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In the mining process of working face, the additional stress generated by the fault changes the law of roadway deformation and failure as well as the law of overburden failure. Aiming at the influence of the fault in the mining process of working face, this study introduced the geological strength index (GSI) to analyze the stress distribution in the elastic-plastic zone of the surrounding rock of the roadway. And similar experiments under different engineering backgrounds were combined to study the characteristics of overburden movement and stress evolution. Based on the conclusions obtained, the roadway support scheme was designed. This study shows that, compared with ordinary mining, through-the-fault mining causes slippage and dislocation of the fault, the load of the overburden is transferred to both sides of the fault, and the stress near the fault accumulates abnormally. The "three zones" characteristics of the overburden movement disappear, the subsidence pattern is changed from "trapezoid" to "inverted triangle", and the influence distance of the advanced mining stress on the working face is extended from 20m to 30m. The instability range of roadway surrounding rock is exponentially correlated with the rupture degree of the surrounding rock. Through the introduction of GSI, the critical instability range of roadway surrounding rock is deduced to be 2.32m. According to the conclusion, the bolt length and roadway reinforced support length are redesigned. Engineering application shows that the deformation rate of the roadway within 60 days is controlled below 0.1~0.5mm/d, the deformation amount is controlled within 150mm, and the roadway deformation is controlled, which generally meets the requirements of use. The research results provide guidance and reference for similar roadway support., Competing Interests: The author(s) declare no competing financial interests.

Measurement while drilling is an important part of the intelligent development of coal mines. The main purpose of this paper is to comprehensively analyze the response characteristics of borehole drilling parameters and find a better method to predict rock mechanical properties based on drilling parameters. Firstly, six concrete blocks and multiple specimens were prepared with different material ratios. Next, the concrete specimens were tested for mechanical properties in the laboratory. Meanwhile, the displacement, rotation speed, torque, and sound pressure level (SPL) were observed during the drilling of the concrete blocks. Finally, the response characteristics of drilling parameters such as rotation speed, rate of penetration (ROP), torque, and SPL were analyzed. Besides, multiple prediction models of rock mechanical parameters were obtained by data analysis. The research results indicate that the drilling process can be classified into the initial stage of drilling (fast speed) and the steady stage of drilling (slow speed). The torque work ratio accounts for more than 99%, which increases with the increase in rock strength. The penetration depth per revolution and torque work ratio are significantly related to rock uniaxial compressive strength, Brazilian tensile strength, cohesion, and elastic modulus. The ROP is the best choice for estimating rock mechanical parameters. This research provides an important reference for laboratory rock mechanics parameter testing and geological features detection based on drilling parameters., Competing Interests: The authors have declared that no competing interests exist.

To investigate the influence of bedding structure and different loading rates on the dynamic fracture characteristics and energy dissipation of Datong coal, a split Hopkinson bar was used to obtain the fracture characteristics of coal samples with different bedding angles. The process of crack initiation and propagation in Datong coal was recorded by the high-speed camera. The formula for the model I fracture toughness of the transversely isotropic material is obtained on the basis of the finite element method (FEM) together with the J-integral. By comparing the incident energy, absorbed energy, fracture energy and residual kinetic energy of Datong coal samples under various impact speeds, the energy dissipation characteristics during the dynamic fracture process of coal considering the bedding structure is acquired. The experimental results indicate that the fracture pattern of notched semi-circular bending (NSCB) Datong coal is tensile failure. After splitting into two parts, the coal sample rotates approximately uniformly around the contact point between the sample and the incident rod. The dynamic fracture toughness is 3.52~8.64 times of the quasi-static fracture toughness for Datong coal. Dynamic fracture toughness increases with increasing impact velocity, and the effect of bedding angle on fracture toughness then decreases. In addition, the residual kinetic energy of coal samples with the same bedding angle increases with the increase of impact speed. The energy utilization rate decreases continuously, and the overall dispersion of statistical data decreases gradually. In rock fragmentation engineering, the optimum loading condition is low-speed loading regardless of energy utilization efficiency or fracture toughness. These conclusions may have significant implications for the optimization of hydraulic fracturing process in coal mass and the further understanding of crack propagation mechanisms in coalbed methane extraction (CME). The anisotropic effect of coal should be fully considered in both these cases., Competing Interests: The authors have declared that no competing interests exist.

The decision matrix method is preferred as a measure of risk evaluation considering the risk value obtained by two risk factors such as the likelihood and severity of a hazard. However, it has some deficiencies since a crisp risk score is assigned for likelihood and severity. In this article, a fuzzy logic-based safety evaluation method to enhance the risk assessment process is introduced to overcome the uncertainties encountered in the classical decision matrix risk assessment method. The proposed method is a more realistic evaluation of the risks which may be available in mechanized coal mines in Turkey. In this way, risky situations and operations in mechanized underground coal mines have been determined by expert knowledge and engineering judgement in linguistic forms. Thus, such an evaluation will be a valuable guide for coal mines in which fully mechanized coal production is expected in the near future.

Purpose of Review: To review the impact of coal mining and resurgence of coal workers' pneumoconiosis (CWP) in 21st century and effect of ambient air pollution on lung function., Recent Findings: At the beginning of 21st century, statistics by National Institute for Occupational Safety and Health showed a steep rise in pneumoconiosis. This was followed by numerous epidemiologic and pathologic studies that confirmed increasing CWP prevalence as well as disease in younger miners and those with a shorter mining tenure. Recent studies have demonstrated that poor dust control in mines, a relative shift in composition of the coal mine dust, small sized mines and increase in surface mining are all possible contributors to this resurgence. There is also growing literature evaluating the effects of worsening air pollution on health, including decreasing lung function and development of emphysema, worsening quality of life measures and lung cancer., Summary: This irreversible but preventable disease currently haunts approximately 60 000 miners across United States and millions across the world. Its resurgence despite the strict dust regulations is a setback from the public health standpoint. The continued reliance on coal for energy will continue to place coal miners at danger of developing disease as well as the world.

Background: Investigation of the safety management efficiency in a coal mine aims to improve its safety management level thus ensuring coal mining safety. However, the safety management efficiency is affected by many factors especially for those coal mines operated underground. Furthermore, the constraint factors that are difficult to be identified and eliminated may impede safety management efficiency., Objective: This work aims to explore the constraints affecting safety management efficiency through a mathematical model accompanied by some effective measures guided by the theory of constraint (TOC)., Methods: An index system for coal mining safety management efficiency (CMSME) is first established. Then a mathematical model roughly identifying the constraint factors is constructed. The principle of the proposed model is a comparison with the changes of the ratio of integrated CMSME and the ratio of each impact factor over a certain period. Thus, a constraint factor may be one whose ratio changes at a slower rate than that of the integrated CMSME. Following this, some measures are adopted to identify one, or more, real constraints. Finally, the constraints may be broken by internal, or external, means., Results: A case study from Quandian coal mine verified the proposed method: the constraints affecting CMSME could be identified and broken through during the production. This research currently is applied to coal mining activities in a few coal mines, and it will be widely used in the future., Conclusions: This paper provides a novel method investigating the constraints affecting CMSME and breaking through them. The case study shows that breaking through constraints during the production is beneficial to CMSME. Furthermore, a coal mine with a high CMSME index may still, at some time, have one, or more, bottleneck constraints.

This study aimed to provide a greater understanding of the systemic factors involved in coal mine accidents and to examine the relationships between the contributing factors across all levels of the system. Ninety-four extraordinarily major coal mine accidents that occurred in China from 1997 to 2011 were analyzed using the human factors analysis and classification system (HFACS). The empirical results showed that the frequencies of unsafe behaviors, inadequate regulation and failure to correct hidden dangers were the highest among five levels, 14 categories and 48 indicators, respectively. The odds ratio technique was applied to quantitatively examine the relationships between contributing factors. Various statistically significant associations were discovered and should receive greater attention in future attempts to develop accident measures. In addition, several strategies concerning the main contributing factors and routes to failure are proposed to prevent accidents from reoccurring in an organization.

This paper intends to use data to verify the correlation between safety culture, safety management system and safety knowledge, safety awareness, and safety habits, which is the correlation between the various parts of the behavior safety "2-4" model. Due to data limitations, the results are limited to the study of safety culture related relationships in coal mining enterprises. This paper first designed a questionnaire containing 30 questions, of which 1⁻5 questions represent safety culture, 6⁻22 questions represent safety management system, and 23⁻30 questions represent safety knowledge, safety awareness and safety habits. Employees of 27 coal mining enterprises in Shandong, Henan, Hunan and other places in China were surveyed and sampled by stratified random sampling, and 1514 valid questionnaires were obtained. After item analysis and correlation analysis, and it was found that, within the data of 1514 questionnaires, the item total correlation coefficients of questions 6, 9, 19 and 28 were all less than 0.2, indicating that the identification degree of these four items was poor, which was deleted. Using the data analysis of the remaining 26 questions in the questionnaire, it was found that the relationship between safety culture and the safety management system, the safety management system and safety knowledge, and safety awareness and safety habits is moderately related; safety culture and safety knowledge, safety awareness and safety habits are weakly related. The conclusion shows that the safety culture directly affects the safety management system; the safety management system directly affects the safety knowledge, safety awareness and safety habits; the safety culture indirectly affects safety knowledge, safety awareness and safety habits. However, why the expected strong correlation is not achieved, and whether the same conclusion can be obtained if the data scale is expanded or other types of enterprises are added for questionnaire measurement, these are questions worthy of further study, which is also the author's next research content.

Spontaneous combustion of coal is one of the major hazards threatening production safety during longwall mining. Mining-induced voids, which provide passages for air leakage, are the key factor triggering spontaneous combustion of coal in longwall goafs. In this study, a comprehensive method, which combined pressure balance, grouting injection, and filling fissures, was proposed to prevent spontaneous combustion of coal in longwall goafs with complex air leakage. Field engineering practice was carried out in Sitai Coal Mine in China. The results demonstrated that with the application of the proposed method, in the working face, the concentration of CO was decreased from 31ppm to 0 and the air leakage quantity was decreased from 261 to below 80 m3min-1. The gas samples analysis from the gob areas also indicated that concentrations of O2 and CO were successively decreased, indicating that the risk of spontaneous combustion of coal in goafs was eliminated. The above mentioned analysis indicates that, the method proposed in this study is useful and efficient. Successful application of this technology could provide reference for the treatment of other coal mines., Competing Interests: This commercial affiliation (Sitai Coal Mine) along with any other relevant declarations relating to employment, consultancy, patents, products in development, or marketed products, etc., does not alter our adherence to PLOS ONE policies on sharing data and materials.

During coal surface mining, several activities such as drilling, blasting, loading, and transport produce large quantities of particulate matter (PM) that is directly emitted into the atmosphere. Occupational exposure to this PM has been associated with an increase of DNA damage, but there is a scarcity of data examining the impact of these industrial operations in cytogenetic endpoints frequency and cancer risk of potentially exposed surrounding populations. In this study, we used a Geographic Information Systems (GIS) approach and Inverse Distance Weighting (IDW) methods to perform a spatial and statistical analysis to explore whether exposure to PM 2.5 and PM 10 pollution, and additional factors, including the enrichment of the PM with inorganic elements, contribute to cytogenetic damage in residents living in proximity to an open-pit coal mining area. Results showed a spatial relationship between exposure to elevated concentrations of PM 2.5, PM 10 and micronuclei frequency in binucleated (MNBN) and mononucleated (MNMONO) cells. Active pits, disposal, and storage areas could be identified as the possible emission sources of combustion elements. Mining activities were also correlated with increased concentrations of highly enriched elements like S, Cu and Cr in the atmosphere, corroborating its role in the inorganic elements pollution around coal mines. Elements enriched in the PM 2.5 fraction contributed to increasing of MNBN but seems to be more related to increased MNMONO frequencies and DNA damage accumulated in vivo. The combined use of GIS and IDW methods could represent an important tool for monitoring potential cancer risk associated to dynamically distributed variables like the PM., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Objective: To explore the difference of cumulative incidence rate of coal workers' pneumoconiosis (CWP) among four large state-owned coal enterprises in northern China, we created an index system for evaluating the quality of comprehensive measures against CWP and applied the system to evaluate and compare the measures of the four coal enterprises., Methods: A two-round Delphi investigation was conducted to identify the indicators in the index system. The weight values of the indicators were calculated with analytic hierarchy process methods. Measures of CWP, mine annals, records and other information in each coal mine of the four enterprises were collected. The evaluation scores, which ranged from 0 to 100, were calculated and compared with., Results: A three-grade index system with 3 first-grade indicators, 9 second-grade indicators and 44 tertiary-grade indicators was established. The expert authority coefficient ( C r ) was 0.75 and the Kendall's coefficient of concordance (Kendall's W ) was 0.15 (χ 2 =193.30, P<0.001). The weight value of 'Geological conditions' was 0.43, equal to 'Dust control engineering technology', and that of 'Occupational health management' was 0.14. The medians and quartiles of the evaluation scores of comprehensive measures against CWP of the four enterprises were 58.38 (54.60~63.02), 64.63 (60.83~67.06), 72.99 (68.92~77.67) and 75.07 (70.73~79.20), respectively., Conclusions: The index system could be effectively used for evaluation and comparison of the comprehensive measures against CWP among different enterprises. The geological conditions and dust control engineering technology played an important role in preventing and controlling CWP., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

In the context of underground coal mining industry, the increased economic issues regarding implementation of additional safety measure systems, along with growing public awareness to ensure high level of workers safety, have put great pressure on the managers towards finding the best solution to ensure safe as well as economically viable alternative selection. Risk-based decision support system plays an important role in finding such solutions amongst candidate alternatives with respect to multiple decision criteria. Therefore, in this paper, a unified risk-based decision-making methodology has been proposed for selecting an appropriate safety measure system in relation to an underground coal mining industry with respect to multiple risk criteria such as financial risk, operating risk, and maintenance risk. The proposed methodology uses interval-valued fuzzy set theory for modelling vagueness and subjectivity in the estimates of fuzzy risk ratings for making appropriate decision. The methodology is based on the aggregative fuzzy risk analysis and multi-criteria decision making. The selection decisions are made within the context of understanding the total integrated risk that is likely to incur while adapting the particular safety system alternative. Effectiveness of the proposed methodology has been validated through a real-time case study. The result in the context of final priority ranking is seemed fairly consistent.

Introduction: Senior managers' attitudes towards safety are very important regarding the safety practices in an organization. The study is to describe the current situation of senior managers' attitudes towards safety in the Chinese coal industry. Method : We evaluated the changing trends as well as the reasons for these changes in the Chinese coal industry in 2009 and in 2014 with 168 senior manager samples from large Chinese state-owned coal enterprises. Evaluations of 15 safety concepts were performed by means of a questionnaire. Results and Conclusions : Results indicate that, in 2014, three concepts were at a very high level (mean > 4.5), and six were at a relatively high level (4.5 > mean > 4.0). Analyses of changing trends revealed that nine concepts improved significantly, while four greatly declined in 2014 compared to those in 2009. The data reported here suggest that the reasons for the significant improvement with respect to the nine concepts include the improvement in social and legal environments, the improvement of the culture of social safety, workers' safety demands being met, and scientific and technical advances in the coal industry. The decline of the four concepts seemed to be caused by a poor awareness of managers in the coal industry that safety creates economic benefits, insufficient information on safety, inadequate attention to the development of a safety culture and safety management methods, and safety organizations and workers' unions not playing their role effectively. Practical Applications : We therefore recommend strengthening the evidence that safety creates economic benefits, providing incentives for employees to encourage their participation in safety management, and paying more attention to the prevention of accidents in coal mines via safety organizations and unions. These results can provide guidelines for workers, industrialists, and government regarding occupational safety in the whole coal industry., Competing Interests: The authors declare no conflict of interest.

This study is a continuation of (Report I) identification of the occupational risk of arterial hypertension (AH) in 13 occupational groups (3842 workers, men). In previous work there was eliminated the influence of traditional factors of the cardiovascular risk, in this study there was implemented the identification of the components of a healthy worker effect (HWE) and the elimination of their influence on the occupational risks of hypertension. Identification and removal of components HWE--the effect of a healthy recruitment (EHR) and the effect of the healthy worker persisting to work (EHWPW--was carried out by the analytic rearranging of the standardized for age and obesity prevalence rate of arterial hypertension with the use of own methodological approaches. For the determination of the presence and severity of EHR there was performed an analysis of the initial prevalence rate of arterial hypertension in the youngest age groups (under 31 years). To overcome HER standardized for age and obesity indices of the arterial hypertension prevalence rate were adjusted by the ratio of the frequency of arterial hypertension in the most young occupational and reference comparable groups. Identification of HWPW was executed by comparing the frequency of AH among workers retiring within 3 years from the occupational groups when compared to the whole sample. Then on the additional risk value there was adjusted the overall prevalence rate of AH in the occupation profession to overcome EHWPW. As a result of the consistent correction and elimination of the influence of HWE components on the prevalence rate of AH, there were obtained risks values, primarily reflecting the impact of occupational factors which can be considered as true occupational risks. Factors of the cardiovascular risk and HWE significantly modified true occupational risks for AH in a number of occupational groups up to inversion. At the same time, the pronouncement of EHR has a paramount importance in the modifying effect.

Coal in India is extracted generally by semi-mechanized and mechanized underground mining methods. The Bord and Pillar (B & P) mining method still continues to be popular where deployment of manual miners is more than that of other mining methods. The study is conducted at haulage based mine of Eastern Coalfields of West Bengal. Underground miners confront with a lot of hazards like extreme hostile environment, awkward working posture, dust, noise as well as low luminosity. It is difficult to delay the onset of fatigue. In order to study the physiological responses of trammers, various parameters like working heart rates, net cardiac cost and relative cardiac cost including recovery heart rate patterns are recorded during their work at site. Workload classification of trammers has been done following various scales of heaviness. The effect of environment on the physiological responses has been observed and suitable recommendations are made. The work tasks are bound to induce musculoskeletal problems and those problems could be better managed through rationalizing the work-rest scheduling.

Coal and gas outbursts have always been a serious threat to the safe and efficient mining of coal resources. Ground stress (especially the tectonic stress) has a notable effect on the occurrence and distribution of outbursts in the field practice. A numerical model considering the effect of coal gas was established to analyze the outburst danger from the perspective of stress conditions. To evaluate the outburst tendency, the potential energy of yielded coal mass accumulated during an outburst initiation was studied. The results showed that the gas pressure and the strength reduction from the adsorbed gas aggravated the coal mass failure and the ground stress altered by tectonics would affect the plastic zone distribution. To demonstrate the outburst tendency, the ratio of potential energy for the outburst initiation and the energy consumption was used. Increase of coal gas and tectonic stress could enhance the potential energy accumulation ratio, meaning larger outburst tendency. The component of potential energy for outburst initiation indicated that the proportion of elastic energy was increased due to tectonic stress. The elastic energy increase is deduced as the cause for a greater outburst danger in a tectonic area from the perspective of stress conditions.

I examine the dismissal of coal mine dust as a mere nuisance, not a potentially serious threat to extractive workers who inhaled it. In the 1930s, the US Public Health Service played a major role in conceptualizing coal mine dust as virtually harmless. Dissent from this position by some federal officials failed to dislodge either that view or the recommendation of minimal limitations on workplace exposure that flowed from it. Privatization of regulatory authority after 1940 ensured that miners would lack protection against respiratory disease. The reform effort that overturned the established misunderstanding in the late 1960s critically depended upon both the production of scientific findings and the emergence of a subaltern movement in the coalfields. This episode illuminates the steep challenges often facing advocates of stronger workplace health standards.

Given the current insatiable demand for coal to build and fuel the world's burgeoning cities the debate about mining-related social, environmental and health injustices remains eminently salient. Furthermore, the core issues appear universally consistent. This paper combines the theoretical base for defining these injustices with reports in the international health literature about the impact of coal mining on local communities. It explores and analyses mechanisms of coal mining related injustice, conflicting priorities and power asymmetries between political and industry interests versus inhabitants of mining communities, and asks what would be required for considerations of health to take precedence over wealth., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

This final rule modifies the Department of Health and Human Services (HHS) regulations for medical examinations of underground coal miners. Existing regulations established specifications for providing, interpreting, classifying, and submitting film-based roentgenograms (now commonly called chest radiographs or X-rays) of underground coal miners. The revised standards modify the requirements to permit the use of film-based radiography systems and add a parallel set of standards permitting the use of digital radiography systems. An additional amendment requires coal mine operators to provide the National Institute for Occupational Safety and Health (NIOSH) with employee rosters to assist the Coal Workers' Health Surveillance Program in improving participation by miners.

This final rule announces updated requirements that the National Institute for Occupational Safety and Health (NIOSH or Agency), located within the Centers for Disease Control and Prevention (CDC) in the Department of Health and Human Services (HHS or Department), will employ to test and approve closed-circuit respirators used for escaping atmospheres considered to be immediately dangerous to life and health, including such respirators required by the Mine Safety and Health Administration (MSHA) for use in underground coal mines. NIOSH and MSHA jointly review and approve this type of respirator used for mine emergencies under regulations concerning approval of respiratory protective devices. NIOSH also approves these respirators for use in other work environments where escape equipment may be provided to workers, such as on vessels operated by U.S. Navy and Coast Guard personnel. The purpose of these updated requirements is to enable NIOSH and MSHA to more effectively ensure the performance, reliability, and safety of CCERs.

Context: Coal worker's pneumoconiosis is a major occupational lung disease in the United States. The disease is primarily controlled through reducing dust exposure in coal mines using technological improvements and through the establishment of dust standards by regulatory means., Objective: To determine if dust standards established in the US Federal Coal Mine Health and Safety Act of 1969 have reduced the prevalence and severity of coal worker's pneumoconiosis., Design: The study population included materials from 6103 deceased coal miners submitted to the National Coal Workers' Autopsy Study from 1971 through 1996. Type and severity of coal worker's pneumoconiosis were classified using standardized diagnostic criteria., Results: Among miners who worked exclusively prior to the 1969 dust standard, 82.6% had coal macules, 46.3% coal nodules, 28.2% silicotic nodules, and 10.3% progressive massive fibrosis. Lower prevalences were noted among miners exposed exclusively to post-1970 dust levels: 58.8% had coal macules, 15.0% coal nodules, 8.0% silicotic nodules, and 1.2% progressive massive fibrosis. The differences in prevalence were highly significant (P < .001) for all types of pneumoconiosis, including progressive massive fibrosis, after adjustment for age, years of mining, and smoking status., Conclusions: The study confirms a beneficial impact of the first 25 years of the dust standard established by the 1969 act on the prevalence and severity of coal worker's pneumoconiosis in US coal miners. However, pneumoconiosis continues to occur among miners who have worked entirely within the contemporary standard, suggesting a need for further reductions in exposure to respirable coal mine dust.

The scrutiny of underground coal mine safety was heightened because of the disasters that occurred in 2006-2007, and more recently in 2010. In the aftermath of the 2006 incidents, the U.S. Congress passed the Mine Improvement and New Emergency Response Act of 2006 (MINER Act), which strengthened the existing regulations and mandated new laws to address various issues related to emergency preparedness and response, escape from an emergency situation, and protection of miners. The National Mining Association-sponsored Mine Safety Technology and Training Commission study highlighted the role of risk management in identifying and controlling major hazards, which are elements that could come together and cause a mine disaster. In 2007 MSHA revised its approach to the "Pattern of Violations" (POV) process in order to target unsafe mines and then force them to remediate conditions in their mines. The POV approach has certain limitations that make it difficult for it to be enforced. One very understandable way to focus on removing threats from major-hazard conditions is to use citation-related reliability analysis. The citation reliability approach, which focuses on the probability of not getting a citation on a given inspector day, is considered an analogue to the maintenance reliability approach, which many mine operators understand and use. In this study, the citation reliability approach was applied to a stratified random sample of 31 underground coal mines to examine its potential for broader application. The results clearly show the best-performing and worst-performing mines for compliance with mine safety standards, and they highlight differences among different mine sizes., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

A monitoring method for diesel particulate matter was published as Method 5040 by the National Institute for Occupational Safety and Health (NIOSH). Organic and elemental carbon are determined by the method, but elemental carbon (EC) is a better exposure measure. The US Mine Safety and Health Administration (MSHA) proposed use of NIOSH 5040 for compliance determinations in metal and nonmetal mines. MSHA also published a rulemaking for coal mines, but no exposure standard was provided. A standard based on particulate carbon is not considered practical because of coal dust interference. Interference may not be a problem if an appropriate size-selective sampler and EC exposure standard are employed. Submicrometer dust concentrations found in previous surveys of nondieselized, underground coal mines were relatively low. If a large fraction of the submicrometer dust is organic and mineral matter, submicrometer EC concentrations would be much lower than submicrometer mass concentrations. Laboratory and field results reported herein indicate the amount of EC contributed by submicrometer coal dust is minor. In a laboratory test, a submicrometer EC concentration of 31 microg m(-3) was found when sampling a respirable coal dust concentration over three times the US compliance limit (2 mg m(-3)). Laboratory results are consistent with surveys of nondieselized coal mines, where EC results ranged from below the method limit of detection to 18 microg m(-3) when size-selective samplers were used to collect dust fractions having particle diameters below 1.5 microm-submicrometer EC concentrations were approximate 7 microg m(-3). In dieselized mines, submicrometer EC concentrations are much higher.

72 miners aged from 30 till 40 years have been surveyed. It was established that to achieve socially acceptable results the miners use corresponding strategy doing their job. Under the influence of the work the functional states mediated not only by conditions of working environment but also by resistivity of the organism are developed. It is shown that highly productive, reliable and effective work is possible under adequate interactions of central and autonomic mechanisms of regulation. Alteration in these interactions, particularly, non-adequate centralization of management processes decreases physical capacity for work. Enhancement of sympathetic effects on periphery that leads to development of hypertensive reactions has been observed. Such alterations are accompanied by an increase in physiological cost of work and decreased productivity of labor.

The goal of this study was to determine whether respiratory symptoms were associated with the lower concentrations of respirable coal mine dust that were required by the U.S. Coal Mine Health and Safety Act (CMHSA) of 1969. The subjects were 1,866 male miners who had participated in the National Study of Coal Workers' Pneumoconiosis (NSCWP) and been tested at least twice, initially in either Round 1 (R1) (1969-71) or Round 2 (R2) (1972-75) and then finally in Round 4 (R4) (1985-88). Self-reported information elicited with a standardized questionnaire was used to determine the presence at the final round (i.e., R4) of chronic bronchitis, shortness of breath, and wheeze. Cumulative coal mine dust exposure was characterized for both the pre- and post-CMHSA periods. Controlling for age and other potential confounders, increased risks for the symptoms were associated with higher levels of both measurements of exposure. Moreover, the adverse effects of the lower, post-CMHSA exposure were evident for shortness of breath and wheeze especially among subjects who had little pre-CMHSA coal mining experience. These findings provide additional evidence of the limitations of the current 2.0 mg/m3 coal mine dust standard to prevent respiratory disease.

Comparative studies on the impact of the detergents Emulkop and Rokafenol N-8 upon the development and course of experimental pneumoconiosis caused by mine dusts were carried out. Albino rats and rabbits were used for the experiment. Methodological assumptions were based on the analogy with the conditions observed at the workplaces where some means of dust control were used. The acute toxicity evaluation was based on determination of the medial lethal dose (DL50) after intragastric administration of the detergents. Irritating action of the detergents on the skin was also evaluated. The effect of the detergents on the aggressiveness of selected dusts was estimated by means of the intratracheal and intraperitoneal tests. At the end of the experimental period (3 and 6 months, respectively) histopathological investigations of the lungs and mediastinal lymph nodes were carried out, and the hydroxyproline (collagen) levels in the pulmonary tissue were determined. According to Hodge and Sterner Chemical Substance Toxicity Classifications, Emulkop has been classified as non-toxic, and Rokafenol N-8 as a weakly toxic substance. On the basis of the investigation results obtained it has been established that: 1) Rokafenol N-8 does not qualify for use in coal mines as a formulation designed for dust control because it doesn't eliminate coniotic changes and causes a significant increase in the level of hydroxyproline (collagen) in pulmonary tissue, 2) in the case of Emulkop our studies have shown that this detergent can be used to prevent pneumoconiosis in coal mine workers.

The aim of the study was to construct and test new equations for calculating FEV1, ITGV and FVC predictive values. Our examined population consisted of 2058 coal miners working underground in Bogdanka colliery (Lublin Basin). The following persons were excluded from out considerations: 1. smokers, 2. miners with pulmonary or allergic diseases history, 3. patients with chronic cough, sputum production or symptoms of chronic rhinitis, 4. persons with bronchial hyperreactivity. Finally, our standard group consisted of 353 coal miners. On the basis of our standard group data, new equations for calculating predictive values were formulated using the multiple regression model. According to these new equations and to equations elaborated by other authors, we calculated predictive values for FEV1, FVC and ITGV in our standard population and expressed results of measurements in percentages of different predictive values. Our predictive values in the standard population were significantly higher than the other authors' values. Percentages of predicted values were lower in the same comparison. We believe that observed differences are linked to a possible self-selection phenomenon in occupationally exposed population, relatively small maximum age of our standard group, possible differences in anthropometric features among examined populations and excluding hyperreactives. Our results seem to emphasize the need of greater attention to the paid on more restrictive use of the specially formulated equations in separate age compartments.

Reliability of mine foremen influences greatly the group microclimate, productivity and safety of work in mines. Engineering and technical personnel with high level of professional reliability shows the best parameters of psychophysiologic status. Criteria are worked out to score the most informative psychophysiologic functions in mine foremen during the preliminary and regular check-ups of such personnel.

Lipid and antioxidant state of clinically normal subjects working in deep mines was studied under natural conditions during one month. Disorders in lipid metabolism and intensified peroxidation were recorded in these subjects. A prophylactic ration has been recommended considering the food status, alimentary risk factors and extreme conditions of miners' labour.

Pulsimetry proved to be the most acceptable method for estimating energy requirements of miners working under extreme conditions with constantly changing ergometric parameters. It has been established that the mean daily energy requirements of miners working in deep coal mines under conditions of high temperature comprise 3500 kcal. Energy requirements for the main types of the physical activity of workers in deep mines have been calculated, basing on basal metabolism, metabolic constants for varying activities have been determined.

Based on the original analysis of the data pertaining to labour routes and the peculiarities of job-placement in mines, the article summaries the hygienic principles for job-placement of coal-miners and provides classification criteria for labour routes in mines. An expert analysis is provided of 146 professions and occupations in coal-mining for workers with different health states and labour ability conditions.

200 newly-engaged young miners were medically examined in an outpatient department. The routine examination techniques were supplemented with studies of the changes after 2 minute-long inhalations of 0.6% acetylcholine chloride and mine dust (78 mg/m3), hemodynamics and electrocardiography indices, as well as the indices of the immunologic and hormonal state. Established was diversified manifestations of the respiratory tract's response to the aerogenic irritations, combined with deviations in the immunologic state indices. The studies provide basis for further improvements in the preventive examination techniques for workers in coal-mining industries.

Vegetative equilibrium disorders in hypertensive-diseased miners resulted from pathologic developments in the limbic -reticular structures. Those were characterized by a hyperfunction of the ergotropic nerve formations. The vegetative control reorientations were accompanied by narrowing the amplitude of the homeostatic regulation vegetative reactions and engaging the mechanisms of adaptation. The vegetative state stabilization in the diseased workers was attained through a partial avoiding ot the most labour-intensive forms of activity and choosing more preferable labour operations. But the latter did not entirely exclude the labour conditions which would result into inadequate vegetative reactions.

The article contains data on the results of the on-the-spot studies of coal mine controllers' labour conditions and relating hygienic factors. It was established that the work at the dispatcher's control point in coal mines was considerably affected by unfavourable factors (low degree of illumination, constructional shortcomings of the control point and seat) with concomitant neuropsychic stress conditions. Revealed were specific functional shifts in CVS and CNS, neuromuscular disorders and the analyzers' malfunctioning. A set of measures was proposed for labour conditions improvement, ergometric perfection of the working place and reduction of neuroemotional tension.

The contributors proposed a differentiated diagnostic technique which included 10 most informative physiologic, anthropometric and biochemical+ indices to provide the most reliable data (95% reliability) on the adaptation and compensatory mechanisms under local vibration and in combination with noise and dust, and with due account of the individual sensitivity to local vibration. Testing of the technique demonstrated its high accuracy in determining the levels of "exhaustion", and of "the normal state" of the adaptation-compensatory mechanisms, and its applicability for vibration disease prognosis in individual++ workers, thus establishing corresponding in preventive medical examinations, occupational selection, preventive measures' planning, and in expert solutions requiring precise diagnostic techniques.

The article deals with the methological issues of preventive measures in the process of technological restructuring of mines in the Russian Federation, with due account of the hygienic stratification of different mines as to the degrees of the labour conditions' potential hazardness, regularities in and prognostics of occupational pathologies decreases and morbidity with temporary disability rates.

The article proposes results of research into exhausts' major components absorption in accumulated and floating dusts in ore mines in which self-propelled diesel vehicles are predominantly used. It was established that ore-mine aerosol particles had a large specific surface and contained a high percentage of carbon-black (1,1-35.1%). Different results were received for both organic and non-organic substances' sorption indices. In the samples, in addition to 3,4-benzapyrene, 11 more polycyclic aromatic hydrocarbons were identified, with concentrations 10-15 times higher than those of 3,4-benzapyrene.

Among the factors producing effects on the formation of indexes of morbidity of the people working in Donbass, the main role is played by the ecological situation in the region, working conditions and lifestyle of the working people. On the basis of morbidity indexes analysis proposals and measures aimed at the preservation and improvement of health of the working people are formulated.

The pattern of forming of the adaptational process to occupational-industrial factors of working in a coal mine depending on the conditions of carrying out practical work was determined. It was found out that the adaptation of young boys to the working activity in deep horizons was accompanied by a more marked tension of the functional status and regulation mechanisms compared to working in less deep horizons.