques at the lateral chest wall varied. Diffuse pleural thickening was evident in 2 workers. Parenchymal abnormalities were not found on chest radiographs. On HRCT, pleural thickening wasobserved in 16 of 18 subjects (88.9%), in the areas of juxtavertebral, diaphragmatic, anterior, lateral, mediastinal and fissural pleura. Curvilinear subpleural lines representing early parenchymal asbestosis were found in the lower posterior lung in three of 18 subjects (16.7%). CONCLUSIONS: In long term asbestos-exposed workers, the asbestos-related pleural disease was 66.7% on chest radiographs and 88.9% on HRCT. The authors suggest that this group should be followed up periodically
Asbestos* ; Asbestosis ; Lung* ; Occupations ; Pleura ; Pleural Diseases* ; Prevalence* ; Radiography, Thoracic* ; Thoracic Wall ; Thorax*

Asbestos is a naturally occurring mineral in the Earth's crust, and it is not confined to the historic and current asbestos mining areas, but rather quite commonly encountered in certain geological environments across the world. The middle-west side of the Korean Peninsula (Chungnam province) has been composed of numerous talc and asbestos ore deposits derived from serpentine and dolomite. These areas have experienced epidemics of malignant mesothelioma and pleural plaques as a result of non-occupational "neighborhood" exposure and naturally occurring asbestos (NOA) exposure. However, asbestosis epidemics from environmental exposure were rare because asbestosis needs relatively high concentration of asbestos exposure. This review summarizes asbestosis epidemics which occurred in the residents who have lived past or current asbestos mining areas and natural in-place asbestos deposits (or asbestos-like mineral deposits) in the world, including Korean asbestosis endemics that occurred in Chungnam province, which has many historic asbestos mining. Also, this manuscript will describe effective public policies for managing NOA, minimizing potential hazards, and protecting public health from asbestos exposure.
Asbestos ; Asbestosis ; Calcium Carbonate ; Environmental Exposure ; Magnesium ; Mesothelioma ; Mining ; Public Health ; Public Policy ; Residence Characteristics ; Talc

BACKGROUND: We assessed the cancer risks of four different Finnish asbestos-exposed cohorts. We also explored if the cohorts with varying profiles of asbestos exposure exhibited varying relative risks of cancer. METHODS: The incident cancer cases for the asbestos-exposed worker cohorts were updated to the end of 2012 using the files of the Finnish Cancer Registry. The previously formed cohorts consisted of asbestos mine workers, asbestosis patients, asbestos sprayers, and workers who had taken part in a screening study based on asbestos exposure at work. RESULTS: The standardized incidence ratio (SIR) for mesothelioma varied from about threefold to > 100-fold in the different cohorts. In the screening cohort the SIR for mesothelioma was highest in 2003–2007, In other cohorts it was more constant in 5-year period inspection. The SIR for lung cancer was about twofold to tenfold in all except the screening cohort. Asbestos sprayers were at the highest risk of mesothelioma and lung cancer. CONCLUSION: The SIR for mesothelioma is high in all of the cohorts that represent different kinds of asbestos exposure. The smaller SIR for mesothelioma in the screening cohort with lowest level of asbestos exposure might suggest dose-responsiveness between asbestos exposure and mesothelioma. It does seem that the highest risk of lung cancer in these cohorts except in the youngest of the cohorts, the screening cohort, is over. The highest SIR for lung cancer of the asbestosis patient and sprayers cohort is explained by their heavy asbestos exposure.
Asbestos ; Asbestosis ; Cohort Studies* ; Follow-Up Studies ; Humans ; Incidence* ; Lung Neoplasms ; Mass Screening ; Mesothelioma ; Miners

Carcinogenicity of asbestos has been well established for decades and it has similar approval standards in most advanced countries based on a number of studies and international meetings. However, Korea has been lagging behind such international standards. In this study, we proposed the approval standards of an occupational cancer due to asbestos through intensive review on the Helsinki Criteria, post-Helsinki studies, job exposure matrix (JEM) based on the analysis of domestic reports and recognized occupational lung cancer cases in Korea. The main contents of proposed approval standards are as follows; (1) In recognizing an asbestos-induced lung cancer, diagnosis of asbestosis should be based on CT. In addition, initial findings of asbestosis on CT should be considered. (2) High Exposure industries and occupations to asbestos should be also taken into account in Korea (3) An expert's determination is warranted in case of a worker who has been concurrently exposed to other carcinogens, even if the asbestos exposure duration is less than 10 years. (4) Determination of a larynx cancer due to asbestos exposure has the same approval standards with an asbestos-induced lung cancer. However, for an ovarian cancer, an expert's judgment is necessary even if asbestosis, pleural plaque or pleural thickening and high concentration asbestos exposure are confirmed. (5) Cigarette smoking status or the extent should not affect determination of an occupational cancer caused by asbestos as smoking and asbestos have a synergistic effect in causing a lung cancer and they are involved in carcinogenesis in a complicated manner.
Asbestos* ; Asbestosis ; Carcinogenesis ; Carcinogens ; Diagnosis ; Judgment ; Korea* ; Laryngeal Neoplasms ; Lung Neoplasms ; Occupations ; Ovarian Neoplasms ; Smoke ; Smoking

Asbestosis is the most important change noted in the lung parenchyma after environmental and occupational exposure to asbestos fibers. It is characterized by diffuse interstitial pulmonary fibrosis. In Korea, the incidence of asbestosis will continue to increase for many years to come and the government enacted the Asbestos Damage Relief Law in 2011 to provide compensation to those suffering from asbestos-related diseases. Radiologic evaluation is necessary for diagnosis of asbestosis, and radiologists play a key role in this process. Therefore, it is important for radiologists to be aware of the various imaging features of asbestosis.
Asbestos ; Asbestosis* ; Compensation and Redress ; Diagnosis* ; Incidence ; Jurisprudence ; Korea* ; Lung ; Occupational Diseases ; Occupational Exposure ; Pulmonary Fibrosis ; Radiography

Diffuse mesotheliomas of the pleura and peritoneum are considered "signal tumors" of asbestos exposure. Although asbestos use in Korea started before the national liberation, it rose abruptly with economic development in 1970's. Considering latent period of mesotheliomas as twenty years, occupational mesothelioma cases would increase rapidly. In Korea construction is a major industry which use asbestos. Because workers in construction industry are mostly composed of daily based workers, it is hard to calculate the number of workers involving asbestos related work, to manage them with organized method, to educate them about adverse effects of asbestos and protection methods, to check health status of them periodically, and to follow them up. Although a case of occupational mesothelioma which was found in a asbestos textile worker have been reported, no case related with construction workers have been reported so far in Korea. The authors experienced occupational malignant pleural mesothelioma combined with asbestosis in a boilermaker and plumber in a construction industry.
Asbestos ; Asbestosis* ; Construction Industry ; Economic Development ; Korea ; Mesothelioma* ; Peritoneum ; Pleura ; Textiles

Occupational lung disease (OLD) is a group of lung diseases caused and/or aggravated by organic and inorganic inhaled dust, fumes, and mist. OLD can develop under various occupational situations. Therefore, occupational history should be considered when evaluating respiratory symptoms. Once OLD is developed, it may not be treated and may even progress after exposure to the causative agents has stopped. The best ways to treat OLD are prevention and early detection by controlling the working environment and conducting regular surveillance of workers. Common OLDs in Korea are coal worker's pneumoconiosis, asbestos-related diseases, and occupational asthma. Recent aspects of these common OLDs in Korea will be described based on recently published studies.
Anthracosis ; Asbestosis ; Asthma ; Asthma, Occupational ; Dust ; Korea ; Lung ; Lung Diseases ; Occupational Diseases ; Pneumoconiosis