Chinese Coal Miners Research Articles

Associations of coal mine dust exposure with arterial stiffness and atherosclerotic cardiovascular disease risk in chinese coal miners.

Whether coal mine dust exposure increases cardiovascular diseases (CVDs) risk was rarely explored. Our objective was to examine the association between coal mine dust exposure and cardiovascular risk. We estimated cumulative coal mine dust exposure (CDE) for 1327 coal miners by combining data on workplace dust concentrations and work history. We used brachial-ankle pulse wave velocity (baPWV, a representative indicator of arterial stiffness) and ten-year atherosclerotic cardiovascular disease (ASCVD) risk to assess potential CVD risk, exploring their associations with CDE. Positive dose-response relationships of CDE with baPWV and ten-year ASCVD risk were observed after adjusting for covariates. Specifically, each 1 standard deviation (SD) increase in CDE was related to a 0.27m/s (95% CI: 0.21, 0.34) increase in baPWV and a 1.29 (95% CI: 1.14, 1.46) elevation in OR(odds ratio) of risk of abnormal baPWV. Moreover, each 1 SD increase in CDE was associated with a 0.74% (95% CI: 0.63%, 0.85%) increase in scores of ten-year ASCVD and a 1.91 (95% CI: 1.62, 2.26) increase in OR of risk of ten-year ASCVD. When compared with groups unexposed to coal mine dust, significant increase in the risk of arterial stiffness and ten-year ASCVD in the highest CDE groups were detected. The study suggested that cumulative exposure to coal mine dust was associated with elevated arterial stiffness and ten-year ASCVD risk in a dose-response manner. These findings contribute valuable insights for cardiovascular risk associated with coal mine dust.

Defining the Primary Work Stress Factors of Chinese Coal Miners-A Mixed-Methods Study.

Studies have indicated that coal miners in China have higher levels of perceived job stress. However, few studies have investigated the work stress structure of coal miners. Our study focused on the work stress of coal miners in China, with a primary aim to determine the work stress structure of coal miners in China using a mixed-methods approach. Semi-structured interviews were performed with thirty-three people (team leaders and frontline coal miners) conducted with participants from various state-owned large- and medium-sized coal mines in China. Grounded theory was used to construct an initial model for the concept of coal miners' work stress. Using the results of this initial survey and findings in the existing literature, we then constructed a preliminary questionnaire regarding coal miners' work stress and administered the questionnaire to 900 coal miners in the Shaanxi, Henan, Inner Mongolia, and Gansu provinces. The results show that the work stress structure for coal miners differs from that for other occupational types in China, due to differences in the Chinese culture and foreign cultural influences. We revised our questionnaire based on these considerations and administered a new survey to the frontline production workers in coal mines. The preliminary questionnaires were revised and analyzed through exploratory and confirmatory factor analysis, resulting in a final formal model for work stress, which was supported by content and structural validity. In this research, we used the framework of grounded theory to conduct an empirical analysis of the structure model of coal miners' work stress. The findings support that the primary work stress factors of Chinese coal miners included the stress of the work environment, job responsibility, interpersonal relationships, career development, the family environment, and organizational systems. Coal enterprises should therefore always take these factors into consideration when developing and implementing safety management policies aimed at to improve the occupational health status of coal miners.

Polymorphisms of adiponectin gene and gene-lipid interaction with hypertension risk in Chinese coal miners: A matched case-control study.

ObjectiveLow serum adiponectin level can predict hypertension development, and adiponectin gene (ADIPOQ) polymorphisms have been reported to be linked with hypertension risk. Whereas, the interaction between ADIPOQ polymorphisms and environmental factors on the susceptibility of hypertension remained unclear. The purpose of this study was to explore the relationship of ADIPOQ polymorphisms with hypertension risk and their interaction with lipid levels in coal miners.MethodsA matched case-control study with 296 case-control pairs was performed in a large coal mining group located in North China. The participants were questioned by trained interviewers, and their ADIPOQ genotype and lipid levels were determined. Logistic regression, stratified analysis, and crossover analysis were applied to evaluate the effects of rs2241766, rs1501299, and rs266729 genotypes and gene–lipid interaction on hypertension risk.ResultsIn this matched case-control study, the genotypes of rs2241766 TG+GG, rs1501299 GT+TT, and rs266729 CG+GG were marginally related to hypertension risk. Individuals with high total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) level were susceptible to hypertension (TC: odds ratio [OR] = 1.807, 95% confidence intervals [95%CI] = 1.266–2.581; LDL-C: OR = 1.981, 95%CI = 1.400–2.803; HDL-C: OR = 1.559, 95%CI = 1.093–2.223). Antagonistic interactions were detected between rs2241766 and TC, rs1501299 and TC, rs2241766 and LDL-C, and rs1501299 and HDL-C (rs2241766 and TC: OR = 0.393, 95%CI = 0.191–0.806; rs1501299 and TC: OR = 0.445, 95%CI = 0.216–0.918; rs2241766 and LDL-C: OR = 0.440, 95%CI = 0.221–0.877; rs1501299 and HDL-C: OR = 0.479, 95%CI = 0.237–0.967). Stratified analysis showed that hypertension risk was high for the subjects with rs2241766 TG+GG or rs1501299 GG under the low lipid level but low for those under the high lipid level. In the case group, the TC and LDL-C levels for rs2241766 TG+GG were lower than those for rs2241766 GG, and the TC and HDL-C levels for rs1501299 GT+TT were higher than those for rs1501299 GG.ConclusionsAlthough the effects of ADIPOQ polymorphisms alone were not remarkable, an antagonistic interaction was observed between ADIPOQ polymorphisms and lipid levels.

HIGH-FREQUENCY ULTRASOUND FOR DETECTING CHRONIC KNEE JOINT LESIONS IN MINERS: AN EXPLORATORY CONTROLLED STUDY

Objective: To explore the clinical value of high-frequency ultrasound in the detection of chronic knee injuries in miners. Methods: A total of 53 Chinese coal miners from the China, as well as 33 nonminers without history of knee conditions were prospectively examined using high-frequency ultrasound. Blood flow was observed using color Doppler flow imaging (CDFI) and power Doppler ultrasound (PDUS). In the event of slow blood flow, parameters for color Doppler were set to maximal gain and minimal noise. Results: Chronic knee joint injuries were detectable as lesions in bursa around the joint and infrapatellar soft tissues. Various proportions of miners had nodular, finger-like or focal protrusions extending from the bursa synovium into the synovial cavity. Such protrusions were observed in the suprapatellar bursa (15, 28.3%), prepatellar bursa (17, 32.1%), and deep infrapatellar bursa (4, 7.5%). Infrapatellar soft tissues were significantly thicker in miners ([Formula: see text][Formula: see text]mm) than of controls ([Formula: see text][Formula: see text]mm; [Formula: see text], [Formula: see text]). Miners showed substantial thickening of the synovia, as well as nodular, finger-like and focal protrusions in the synovia of suprapatellar bursa and/or prepatellar bursa (infrapatellar bursa). Synovium in miners showed more blood flow signals, especially in the supra- and prepatellar bursae, than synovium in controls. Echoes from the interior of infrapatellar soft tissues were enhanced and uneven in 47 of 53 miners, showing hyperecho patterns of scattered dots, short lines or flakes. Conclusion: Ultrasound can complement X-ray imaging and magnetic resonance imaging for detecting and characterizing chronic knee joint injuries in miners.

The influence of psychosocial safety climate on miners’ safety behavior: A cross-level research

Safety behavior is critical for workplace safety in a high-risk industry, but few studies have addressed how a psychosocial safety climate affects safety behavior. This study aims to validate the influence of psychosocial safety climate on safety behavior among Chinese underground coal miners’ and examine the mediating role of perceived organization support and mental health. We selected the1600 miners from 35 coal mines in Shanxi Province. The hierarchical linear model method was adopted in the research framework. The findings revealed that psychosocial safety climate cross-level positively affects safety behavior. The psychosocial safety climate impacts safety behavior through the mediating role of perceived organization support, mental health and chain mediation of perceived organization support and mental health. Coal managers should pay more attention to psychosocial safety climate construct, thus can enhance perceived organization support and protect mental health, which can improve safety behaviors.

The study of the impact by atractylenolide-1 on inflammatory cytokine, autophagy and apoptosis in alveolar macrophages of silicosis patients

Objective: To explore the effect of atractylenolide-1 (ATL-Ⅰ) on alveolar macrophages in silicosis patients. Methods: In December 2019, 12 male silicosis patients treated in Beidaihe Sanatorium for Chinese Coal Miners from July to September 2019 were selected by random sampling. Their alveolar macrophages were collected and divided into control group, ATL-Ⅰ group (100 μmol/L) and dimethyl sulfoxide (DMSO) group (100 μmol/L) . The exprossion levels of inflammatory factor interleukin-1β (IL-1β) , interleukin-6 (IL-6) , tumor necrosis factor α (TNF-α) were detected by enzyme-linked immunosorbent assay. The expression levels of autophagy associated protein microtubule associated protein light chain 3 (LC3) , autophagy substrate protein p62, lysosome associated membrane protein 2 (LAMP2) , apoptosis associated protein Cleaved caspase-3, nuclear factor kappa B (NF-κB) and its phosphorylated form (p-NF-κB) were detected by Western blot. Results: Compared with the control group and DMSO group, the expression levels of IL-1β, IL-6, TNF-α in alveolar macrophages decreased significantly in the ATL-Ⅰ group (P<0.05) , and the expression levels of p-NF-κB, the ratio of LC3-Ⅱ/LC3-Ⅰ also decreased significantly in the ATL-Ⅰ group (P<0.05) . However, the expression levels of NF-κB, LAMP2, p62 and Cleaved caspase-3 in the ATL-Ⅰ group were not statistically different from those in the control group and DMSO group (P>0.05) . There was no statistically significant differences in the expression of the above indexes between the control group and DMSO group (P>0.05) . Conclusion: ATL-Ⅰ may reduce the release of inflammatory factors from alveolar macrophages and inhibit the activity of autophagy in silicosis patients, but it may not reduce the level of apoptosis.

The Role of Work Engagement in the Association between Psychological Capital and Safety Citizenship Behavior in Coal Miners: A Mediation Analysis.

With the development of science and technology and the increasing importance attached by to these domains by the state and government departments in recent years, China’s coal production and safety supervision level continue to increase. However, the prevalence of frequent coal mine safety accidents has not been effectively curbed. The main purpose of this study was to explore the mediating role of work engagement in the relationship between psychological capital and safety citizenship behavior among Chinese coal miners. Data for 317 coal miners were collected from five coal and energy enterprises. The Psychological Capital Questionnaire (PCQ), the Job Engagement Scale (JES), and the Safety Citizenship Behavior Scale (SCBS) were used to evaluate the coal miners’ psychological capital, work engagement, and safety citizenship behavior. The causal steps approach and bootstrap Method were used in this study to assess the proposed mediation models. A correlation analysis indicated that psychological capital, work engagement, and safety citizenship behavior were significantly correlated with each other. Furthermore, the mediation analysis showed that work engagement mediated the relationship between psychological capital and safety citizenship behavior. Psychological capital does not only have a direct impact on coal miners’ safety citizenship behavior, but it also has an indirect impact on coal miners’ safety citizenship behavior via work engagement. Therefore, effectively enhancing an individual’s psychological capital and work engagement may be a basic factor determining coal miners’ safety citizenship behavior, which further promotes safety production within the enterprise.

A Comprehensive Model of the Relationship between Miners’ Work Commitment, Cultural Emotion and Unemployment Risk Perception

The psychological health and work commitment of miners are prerequisites to ensuring their sustainable safety behavior, and it is also significant to the sustainable development of coal mines in China. In this context, we conducted a questionnaire survey among coal miners of state-owned coal enterprises to explore the relationships between cultural emotion, unemployment risk perception, Big Five personality traits, and work commitment. The results reveal that (1) cultural emotion and its three dimensions played a significant positive role in promoting work commitment. (2) Unemployment risk perception, policy unemployment risk perception, and individual differential unemployment risk perception had a negative moderating effect. (3) Moreover, work commitment was associated with differences in personality characteristics except for agreeableness. This research is of important theoretical value and practical significance, as it can guide Chinese coal miners to increase their work commitment and thereby improve safety in production.

Relative Telomere Length in Peripheral Blood Cells and Hypertension Risk among Mine Workers: A Case-Control Study in Chinese Coal Miners.

Hypertension is a common chronic disease in middle-aged and elderly people and is an important risk factor for many cardiovascular diseases. Its pathogenesis remains unclear. Epidemiological studies have found that the loss of telomere length in peripheral blood cells can increase the risk of coronary heart disease, myocardial infarction, and other diseases. However, a correlation between loss of telomere length and hypertension has not been established. In this study, we aimed to explore the association between telomere length and the risk of essential hypertension (EH) in Chinese coal miners. A case-control study was performed with 215 EH patients and 222 healthy controls in a large coal mining group located in North China. Face-to-face interviews were conducted by trained staff with the necessary medical knowledge. Relative telomere length (RTL) was measured by a quantitative real-time PCR assay using DNA extracted from peripheral blood. In the control group, the age-adjusted RTL was statistically significantly lower in miners performing hard physical labour compared with nonphysical labour (P = 0.043). A significantly shorter age-adjusted RTL was found in the control group of participants who consumed alcohol regularly compared with those who do not consume alcohol (P = 0.024). Age-adjusted RTL was negatively correlated with body mass index (BMI) and alcohol consumption. Hypertension was also found to be significantly correlated with factors such as age, BMI, alcohol consumption, smoking, and tea consumption. Our results suggest that RTL is associated with hypertension in coal miners.

Who Reports Low Interactive Psychology Status? An Investigation Based on Chinese Coal Miners.

In mine safety and health research, psychological issues have always been neglected. This paper aims to identify the psychological perceptions of workers with respect to the mine environment and interpersonal environment across the whole production system. A survey was designed that measured the miners’ demographic details and perceptions of two affect-based interactions; three resource-based interactions for the manager, supervisor, co-worker; and three actual environment interactions. A total of 642 frontline coal miners from six mines located in six provinces in China completed the survey. The main results indicated that that miners reported low psychology status, especially those over 51 years old, with a monthly income of 2000–4000 and junior school education. Second, there was a high proportion of inferior value in environmental interactions. Meanwhile, the miners’ interactions with their co-workers were perceived as the most positive and those with their managers as the least in interpersonal interactions. Third, there were significant differences in sub-dimension interactions (actual environment, resource-based, affect-based interactions) that certainly existed in these interactive roles. Additionally, the dissociated type of miners with manager and supervisor (low resource and affect-based interaction) reached 23.99~24.45%. This study revealed the inner psychological risk factors for safety and health work in coal mines and provides an essential guideline for mining industries.

Associations between dietary patterns and 10-year cardiovascular disease risk score levels among Chinese coal miners\u2014\u2014a cross-sectional study

BackgroundDiet-related cardiovascular diseases have produced a large health burden in China. Coal miners are a high-risk population for cardiovascular disease, but there is little evidence concerning associations between coal miners’ dietary patterns and their 10-year cardiovascular disease risk score levels.MethodsThe study included 2632 participants and focused on dietary patterns associated with higher 10-year cardiovascular disease risk score levels. A valid semi-quantitative food frequency questionnaire was used to collect data regarding dietary intake, and dietary patterns were identified using factor analysis combined with cluster analysis. Logistic regression was used to assess associations between dietary patterns and 10-year cardiovascular disease risk score levels.ResultsFor ground workers, compared with the ‘Healthy’ pattern, the ‘High-salt’ and ‘Refined grains’ patterns were significantly associated with higher 10-year atherosclerotic cardiovascular disease risk score level (OR: 1.50, 95% CI: 1.02–2.21; OR: 1.92, 95% CI: 1.26–2.93) and 10-year ischemic cardiovascular disease risk score level (OR: 2.18, 95% CI: 1.25–3.80; OR: 2.64, 95% CI: 1.48–4.72) adjusted for gender, and behavioural and socioeconomic factors. The ‘High-fat and salt’ pattern was significantly associated with higher 10-year ischemic cardiovascular disease risk score level (OR: 1.97, 95% CI: 1.13–3.42). For underground workers, the ‘High-salt’ pattern was significantly associated with higher 10-year atherosclerotic cardiovascular disease risk score level (OR: 1.65, 95% CI: 1.16–2.36) and 10-year ischemic cardiovascular disease risk score level (OR: 1.76, 95% CI: 1.09–2.84).ConclusionsThis study provides evidence for dietary patterns associated with higher 10-year cardiovascular disease risk score levels in Chinese miners, and facilitates relevant departments in designing effective dietary guidelines to ameliorate dietary structures.

Development and validation of the quality of life scale for Chinese coal miners with pneumoconiosis (QOL-CMP): Measurement method and empirical study

Over the past decades, there has been enormous concern about labor conditions in developing countries particularly around work for the coal production market. Quality of Life (QOL) is of vital importance to be considered and promoted for occupational disease and safety accident prevention, which makes it urgent to undertake research on coal miners’ QOL. This study addresses QOL issues related to Occupational Safety and Health for people suffering occupational disease from work demanded because of energy trade arrangements. The research was designed to develop a scale for coal miners with pneumoconiosis (CMP) for measuring the QOL of these patients. This scale was developed using the combined generic and disease-specific theory. As indicated by the research results based on grounded theory (50 patient in-depth interview records and 322 opening questionnaires) and formal investigation (1345 questionnaires), this scale consists of five dimensions: physiological quality, psychological quality, environmental quality, relationship quality and economic quality based on 63 items. The perceived QOL was found to differ significantly among demographic variables and length of hospital stay. The patients were divided into five clustering groups by K-means cluster analysis: economically comfort (16.51%), physiologically comfort (14.20%), psychologically comfort (18.36%), environmentally comfort (18.36%), and the trapped (37.10%). The overall QOL scores in the psychologically comfort group (2.33) were higher than that in other groups and the scores in the trapped group (highest occupation) were lowest (1.74). The QOL-CMP scale exhibited reasonable degrees of validity and reliability. Management suggestions are proposed to provide a reference for improving the overall QOL of Chinese coal miners with pneumoconiosis, which greatly enhances the research content of occupational health and energy sustainability.

The utility of health belief model to explain self-protective behaviour against pneumoconiosis in Chinese underground coal miners: a cross-sectional study

ObjectivesCoal workers’ pneumoconiosis is caused by exposure to respirable coal mine dust. The self-protection of underground coal miners (UCM) plays an irreplaceable role against this threat. The purpose of this...

Work-family conflict and mental health among Chinese underground coal miners: the moderating role of psychological capital

ABSTRACTWork-family conflict among underground coal miners not only leads their mental disorders but also may cause coal accidents. The purpose of the study is to explore the relationship between Work-family conflict (WFC) and mental health, testing the Psychological capital (PsyCap) plays a moderating role in this relationship. The cross-sectional survey was performed in Shanxi Province, China during the August to October 2017. 986 miners from five coal mines were recruited in this study. Hierarchical linear regression analyses were performed to explore the moderating role of psychological capital. The result showed that Work-family conflict was positively related to Anxiety Symptoms and Depressive Symptoms. Psychological capital (PsyCap) moderated the relationship between WFC and Anxiety, Depressive Symptoms. The findings illustrate that psychological capital was an important way to improve miners’ mental health. Managers should promote organization support and investment in PsyCap to improve miners’ mental health.

A novel in-seam borehole hydraulic flushing gas extraction technology in the heading face: Enhanced permeability mechanism, gas flow characteristics, and application

The heading face in soft and low-permeability coal seams is one of the most high-risk areas for Chinese coal and gas miners because of the number of outburst-related accidents. To prevent and control these disasters, the in-seam borehole gas extraction technology is widely used because of its low construction cost. Unfortunately, few studies consider its gas extraction efficiency.Thus, a new in-seam borehole hydraulic flushing (ISBHF) gas extraction technology is proposed in this paper, where the hydraulic flushing technology is used to enhance the gas extraction of in-seam boreholes. Based on the engineering background in the Xinjing coal mine, a detailed study of this new technology is conducted. First, we model the permeability-increasing mechanism of this technology and the gas flow characteristics of the hydraulic flushing boreholes using a finite-element method. During this process, the strain-softening behavior of the coal mass and the effect of the coal mass failure on the permeability evolution are considered. Second, a reasonable gas extraction scheme is designed, which considers the divergent characteristics of boreholes in the heading face and the interactions among multiple boreholes in the gas extraction process. Finally, the gas extraction scheme is implemented at the S5 intake airflow roadway to verify the simulation results and to evaluate the efficiency of this technology.The field test results are consistent with the simulation results, which validates our model. Moreover, using this new technology, the number of gas extraction boreholes in the heading face decreased by 50%. Conversely, the gas extraction-based concentration and flow increased 10- and 6-fold, respectively, which results in a 65% decrease in gas extraction time and a 100% increase in monthly excavation length of the coal mine roadway. These results indicate that this new technology is a promising method to achieve efficient gas extraction and rapid excavation in the heading face of soft and low-permeability coal seams.

Prevalence of dyslipidaemia and risk factors in Chinese coal miners: a cross-sectional survey study

BackgroundAlthough coal miners are susceptible to dyslipidaemia owing to their highly risky and stressful working environment as well as unhealthy lifestyle, very few studies have focused on this issue thus far. Therefore, this study investigated the current epidemiological characteristics of dyslipidaemia among Chinese coal miners.MethodsDemographic, anthropometric, and biochemical data were gathered from 4341 coal miners in China. Dyslipidaemia was diagnosed based on the serum lipid levels. Univariate and multivariate logistic regression analyses were used to assess the related risk factors for dyslipidaemia.ResultsThe average concentrations of total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were 5.01 ± 0.93 mmol/L, 1.90 ± 1.72 mmol/L, 1.21 ± 0.35 mmol/L, and 3.15 ± 0.80 mmol/L, respectively. Additionally, 38.08% of participants had a high TC level, 25.84% had a low HDL-C level, 35.08% had a high LDL-C level, and 40.46% had a high TG level. The overall prevalence of dyslipidaemia was 68.28% (95% CI: 66.90–69.66%). Factors associated with dyslipidaemia were age, sex, marital status, monthly family income, type of work, length of service, smoking status, smoking index, drinking status, alcohol consumption per day, elevated fasting glucose, hypertension, obesity and abdominal obesity.ConclusionsOur study’s results indicated a very high prevalence of dyslipidaemia among Chinese coal miners and identified various risk factors for dyslipidaemia.

Musculoskeletal disorders, personality traits, psychological distress, and accident proneness of Chinese coal miners.

Human factors comprise one of the important reasons leading to the casualty accidents in coal mines. The aim of this study was to analyze the relationships among musculoskeletal disorders (MSDs), personality traits, psychological distress, and accident proneness of coal miners. There were 1500 Chinese coal miners surveyed in this study. Among these miners, 992 valid samples were obtained. The study surveyed the MSDs, personality traits, psychological distress, and accident proneness of coal miners with MSDs Likert scale, Eysenck personality questionnaire, Symptom Checklist-90 (SCL-90) scale, and accident proneness questionnaire, respectively. The highest MSDs level was found in the waist. The increasing working age of the miners was connected with increased MSDs and psychological distress. Significant differences in MSDs and psychological distress of miners from different types of work were observed. Coal miners with higher MSDs had higher accident proneness. Coal miners with higher neuroticism dimension of Eysenck personality and more serious psychological distress had higher accident proneness. Phobic anxiety, paranoid ideation and psychoticism dimension of psychological distress were the three most important indicators that had significant positive relationships with accident proneness. The MSDs, neuroticism dimension, and psychological distress of the coal mine workers are important to work safety and require serious attention. Some implications concerning coal mine safety management in China were provided.

Mitochondrial DNA copy number in peripheral blood cell and hypertension risk among mining workers: a case–control study in Chinese coal miners

Alteration of mitochondrial DNA (mtDNA) copy number, which reflects oxidant-induced cell damage, has been observed in a wide range of human diseases. However, whether it correlates with hypertension has not been elucidated. We aimed to explore the association between mtDNA copy number and the risk of hypertension in Chinese coal miners. A case-control study was performed with 378 hypertension patients and 325 healthy controls in a large coal mining group located in North China. Face-to-face interviews were conducted by trained staffs with necessary medical knowledge. The mtDNA copy number was measured by a quantitative real-time PCR assay using DNA extracted from peripheral blood. No significant differences in mtDNA copy number were observed between hypertension patients and healthy controls. However, in both case and control groups, the mtDNA copy number was statistically significantly lower in the elder population (≥45 years old) compared with the younger subjects (<45 years old; 7.17 vs 6.64, P=0.005 and 7.21 vs 6.84, P=0.036). A significantly higher mtDNA copy number could be found in hypertension patients consuming alcohol regularly compared with no alcohol consumption patients (7.09 vs 6.69); mtDNA copy number was also positively correlated with age and alcohol consumption. Hypertension was found significantly correlated with factors such as age, work duration, monthly family income and drinking status. Our results suggest that the mtDNA copy number is not associated with hypertension in coal miners.

Meta-Analysis of Chinese Coal Miners’ Mental Illness under SCL Index System

Objective: Under SCL index system, through the comparative study, this paper investigates whether there are significant differences in mental illness tendency between Chinese coal mine workers underground and on the ground. Methods: This paper uses computer to retrieve in Medline, Sciencedirect, Web of Science, the Cochrane Library, Springerlink, CNKI, Wanfang and Weipu database. The retrieval time is from the very beginning of building database to the March of 2015. After the extraction of available data, Stata 10.1 analysis software was applied to heterogeneity test on the research. Then the paper uses the random effects model to calculate and combine odds ratio as well as 95% confidence interval. Results: 15 articles were finally included by using Meta analysis. Collating data of the experimental group and control group, this paper carries on forest figure mapping, publication bias test, sensitivity analysis and cumulative Meta analysis, and one study result is found to have great deviation impact on the overall conclusion. Eliminating the above research result, the results are greatly improved. Conclusion: Through the result of the Meta analysis, this paper concludes that there are significant differences in mental illness tendency between Chinese coal mine workers underground and on the ground.

Prevalence of hypertension and noise-induced hearing loss in Chinese coal miners.

Owing to inconsistent epidemiologic evidence and the presence of confounding factors, the relation between occupational noise exposure and hypertension still remained unclear. We aimed to assess whether Chinese coal miners were at risk of developing hypertension and noise induced hearing loss (NIHL), and whether occupational noise exposure was a risk factor of hypertension. A questionnaire was designed to collect information from 738 study participants, all of whom were employees from the Datun Xuzhou Coal Company. The participants were divided into a noise-exposed group and a control group based on the noise level to which they were exposed in the workplace. The differences in the mean of systolic blood pressure (SBP) and diastolic blood pressure (DBP) were compared between the noise-exposed and control groups. Also the prevalence and age-adjusted odds ratio (OR) [95% confidence intervals (CIs)] of audiometric deficit and hypertension was compared in the study. Binary logistic regression was used to assess the relation between occupational noise level and hypertension while controlling for potential confounding factors. Hypertension was more prevalent in noise-exposed group than the control group, 29.2% vs. 21.2% (P=0.012). The noise-exposed group faced an increased risk of hypertension (age-adjusted OR =1.52, 95% CI =1.07-2.15) when the control group was used as reference. The mean values of SBP and DBP of the noise-exposed groups were significantly higher than the control group (P=0.006 and P=0.002 respectively). Hearing loss at low frequencies was significantly more prevalent in the noise-exposed group than the control group, 12.8% vs. 7.4% (P=0.015), while the noise-exposed group faced the increased risk of hearing loss at low frequencies (age-adjusted OR =1.81, 95% CI =1.10-2.96). LEX, 8h (OR =1.036, 95% CI =1.012-1.060) was an independent risk of hypertension when controlling for potential confounding factors. We found that the occupational noise had an effect on the hypertension and hearing loss of Chinese coal miners. And the occupational noise was an independent risk factor for hypertension and could increase the values of SBP and DBP.