Silicosis among Cape gemstone workers : tigers' eye pneumoconiosis

Silicosis continues to be an important occupational disease in South Africa, particularly in small, poorly regulated industries. A case series is described of six workers who developed silicosis whilst involved in the processing of semi-precious gem stones. They had been employed as stone sculptors in lapidaries where they processed tigers' eye, rose quartz, amethyst, quartz crystal and a variety of other locally occurring semi-precious stones. In five of the cases exposure was in small and poorly regulated lapidaries without specific dust control measures. The sixth was detected during the course of a health and hygiene survey (including dust sampling) that I conducted in one of two lapidaries still operating in the Western Cape. These workers developed serious disease. Progressive massive fibrosis (PMF) was noted in 4 of the 6 cases, three of whom had progression of their disease after cessation of exposure. With the development of PMF the initial restrictive pulmonary function abnormalities were followed by steadily worsening airflow obstruction. Lung biopsies confirmed silicosis in one case and were suggestive in a further two. Tuberculosis was confirmed in two cases and suspected and treated in a third. Workmen's' Compensation was awarded in five cases. The survey confirmed that in semiprecious gem stone processing, the risk of silicosis appears to be confined to stone sculptors. Tried and proven techniques of general and local exhaust ventilation combined with water or oil to control dust at source were capable of effectively reducing dust emission to acceptable levels

Occupational respiratory diseases

Shipping list no.: 87-222-P."September 1986."S/N 017-033-00425-1 Item 499-F-2Also available via the World Wide Web.Includes bibliographies and index

THE PREVALENCE AND PREDICTION OF PULMONARY FIBROSIS IN AN

This thesis describes an ancillary project to the Early Diagnosis of Mesothelioma and Lung Cancer in Prior Asbestos Workers study and was conducted to determine the effects of asbestos exposure, pulmonary function and cigarette smoking in the prediction of pulmonary fibrosis. 613 workers who were occupationally exposed to asbestos for an average of 25.9 (SD=14.69) years were sampled from Sarnia, Ontario. A structured questionnaire was administered during a face-to-face interview along with a low-dose computed tomography (LDCT) of the thorax. Of them, 65 workers (10.7%, 95%CI 8.12—12.24) had LDCT-detected pulmonary fibrosis. The model predicting fibrosis included the variables age, smoking (dichotomized), post FVC % splines and post- FEV1% splines. This model had a receiver operator characteristic area under the curve of 0.738. The calibration of the model was evaluated with R statistical program and the bootstrap optimism-corrected calibration slope was 0.692. Thus, our model demonstrated moderate predictive performance

Validation of biomarkers for improved assessment of exposure and early effect from exposure to crystalline silica

This is the third phase of a project to identify, confirm, and operationalise biomarkers for crystalline silica dust exposure that could be used for surveillance of dust exposure levels in South African mines. The first phase of the project involved a comprehensive review of the relevant literature [Gulumian et al., 2006] from which ten potential biomarkers of effect were identified as being worthy of further investigation. The second phase of the project examined the ten identified biomarkers in silica dustexposed and unexposed black male subjects [Murray et al., 2006]. Two of the ten short listed biomarkers, namely erythrocyte glutathione peroxidase (GPx) and serum Clara cell protein 16 (CC16), were found to have significantly reduced levels in the silica dust-exposed versus unexposed subjects. In addition, the biomarkers were found to be unaffected by HIV sero-status, smoking, age and the presence of silicosis. As a result, this third phase of the project aimed to confirm the levels of and further analyze GPx and CC16 in miners exposed to crystalline silica dust. This third phase involved the measurement of the levels of erythrocyte GPx and serum CC16 in 80 adult male gold miners upon their return from leave and then again two to six months after they had returned to work (involving exposure to crystalline silica). Before the field work was conducted, however, the optimal operational parameters for the biomarkers (namely storage temperature, delay in time between blood collection and separation, laboratory temperature and storage duration) were established. The results of these optimization experiments were used to develop Standard Operating Procedures (SOPs) for biomarker specimen handling and storage under field conditions, and for laboratory assays. In this phase, the findings of the second phase were confirmed in that the levels of GPx and CC16 were lowered in miners exposed to crystalline silica dust and were unaffected by age, race and cigarette smoking. In addition, while CC16 was unaffected by the presence of radiological silicosis, GPx may have been affected. Finally, the decrease in the levels of GPx activity and CC16 concentration observed in the study were unaffected by the level of silica dust exposure (high or low) as determined by job category or by the duration of crystalline silica exposure. Regarding the levels of GPx activity, the results suggested that GPx levels decrease after two to six months of chronic exposure to crystalline silica dust and remain decreased (throughout the working week and over a weekend) and then increase or even recover to normal levels during a period of leave. It was therefore concluded that GPx activity levels rise and fall, in response to silica dust exposure, gradually and over periods of some time, possibly months. The CC16 results were, however, less promising. After two to six months of chronic exposure to crystalline silica dust there was a significant change in CC16 on a Wednesday afternoon following an 8-hour shift and during the duration of a shift. In addition, there is the possibility that the observed changes were due to a time-dependent diurnal variation in the CC16 levels. It was concluded that the results of the current phase warrant further research into the use of erythrocyte GPx and serum CC16 as biomarkers of early effect from crystalline silica exposure

THE EFFECTS AND CONTROL OF DISEASES ASSOCIATED WITH EXPOSURE TO ASBESTOS IN A NAVAL DOCKYARD

PhDA review of the literature relating to the diseases associated with exposure to asbestos is followed by a description of processes involving materials containing asbestos, and the men employed, in HJ Dockyard, Devonport. The development of preventive measures is explained, and details are given of the precautionary methods which have been introduced as a direct result of the present survey. An account is presented of an extensive survey of the dust concentrations occurring in most of the processes involving asbestos materials in the Dockyard. This survey shows the degree of risk to which men have probably been exposed in the past, and explains how many men, not previously thought to have been at risk, have been exposed to high dust concentrations. A detailed study of the clinical, radiological and physiological changes occurring in the men exposed to asbestos is described, and this is followed by a proportional mortality study of the lung and gastro-intestinal neoplasms occurring in Plymouth males. The report concludes with a general discussion of. the data

Asbestos bibliography (revised)

"This publication is a compendium of NIOSH research and recommendatiions on asbestos. This publication is divided into three Parts: Part I consists of full or partial text of selected NIOSH documents on asbestos. These documents provide an overview of NIOSH research on the health hazards of asbestos and NIOSH recommendations on workplace exposure to asbestos. Part II contains a comprehensive bibliography of NIOSH documents on asbestos. It is divided into two sections: (1) NIOSH-authored documents (which include numbered publications, testimony, journal articles, and miscellaneous reports) and (2) NIOSH-funded documents (which include grant and contract reports). Part III contains summary asbestos information from other Federal agencies. " - NIOSHTIC-2"NIOSHTIC No 20000043"The Division of Surveillance, Hazard Evaluations, and Field Studies, National Institute for Occupational Safety and Health (NIOSH), having primary responsibility for development of a NIOSH position paper on health effects of occupational asbestos exposure, has critiqued all available data and prepared the following document for publication and transmittal to the Occupational Safety and Health Administration (OSHA), as requested by the Assistant Secretary of Labor. Primary responsibility for development of this document was shared by Richard A. Lemen and John M. Dement, with technical consultation provided by Dr. Joseph K. Wagoner." - p. 1

Mortality of Quebec chrysotile workers in relation to radiological findings while still employed

Two cohorts of Quebec chrysotile miners and millers were selected in order to study how radiological changes in asbestos workers predict mortality. Cohort "A" comprised 988 men, with dust exposure, smoking history, respiratory symptoms and lung function recorded in 1967- 68, and six independent readings of an earlier chest radiograph; 130 men had died before 1976. Cohort "B" comprised all 4,559 men not in Cohort "A" who were born 1891 through 1920, with at least a month's employment and an x-ray; dust exposure, smoking history and a single x-ray reading were obtained. By the end of 1975, there had been 1,455 deaths in Cohort "B". A high Relative Risk (RR) of total mortality was related to each radiographic feature, cigarette smoking, excessive dust exposure, and, in Cohort "A", dyspnoea and poorer function. Death from pneumoaonioois was associated with small irregular parenchymal opacities, of profusion usually greater than 1/0, and with heavy dust exposure, but not with smoking. Almost all who died from chest cancer had smoked cigarettes (very high RR), have been heavily exposed to asbestos (high RR), or both. About half their x-rays showed pneumoconiotic change. There was insufficient evidence to determine whether chest cancer was a complication of asbestosis or an independent reaction to asbestos exposure. Five of the six mesothelioma cases had positive but varied radiographic appearances. The contribution of asbestos dust to some deaths attributed to heart disease was substantiated by high RRs for severe exposure, and for small parenchymal opac ities; smokers, and the breathless, also had high risks. Other neoplasms showed no consistent dust or x-ray patterns. RRs of deaths from some other causes were high for certain radiographic features. Not all these results can yet be explained. The main findings validated the UICC/Cincinnati classification convincingly. Studies to permit generalization are recommended

Asbestos, Asbestosis, and Cancer: Helsinki Criteria for Diagnosis and Attribution 2014

The report summarizes the current, up-to-date information on the methods for managing and eliminating asbestos-related diseases.1

Best practices for dust control in coal mining

"The extraction, transport, and processing of coal produces respirable-sized dust that can be inhaled by miners and cause disabling and potentially fatal lung diseases known as coal workers' pneumoconiosis (CWP, commonly called "black lung") or silicosis. Once contracted, there is no cure for these lung diseases, so prevention is the goal. Since 1970, NIOSH has offered health screenings to underground coal miners to identify CWP in individuals and to track CWP prevalence across the industry. After an initial 30-year downward trend, CWP prevalence has been increasing over the last 20 years. Coal dust particles larger in size than respirable dust, known as float coal dust, are also produced during mining. Float coal dust settles out of the ventilating air onto the floor, ribs, and roof of underground mining entries. This dust can be lifted back into the air from these surfaces to fuel powerful explosions, which have contributed to numerous fatal mine disasters. To address these issues, coal mine operators search for and implement control technologies that limit worker exposure to respirable dust and minimize the deposition of float coal dust. The controls discussed in this second edition of this handbook range from long-utilized controls that have developed into industry standards to emerging controls that continue to be researched. The handbook is divided into six chapters. Chapter 1 discusses the health effects of exposure to respirable coal and silica dust. Chapter 2 discusses respirable dust sampling instruments and sampling methods. Chapters 3, 4, and 5 focus on respirable dust control technologies for longwall mining, continuous mining, and surface mining, respectively. Chapter 6 discusses float coal dust sampling and control technologies." - NIOSHTIC-2NIOSHTIC no. 20063272Suggested Citation: NIOSH [2021]. Best practices for dust control in coal mining, second edition. By Colinet JF, Halldin CN, Schall J. Pittsburgh PA: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 2021-119, IC 9532. https://doi.org/10.26616/NIOSHPUB20211192021-119_web.pdf20211016