[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.

Fibrose maciça progressiva em trabalhadores expostos à sílica: achados na tomografia computadorizada de alta resolução / Progressive massive fibrosis in silica-exposed workers: high-resolution computed tomography findings

OBJETIVO: Avaliar as características radiológicas das massas conglomeradas pela tomografia computadorizada de alta resolução de tórax. MÉTODOS: Foram selecionados 75 pacientes silicóticos, a maioria jateadores de areia, portadores de fibrose maciça progressiva, atendidos no Hospital Universitário Antônio Pedro entre 1986 e 2004. Os pacientes foram submetidos a avaliação clínica, radiografia simples de tórax e tomografia computadorizada de alta resolução. RESULTADOS: Mais da metade dos pacientes com silicose complicada mostrou na radiografia de tórax grandes opacidades dos tipos B e C, denotando a gravidade da doença nesses pacientes. Dos 75 casos, apenas um apresentou massa unilateral simulando câncer de pulmão. Quarenta e quatro pacientes realizaram tomografia computadorizada de alta resolução do tórax. As massas predominaram nos terços superiores e posteriores (88,6 por cento). Broncograma aéreo e calcificações no interior das massas foram observados em 70,4 por cento e 63,8 por cento dos casos, respectivamente. História de tuberculose foi relatada em 52 por cento dos pacientes estudados. CONCLUSÃO: Na grande maioria dos casos as massas eram bilaterais, predominando nas regiões póstero-superiores dos pulmões, com broncogramas aéreos e calcificações de permeio. Associação com calcificações linfonodais foi um achado freqüente. A exposição a elevadas concentrações de poeira e a tuberculose foram consideradas fatores de risco para o desenvolvimento da fibrose maciça progressiva.

OBJECTIVE: To evaluate the radiological characteristics of conglomerate masses using high-resolution computed tomography of the chest. METHODS: From among the patients treated between 1986 and 2004 at the Antonio Pedro University Hospital, 75 patients with silicosis and massive fibrosis, most working in the field of sandblasting, were selected for study. These patients were submitted to a clinical evaluation, chest X-ray and high-resolution computed tomography of the chest. RESULTS: In more than half of the patients with accelerated silicosis, the chest X-ray revealed large type B and C opacities, denoting the severity of the disease in those patients. In 1 case, a unilateral mass simulating lung cancer was observed. High-resolution computed tomography scans of the chest were acquired for 44 patients. In most cases (88.6 percent), the masses were located in the superior and posterior thirds of the lung. Common findings within the masses included air bronchograms (in 70.4 percent) and calcifications (in 63.6 percent). A history of tuberculosis was reported by 52 percent of the patients. CONCLUSION: In the vast majority of cases, the masses were bilateral, predominantly located in the superior and posterior regions of the lung, featuring air bronchograms and interposed calcifications. Concomitant calcification of the mediastinal and hilar lymph nodes was another common finding. Exposure to high concentrations of dust and having a history of tuberculosis were considered significant risk factors for the development of progressive massive fibrosis.

Progressive massive fibrosis in silica-exposed workers. High-resolution computed tomography findings.

OBJECTIVE: To evaluate the radiological characteristics of conglomerate masses using high-resolution computed tomography of the chest. METHODS: From among the patients treated between 1986 and 2004 at the Antonio Pedro University Hospital, 75 patients with silicosis and massive fibrosis, most working in the field of sandblasting, were selected for study. These patients were submitted to a clinical evaluation, chest X-ray and high-resolution computed tomography of the chest. RESULTS: In more than half of the patients with accelerated silicosis, the chest X-ray revealed large type B and C opacities, denoting the severity of the disease in those patients. In 1 case, a unilateral mass simulating lung cancer was observed. High-resolution computed tomography scans of the chest were acquired for 44 patients. In most cases (88.6%), the masses were located in the superior and posterior thirds of the lung. Common findings within the masses included air bronchograms (in 70.4%) and calcifications (in 63.6%). A history of tuberculosis was reported by 52% of the patients. CONCLUSION: In the vast majority of cases, the masses were bilateral, predominantly located in the superior and posterior regions of the lung, featuring air bronchograms and interposed calcifications. Concomitant calcification of the mediastinal and hilar lymph nodes was another common finding. Exposure to high concentrations of dust and having a history of tuberculosis were considered significant risk factors for the development of progressive massive fibrosis.

Spirometric measurements among quartz stone ex-workers of Gujarat, India.

The present cross sectional study was carried out among 134 ex-workers from quartz stone crushing units. Using the interview technique as a tool for data collection, demographic and occupational details of the subjects were recorded on the predesigned proforma. Standard diagnostic criteria were used for diagnosing silicosis and silico-tuberculosis. The pulmonary functions of the subjects were measured with Spirovit SP-10. The mean age of the males was found to be 33.18 +/- 10.39 yr and that of the females was 30.10 +/- 9.3 yr and for the whole group was 31.77 +/- 9.99 yr. Mean duration of exposure was 2.74 +/- 1.65 yr. The study variables included age, sex, duration of exposure, smoking and respiratory morbidity. Forced Vital Capacity (FVC) which suggests lung parenchymal disorders was found to be significantly reduced with female sex, presence of smoking, increasing duration of exposure and presence of pneumoconiosis, whereas the lung function parameters indicating the status of airways were found to be significantly reduced with all the factors. Therefore, it was concluded that quartz stone workers exposed to approximately 100% free silica had deteriorated lung function which can be attributed mainly to respiratory disorders along with other epidemiological factors such as age, sex, duration of exposure and smoking.

[Bronchoalveolar lavage in the diagnosis of occupational pulmonary diseases in miners]. / Bronkhoal'veoliarnyi lavazh v diahnostytsi profesiinykh lehenevykh zakhvoriuvan' u hirnykiv.

One of objective methods of early and differential diagnosis of occupational pulmonary diseases in miners (pneumoconiosis, silicotuberculosis, dust bronchitis) is bronchoscopy with a cytologic examination of bronchoalveolar lavage fluid (BAF). BAF-examination was carried out in a total of 88 patients with incipient and advanced forms of dust bronchitis, pneumoconiosis and silicotuberculosis. A direct relationship has been revealed between a decline in local cell-bound immunity caused by a dust-inducted affection mononuclear phagocytes and advancing of stages of dust-related diseases.

Uranium mining in Germany: incidence of occupational diseases 1946-1999.

OBJECTIVES: In East Germany, uranium mining was performed on a large scale for approximately 45 years (1946-1990). In particular, the poor working conditions during the post-war years until 1955 led to a high level of occupational diseases. The present study gives an overview of the occurrence of occupational diseases during the mining period as well as after uranium mining was stopped in 1990. METHODS: The number of occupational diseases which occurred during the mining period was calculated from the files of the former Wismut SDAG. Although exposure to uranium ceased after 1990, new cases of occupational diseases were recognized after that date. These were recorded by the German Federation Of Institutions For Statutory Accident Insurance And Prevention (HVBG). RESULTS AND CONCLUSIONS: Today, more than 35,000 cases of occupational diseases are known, and many more are expected. About two-thirds of them are lung diseases: 16,376 cases of silicosis/silicotuberculosis and 7,695 cases of bronchial carcinomas. The increase in the number of recognized occupational diseases is shown and discussed against the background of changes in criteria for recognition and in working conditions as well as the duration of the latency period.

Mortality from lung cancer among silicotic patients in Sardinia: an update study with 10 more years of follow up.

OBJECTIVES: To evaluate the association between silica, silicosis and lung cancer, the mortality of 724 patients with silicosis, first diagnosed by standard chest x ray film between 1964 and 1970, has been analysed by a cohort study extended to 31 December 1997. METHODS: Smoking and detailed occupational histories were available for each member of the cohort as well as the estimated lifetime exposure to respirable silica dust and radon daughters. Two independent readers blindly classified standard radiographs according to the 12 point International Labour Organisation (ILO) scale. Lung function tests meeting the American Thoracic Society's criteria were available for 665 patients. Standardised mortality ratios (SMRs) for selected causes of death were based on the age specific Sardinian regional death rates. RESULTS: The mortality for all causes was significantly higher than expected (SMR 1.35, 95% confidence interval (95% CI) 1.24 to 1.46) mainly due to tuberculosis (SMR 22.0) and to non-malignant chronic respiratory diseases (NMCRD) (SMR 6.03). All cancer deaths were within the expected numbers (SMR 0.93; 95% CI 0.76 to 1.14). The SMR for lung cancer was 1.37 (95% CI 0.98 to 1.91, 34 observed), increasing to 1.65 (95% CI 0.98 to 2.77) allowing for 20 years of latency since the first diagnosis of silicosis. Although mortality from NMCRD was strongly associated to the severity of radiological silicosis and to the extent of the cumulative exposure to silica, SMR for lung cancer was weakly related to the ILO categories and to the cumulative exposure to silica dust only after 20 years of lag interval. A significant excess of deaths from lung cancer (SMR 2.35) was found among silicotic patients previously employed in underground metal mines characterised by a relatively high airborne concentration of radon daughters and among ever smokers who showed an airflow obstruction at the time of the first diagnosis of silicosis (SMR 3.29). Mortality for lung cancer related to exposure was evaluated with both the Cox's proportional hazards modelling within the entire cohort and a nested case-control study (34 cases of lung cancer and 136 matched controls). Both multivariate analyses did not show any significant association with cumulative exposure to silica or severity of silicosis, but confirmed the association between mortality for lung cancer and relatively high exposure to radon, smoking, and airflow obstruction as significant covariates. CONCLUSIONS: The findings indicate that the slightly increased mortality for lung cancer in this cohort of silicotic patients was significantly associated with other risk factors-such as cigarette smoking, airflow obstruction, and estimated exposure to radon daughters in underground mines-rather than to the severity of radiological silicosis or to the cumulative exposure to crystalline silica dust itself.

[Occupational disease among miners of the Kursk Magnetic Anomaly (from the experience of the work of the Institute of Industrial Hygiene and Occupational Diseases in Heavy Metallurgy)]. / Professional'naia zabolevaemost' sredi rabochikh gornorudnykh predpriiatii Kurskoi magnitnoi anomalii (Iz opyta raboty instituta--kuratora po problemam gigieny truda i professional'nykh zabolevanii v chernoi metallurgii.

The materials are first to present analysis of occupational morbidity among miners of variable age, length of service, various occupations, who work at Kursk Magnetic Anomaly. The recommendations on lower occupational morbidity are presented.

The principles of predicting the individual risk of silicosis and silicotuberculosis.

A series of investigations conducted in different "silicosis-risk" industries using a methodology based on the mathematical theory of pattern recognition has shown that in the given conditions of dust exposure, the probability of contracting pneumoconiosis depends for each individual on a complex influence of many factors, both environmental and intrinsic for the individual. Genetic predisposition was one of the most important factors and while the direction in which a factor influences predisposition was the same in every industry, its relative contribution to predisposition to simple silicosis was different in the studied working populations. So a reliable prediction of the high probability of this form of pneumoconiosis on the basis of such a multifactorial analysis is possible only with respect to specific conditions of a particular industry. The complex of factors determining predisposition to silicotuberculosis is more general: this complex comprises both factors influencing susceptibility to silica dust and specially those influencing susceptibility to tuberculosis. Despite the low prevalence of genetic resistance to pneumoconiosis in working populations, the risk of contracting the disease in modern industrial conditions of relatively low dust exposure is high only for a proportion of workers for whom the genotype of predisposition to silicosis or to silicotuberculosis coincides with a most unfavourable combination of non-genetic factors enhancing this predisposition. In the opinion of the authors, the task of screening off those applicants for a "silicosis-risk" employment for whom the risk may be estimated as high on the basis of the developed methodology, is quite feasible.

Mortality of workers compensated for silicosis during the period 1959-1963 in the Veneto region of Italy.

After reports appeared from other countries indicating an excess risk of lung cancer among silicotics, a cohort of workers compensated for silicosis during the period 1959-1963 in the Veneto region of Italy was constructed and followed for mortality through 1984. The results of the study showed a large mortality excess for infectious diseases (180 observed versus 9.5 expected), due to silicotuberculosis, and for diseases of the respiratory system (270 observed versus 33.5 expected) due to silicosis. An elevated standardized mortality ratio of 239 (70 observed versus 29.3 expected) from lung cancer was also detected. An increasing pattern was observed with time since first exposure, while the relationship with employment category and duration of exposure was less clear-cut. The lung cancer excess was also strongly associated with cigarette smoking, there being a dose-response relationship with daily cigarette consumption. The study confirms the results from other epidemiologic studies on silicotics which show this pathological condition to be associated with increased lung cancer mortality.

Mortality experience of Vermont granite workers.

The proportional mortality experience (1952-1978) of 969 deceased white male granite workers was compared with that of United States white males. Industrial hygiene information was combined with work histories to develop an estimate of lifetime granite dust exposure for each individual. Subjects were grouped into four cumulative exposure categories, and exposure-response relationships were examined. Trends of increasing silicosis and tuberculosis with increasing lifetime exposure were observed. These are consistent with earlier findings. With the exception of excess suicide among granite workers dying before 1970, there was little evidence of association between other causes of death and employment in the granite industry.