Farewell, king coal!

Coal mining provided the power for the industrial development of the West, at great cost to the health of the workforce and, from industrial pollution, of the population. Medical appreciation of the diseases of miners was slow to develop and has been marked by controversy relating to the roles of coal and quartz and the causation of emphysema. Research by the MRC and the British coal industry resolved these issues as the industry itself declined. However, from the research has come an understanding of the influence of inhalation of different inhaled pollutants on human health that has been applied to predicting and preventing possible hazards of developing nanotechnologies.

"Acute" silicosis at the 1930 Johannesburg Conference on silicosis and in its aftermath: Controversies over a distinct entity later recognized as silicoproteinosis.

BACKGROUND: Very rapidly progressive "acute silicosis" was observed prior to the 1930 International Labour Office Conference on silicosis, but its clinical significance and pathologic relationship to classic silica caused pneumoconiosis were not settled. METHODS: Textual analysis of the 1930 Conference proceedings identified data relevant to rapidly progressive silicosis. Standard bibliographic searches identified relevant biomedical literature dating from before and after the Conference. RESULTS: The 1930 Johannesburg Conference contained descriptions of acute silicosis, especially in the abrasive powders industry, but acute silica-related lung disease did not conform to a three-stage disease model in which tuberculosis supra-infection caused advanced disease, a model accepted at the Conference. Over following decades, additional reports appeared of rapidly progressive silicosis, unrelated to tuberculosis. Pulmonary alveolar proteinosis was identified only in 1958. CONCLUSIONS: Adoption by the 1930 Johannesburg Conference of a classification scheme into which acute rapidly progressive disease unrelated to tuberculosis fitted poorly may have impeded the understanding of acute silicosis and its importance.

Complicated silicotuberculosis in a South African gold miner: A case report.

We present a case of complicated silicotuberculosis in a former gold miner with a sufficiently heavy silica dust exposure to cause International Labor Organization grade 2/2 silicosis after a cumulative exposure duration of 11 years. We describe a cascade of complications-active pulmonary tuberculosis despite recent isoniazid prophylactic therapy, non-tuberculous mycobacterial disease, chronic airways obstruction, and spontaneous pneumothorax-and the difficulties, which arose, in diagnosis and management of such combined disease. We highlight three implications of such cases: the need to understand the interaction of silicosis and tuberculosis in this setting, the importance of maintaining continuity of care in the management of these conditions in miners and former miners, and control of silica dust exposure as a primary form of prevention of tuberculosis.

The pathologist's view of silicosis in 1930 and in 2015. The Johannesburg Conference legacy.

The 1930 International Labour Office Conference on silicosis in Johannesburg was a turning point in the history of silicosis and in the recognition of the associated pathologic patterns. Since 1930, pneumoconioses such as silicosis have become much rarer in developed countries and can now be diagnosed at an early stage based on clinical and radiologic criteria. However, in spite of these advances, pathologists must remember to look for silica in tissues, particularly when clinical and radiologic findings are more uncertain. Furthermore, nowadays pathologists essentially observe silicotic lesions as incidental findings adjacent to lung cancers. In addition to identifying the characteristic lesions, pathologists must also try to identify their causative agent, in the case of crystalline silica firstly by using polarized light examination, followed as appropriate by more sophisticated devices. Finally, pathologists and clinicians must always keep in mind the various implications of exposure to silica compounds in a wide range of diseases.

Conspicuous disease: The surveillance of silicosis in South Africa, 1910-1970.

Scholarly understanding of the nature of the science around silicosis has been strongly influenced, in recent years, by the idea that the mine doctors were responsible for hiding an epidemic, on the mines and in the countryside. In this paper, I try to show that the opposite was in fact the case, and that the science and government institutions for the regulation of silicosis and tuberculosis in white and black male workers were distinctively elaborated, and very largely successful in tracking and controlling the disease. This singular visibility, funded by the mines, stands in marked contrast with disease in general in South Africa, and forms a major part of the explanation for the very strong association of silicosis with mine work.

From the 1930 International Johannesburg conference on silicosis, to "tables" of occupational diseases, France, 2000 onward: A comparative reading.

Through the concept of "thought collectives" in particular, Ludwik Fleck was a pioneer in demonstrating how much scientific knowledge is inherently made up of social and historical material. In this article, I propose to follow a Fleckian path by comparing the proceedings of the 1930 International Labour Office Conference on silicosis in Johannesburg on the one hand, and on the other the content of the debates that took place in France in the 2000s to revise the "tables" of occupational diseases which define the compensation rules for salaried workers in the French general (as well as the farm) health insurance scheme. The text offers an analysis of the striking similarities between these two distant sources, pointing out particularly the repetitiveness of ignorance and knowledge, and the nature of what can be admitted as a body of "evidence" in medico-legal issues such as the definition and compensation of occupational diseases.

[Misdiagnosis of pneumoconiosis or silicotuberculosis in China: a pooled analysis of 1178 cases].

OBJECTIVE: To investigate the situation and causes of misdiagnosis of pneumoconiosis or silicotuberculosis in China by pooled analysis, and to provide a reference for the clinical diagnosis of pneumoconiosis in China and reduce the misdiagnosis rate. METHODS: A computer search was performed to collect the studies on the misdiagnosis of pneumoconiosis or silicotuberculosis published in China from 1985 to 2013. The obtained data were subjected to pooled analysis to investigate the causes of misdiagnosis and seek the measures for reducing misdiagnosis. RESULTS: Fifty-nine studies involving 1178 cases of misdiagnosed pneumoconiosis or silicotuberculosis were collected. There were 13 causes of misdiagnosis, and the most common one was the poor ability of identification due to inadequate experience in reading chest X-ray films (45.93%), followed by neglect of patient's occupational history (44.99%). Other causes of misdiagnosis included complex X-ray findings that are difficult to judge (29.03%), poor quality of chest radiographs (23.09%), and lack of regular health supervision (19.95%). CONCLUSION: Inadequate experience of physicians is the main cause of misdiagnosis of pneumoconiosis or silicotuberculosis. To reduce misdiagnosis of the disease, measures should be taken to enhance the training and evaluation of knowledge and skills of diagnosis and differential diagnosis of pneumoconiosis among physicians.

Experimental cytomorphological studies of the reaction of mononuclear phagocyte system in granulomatosis of mixed (silicotic and tuberculous) etiology.

Silicon dioxide in combination with Mycobacterium tuberculosis in BCG vaccine is characterized by a significantly higher granuloma-inducing activity than BCG or silicon dioxide alone. Cell "dissociation" from granulomas is not characteristic of granulomas induced by silicon dioxide or its combination with BCG (in contrast to BCG-induced granulomas). A steady increase in the counts and size, particularly on days 120-180, mainly at the expense of fibroblast accumulation and subtotal fibrosis, are intrinsic to these granulomas. Monocyte retention in the bone marrow is characteristic starting from day 56 until day 180 after injection of both granulomatous factors alone or in combination, particularly so in BCG granulomatosis.

Effect of preliminary load of macrophages with silicium dioxide on phagocytosis of BCG strain micobacteria by macrophages and antimicrobial activity.

We studied the effect of preliminary loading of peritoneal macrophages with silicium dioxide on in vitro viability, phagocytosis of BCG strain mycobacteria, and the capability to destroy the phagocytosed mycobacterium tuberculosis. It was shown that preliminary loading of macrophages with silicium dioxide did not reduce their viability and stimulated phagocytosis of BCG strain mycobacteria, but reduced their antibacterial activity.

Analysis of fibrotic depositions in granulomas in chronic silicotuberculosis in mice.

The stimulating effect of silicon dioxide on fibroblast proliferation in granulomas of male CBA mice surpasses that of BCG vaccine mycobacteria. The number of fibroblasts in granulomas after combined treatment with BCG and SiO2 increased by more than 3 times compared to individual treatment with BCG and by 2 times compared to treatment with SiO2 alone. In silicosis and silicotuberculosis, collagen and argyrophilic fibers in granulomas during the period from 4 to 6 months after administration of granulomogenic factors occupied more than 90% granuloma volume, which 3-fold surpassed the corresponding parameter in mice infected with BCG vaccine alone. In silicosis, pronounced fibrosis was determined by relatively high proliferative and synthetic activities of fibroblasts, while in silicotuberculosis it was achieved due to significantly higher proliferative activity against the background of lower synthetic activity.

[Prospective analysis of clinical course and outcomes in silicosis patients].

The authors revealed features of clinical course and outcomes in patients with silicosis and silicotuberculosis, who worked on iron industry enterprise. The article covers comparative analysis of survival rate and mortality among silicosis patients over 14 years of observation.

[Pathomorphology of specific inflammation in silicotuberculosis].

Silicotuberculosis is an independent disease that arising in patients with silicosis from exacerbation of old tuberculous foci in the lung, less frequently in the lymph nodes and other organs. In silicotiberculosis, there are common secondary tuberculosis forms that are located mainly in the lung, which are rarely accompanied by a rapid progression. Characteristic morphological signs of early, nodal and nodular silicosis are observed. Silicotuberculosis is an independent disease that arises in patients from an exacerbation of old tuberculous foci in the lung, less frequently in the lymph nodes and other organs. In silicotuberculosis, there are usually secondary tuberculosis forms that are located mainly in the lung, which are rarely accompanied by a rapid progression. The characteristic morphological signs of early, nodal, and nodular silicosis are observed. Thoracic and abdominal lymph nodes, lymphatic and blood vessels, the bronchi and pulmonary surfactant system were explored. In silicosis, tuberculosis, and silicotuberculosis, silicon levels and spodograms of some visceral organs were studied and trace elements were determined in the lung.

Respiratory health of female stone grinders with free silica dust exposure in Gujarat, India.

Eighty-five female quartz mill stone-grinding workers belonging to the Naika, Rathwa and Damor tribes of Chhotaudepur village of the Godhra region of Gujarat, Western India were surveyed and examined to assess health effects related to free silica dust exposure. The mean age for the subjects was 28.2 +/- 9.2 years, while the mean duration of exposure was 2.04 +/- 1.7 years. Chest radiographs showed findings suggestive of silicosis in 14%, silico-tuberculosis in 11.6% and tuberculosis in 8.1% of the study subjects. Respiratory morbidity was significantly associated with duration of exposure (X2 = 9.9, df = 2, p<0.007). On spirometry, obstructive, restrictive and combined (restrictive as well as obstructive) changes were found in 12.8%, 10.5% and 3.5% of the subjects, respectively. Overall, about one-third of subjects displayed abnormal pulmonary function and respiratory morbidity on chest radiographs.

Silicotuberculosis with oesophagobronchial fistulas and broncholithiasis: a case report.

A 76-year-old woman was admitted to the hospital four times from November 2007 to June 2009. In this complex case, the patient had silicosis complicated by broncholithiasis, oesophagobronchial fistulas, and relapsed tuberculosis. She had worked as a stone crusher for 3 years and was exposed to a large amount of quartz dust. Barium oesophagography, gastroesophageal endoscopy, and biopsy suggested oesophageal-related chronic inflammation and ulceration, which may have caused the repeated oesophagobronchial fistulas. Bronchoscopy revealed a free broncholithiasis in the left mainstem bronchus. The patient was admitted a fourth time because of silicotuberculosis relapse. After 9 months of antituberculosis treatment, the patient recovered and was still clinically well at the time of this writing.

Silicotuberculosis with Esophagobronchial Fistula and Broncholithiasis.

A 69-year-old woman was admitted to hospital 4 times from November 2007 to June 2009. The patient had silicosis complicated by broncholithiasis, esophagobronchial fistula, and relapsed tuberculosis. She had worked as a stone crusher for 3 years and was exposed to a large amount of quartz dust. Barium esophagography, gastroesophageal endoscopy, and biopsy suggested esophageal-related chronic inflammation and ulcer, which probably caused the repeated esophagobronchial fistulas observed. Bronchoscopy revealed a free broncholithiasis in the left main bronchus. The patient was readmitted a fourth time, for the relapse of silicotuberculosis. After 9 months of antituberculous therapy, she was doing well until the recent last follow-up visit.

[A case of silicotuberculosis with difficulty in its diagnosis].

A 68-year-old man who had worked as a stone mason for more than 50 years with a heavy smoking history consulted our clinic with symptoms of cough, low grade fever, weightloss, malaise and a single expectoration of hemo-sputum. He had been diagnosed as silicosis by the mass survey 5 years ago based on nodular shadows with egg-shell calcification in hilar lymphnodes on his chest radiography, and has received chest radiographic examination once a year. As the author was not so familiar with the radiographic features of silicotuberculosis, it was difficult to interprete ill-defined contour of silicotic nodules accompanied by patchy opacities formation in right midlung field and silicotic conglomeration accompanied by an ischemic cavity in the left basal segments. A definitive diagnosis could not be established until 10 months later when a second attack of exacerbation of silicotuberculosis occurred showing multiple thin walled fresh tuberculous cavities on the chest radiography with positive smear and culture. Among multiple tuberculous cavities, there was a cirrhotic-walled cavity caused by endogenous reactivation of a quiescent tuberculous lesion on the right apex. This lesion was considered to be the source of dissemination of this case. Finally, it took about two and a half years before establishing the diagnosis in this case because of a series of doctors delays. He was treated successfully with antituberculous drugs for one and a half years including one year rifampicin medication. The clinico-pathological findings of silicotic conglomeration in the left basal segments were discussed based on the findings of transbronchial biopsy from occluded B10 and chest radiographic findings, and it was revealed that silicotic conglomeration might consist of inflammatory granulation combined with granulomatous tubercle, but not a fibrous lesion.

[Silicotuberculosis]. / La silicotuberculose.

OBJECTIVE: Tuberculosis is a serious and common complication of silicosis. The aim of this study is to describe the epidemiological, clinical, radiological and progressive aspects of this pathological entity. PATIENTS AND METHODS: The study concerns 23 cases of silicotuberculosis which were collected at the service of respiratory diseases at CHU Ibn Rochd of Casablanca, Morocco during 12years (2003-2015). RESULTS: All patients were men. They were 7 diggers, 5 rock crushers, 7 miners and 4 masons. The mean duration of silica exposure was 11years. The symptomatology was dominated by dyspnea and persistent bronchial syndrome. Imagery showed tumor-like opacities in all cases, associated with mediastinal calcified lymphadenopathy in 9 cases, with micronodules in 8 cases and an excavated opacity in 2 cases. The diagnosis of tuberculosis was confirmed by isolation of the Koch's bacillus in sputum in 13% of cases in the bronchial aspirate in 52% and culture in sputum post-bronchoscopy in 13%. The bronchial biopsies confirmed the diagnosis in 2 cases. Tuberculosis had complicated silicosis 9years on average after the cessation of exposure to silica in 65% of cases. The antituberculous treatment was started in all patients with good clinical outcome in 22 cases. We had deplored a case of death by acute respiratory failure. CONCLUSION: Silicosis increases the risk of tuberculosis, hence the importance of TB screening in all patients with silicosis.