This paper examines methods for limiting occupational silica exposures for roof bolting personnel in underground coal mining. A canopy air curtain and an air tube were evaluated as means to provide filtered air over the breathing zone of these personnel. Laboratory testing showed that dust reductions beneath the air curtain and air tube approached 60 percent and 40 percent, respectively, with l...

It is well recognised that exposure to respirable coalmine dust causes a reduction in lung function but it has not been clear whether the impairment of function is sufficient to cause disability, unless progressive massive fibrosis occurs. From a study of 4059 men without progressive massive fibrosis who worked in the coal industry for at least ten years from the 1950s, and who were followed up...

Diamond, the hardest of all minerals, was classed as an inert material, similar to anthracite and corundum, by Gardner (1938) on the basis of intravenous injection experiments in rabbits. By intraperitoneal injection into mice Bovet (1952) produced collagenous nodules in places where much diamond dust was accumulated. But it took six months to one year for such nodules to form as against a few ...

Since 1982 standard calibration materials recommended for respirable crystalline silica analysis by the Mine Safety and Health Administration (MSHA) P7 Infrared Method and the National Institute for Occupational Safety and Health (NIOSH) X-ray Diffraction (XRD) Analytical Method 7500 have undergone minor changes in size distribution. However, a critical assumption has been made that the crystal...

The Mine Safety and Health Administration (MSHA) specification for rock dust used in underground coal mines, as defined by 30 CFR 75.2, requires 70% of the material to pass through a 200 mesh sieve (<75 µm). However, in a collection of rock dusts, 47% were found to not meet the criteria. Upon further investigation, it was determined that some of the samples did meet the specification, but were ...

BACKGROUND COPD may develop due to variation in the functioning of antioxidants along with smoking and environmental factors in genetically susceptible individuals. Since there are different views about the antioxidants responsible for detoxifying xenobiotic compound in the human body whose functional variation may lead to obstructive disease, this associative study has been taken up between GS...

Disabilities of coal miners due to black-lung decease morbidities are rather high (up to 10 men per 1 million tons of mined coal). Besides that, dangerous to health biological activity is also proper to various carbon nanoparticles. The analysis of relationships between coal miner morbidities, biological activities of coals and bibliographical data has shown that: activity of coals is mainly de...