Occupational health risk assessment of noise in a coal mining enterprise in Shaanxi Province / 公共卫生与预防医学

Objective To evaluate the noise hazard level of a coal mining enterprise, and identify high-risk operation types and people, and to provide a basis for preventing and controlling the health damage caused by noise. Methods A large coal mining enterprise in Shaanxi Province was selected as the research object. The noise monitoring data of the coal mine over the years was used to calculate the noise exposure matrix of each post in the enterprise, and the classification of occupational hazards at workplaces (GBZ/T 229.4-2012) was used to assess the occupational health risk levels. Results Among the 22 noise-exposed positions in the enterprise, the 8-hour working day equivalent sound level in positions of shearer driver, horseshoe driver, crusher driver, shuttle driver, relaxation screen driver, and grading screen driver were all higher than the occupational exposure limit of noise. In 2021, the noise exposure levels of shearer drivers, crusher drivers, and coal-selecting workers were all higher than 90 dB (A), and the occupational hazard level was moderate hazard level. In addition, the noise exposure levels of most other jobs also exceeded the occupational exposure limit. Conclusion The noise hazards in the coal mine industry are mainly concentrated in the posts of the coal mining system, tunneling system, and screening workshop. Among them, the shearer driver, the crusher driver, and the coal preparation workers have higher noise exposure levels. It is recommended to take corresponding noise reduction measures and strengthen the protection level to reduce the noise exposure risk of workers.

Analysis of epidemiological characteristics of newly diagnosed occupational pneumoconiosis in Henan Province from 2006 to 2020 / 中国职业医学

Objective: To analyze the epidemiological distribution of new occupational pneumoconiosis (hereinafter referred as pneumoconiosis) in Henan Province from 2006 to 2020. Methods: Clinical data of newly recruited pneumoconiosis cases from 2006 to 2020 in Henan Province were retrospectively analyzed. Results: A total of 9 624 cases of newly diagnosed pneumoconiosis were reported in Henan Province in the past 15 years, of which 98.6% were males. The number of cases had two peaks, one in 2009-2011 and the other in 2014-2017. There were 12 types of pneumoconiosis of all reported cases except for mica pneumoconiosis, in which coal workers' pneumoconiosis and silicosis accounted for 96.0%. The incidence of phase Ⅰ, Ⅱ and Ⅲ pneumoconiosis was 64.7%, 21.0% and 14.3%, respectively. The incidence of phase Ⅱ and Ⅲ silicosis was higher than that of coal miners' pneumoconiosis (56.3% vs 22.7%, P<0.01). Patients with pneumoconiosis were mainly distributed in Zhengzhou City, Sanmenxia City, Luoyang City, Pingdingshan City and Hebi City, accounting for 85.0%. The enterprises involved were mainly mining industry, large- and medium-sized enterprises, state-owned enterprises and collective enterprises. The top five position of patients were coal miners, rock drillers, excavators, coal mixed workers and pure coal miners, total accounting for 72.0%. There were 196 enterprises reported ≥10 cases, accounting for 17.2% of all enterprises and 80.3% of the total of newly diagnosed pneumoconiosis cases. The median (M) of onset age of new cases was 49 years old, and the M of onset of working age was 16 years. The onset age of silicosis was younger (M: 49 vs 48 years old, P<0.05), while the onset of working age was longer (M: 10 vs 20 years, P<0.05), compared with that of coal workers' pneumoconiosis. Conclusion: The incidence of pneumoconiosis in Henan Province were disease clustering distribution, regional distribution, industry of enterprise, enterprise scale, enterprise type, nature and working position distribution of enterprises. And it showed the characteristics of group incidence. The prevention and control treatment of pneumoconiosis should be strengthened in key areas, key enterprises and key diseases and jobs.

Analysis of the prevalence and social security situation of pneumoconiosis in non-coal mine industry in Jiangsu Province / 中华劳动卫生职业病杂志

Objective: To understand the social security situation of current cases of pneumoconiosis in non-coal mine industries in Jiangsu Province, and to provide reference for the treatment and security work of pneumoconiosis patients. Methods: From January to October 2020, a follow-up survey was conducted on 4038 cases of pneumoconiosis in non-coal mine industries of the province from October 1949 to December 2019. The age, type of pneumoconiosis, industry type, and social security status of the patients were collected. Namely, work-related injury insurance, employer compensation, basic medical insurance for urban and rural residents, major illness insurance, etc. SPSS 19.0 was used for statistical description and analysis. Results: The cases of pneumoconiosis in non-coal mine industries in Jiangsu Province ranged in age from 36 to 105 (70.78±8.43) years old, and had been exposed to dust for 1 to 55 (19.27±9.29) years. Silicosis was the main form (3875 cases, 95.96%), and non-metallic mining and dressing industry was the main form (2618 cases, 64.83%). A total of 3991 cases (98.84%) of pneumoconiosis patients enjoyed social security, most of them were urban and rural residents with basic medical insurance (3624 cases, 89.75%), but there were still 47 patients without any social security. 15 cases (0.37%) enjoyed the subsistence allowance, with the monthly allowance amount ranging from 104 to 3960 yuan, with the average amount of 954.87 yuan/month. Conclusion: In Jiangsu Province, the proportion of pneumoconiosis patients in non-coal mine industries enjoying social security is relatively high, but there are still patients who do not enjoy any social security, and the difference in the amount of subsistence allowance is slightly larger. It is necessary to further improve the medical security of pneumoconiosis patients and improve their quality of life.

Investigation of radioactivity level in an open-pit coal mine in Xinjiang, China and evaluation of personnel exposure dose / 中国辐射卫生

@#<b>Objective</b> To investigate and analyze the levels of γ dose rate and radon concentration at all sites in a large open-pit coal mine with radioactivity that had been mined for many years in Xinjiang, China, and to estimate the effective dose exposed to the personnel. <b>Methods</b> A portable γ dose-rate instrument FH40G was used for fixed-point monitoring of the mining area, and a continuous radon detector was used for 24 h continuous monitoring of radon concentration level in the site. The personnel exposure dose was estimated according to the measured γ dose rate and radon concentration. <b>Results</b> In this open-pit coal mine, the range of γ dose rate was 51.4-435.8 nGy/h; the mean 24 h radon concentration was 15-25 Bq/m³; the range of annual effective dose to the personnel was 0.29-1.29 mSv/a. <b>Conclusion</b> According to the results of the survey, radon concentration levels at all sites are low, and no remedial action is required. The personnel exposure dose at most of the sites is far below the standard requirements, and some protective measures need to be taken in some areas of the dump.

A case of pulmonary aspergillus infection in underground coal mine workers / 中华劳动卫生职业病杂志

The underground environment is dark and humid, and it is easy to breed pathogenic microorganisms. A lump in the right lung of a coal mine underground transport worker was found druing occupational health examination. CT examination showed that the lump was located in the posterior segment of the upper lobe of the right lung, with point strip calcification, liquefaction necrosis, and proximal bronchial stenosis and occlusion. MRI examination FS-T(2)WI and DWI showed "target sign", annular low signal around the central high signal, and low mixed signal around the periphery, and annular high signal in the isosignal lesions on T(1)WI. Then the pulmonary aspergillus infection was confirmed by pathology.

Application of a light-weighted convolutional neural network for automatic recognition of coal workers' pneumoconiosis in the early stage / 中华劳动卫生职业病杂志

Objective: To construct and verify a light-weighted convolutional neural network (CNN), and explore its application value for screening the early stage (subcategory 0/1 and stage Ⅰ of pneumoconiosis) of coal workers' pneumoconiosis (CWP) from digital chest radiography (DR) . Methods: A total of 1225 DR images of coal workers who were examined at an Occupational Disease Prevention and Control Institute in Anhui Province from October 2018 to March 2021 were retrospectively collected. All DR images were collectively diagnosed by 3 radiologists with diagnostic qualifications and gave diagnostic results. There were 692 DR images with small opacity profusion 0/- or 0/0 and 533 DR images with small opacity profusion 0/1 to stage Ⅲ of pneumoconiosis. The original chest radiographs were preprocessed differently to generate four datasets, namely 16-bit grayscale original image set (Origin16), 8-bit grayscale original image set (Origin 8), 16-bit grayscale histogram equalized image set (HE16) and 8-bit grayscale histogram equalized image set (HE8). The light-weighted CNN, ShuffleNet, was applied to train the generated prediction model on the four datasets separately. The performance of the four models for pneumoconiosis prediction was evaluated on a test set containing 130 DR images using measures such as the receiver operating characteristic (ROC) curve, accuracy, sensitivity, specificity, and Youden index. The Kappa consistency test was used to compare the agreement between the model predictions and the physician diagnosed pneumoconiosis results. Results: Origin16 model achieved the highest ROC area under the curve (AUC=0.958), accuracy (92.3%), specificity (92.9%), and Youden index (0.8452) for predicting pneumoconiosis, with a sensitivity of 91.7%. And the highest consistency between identification and physician diagnosis was observed for Origin16 model (Kappa value was 0.845, 95%CI: 0.753-0.937, P<0.001). HE16 model had the highest sensitivity (98.3%) . Conclusion: The light-weighted CNN ShuffleNet model can efficiently identify the early stages of CWP, and its application in the early screening of CWP can effectively improve physicians' work efficiency.

Case-control study on fragility fractures in coal miners: A comparison between surface and underground workers / 环境与职业医学

Background The prevalence of osteoporosis and osteopenia is higher among underground coal miners than surface workers. The special underground work environment and unhealthy habits such as smoking, drinking, and a high-salt diet may lead to changes in bone metabolism, increasing the risk of fragility fractures and placing a heavy economic burden on individuals and society. Objective To identify potential factors influencing fragility fractures among coal miners in different working environments and to provide a basis for targeted preventive measures to reduce the occurrence of fragility fractures. Methods Male participants who attended at least one of the physical examinations in Kailuan Group between June 2006 and December 2020 were included in the study. The participants were divided into two groups based on their working environment: surface or underground. A case-control study was conducted, where patients with new fragility fractures served as the case group and participants without fragility fractures served as the control group. The two groups were matched with a case:control ratio of 1:4 by age (±1 year) and the same year of physical examination. The matching process was repeated twice, once for the surface working population and once for the underground working population. The analysis of risk factors was conducted using conditional logistic regression models. Results Among a total of 113138 employees in Kailuan Group, 82631 surface workers and 30507 underground workers were included, respectively. The number of individuals who suffered fragility fractures was 1375, accounting for 1.22% of the total population. The incidence of fragility fractures in underground workers was significantly higher than that in surface workers (1.63%>1.07%, P<0.001). The results of conditional logistic regression model showed that current smoking (OR=1.26, 95%CI: 1.05, 1.51), manual labor (OR=1.37, 95%CI: 1.06, 1.78), diabetes (OR=1.26, 95%CI: 1.04, 1.54), sinus tachycardia (OR=1.81, 95%CI: 1.23, 2.66), history of stroke (OR=1.51, 95%CI: 1.09, 2.09), education at college and above (OR=0.65, 95%CI: 0.45, 0.95), high income level (OR=0.69, 95%CI: 0.54, 0.90), elevated hemoglobin (OR=0.91, 95%CI: 0.85, 0.98), and elevated total cholesterol (OR=0.90, 95%CI: 0.82, 0.99) were associated with fragility fractures in the surface working population of coal mines; current smoking (OR=1.48, 95%CI: 1.17, 1.87), current drinking (OR=1.26, 95%CI: 1.01, 1.56), manual labor (OR=2.64, 95%CI: 1.41, 4.94), history of dust exposure (OR=1.28, 95%CI: 1.03, 1.58), and obesity (OR=0.72, 95%CI: 0.52, 0.96) were associated with fragility fractures in the underground working population of coal mines. Conclusion In preventing fragility fractures, special attention should be paid to the bone health of underground workers engaged in manual labor or having a history of dust exposure. It is important to correct their unhealthy behaviors in a timely manner, such as smoking and drinking, and to appropriately increase body weight to prevent fragility fractures. For surface workers, particular attention should be given to the high-risk group for fragility fractures, such as low family income per capita, manual labor, and having a history of stroke or diabetes; in addition, close monitoring of their resting heart rate, hemoglobin levels, and total cholesterol levels may help prevent fragility fractures.

Application of two occupational health risk assessment methods for dust hazards in non-coal underground mines / 环境与职业医学

Background The mining of non-coal underground mines may come into contact with various types of dust, such as lead, zinc, copper, and non-metallic minerals. Dust of various kinds commonly exists in all aspects of mining and selection, and is one of the main occupational hazard groups in non-coal underground mines. Objective To compare the application of two risk assessment methods in the occupational health risk assessment of productive dust in non-coal underground mines, and to provide a reference for the selection of dust hazard health risk assessment methods and the management of dust hazards in non-coal mines. Methods A field investigation of the dust hazards of three typical non-coal underground mining enterprises (lead-zinc mines, copper mines, and fluorite mines) was carried out, and the comprehensive index method and the occupational health risk assessment method from the International Council on Mining and Metals (ICMM) were used to perform risk assessments. The comprehensiveindex method considers the following factors: dust monitoring data, the aerodynamic diameter of dust, hazard control measures, occupational health management, daily usage, and daily exposure time to determine exposure levels. The ICMM method determines the risk level based on the consequences caused by dust, exposure probability, exposure time, and uncertainty coefficient. Kendall consistency test was used to compare agreement between the results generated by the two methods. Results The results generated by the comprehensive index method were as follows: level 3 (medium risk) or level 4 (high risk) for silica dust or lead dust; level 1 (negligible risk) or level 2 (low risk) for other dust (dust with free SiO2 content<10% and containing lead, zinc, and copper, using other dust limit values for comparison), fluorspar mixed dust, fluorine and its compounds, zinc oxide, and copper dust. The risk levels graded by the ICMM method were as follows: level 4 (very high risk) and level 3 (high risk) for exposure to silica dust and lead dust, respectively, and level 1 (tolerable risk) or level 2 (potential risk) for exposure to other dust (dust with free SiO2 content <10% and containing lead, zinc, and copper, using other dust limit values for comparison), fluorspar mixed dust, fluorine and its compounds, zinc oxide, and copper dust. The consistency level between the results graded by the two methods was very high (Kendall W coefficient=0.974, P < 0.05). Conclusion For the occupational health risk assessment of productive dust in non-coal underground mines, the consistency level of risk assessment results between the ICMM method and the comprehensive index method is very high. The ICMM method is more convenient to operate and should be preferred in assessing health risks of dust hazard in non-coal underground mines.

Analyzing the current status of newly diagnosed occupational pneumoconiosis patients in Zhangdian District of Zibo City / 中国职业医学

Objective To analyze the distribution, survival conditions, and medical support of newly diagnosed occupational pneumoconiosis (hereinafter referred to as pneumoconiosis) patients in Zhangdian District, Zibo City. Methods A total of 1 189 newly diagnosed pneumoconiosis patients in Zhangdian District from 1956 to 2019 were selected as the study subjects using retrospective method. Data of their age of onset, years of occupational exposure, category of working industry, type of pneumoconiosis, and status of medical support was collected and analyzed. Results The median and the 25th-75th percentiles ［M (P25, P75)］ of the age of onset were 51.8 (45.5, 56.1) years, and the mortality was 37.0%. The majority of pneumoconiosis cases were silicosis (45.2%) and coal workers' pneumoconiosis (39.8%). The highest prevalence of pneumoconiosis was in the coal mining and washing industry (42.4%), followed by manufacturing (33.4%). Pneumoconiosis patients in stage Ⅰ,Ⅱ, and Ⅲ accounted for 89.1%, 8.7%, and 2.2%, respectively. The M (P25, P75) of the length of work exposed to dust were 24.1 (16.5, 29.9) years.The higher stage of pneumoconiosis the shorter of the length of work exposed to dust among these pneumoconiosis patients(all P<0.05). The overall survival rate, the 5-year survival rate and the 10-year survival rate of these pneumoconiosis patients were 63.0%, 92.3% and 85.9%, respectively. Among the 749 surviving cases, 60.8% were aged 60.0 to <80.0 years. In terms of social security, 100.0% surviving cases enjoyed basic medical insurance, meanwhile, 96.1% and 81.8% patients were covered by major medical insurances and occupational injury insurances, respectively. The M (P25, P75) of age at death were 73.1 (64.0, 77.1) years. The main causes of death were respiratory diseases (59.3%) and malignant tumors (20.4%). Conclusion The prevalent types of pneumoconiosis in Zhangdian District, Zibo City, are coal workers' pneumoconiosis and silicosis. Medical support and assistance are relatively limited. The pneumoconiosis prevention and control focus should be on silicosis and coal workers' pneumoconiosis, particularly in the manufacturing industry.

Analyzing the distribution characteristics of occupational pneumoconiosis in Sichuan Province, 2012-2021 / 中国职业医学

Objective: To analyze the distribution feature of occupational pneumoconiosis in Sichuan Province. Methods: The cases of newly diagnosed occupational pneumoconiosis from 2012 to 2021 in Sichuan Province were collected from the Occupational Diseases and Hazards Monitoring Information System under China Disease Prevention and Control Information System, and were analyzed retrospectively. Results: From 2012 to 2021, there were 30 136 newly diagnosed occupational pneumoconiosis cases in Sichuan Province. The average age of patients was 55.2 years and the median work age was 12.1 years. There were 6 471 cases (accounting for 21.5%) exposed to dust for less than 5.0 years. The number of the cases declined in newly diagnosed occupational pneumoconiosis and occupational pneumoconiosis with less than 5.0 years of dust exposure. The numbers of coal workers' pneumoconiosis and silicosis were 16 210 and 13 577, respectively (accounting for 98.9% of the total cases). The majority of pneumoconiosis cases were classified as stage Ⅰ(accounting for 67.1%). The cases from Leshan City, Bazhong City, Dazhou City, Yibin City, Guangyuan City and Luzhou City accounted for 68.8% of the total cases. The main types of work were coal miner and excavation worker, which accounted for 31.7% and 18.8%, respectively. The scale of enterprises was mostly small and micro, accounting for 35.1% of the cases, and the industry distribution was mostly coal mining and washing, accounting for 53.4% of the cases. Conclusion: In Sichuan Province, the number of cases shows an overall decline in both newly diagnosed occupational pneumoconiosis and occupational pneumoconiosis with less than 5.0 years of dust exposure, with a relatively short duration of occupational exposure. The key cities for pneumoconiosis prevention and control are Leshan City, Bazhong City, and Dazhou City, while the key industry is coal mining and washing.

Monitoring results of coal-burning-borne endemic fluorosis in Yunnan Province in 2020 / 中华地方病学杂志

Objective:To learn about the current situation of prevention and control of coal-burning-borne endemic fluorosis (coal burning fluorosis for short) in Yunnan Province, and comprehensively evaluate the implementation effect of prevention and control measures.Methods:From August to November 2020, according to the requirements of the Monitoring Program of Yunnan Province for Coal-burning-borne Endemic Fluorosis (2019 edition), monitoring was carried out in all natural villages in the disease areas of 13 counties (cities and districts, hereinafter referred to as counties) of the province, and 30 households were selected from each natural village to monitor the use of stoves and the formation of related healthy living behaviors. At the same time, children aged 8 - 12 years in the natural villages in the disease areas were examined for the prevalence of dental fluorosis. The evaluation for control and elimination of disease areas was carried out in accordance with the Evaluation Approach for Control and Elimination of Priority Endemic Diseases (2019 edition).Results:A total of 392 244 households were investigated, and the rates of qualified improved stoves, the correct utilization of qualified improved stoves and correct drying of corn and pepper were 99.42% (389 982/392 244), 99.70% (388 796/389 982) and 99.07% (388 579/392 244), respectively. A total of 227 057 children aged 8 - 12 years were examined, 9 413 children of dental fluorosis were detected, the detection rate of dental fluorosis was 4.15%, the dental fluorosis index was 0.10, and the prevalence intensity was negative. Taking the county as a unit, except Fuyuan and Zhenxiong, which reached the control standard of the disease area, the remaining 11 counties reached the elimination standard.Conclusion:The prevention and control measures on coal burning fluorosis are implemented well in Yunnan Province and healthy lifestyle has gradually taken shape, with the overall condition of the disease reduced.

Analysis of monitoring results of coal-burning-borne endemic arsenism in Shaanxi Province from 2015 to 2020 / 中华地方病学杂志

Objective:To learn about the changes of the condition of coal-burning-borne endemic arsenism, the use of improved stoves and the formation of health-related behaviors in Shaanxi Province, and evaluate the effect of prevention and control measures.Methods:From 2015 to 2020, according to the "Implementation Plan for Monitoring Coal-burning-borne Endemic Arsenism in Shaanxi Province", regular field surveys were carried out in 4 natural villages, 2 counties in Ankang City and Hanzhong City, Shaanxi Province, to learn about the basic prevention and control situation in the monitoring village. Using the simple random sampling method, 10 families in each village were selected to investigate the use of stoves and the formation of health-related behaviors, and 5 of these families were selected to collect coal samples for arsenic content determination in accordance with the "Determination of Arsenic in Coal" (GB/T 3058-2008). According to the "Diagnosis of Endemic Arsenicosis" (WS/T 211-2015), the condition of the people exposed to high arsenic coal in the monitoring village was investigated. Urine samples of 30 adult patients (half males and half females) with arsenic poisoning were collected, the content of arsenic in urine was determined by the "Urine-Determination of Arsenic-Silver Diethyldithiocarbamate-Triethanolamine-Spectrophotometric Method" (WS/T 28-1996).Results:A total of 240 households were monitored in the past 6 years, and the quality conformance and correct utilization rates of improved stoves in the households monitored in the disease areas remained at 100.00% in 2018 - 2020. The utilization rate of clean energy increased from 75.00% (30/40) in 2015 to 100.00% (40/40) in 2018 - 2020 (χ 2trend = 25.5, P < 0.001). The 73.75% (177/240) of households using a variety of clean energy. From 2018 to 2020, the correct drying, storage and pre-processing washing rates of corn and pepper continued to reach 100.00% (40/40). The arsenic content of coal ( n = 120) in the disease areas was (118.09 ± 57.91) mg/kg, ranging from 16.70 to 280.94 mg/kg. The detection rate of arsenic poisoning decreased from 6.34% (231/3 646) in 2015 to 2.90% (109/3 754) in 2020 (χ 2trend = 121.8, P < 0.001), and no skin cancer or Bowen's disease was detected. The geometric mean of arsenic content in urine ( n = 720) was 0.038 1 mg/L, ranging from 0.000 5 to 0.312 9 mg/L. Conclusions:The condition of coal-burning-borne endemic arsenism areas in Shaanxi Province has reached the national elimination standard. The quality and correct utilization rate of improved stoves and the rate of using clean energy have increased. The healthy-related behaviors the people in the endemic areas have been basically formed. The prevention and control work has achieved good results.

Álbum/Relatório das Atividades das Pequenas Irmãs da Divina Providência: registros da assistência médico-social na Região Carbonífera Catarinense, 1955-1957 / Album/Report by the Pequenas Irmãs da Divina Providência: records of social and medical assistance in the coal-producing region of southern Santa Catarina, 1955-1957

Resumo Na primeira metade do século XX, a Região Carbonífera Catarinense passou por um intenso processo de industrialização que impactou diretamente as diferentes formas de vida. Como resultado da exploração do carvão mineral, a região enfrentou uma série de problemas sanitários que dificultavam o próprio processo de acumulação do capital. Diante da incapacidade de o poder público atender às demandas sanitárias, o empresariado local estabeleceu parcerias com congregações religiosas femininas para prestar serviços assistenciais em suas vilas operárias. Como resultado dessa relação, as Pequenas Irmãs da Divina Providência produziram um álbum/relatório, composto por textos, desenhos e fotografias que retratam suas atividades assistenciais, entre 1955 e 1957, em uma das vilas da região.

Abstract During the first half of the twentieth century, the coal-producing region of Santa Catarina state underwent intense industrialization that directly impacted various ways of life; various health problems emerged in the region as a result of coal mining and impeded economic progress. As the government was unable to meet health demands, local businesses established partnerships with female religious orders that provided assistance services in the villages where workers lived. As part of such a partnership, the Pequenas Irmãs da Divina Providência created an album of texts, drawings, and photographs as a report describing their activities from 1955 to 1957 in one such village in the region.

Caracterización de un Consorcio Microbiano Metanogénico de una Mina de Carbón en la Cuenca de Bogotá / Characterization of a Methanogenic Microbial Consortium from a Coal Mine in Bogotá Basin

RESUMEN En el trabajo se estudió un consorcio microbiano metanogénico de una mina de carbón de la cuenca de Bogotá en Colombia. Se establecieron cultivos de enriquecimiento de carbón ex situ para el crecimiento y la producción de gas de novo. El gas biogénico producido por los cultivos se analizó mediante cromatografía de gases con detectores de ionización de llama y conductividad térmica. Los cultivos se utilizaron para aislar estirpes microbianas y para generar bibliotecas del gene 16S rARN empleando de cebadores de bacteria y de arquea. El análisis de cromatografía de gases mostró producción de metano a 37 oC, pero no a 60 oC, donde el CO2 fue el componente principal del gas biogénico. El análisis de la secuencia del gen 16S rARN de estirpes microbianos y de las bibliotecas de clones, estableció que el consorcio microbiano metanogénico estuvo formado por especies de bacterias de los géneros Bacillus y Gracilibacter más la arquea del género Methanothermobacter. El consorcio microbiano metanogénico identificado es potencialmente responsable de la generación de gas biogénico en la mina de carbón La Ciscuda. Los resultados sugirieron que los metanógenos de este consorcio producían metano por vía hidrogenotrófica o de reducción de CO2.

ABSTRACT The work studied the methanogenic microbial consortium in a coal mine from the Bogotá basin in Colombia. Ex situ coal-enrichment cultures were established for in vitro growth and de novo gas production. Biogenic gas produced by cultures was analyzed by gas chromatography using thermal conductivity and flame ionization detectors. Cultures were used to isolate microbial specimens and to generate 16S rRNA gene libraries employing bacterial and archaeal primer sets. The gas chromatographic analysis showed methane production at 37 oC, but not at 60 oC, where CO2 was the major component of the biogenic gas. 16S rRNA gene sequence analysis of microbial isolates and clone libraries established that the methanogenic microbial consortium was formed by bacteria species from Bacillus and Gracilibacter genera plus archaea from the Methanothermobacter genus. This meth-anogenic microbial consortium was potentially responsible for biogenic gas generation in La Ciscuda coal mine. The results suggested that these methanogens produced methane by hydrogenotrophic or CO2 reduction pathways.

Natural radioactive level in raw coal of coal mines in some regions of China / 中国辐射卫生

Objective To understand the activity concentrations of natural radionuclides 40K, 226Ra, 232Th, and 238U in raw coal of coal mines in some regions of China, and to explore the correlation between ore with different activity concentrations and the concentration of radon and its progeny in the workplace. Methods Raw coal samples were collected in twelve coal mines in five provinces, and the activity concentrations of 40K, 226Ra, 232Th, and 238U were measured by a high-purity germanium γ-ray spectrometric system. Results The activity concentrations of four natural radionuclides in the raw coal samples of twelve coal mines were all lower than 1000 Bq/kg, and the activity concentration of 238U in one coal mine was close to 100 Bq/kg. The content of 40K, 226Ra, 232Th, and 238U in different coal mines varied greatly, but 226Ra, 232Th, and 238U were basically at the same level in the same coal mine. Conclusion None of the 12 coal mines belong to radio active mines. One of the coal mines investigated has the activity concentrations of 226Ra, 232Th, and 238U close to the standard limit for restricted-use management mines. It is suggested to study the correlation between the content of 226Ra in raw ore, intermediate products, tailings(slag), or other residues and the concentration of radon and its progeny in mines. Monitoring and protection of radon and its progeny in the decay chain should be strengthened for coal mines with high activity concentrations of natural radionuclides 226Ra, 232Th, and 238U.

Investigation on occupational hazards of non-coal mines in Hunan Province in 2021 / 中国职业医学

@#Abstract: Objective - To understand the status of occupational hazards in non coal mine mountains in Hunan Province. Methods - - A cross sectional survey was conducted on 432 non coal mining enterprises in Hunan Province in 2021. The field ， occupational health survey occupational disease hazard factors detection and occupational health monitoring data analysis were Results - carried out. Limited liability companies and private enterprises were the main economic types of non coal mining ， ， mountains in Hunan Province accounting for 55.3% and 32.4% respectively. The size of enterprises was mainly small and ， ； - micro enterprises accounting for 59.3% and 35.2% respectively 78.0% of the enterprises were in non metallic mining. The - ， over standard rates of silica dust and noise in workplaces were 17.1% and 29.4% respectively. The exposure rate of ， （P ） occupational hazard factor was 47.3%. The smaller the enterprise scale the higher the exposure rate <0.01 . The number of ， ， people exposed to silica dust and noise was the largest with the exposure rate of 29.4% and 31.0% respectively. The rates of ， occupational health training for persons in charge of enterprises occupational health management personnel and workers were ， ， ， 73.8% 73.4% and 85.0% respectively. The smaller the enterprise scale the lower the occupational health training rates of ， ， enterprise leaders occupational health management personnel and workers and the lower the implementation rates of （ P ） - - enterprise occupational health examination all <0.05 . The fully installed rate and effective rate of occupational disease ； prevention facilities were 6.9% and 1.6% respectively and the fully deployed rate and effective wearing rate of personal ， protective equipment were 11.1% and 6.2% respectively. The detection rates of occupational contraindications and suspected ， Conclusion occupational diseases in workers exposed to silica dust and noise were 2.0% and 2.9% respectively. The - ， occupational risks such as silica dust and noise are serious in non coal mine mountains of Hunan Province and the foundation of occupational health management is weak in small and micro enterprises.

Construction of a multi-level model for evaluating the association between the number of dust exposed workers and raw coal production / 中国职业医学

@#Abstract: Objective （ Based on the data from the ″Occupational Diseases Hazardous Items Reporting System″ hereinafter ）， referred to as the ″Reporting System″ a method was constructed to estimate the number of occupational dust exposed workers （ ） in coal mining and washing enterprises hereinafter referred to as "coal workers" at the provincial administrative level. Methods ， A typical sampling method was used to study 1 808 coal enterprises in Shanxi Province Inner Mongolia Autonomous ， ， Region Shaanxi Province and Xinjiang Uygur Autonomous Region in 2020 in the Reporting System. Based on the data of 1 217 ， ， - coal enterprises that were coal mining or integrated coal mining and washing enterprises a multi level model was established to analyze the association between the number of coal workers and raw coal production. Two scenarios were set up based on the ， enterprise scale composition ratio to estimate the number of underreported coal workers and the number of coal workers in each Results provincial administrative region was corrected. The data of the Reporting System in 2020 showed that the ranking of ， raw coal production and the number of coal workers from most to least were Shanxi Province Inner Mongolia Autonomous ， ， Region Shaanxi Province and Xinjiang Uygur Autonomous Region with a total of 1 002 842 coal workers. The random intercept ， model using raw coal production enterprise scale and their interaction terms was fitted optimally with a −2 log likelihood value of 2 005.96 and Akaike information criterion value of 2 017.95. The factors affecting the number of coal workers included raw ， coal production and its interaction with the scale of enterprises. For every 1.00% change in raw coal production the number of ， coal workers in small and micro enterprises changed by 0.62% and the number of coal workers in large and medium enterprises changed by 0.13% more than that in small and micro enterprises. The corrected total number of coal workers for the four ， Conclusion provincial administrative regions was 1 125 515 and 1 089 321 for the two hypothetical scenarios respectively.The multi level model constructed with the data of raw coal production enterprise scale and their interaction terms of four ， provincial administrative regions could estimate the number of coal workers accurately and could better correct the number of coal workers in each provincial administrative region.

Effect of occupational stress on job burnout among coal miners: The mediating role of work-family conflict / 环境与职业医学

Background The highly prevalent of occupational stress and job burnout of coal miners seriously affect their physical and mental health. Objective To investigate the levels of occupational stress and job burnout in coal mine workers, and to analyze the mediating effect of work-family conflict between these two conditions. Methods A total of 1500 coal miners were included by random cluster sampling method from February to October 2019. The levels of occupational stress, work-family conflict, and job burnout of the study participants were evaluated using the Effort-Reward Imbalance Inventory scale (ERI), the Work-Family Conflict Scale, and the Chinese version of the Burnout Scale, and compared among coal miners with different demographic characteristics. Partial correlation analysis was used to find the correlations between indicators; SPSS AOMS 26.0 software was used to analyze the potential mediating effect among occupational stress, work-family conflict, and job burnout in the coal miners in Xinjiang. Results The study included 1247 male coal miners with a valid questionnaire return rate of 83.13%. The M (P25, P75) score of job burnout was 55.00 (47.00, 62.00). Except for gender and monthly income, the differences of job burnout scores among coal miners grouped with selected demographic characteristics were statistically significant (P<0.05). The M (P25, P75) scores of ERI and work-family conflict of coal miners were 1.01 (0.85, 1.21) and 51.00 (44.00, 57.00) respectively, and the differences of ERI and work-family conflict scores among different job types were statistically significant (P<0.05). ERI values were positively correlated with burnout (rs=0.212), emotional exhaustion (rs=0.188), and depersonalization (rs=0.244) scores (all P<0.01); work-family conflict scores were positively correlated with burnout (rs=0.382), emotional exhaustion (rs=0.360), depersonalization (rs=0.370), and reduced sense of accomplishment (rs=0.105) scores (all P<0.01). The regression results showed a significant positive effect of occupational stress on job burnout and work-family conflict (b=7.117, b=8.347, P<0.001), and a mediating effect of work-family conflict on the association between occupational stress and job burnout, with a mediating effect value of 0.249 (50.92% of the total effect of 0.489, P=0.002). Conclusion Work-family conflict may act as a mediating role between occupational stress and job burnout in coal miners, which suggests an indirect effect on occurrence of job burnout.

Effects of occupational stress and mental health on work-related musculoskeletal disorders in coal mine workers in Xinjiang / 环境与职业医学

Background The occurrence of musculoskeletal disorders in coal mine workers remains high, and psychological factors are one of the important factors. Objective To explore the occupational stress level, mental health status, and prevalence of work-related musculoskeletal disorders (WMSDs) of coal miners in Xinjiang, and to analyze the effects of occupational stress and mental health on WMSDs. Methods From August 2018 to August 2019, 1300 workers of 4 coal mines were selected by cluster sampling method. Musculoskeletal Disorders Questionnaire, Effort-Reward Imbalance (ERI) Scale, Self Reporting Inventory (SCL-90) were used to investigate the prevalence of WMSDs, occupational stress, and mental health. Results A total of 1177 valid questionnaires were collected, with a valid rate of 90.5%. The prevalence rate of WMSDs was 66.4%, the positive rate of occupational stress was 50.2%, and the positive rate of psychological symptoms was 53.4%. The M (P25, P75) ERI score was 1.0 (0.9,1.2), and the M (P25, P75) SCL-90 score was 138.0 (117.0,184.0). The prevalence rate of WMSDs in ≥3 sites was 45.0% in the occupational stress group and 46.0% in the positive psychological symptoms group. The results of binary logistic regression analysis showed that reporting occupational stress (OR=1.835, 95%CI: 1.380-2.440) and positive psychological symptoms (OR=1.461, 95%CI: 1.083-1.969) were positively associated with the prevalence of WMSDs; those being female (OR=2.393, 95%CI: 1.544-3.709), aged≥30 years (OR30-＜40=2.344, 95%CI: 1.507-3.645; OR40-＜50=2.395, 95%CI: 1.541-3.723; OR50-60=5.115, 95%CI: 2.872-9.111), with length of service>15 years (OR=2.283, 95%CI: 1.537-3.392), and being coal diggers (OR=1.591, 95%CI: 1.070-2.365) showed higher risks of reporting WMSDs; those with education level at high school and above (ORhigh school=0.399, 95%CI: 0.279-0.571; ORcollege and above=0.220, 95%CI: 0.157-0.310), and monthly income>8000 yuan (OR=0.364, 95%CI: 0.227-0.582) showed lower risks of reporting WMSDs. The results of structural equation model showed that in model 1 with mental health as the intermediate variable, occupational stress and mental health directly affected WMSDs, and the standardized path coefficients (β) were 0.10 and 0.25 respectively; ERI also directly affected mental health with a β of 0.20. In model 2 with WMSDs as the intermediate variable, ERI and WMSDs directly affected mental health, and the β values were 0.16 and 0.25 respectively; ERI also directly affected WMSDs with a β of 0.16. Conclusion The prevalence rate of WMSDs in selected coal mine workers is high, and occupational stress and mental health affect the occurrence of WMSDs.