Silicosis and coal worker's pneumoconiosis are serious occupational respiratory diseases associated with the coal mining industry and the inhalation of respirable dusts that contain crystalline silica. Silica exposure is an occupational health priority even when exposure has ceased or is below the occupational exposure limit (0.1 mg/m3). The objective of this study was to determine the individual contributions of the underground coal mining tasks to the total amount of respirable dust and respirable silica dust concentrations found in this environment. The tasks that were identified were continuous miner (CM) cutting, construction, the transfer point, tipping and roof bolting. Respirable dust sampling was conducted at the intake and return of each task, as well as at the intake and return of the section and the intake airway to the section. The five occupations that perform these tasks were also sampled to determine the personal exposure levels. Respirable dust concentrations and small concentrations of respirable silica dust were found in the intake airway and intake of the section, indicating that the air that enters the section is already contaminated. The respirable dust-generating hierarchy of the individual tasks was: transfer point>CM right cutting> CM left cutting> CM face cutting> construction> roof bolting > tipping. For respirable silica dust the hierarchy was: CM left cutting> construction> transfer point> CM right cutting. CM face cutting, tipping and roof bolting generated concentrations of below quantifiable levels. The personal exposures also differed and the eM and stamler operators had the highest exposure to respirable dust (3.417 ± 0.862 mg/m3) and respirable silica dust (0.179 ± 0.388 mg/m3) concentrations, respectively. Recommendations have been included for lowering the respirable dust and silica dust concentrations that are generated and that the workers are exposed to underground. / Thesis (M.Sc. (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2010.

Silicosis and coal worker's pneumoconiosis are serious occupational respiratory diseases associated with the coal mining industry and the inhalation of respirable dusts that contain crystalline silica. Silica exposure is an occupational health priority even when exposure has ceased or is below the occupational exposure limit (0.1 mg/m3). The objective of this study was to determine the individual contributions of the underground coal mining tasks to the total amount of respirable dust and respirable silica dust concentrations found in this environment. The tasks that were identified were continuous miner (CM) cutting, construction, the transfer point, tipping and roof bolting. Respirable dust sampling was conducted at the intake and return of each task, as well as at the intake and return of the section and the intake airway to the section. The five occupations that perform these tasks were also sampled to determine the personal exposure levels. Respirable dust concentrations and small concentrations of respirable silica dust were found in the intake airway and intake of the section, indicating that the air that enters the section is already contaminated. The respirable dust-generating hierarchy of the individual tasks was: transfer point>CM right cutting> CM left cutting> CM face cutting> construction> roof bolting > tipping. For respirable silica dust the hierarchy was: CM left cutting> construction> transfer point> CM right cutting. CM face cutting, tipping and roof bolting generated concentrations of below quantifiable levels. The personal exposures also differed and the eM and stamler operators had the highest exposure to respirable dust (3.417 ± 0.862 mg/m3) and respirable silica dust (0.179 ± 0.388 mg/m3) concentrations, respectively. Recommendations have been included for lowering the respirable dust and silica dust concentrations that are generated and that the workers are exposed to underground. / Thesis (M.Sc. (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2010.

MPH, Occupational Hygiene, School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, 2009 / Introduction: By 2030 silicosis should be eliminated in South Africa. This statement was made by the Labour Minister, Mr. Membathisi Mdladlana on 28 June 2004 during the launch of the National Programme for the Elimination of Silicosis in Johannesburg. Following this launch the mining industry set its own milestone, which is to eradicate this disease by 2014. Historically research has generally focused on the health effects associated with exposures to coal dust, whilst limited work has been done on personal exposures to respirable crystalline silica (commonly known as quartz), which is the main cause of silicosis in the mining industry. Given the number of people that are involved in coal mining, together with the seriousness of diseases associated with respirable quartz exposure, such as silicosis and tuberculosis, it is important to quantify these exposures. The aim of this study was to ascertain the magnitude of employee exposures to respirable quartz, in the Mpumalanga region of the South African coal mining industry, over the period 2002 and 2006. Objectives: The objectives of this study are: • To describe respirable quartz concentrations in 41 coal mines in the Mpumalanga region of South Africa over the period 2002 to 2006; • To compare respirable quartz concentrations in nine magisterial districts of the Mpumalanga region of South Africa over the period 2002 to 2006, to the South African Occupational exposure limit of 0.1 mg/m3 and the American Congress of Governmental Industrial Hygienists (ACGIH) Threshold Limit value of 0.025 mg/m3; • To describe twenty four activity areas in 41 coal mines in the Mpumalanga region of South Africa, over the period 2002 to 2006, which exceed 50 % of the South African Occupational exposure limit of 0.1 mg/m3 (generally referred to as the action limit). 3 Methodology: The study setting comprises the workings of coal mines within the Mpumalanga region, where various types of occupations exist. The research conducted consisted of a descriptive study of retrospective respirable Time Weighted Average quartz concentration results obtained from mines that use the company Colliery Environmental Control Services (CECS) as their occupational hygiene service provider. CECS provided the data that was analysed for this research. Sample collection and analysis for respirable quartz was done using widely accepted International methodologies. Results: The overall median respirable quartz concentration for all mines were 0.007 mg/m3, whilst the mean was 0.038 mg/m3. The highest respirable quartz concentration measured was 2.197 mg/m3 and the lowest 0.000 mg/m3. The majority of the mines, i.e. 30, are situated in the Kriel, Secunda and Witbank magisterial districts, these districts account for 78 % of the total number of measurements taken. A total of 191 measurements (8 %) and 674 (29 %) exceeded the South African OEL of 0.1 mg/m3 and ACGIH TLV of 0.025 mg/m3 respectively with the Secunda district having the most measurements that exceeded both sets of limits (58 and 205 respectively). The majority of measurements, i.e. 1784 (76 %), were from six activity areas and four hundred and ninety one (21 %) of the total measurements taken were from the continuous miner activity area. The highest ranked activity area is the longwall mining one, which has a median respirable quartz concentration of 0.044 mg/m3. The highest respirable quartz concentration, 2.197 mg/m3, was measured in the roving plant activity area, which was followed by measurements of 1.706 mg/m3 and 1.528 mg/m3 in the continuous miner and unknown activity areas respectively. The longwall mining activity area recorded the most measurements that exceeded the 50 % action limit and 0.1 mg/m3 OEL, these been 47 and 38 respectively. 4 Discussion and Conclusion: This research report describes similar exposure findings as has been reported internationally. Persons employed in the high risk activity areas on the 41 mines studied over the period 2002 to 2006 in the Mpumalanga region are at risk of developing quartz-associated diseases, such as silicosis. Recommendations: It is recommended that the effectiveness of implemented interventions need to be investigated and appropriate intervention strategies be implemented. Airborne quartz contents from the nine magisterial districts and 24 activity areas should be analysed and individual samples taken from the high risk tasks should be individually analysed for their percentage airborne quartz content.

Silica is a common silicon dioxide (SiO2) that can be crystalline or non-crystalline (amorphous). Amorphous silica is considered to be less hazardous than crystalline silica. Three dominant crystalline polymorphs exist, with silica quartz being the most common. Exposure to respirable crystalline silica (quartz) causes silicosis, a lung scarring disease. The aim of this study was to identify and quantify the silica exposure in respirable dust personal exposure samples, as well as in representative bulk samples which are large samples taken from the sources of airborne dust obtained from different mining and production plants involved in the production of titanium dioxide from beach sand. This is needed to determine the degree of risk of developing silicosis. Forty five workers employed in different mining and production plants participated in this study. Their eight-hour personal exposure to respirable particulate was determined. Personal respirable dust exposure samples and bulk samples were analyzed for silica by an accredited laboratory by means of X-ray diffraction based on NIOSH method 7500. Silica quartz was detected in personal respirable dust samples and bulk dust samples obtained from the mining and production plants, but amorphous silica was only detected in three personal exposure samples at the Slag plant and in the bulk sample obtained from the Roaster plant. All the silica quartz and amorphous silica concentrations in personal exposure samples were well below their respective exposure limits of 0.1 mg/m3 (quartz) and 3 mg/m3 (amorphous). No significant differences were found between the silica quartz concentrations in personal respirable exposure samples obtained from the mining ponds and the production plants, although a practical significance was found between some mining and production area personal exposure samples. The non-significant differences found between exposure concentrations and a practical significance suggest the necessity of involving a larger sample group in future. Other studies done in non-mining industries showed that some workers were over exposed to respirable silica dust. Compared to these findings the results of the present study showed the opposite, with respirable silica dust levels being below the South African action level and OEL. Further research, involving more samples, spread over a longer period of time, would probably be able to show a clear trend as to how quartz structures and exposure profiles change from the mining to the various production processes. Overexposure to silica quartz anywhere at the mine and production processes is considered unlikely, with the risk of developing silicosis being low. / Thesis (MSc (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2013

Silica is a common silicon dioxide (SiO2) that can be crystalline or non-crystalline (amorphous). Amorphous silica is considered to be less hazardous than crystalline silica. Three dominant crystalline polymorphs exist, with silica quartz being the most common. Exposure to respirable crystalline silica (quartz) causes silicosis, a lung scarring disease. The aim of this study was to identify and quantify the silica exposure in respirable dust personal exposure samples, as well as in representative bulk samples which are large samples taken from the sources of airborne dust obtained from different mining and production plants involved in the production of titanium dioxide from beach sand. This is needed to determine the degree of risk of developing silicosis. Forty five workers employed in different mining and production plants participated in this study. Their eight-hour personal exposure to respirable particulate was determined. Personal respirable dust exposure samples and bulk samples were analyzed for silica by an accredited laboratory by means of X-ray diffraction based on NIOSH method 7500. Silica quartz was detected in personal respirable dust samples and bulk dust samples obtained from the mining and production plants, but amorphous silica was only detected in three personal exposure samples at the Slag plant and in the bulk sample obtained from the Roaster plant. All the silica quartz and amorphous silica concentrations in personal exposure samples were well below their respective exposure limits of 0.1 mg/m3 (quartz) and 3 mg/m3 (amorphous). No significant differences were found between the silica quartz concentrations in personal respirable exposure samples obtained from the mining ponds and the production plants, although a practical significance was found between some mining and production area personal exposure samples. The non-significant differences found between exposure concentrations and a practical significance suggest the necessity of involving a larger sample group in future. Other studies done in non-mining industries showed that some workers were over exposed to respirable silica dust. Compared to these findings the results of the present study showed the opposite, with respirable silica dust levels being below the South African action level and OEL. Further research, involving more samples, spread over a longer period of time, would probably be able to show a clear trend as to how quartz structures and exposure profiles change from the mining to the various production processes. Overexposure to silica quartz anywhere at the mine and production processes is considered unlikely, with the risk of developing silicosis being low. / Thesis (MSc (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2013

Continuous personal dust monitors (CPDMs) are widely used to monitor respirable coal mine dust (RCMD) to reduce miners' exposures, but they are unable to directly assess respirable crystalline silica (RCS) concentrations, which are linked to the recent rise of respiratory diseases among coal miners. This incompatibility is due to the composition of the CPDM's internal filter stub. The stub consists of a fibrous borosilicate filter attached to a polypropylene (PP) backing and a polytetrafluoroethylene (PTFE) binder, which interferes with standard analytical techniques. This study developed a method for indirect analysis of dust collected on the CPDM filter stub using portable direct-on-filter Fourier Transform infrared spectroscopy (DOF-FTIR) to rapidly quantify quartz, the primary analyte of silica in coal mines. The research consisted of four studies that developed and evaluated a three-step process for dust recovery, deposition, and analysis. These studies investigated techniques for separating dust from the CPDM filter media, compared mechanisms for dust deposition onto various substrates, and assessed the ability of FTIR and scanning electron microscopy with energy dispersive X-ray (SEM-EDX) to analyze the mineral characteristics of recovered dust. The resulting method involves submerging CPDM filter stubs in 5 mL of isopropyl alcohol (IPA) and shaking them for 1 minute, followed by deposition of the dust onto a 25-mm polyvinyl chloride (PVC) filter using a syringe-based system. The PVC filter was then scanned at four 8-mm offset locations at 90° intervals from the center. Evaluating this method using field and lab-generated CPDM filter stubs revealed low dust recovery from the stubs. It was also observed that results tended to underpredict the quartz mass as the total sample mass increased. Though adjustments for recovery can be made using a scale and the method can be limited to lower mass samples, more efforts can be made to investigate better dust recovery and improve quartz determination of the samples to increase confidence in the method. / Doctor of Philosophy / To reduce respiratory diseases among coal miners, US regulation requires dust sampling in underground coal mines to monitor the total respirable coal mine dust (RCMD) concentration miners are exposed to using a specific device, the continuous personal dust monitor (CPDM). However, the CPDM cannot be used to directly differentiate the characteristics of the dust, particularly silica, which is particularly hazardous. To do this, a method to indirectly analyze the dust collected on the CPDM's internal filter stub has been evaluated using a three-step method to recover the dust, deposit the dust onto a different filter type, and then analyze the dust using a spectrometer to determine the silica mass. Four studies were performed to develop the full method. These studies investigated how dust can be recovered from filters, how to deposit dust onto another filter, and how to then analyze the dust to determine its characteristics. This was done using multiple methods to determine the optimum three-step method to quantify the silica mass in the recovered dust. The studies ultimately developed a method involving submerging the CPDM filter stub in 5 mL of isopropyl alcohol (IPA) and shaking it for 1 minute to dislodge the dust. Then, the recovered dust was deposited on a 25-mm polyvinyl chloride (PVC) filter using a syringe. After deposition, the PVC filter was finally scanned at four 8-mm offset locations at 90° intervals from the center of the filter. These scans were then used to determine the silica mass. After testing this three-step method on field and lab-generated CPDM filter stubs, results showed low dust recovery from the stubs. It was also observed that results tended to underpredict the silica mass as the total RCMD mass increased. Although the dust left behind on the filter can be determined using a scale and the method can be limited to samples with smaller masses to avoid underpredicting the quartz mass, more work can be done to improve dust recovery, improve the silica determination, and put more confidence in the method.

M.P.H., Faculty of Health Sciences, 2008 / Introduction The Department of Minerals and Energy (DME) in South Africa issued a Directive B7, titled “A Guideline for the Ventilating of Mechanical Miner Sections” to the coal mining industry. The main purpose of this directive was to reduce respirable dust exposures at the coal face with the long term objective of reducing the incidence of Coal Workers Pneumoconiosis (CWP). This study attempts to evaluate the appropriateness of the DME approach by comparing respirable coal dust results from personal samples from occupations at the coal face to the results obtained from engineering samples at the continuous miner. Objectives The objectives of this study are to: • Describe personal respirable coal dust concentrations of the occupations within the continuous miner Homogeneous Exposure Group (HEG) in five underground coal mines in Mpumalanga from January 2005 to December 2006. • Describe environmental engineering respirable coal dust concentrations of the continuous miner operator position in five underground coal mines in Mpumalanga from January 2005 to December 2006. • Compare personal respirable coal dust concentrations to Environmental Engineering Dust (EED) concentrations in five coal mines in Mpumalanga from January 2005 to December 2006. Methodology This study is descriptive in nature and was carried out utilizing historical respirable coal dust data from underground coal bord and pillar production sections. Data was supplied by Collieries Environmental Control Services (CECS) who provided a coal sampling and analysis service to South African collieries. Data provided was from five large underground coal mines in the Mpumalanga coal fields. The study population consisted of occupations within the HEG of workers deployed at the coal face who were linked to Continuous Miner (CM) production activities and results from EED sampling. Results When comparing the personal sampling results to EED sampling results for each individual mine, it is evident that all the mines had lower personal sampling results than EED results, thus establishing a definite trend. When combining all the mines in the two data sets it is also evident that EED sampling results are significantly higher than personal sampling results confirming the trend observed on individual mines. Correlation tests carried out between the two data sets indicated that there is no correlation between the personal and EED sampling results. The poor correlation between the two data sets indicates that the EED sampling position is not ideal and does not take account of the actual contaminant levels leaving the coal-winning heading. Discussion and conclusion The DME directive by way of a simple calculation took the countries personal Occupational Exposure Limit (OEL) of 2 mg/m3 and formulated a limit of 5 mg/m3 for EED sampling results. Simple extrapolation of the EED results indicates that personal exposure is exceeded more than two-fold and thus the limit of 5 mg/m3 as set by Directive B7 cannot be compared to the personal respirable coal dust OEL of 2 mg/m3. The basis of the initial calculation used to derive the 5 mg/m3 limit assumed that the shift lengths were in the region of 8 hours and cutting times around 40% of the shift, while most coal mines now have shift lengths ranging from 9 to 10 hours. In conclusion it is evident that the required limit of 5 mg/m3 as set out by Directive B7 cannot be related to the personal exposures limit of 2 mg/m3. Poor correlation results observed indicate that the EED sampling position does not account for the respirable dust concentrations leaving coal-winning headings and may be affected by the re-circulation of contaminated air over the sampling position. In addition the EED sampling position does not give an indication of the respirable dust capture efficiency of scrubber fans.

Coal workers’ pneumoconiosis (CWP), commonly referred to as black lung, is a chronic lung disease that results from the inhalation and deposition of coal dust in the lungs. While this disease continues to afflict coal miners, its prevalence has steadily declined over three decades since 1970. Based on a voluntary X-ray surveillance program, conducted by the National Institute for Occupational Safety and Health (NIOSH), this downward trend, however, ended in 2000 and has actually begun to rise. The Mine Safety and Health Administration (MSHA) instituted a Comprehensive Initiative to “End Black Lung” to combat the reported upturn in black lung disease. Rulemaking, with the intent of strengthening respirable dust regulations, is a major part of this initiative. This thesis addresses a controversial aspect of the newly proposed rules – single-shift compliance sampling. Establishing new requirements for respirable dust compliance requires an understanding of both the accuracy and variability of measurements. Measurement variability is especially important in underground mining where the workplace is constantly moving and ventilation controls are continually changing. The results of a ventilation study performed in three underground coal mines are presented in this thesis. A total of 600 dust-concentration measurements were obtained in this study using Continuous Personal Dust Monitors (CPDMs). The data was analyzed to determine the variability associated with taking dust measurements in the mining workplace. The Johnson transformation was found to produce the best-fit distribution model for the data. This thesis summarizes the results of this study and presents a statistical procedure for establishing an exposure limit.

Purpose. Exposures to paper dust, classified as Particulates Not Otherwise Regulated (PNOR), in an industrial setting can cause irritation to the eyes, skin, throat and upper respiratory tract. An exposure assessment was conducted to evaluate the paper dust exposures in the coupon manufacturing facility during a normal production working period. Methods. Total and respirable personal dust sampling was performed according to NIOSH 0500 and 0600 methods. Six total dust samples and seven respirable dust samples were taken within the sampling areas where airborne paper dust was produced to evaluate the Time Weighted Average (TWA) of the exposed employees. Results. Results showed that the TWAs for total dust within the three sampling areas ranged from 0.4% to 4.7% of the Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (PEL) and 0.5% to 7.1% of the American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV), except sample RD-4 in the Baler Room. TWAs for respirable dust within the Press Room and Collation Area ranged from 0.8% to 0.9% of the OSHA PEL for all samples and 1.4% to 1.5% of the ACGIH TLV. Descriptive statistics showed the sample standard deviation for both total and respirable dust to be below 1.0. The coefficient of variation for TWAs of total dust in the Press Room was 32.7% while all other total dust and respirable dust coefficient of variations for TWA ranged from 1.3% to 3.4%. Conclusion. Exposures to paper dust ranged from 0.4% to 7.1% of either the OSHA PEL or ACGIH TLV with an exception of sample RD-4 in the Baler Room which was 34% of the OSHA PEL and 56.7% of the ACGIH TLV. Identical respirable dust data and variable total dust data in the Press Room and Collation Area suggest that the dust being generated is of a larger particle size and therefore affects the nose, throat, and upper lungs. The engineering and administrative controls present appeared to be adequate based on the sampling data. Respiratory Personal Protective Equipment (PPE) was not considered a requirement but should be permitted if requested. Present workplace practices also appeared adequate based on the sampling data.

Air pollution is one of many issues that have a direct impact upon the economy and the well-being of society in South Africa. Domestic coal combustion contributes significantly to the air pollution problem in the country. Both qualitative and quantitative methods of data collection have been employed in this study. A questionnaire survey was conducted in 100 households in Doornkop (Soweto) and 100 households in KwaGuqa (Witbank). The observations were carried out simultaneously while the questionnaire surveys were being administered in both study areas. Interviews were also held with Eskom (the Electricity Supply Commission of South Africa) officials. Finally, the indoor concentrations and elemental composition of respirable particulate matter (PM7) were measured in three different types of households: electrified without coal burning, electrified with coal burning, and un-electrified with coal burning. The results show that township households, whether electrified or not, continue to burn coal. In both study areas, 80 % of electrified households burn coal for space heating and cooking. Although the major obstacles preventing people from discontinuing domestic coal combustion are poverty and the ready availability and social acceptability of coal, the social value of a fire inside township households cannot be underrated. Previously developed coal-supply networks still exist in the townships and makes coal utilisation very convenient. The findings also point to use of multiple fuels in the communities studied. The key fuels used for domestic energy supply are coal, electricity and paraffin. Emergent patterns of domestic coal combustion, driven in part by various societal dimensions, are also observed. Further, despite the previously observed increase in respiratory ailments in winter, township residents do not think that such increases are linked to domestic coal combustion. The study, as shown here, is in line with theories of the energy ladder which posits that as people’s financial situations improve, their energy-use patterns change. Indoor aerosol concentrations followed the same trends in all selected households with morning and evening peaks. These peaks are directly related to the making of coal fires. The highest aerosol levels, reaching a maximum of 2344.89 μg.m-3, are recorded in the un-electrified coal-burning household. Aerosol concentrations are slightly lower, averaging 1854.07 μg.m-3, in the electrified coal-burning household, implying a slight decrease in the amount of coal burnt. The lowest aerosol concentrations, averaging 478.74 μg.m-3, are recorded in the electrified household with no coal-burning. Elemental analysis reveals that the biggest contributor to respirable particles in KwaGuqa is soil dust followed by coal smoke, and then emissions from neighbouring steel smelters, whilst traffic emissions are the lowest contributor. Most importantly, it is people’s activities that determine the type and levels of respirable aerosols that they are exposed to as compared to the fuel-use patterns and types of fuels used in their household. In conclusion, electrification might phase out domestic coal combustion in the long term but only if the economic status of coal users improves. Alternatively, there is an opportunity to reduce emissions by introducing a low-smoke solid fuel, however, households will only use it if it is priced competitively and its heating and ignition properties are similar to, or better than, those of coal.