نتایج جستجو برای: coal dust
تعداد نتایج: 72607 فیلتر نتایج به سال:
SUBJECTS On the basis of changes seen in the chest x ray films 95 male anthracosilicotic patients were recruited with the study. They included 24 suspected cases, 25 cases in category 1, 24 in category 2, and 22 in category 3. In addition, the study included 20 cases of anthracosilicotuberculosis. The ages of the subjects ranged from 32 to 73 (mean 48-7 +±9.1) with a working life from six to 34...
According to statistics, the coal spontaneous combustion fire accounted for more than 94% of the total number of coal mine fire, of which 60% occur in gob [1]. With the mining depth increasing, coal pillar become so easy to be crushed that coal spontaneous combustion is easier to occur. The fire’s occurrence and development not only affect the safety in production and the surrounding environmen...
Abstract: In order to find the main direction of energy saving and emission reduction in coal mine areas, this paper established a system dynamic model for energy consumption and environmental pollution produced in coal mining process, and took a typical coal mine as the case to simulate the energy saving and emission reduction in coal mining area. And through the analysis of simulation results...
The association between exposure to dust and pulmonary function was studied by longitudinal and cross sectional analyses in a group of United States underground coal miners beginning work in or after 1970. Quantitative estimates of exposure to respirable coal mine dust were derived from air samples taken periodically over the entire study period. The cohort included 977 miners examined both in ...
Research published in this journal and elsewhere has demonstrated an increased risk of pneumoconiosis and more recently chronic obstructive pulmonary disease among coal miners. Despite this extensive research base, many puzzles remain such as the deficit of lung cancer reported in many studies of coal miners. These findings are surprising since in addition to coal dust, miners are exposed to ot...
Mineral dust exposure can result in emphysema and chronic airflow obstruction. We postulated that dust-induced emphysema has a pathogenesis similar to that in cigarette smoke-induced emphysema, namely, excess release of proteolytic enzymes from dust-evoked inflammatory cells, and inactivation of alpha-1-antitrypsin (A1AT) by dust-catalyzed formation of oxidants. To test this theory we examined ...
The usefulness of pulmonary carcinogenicity data from rats exposed to high concentrations of particles for quantitatively predicting lung cancer risk in humans exposed to much lower environmental or occupational concentrations has been questioned. The results of several chronic inhalation bioassays of poorly soluble, nonfibrous particles have suggested that rats may be more prone than other rod...
OBJECTIVE To investigate if blood Cu++/Zn++ superoxide dismutase, glutathione peroxidase, catalase, and total plasma antioxidant activities could be markers of biological activity resulting from exposure to respirable coal mine dust in active miners, and of pneumoconiosis in retired miners. METHODS Blood samples were randomly obtained from active surface workers (n = 30) and underground miner...
The current carcinogenicity study with female rats focused on the toxicity and carcinogenicity of intratracheally instilled fine and ultrafine granular dusts. The positive control, crystalline silica, elicited the greatest magnitude and progression of pulmonary inflammatory reactions, fibrosis and the highest incidence of primary lung tumors (39.6%). Addition of poly-2-vinylpyridine-N-oxide dec...
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