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.

Objetivo. No Brasil encontram-se em crescimento os índices de prevalência das doenças crônicas causadas pela exposição dos trabalhadores a poeiras minerais. Realizou-se estudo com objetivo de avaliar as condições de trabalho e de saúde dos trabalhadores em marmorarias e propor ações preventivas. Métodos. Realizou-se estudo transversal em 27 marmorarias, no Município de São Paulo que executavam o beneficiamento final de rochas ornamentais, incluindo: a) avaliação da exposição a poeiras e à sílica cristalina respirável por meio de coleta de amostras de ar (n=762), análise por gravimetria e Difração de Raios X e acumulação das exposições estimadas por função conforme história ocupacional; b) aplicação de questionário de sintomas respiratórios (n=267) e avaliação médica, por espirometria e radiogradia de tórax; d) correlação dos resultados de exposição acumulada com achados clínicos e radiológicos por meio de análises estatísticas; e) levantamento de informações sobre os processos de trabalho e alternativas de controle. Resultados. Para os acabadores encontrou-se a maior exposição: concentração de 0,36 mg/m³ (IC95% 0,29 e 0,42) para os granitos e de 0,19 mg/m3 (IC95% 0,16-0,22) para a mistura de matérias-primas. Para estimativa de exposição acumulada à sílica cristalina respirável com mediana de 0,56 mg/m3-anos existiu risco de Odds Ratio igual a 1,2 (IC95% 1,02-1,40) de o trabalhador exposto apresentar classificação radiológica com alterações, presença de pequenas opacidades - profusão ³ 0/1, em relação a um trabalhador não-exposto. A população possuía baixo nível de escolaridade e de renda familiar, com média de idade 35,8 (±11,6) anos. Conclusões. Há exposição excessiva à sílica cristalina respirável nas marmorarias, com valores de concentração ultrapassando até 54 vezes o valor de referência recomendado pela NIOSH 0,05 mg/m3. As matérias-primas mais perigosas foram rochas silicáticas (silestoneÒ, granitos, arenitos e quartzitos). Entre as medidas de controle para as poeiras, caracterizaram-se como mais eficientes as aplicadas a úmido em máquinas e ferramentas. / Objective. In Brazil it can be seen growing prevalence rates of chronic diseases due to occupational exposure to mineral dusts, being silicosis the greater prevalence of pneumoconiosis. A study was carried out with the aim to evaluate the work conditions and of the workers’ health in granite and marble sheds and to propose preventive actions. Methods: A cross sectional study was performed among 27 sheds in Sao Paulo county that perform the finishing work of ornamental rocks. The study included: a) evaluation of dust exposure and respirable crystalline silica, by means of air sampling (n=762), analysis by gravimetry and X-Ray diffraction, and cumulative silica exposure estimates in each job according to the occupational history; b) applying a questionnaire of respiratory symptoms (n=267) and medical evaluation, espirometry and chest X-Ray; d) results correlation of cumulative exposure with the clinical and radiological data by statistical means; e) search of working process information and control alternatives. Results: Finishing workers had the greater exposition: concentration of 0.36 mg/m3 (CI95% 0.29-0.42) for granites and of 0.19 mg/m3 (CI95% 0.16-0.22) for the mixture of raw materials. To the estimated cumulative exposure to respirable crystalline silica with median equal to 0.56 mg/m3-years there was a risk Odds Ratio =OR=1.20 (CI95%1.02 1.40) of the exposed worked to present an altered radiological classification with alterations, presence of small opacities - perfusion ≥0/1, in relation to a non exposed worker. The population studied had low scholar education and low familiar income, with average age 35.8 (±11,6) years. Conclusions: There is excessive exposure to respirable crystalline silica in sheds with concentrations 54 times over the recommended exposure limit by NIOSH of 0.05 mg/m3. The most dangerous raw materials were silicatious rocks (silestoneÒ, granites, sandstones and quartzites). Among the control measures for dusts, were characterized as more efficient the applied ones the humid in machines and tools.

Objetivo. No Brasil encontram-se em crescimento os índices de prevalência das doenças crônicas causadas pela exposição dos trabalhadores a poeiras minerais. Realizou-se estudo com objetivo de avaliar as condições de trabalho e de saúde dos trabalhadores em marmorarias e propor ações preventivas. Métodos. Realizou-se estudo transversal em 27 marmorarias, no Município de São Paulo que executavam o beneficiamento final de rochas ornamentais, incluindo: a) avaliação da exposição a poeiras e à sílica cristalina respirável por meio de coleta de amostras de ar (n=762), análise por gravimetria e Difração de Raios X e acumulação das exposições estimadas por função conforme história ocupacional; b) aplicação de questionário de sintomas respiratórios (n=267) e avaliação médica, por espirometria e radiogradia de tórax; d) correlação dos resultados de exposição acumulada com achados clínicos e radiológicos por meio de análises estatísticas; e) levantamento de informações sobre os processos de trabalho e alternativas de controle. Resultados. Para os acabadores encontrou-se a maior exposição: concentração de 0,36 mg/m³ (IC95% 0,29 e 0,42) para os granitos e de 0,19 mg/m3 (IC95% 0,16-0,22) para a mistura de matérias-primas. Para estimativa de exposição acumulada à sílica cristalina respirável com mediana de 0,56 mg/m3-anos existiu risco de Odds Ratio igual a 1,2 (IC95% 1,02-1,40) de o trabalhador exposto apresentar classificação radiológica com alterações, presença de pequenas opacidades - profusão ³ 0/1, em relação a um trabalhador não-exposto. A população possuía baixo nível de escolaridade e de renda familiar, com média de idade 35,8 (±11,6) anos. Conclusões. Há exposição excessiva à sílica cristalina respirável nas marmorarias, com valores de concentração ultrapassando até 54 vezes o valor de referência recomendado pela NIOSH 0,05 mg/m3. As matérias-primas mais perigosas foram rochas silicáticas (silestoneÒ, granitos, arenitos e quartzitos). Entre as medidas de controle para as poeiras, caracterizaram-se como mais eficientes as aplicadas a úmido em máquinas e ferramentas. / Objective. In Brazil it can be seen growing prevalence rates of chronic diseases due to occupational exposure to mineral dusts, being silicosis the greater prevalence of pneumoconiosis. A study was carried out with the aim to evaluate the work conditions and of the workers’ health in granite and marble sheds and to propose preventive actions. Methods: A cross sectional study was performed among 27 sheds in Sao Paulo county that perform the finishing work of ornamental rocks. The study included: a) evaluation of dust exposure and respirable crystalline silica, by means of air sampling (n=762), analysis by gravimetry and X-Ray diffraction, and cumulative silica exposure estimates in each job according to the occupational history; b) applying a questionnaire of respiratory symptoms (n=267) and medical evaluation, espirometry and chest X-Ray; d) results correlation of cumulative exposure with the clinical and radiological data by statistical means; e) search of working process information and control alternatives. Results: Finishing workers had the greater exposition: concentration of 0.36 mg/m3 (CI95% 0.29-0.42) for granites and of 0.19 mg/m3 (CI95% 0.16-0.22) for the mixture of raw materials. To the estimated cumulative exposure to respirable crystalline silica with median equal to 0.56 mg/m3-years there was a risk Odds Ratio =OR=1.20 (CI95%1.02 1.40) of the exposed worked to present an altered radiological classification with alterations, presence of small opacities - perfusion ≥0/1, in relation to a non exposed worker. The population studied had low scholar education and low familiar income, with average age 35.8 (±11,6) years. Conclusions: There is excessive exposure to respirable crystalline silica in sheds with concentrations 54 times over the recommended exposure limit by NIOSH of 0.05 mg/m3. The most dangerous raw materials were silicatious rocks (silestoneÒ, granites, sandstones and quartzites). Among the control measures for dusts, were characterized as more efficient the applied ones the humid in machines and tools.