Respirable dust levels - surface work areas of underground coal mines and surface coal mines.
Explore the source record for details and available documents.
SEARCH · Search PubMed
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
Thirty-two cases (20.13%) of primary lung cancer from 159 coal miner autopsies of Beijing coal mining area are reported in this study. The ratio of peripheral type to central type of lung cancer is 1.9:1; among them the adenocarcinoma is the most frequent (56.25%). Pathological examination shows that the diffuse interstitial type is the most common lung cancer. The occurrence of adenocarcinoma and the degree of lung fibrosis is related. The average number of ferruginous bodies is 190.2 +/- 8.06 in adenocarcinoma, 165.4 +/- 2.60 in squamous carcinoma, the difference is statistically significant (P < 0.05). The amount of trace elements-Fe, Al, Al/Si and Zn/Cu in lung with cancer is less than that without cancer. This article also discusses the relationship between coal mine pneumoconiosis with lung cancer of the formation of ferruginous bodies in the lung tissue of coal miner autopsies, which resembles the lung cancer combined with asbestosis. We also discussed the carcinogenesis of trace element in lung.
Coal fly ashes (CFA) are complex particles of a variable composition, which is mainly dependent on the combustion process, the source of coal and the precipitation technique. Toxic constituents in these particles are considered to be metals, polycyclic aromatic hydrocarbons and silica. The purpose of this review was to study the in vitro and in vivo data on coal fly ash and relate the studied endpoints to the role of (crystalline) silica, considering its recent classification as a human carcinogen. For most of the effects coal mine dust was chosen as a reference, since it contains up to 10% of crystalline silica (alpha-quartz) and is well studied both in vivo and in vitro. Most studies on fly ash toxicity were not designed to elucidate the effect of its silica-content nor did they include coal mine dust as a reference. Taking this into account, both in vitro and in vivo experimental studies show lower toxicity, inflammatory potential and fibrogenicity of CFA compared to silica and coal mine dust. Although in vitro and in vivo studies suggest genotoxic effects of fly ash, the data are limited and do not clarify the role of silica. Epidemiological studies in fly ash exposed working populations have found no evidence for effects commonly seen in coal workers (pneumoconiosis, emphysema) with the exception of airway obstruction at high exposure. In conclusion, the available data suggest that the hazard of coal fly ash is not to be assessed by merely adding the hazards of individual components. A closer investigation of 'matrix' effects on silica's toxicity in general seems an obligatory step in future risk assessment on fly ashes and other particles that incorporate silica as a component.
Occupational exposure to coal mine dust causes coal workers' pneumoconiosis (CWP) and other pulmonary diseases by mechanisms that remain unclear. Because the hydroxyl radicals (.OH) may play an important role in the pathogenesis of CWP, we studied the potential role of bituminous coal mine dust samples for catalyzing the generation of .OH from hydrogen peroxide (H2O2). These coal mine dusts evaluated represented two geographic areas with diversity in CWP prevalence. Electron spin resonance (ESR), with the aid of spin trapping techniques, was used to measure the .OH radical generation. Bituminous coal mine dusts representing the Pittsburgh seam in the eastern United States and Blind Canyon seam in the mid-western United States were used together with a standard coal dust obtained from the National Institute of Standards and Technology, Gaithersburg, MD. All the coal mine dust samples generated varying levels of .OH radicals from H2O2 in the presence of a .OH spin trap 5,5-dimethyl-l-pyrroline-N-oxide (DMPO). .OH radical generation by the coal from H2O2 was effectively inhibited by deferoxamine and catalase, but only partially inhibited by superoxide dismutase. Metal chelators DETAPAC and EDTA enhanced the radical generation. These results indicated that the Fenton reaction is predominantly involved in the generation of .OH radicals from H2O2. The .OH-generating potential of all the coal dusts showed a positive correlation with the surface iron content of coal mine dusts. In addition, the potential to induce lipid peroxidation by the coal samples exhibited a good correlation with the available surface iron. Based on the results presented here, we propose that higher concentrations of surface iron in coal mine dust may be involved in the generation of increased levels of .OH radicals and may play an important role in the development of CWP in different coal mining areas.
Solvents like dichloromethane generally are used to yield exhausted extraction amounts of the organic compounds in coals. Leaching of coal mine dust by dichloromethane yields extracts with comparable amounts of alkanes, aromatics, and phenolic compounds. Dominantly phenolic compounds are leached from coal mine dust by aqueous solutions saturated in lecithin because of their high water solubility. High concentrations of phenolic compounds can be extracted from coal mine dust generated from low-rank coals. Phenolic compounds leached by fluids adapted to physiological conditions correlate with high cytotoxicities of the dust from low-rank coals. Adaptation of leaching fluids to physiological conditions allows a more realistic estimation of experiments. Coal mine dust with varying coal content of different ranks can be seen as a parameter reinforcing the cytotoxic potential of coal mine dust.
Underground U.S. coal miners were studied cross-sectionally for the association of respirable coal mine dust exposure with pulmonary function and symptoms of airways obstruction. The study group included 1,185 miners participating in Round 4 of the National Study of Coal Workers' Pneumoconiosis who had started mining in or after 1970 when comprehensive exposure regulations first came into effect. Quantitative estimates of cumulative exposure, derived using respirable dust measurements taken by the Mine Safety and Health Administration over the entire study period, were used in linear and logistic regression models on indicators of pulmonary function and chest symptoms while controlling for smoking status, pack-years, and other potential confounders. Statistically significant associations between log cumulative exposure and decrements in FVC, FEV1, and FEV1/FVC were observed. In logistic models, statistically significant associations of cumulative exposure with increasing prevalence of FEV1 and FEV1/FVC less than 80% predicted and symptoms including chronic phlegm, chronic bronchitis, breathlessness, wheeze, and wheeze with shortness of breath were found. It is concluded that exposures to respirable coal mine dust present in U.S. mines since 1970 continue to affect respiratory health in underground miners.
Coal-mine owners are required to measure miner exposures to respirable dust so that compliance with Federal health regulations can be monitored. This study analyzes the problem of possible underreporting of dust exposures. Using two statistical approaches, data for three mining occupations in 54 large underground coal mines during 1976-1978 are examined for evidence of underreporting. First, regression estimates compare dust concentrations reported by coal-mine owners with those reported by government health inspectors. Then, the statistical distribution of concentrations reported by coal-mine owners are examined for the size and nature of their deviation from log-normality. Both approaches suggest widespread underreporting.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Blood and urine content of electrolytes and creatinine was determined in 76 essentially healthy miners before and after work shift, as was activity of plasma renin, blood plasma level of aldosterone and its urinary excretion, with the aid of radioimmunoassay. The greatest activity of the renin-angiotensine-aldosterone system (RAAS) occurred in those individuals engaged in hard physical labour under most harsh conditions of underground workings, this being recordable not only is response to the load but also from the very start. Controls and miners doing jobs of medium-level strenuousness demonstrated changes in the correlations between RAAS and water-salt balance after the work shift as compared with those before the work shift, while in those miners engaged in hard work correlations RAAS-water-salt exchange remained practically the same throughout the study.
Analyses of structural aberrations of chromosomes and of the body burden of lead-210 were carried out in a group of workers occupationally exposed to chemical pollutants and low doses of ionizing radiation during a technological process in which coal is used as fuel. A parallel study was performed in a control group of workers. In the exposed group the percentage of chromatid and chromosome aberrations and the results of radiochemical analyses were higher than in the control group.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Mechanism underlying heat disorders in deep mine workers presents unidirectional changes on the background of adaptational process. Studies of clinical and functional state of the deep mine workers with heat disorders prove acute and chronic course of overheating.
The aim of this study was to determine the bronchoalveolar leukocyte response to airborne coal mine dust; quartz and titanium dioxide were used as positive and negative controls, respectively. Groups of rats were exposed to airborne mass concentrations of 10 and 50 mg/m3 of the dusts for 7 hr/day, 5 days/week and their bronchoalveolar space was lavaged at time points between 2 and 75 days of exposure, to assess the leukocyte response. This study revealed time-dependent and airborne mass concentration-dependent recruitment of neutrophils and macrophages into the bronchoalveolar region with coal mine dust inhalation but no real difference in the magnitude of the response between coal mine dusts from collieries mining coal of different rank and quartz content although the maximum quartz content in the dusts used was 6%. The inflammatory response was much less than that produced by quartz, at similar airborne mass concentrations, and more than that produced by titanium dioxide which was, in general, a poor inflammogen in the rat lung. Groups of rats were exposed to the airborne dusts for 32 or 75 days, then removed from the exposure chambers, and allowed to recover by breathing room air for a further 64 days. During this recovery period there was marked progression of the leukocyte response with quartz and persistence of the response with coal mine dust. Chronic recruitment of leukocytes to the lungs of individuals inhaling coal mine dust is likely to be an important factor in the development of coal workers' pneumoconiosis.
Historically coal mining populations have been reported to have elevated stomach cancer incidence rates. To identify which factors might be associated with cases who reside in these high risk areas, and specifically if particulate exposures from coal mining and coal utilization are associated with risk, a mining area of western Pennsylvania was defined for a retrospective case-control study. One hundred seventy-eight resident cases, identified from certificates of death, were compared to three controls: digestive cancer deaths, arteriosclerotic heart disease deaths, and neighborhood (living) controls. Controls were matched to each case on age, race, sex, and residence. Interviews were conducted during 1981 and 1982. Excess risks were shown for foreign born and eastern Europeans. Coal mining was not shown to be a risk factor for males, while an association was seen for female cases whose husbands were miners. Farming was a risk factor for males and females. Marked decreased risks were shown for gas heating and cooking fuels, with elevated risks for coal, wood and oil heating fuels, and wood cooking fuel. These findings are associated with lower socioeconomic status, and suggest environmental exposures or lifestyles that are directly and indirectly related to these risks factors. The marked inverse relationship between stomach cancer and use of gas heating and cooking fuel may be of important etiologic significance, especially in association with dietary changes. Further evaluation of prior use of various types of heating and cooking fuels needs to be considered especially using incident rather than case deaths.
Explore the source record for details and available documents.
Exposure of miners to respirable coal mine dust and to respirable quartz silica at surface coal mines in the United States during 1982-1986 were evaluated by job category using data collected by coal mine operators and Mine Safety and Health Administration (MSHA) inspectors. Average coal mine dust concentrations were usually well below the MSHA Permissible Exposure Limit (PEL) for all job categories, but at least 10% of the samples obtained from some coal preparation plant job areas and most drilling job areas had concentrations that exceeded the 2.0 mg/m3 limit. In contrast, a very high proportion of samples from surface mine driller areas exceeded the quartz PEL. Of all samples collected for highwall drill operators and helpers, 78% and 77%, respectively, were greater than the 0.1 mg/m3 quartz exposure limit (average concentrations were .32 and .36 mg/m3, respectively). Although MSHA compliance data may not be entirely adequate for assessing chronic exposure to quartz, these data and the results of other NIOSH studies nonetheless indicate excessive exposure to silica in a group of surface coal miners.