Eastern Coalfields Research Articles

High prevalence of alcohol use disorder & psychiatric comorbidity among coal mine workers: Observations from a cross-sectional study in West Bengal.

Background & objectives Tobacco (30%), alcohol (21.4%) and cannabis (3%) are the three most commonly abused substances in India. Tobacco and alcohol abuse have higher prevalence rates among different occupational groups as compared to that in general population in the country. Both tobacco and alcohol lead to significant occupational harm in terms of absenteeism, injuries, sickness and lost productivity. This study estimated the patterns of substance use and associated common psychiatric comorbidity in a sample of coal mine workers. Methods Coal mine workers at the age of 18 yr or above engaged in mining activities (skilled/semi-skilled/unskilled) were recruited from the Raniganj - Asansol coal mining areas of Eastern Coalfields Limited (ECL). Participants were screened to identify patterns of substance use and other common mental health problems. All participants were administered ASSIST (The Alcohol, Smoking and Substance Involvement Screening Test); GENACIS (Gender, Alcohol and Culture: An International Study) modified questionnaire; and Hospital Anxiety and Depression Scale (HADS) for primary screening for anxiety and depression. Results Out of 202 participants 69 per cent (n=140) were found with either 'hazardous and harmful' (moderate risk); or 'dependent' (high risk) patterns of use of either tobacco or alcohol or cannabis or of more than one substance. Only 31 per cent (n=62) were 'low-risk' for all substances. Almost 65 per cent (n=132) and 49 per cent (n=99) participants out of the whole sample (n=202) belonged to 'hazardous and harmful' (moderate risk) and 'dependent' (high risk) pattern of tobacco and alcohol consumption, respectively. About 28.8 per cent (n=38) and 23.7 per cent (n=31) of all participants had anxiety and depression, respectively. Combined moderate to high use of both alcohol and tobacco use was significantly associated with the risk of having anxiety [adjusted odds ratio (AOR)=4.896, P<0.015] and depression (AOR=5.335, P<0.012). Interpretation & conclusions Alcohol and tobacco are major substance abuse problems among coal mine workers. This population requires early community and primary care based brief intervention as well as additional community-based pharmacotherapy for substance dependence problems as well as intervention for common mental health issues.

Geo-sustainability Challenges and Remediation Strategies: A GIS-based Assessment of Sripur Coalmine Areas, West Bengal, India

This study examines the health, risk, and safety aspects of coal mining in the Sripur area, focusing on the Bhanora West Block, Asansol, West Bengal, India as one of the 14 operational mines of Eastern Coalfields Limited in Asansol. The study addresses the increasing risks of accidents, fires, and subsidence in active, ageing, and closed mines and storage yards. The study’s incorporation of field surveys, satellite imagery, and environmental data ensures that the findings are based on a well-rounded and multi-faceted dataset. The satellite imagery data (GIS and Remote Sensing) are perceived along with available literature and environmental impact compliance reports from time to time, with particular interest in the Bhanora West coal mine, both open cast and underground. The aspect, Hill shade, LULC and stream order maps of the Damodar are generated using Q-GIS, 3.28.7. The environmental clearance data, accident data, subsidence area, and landslide data are analysed. A vast area in Sripur is observed to be under subsidence, with cracks appearing even near residential areas. The flow of the Nunia nallah is nearby, and old closed mines are not adequately backfilled, so the chance of seepage cannot be neglected though regularly attended. Pneumoconiosis (CWP), a lung disease (black lung), chronic obstructive pulmonary disease (COPD), and silicosis are common in Sripur due to dust and substandard water. Effective and riskless mining extractions using proper technologies can avoid mining hazards, such as subsidence, the influx of water in underground mines, health hazards, air/water pollution, mine fire, and intact physical landscape and observing criteria of sustainable Development Goal SDG-1 SDG-3, SDG-6, SDG 12, SDG-13, and SDG 16.

ASSESSING THE EFFECTIVENESS OF CSR PRACTICES: A STUDY ON SOUTH EASTERN COALFIELDS LIMITED, BILASPUR

An industry heavyweight, South Eastern Coalfields Limited (SECL) in Bilaspur is the subject of this research study that evaluates the efficacy of its CSR initiatives. The study's overarching goals are to ascertain whether or not SECL's CSR practices are in line with larger CSR concepts and objectives and assess the ways in which these activities have affected local people and the environment.This research makes use of a mixed-methods strategy, integrating quantitative results from surveys of local stakeholders (such as workers, residents, and government officials) with qualitative information gleaned via in-depth interviews and document review. Important parts of SECL's CSR initiatives, including health and education programs, community development, environmental management, and economic benefits, are the subject of the study.Improvements to community infrastructure, educational opportunities, and healthcare services have been directly attributed to SECL's CSR programs, according to the findings. Still, questions about stakeholder involvement and the projects' long-term viability persist. While SECL's CSR procedures are in line with industry norms and have a beneficial influence on local development, the analysis also shows that there is room for improvement in terms of transparency and targeting.At the conclusion of the article, we suggest several ways that SECL might improve its CSR practices. These include making sure that programs are sustainable, communicating with stakeholders better, and measuring and reporting CSR achievements better. This research offers valuable information for corporate social responsibility practitioners and policymakers, while also adding to our knowledge of how successful CSR is in the mining industry.

Comprehensive geospatial mapping and monitoring of an eastern coalfield in India

Geospatial mapping and monitoring are crucial for designing slopes in opencast mining, as failure can result in significant economic and life loss. To overcome these issues, the present investigation evaluated the Digital Elevation Model (DEM) generated using high resolution Cartosat-1 satellite imagery. Simultaneously, mapping of shaded relief map, aspect map and slope maps was done for the monitoring of Shatabdi opencast coal mine of Jharia region, an eastern coalfield region of India. Shaded relief map was categorized in to low, moderate and high categories and maximum area was covered by moderate to high shades. The constructed aspect map encompasses the range between 0 and 360 degrees of direction, with categorization and representation through distinct colors. The slope map was classified into various categories based on degrees of slope, including very gentle, gentle, moderate, moderately steep, steep, and very steep slopes. The maps were ground validated using Differential Global Positioning System (DGPS) collected data points by field visit in the region. For opencast mines to operate safely and profitably, slope stability in different stages of mining must be mapped and monitored. The study synthesizes data from diverse sources, highlighting the role of geospatial technology in addressing multiple research gaps within the mining industries prior to leveraging Cartosat-1 satellite data. Slope mapping and monitoring of coalfield regions are crucial to reducing construction costs, mitigation of natural hazard risks like flooding and landslides, and effective conservation of natural resources such as soils, vegetation, and water systems. The present study benefits policymakers, environmental planners and government in formulating policies to ensure safety, reliability, and enhance the economic growth of workers and the country.

Petrology and association of rare earth elements in magmatically altered high-ash coal of Indian origin

The extraction of valuables from waste has gained momentum. Thermal influence alters both the organic and inorganic components of coal. Insufficient knowledge on the association of rare earth elements (REEs) with the parent matrix of thermally altered high-ash coals (63% ash) limits the potential for such coals being utilized for isolation of valuables. In this study, we analyzed the distribution and occurrence modes of REEs within a magmatically altered high-ash coal via nine-step sequential extraction, combining Tessier and BCR methods. The total concentration of REEs in the coal sample, on whole coal basis, was found to be 820 ppm, which is significantly higher than the world average. Major mineral oxides were deduced to be those of Si, Fe, Al, Ca, Mg, and Ti. Sequential extraction confirmed that about 66% of HREE and 25% of LREE were included in the residual fraction. LREEs were concluded to be primarily in ionic form, whereas HREEs were speculated to be associated with the TiO2 phase. XRD analyses showed that thermal alteration affected the dolomite phase specifically, which selectively got removed where carbonate-bound elements were assessed. Petrographic analysis supported the magmatic influence and demonstrated the presence of mosaic structures and pores containing unfused vitrinite, with a reflectance value of 3.6. To summarize, the present study pertaining to delineation of association of valuables in high-ash heat-altered coals from an Eastern coalfield in India can potentially open up new avenues for utilizing such coals, which are otherwise considered waste.

Study of mineralogy and distribution of rare earth elements in coal block of Eastern Coalfield, India

ABSTRACT Coal by-products are continuing to be explored as secondary resources for extraction of rare earth elements (REEs). Nevertheless, the knowledge of their geological abundance is still scarce compared to the high global demand. The present investigation aims to study the distribution of REEs in coal samples acquired from Eastern coalfield, India. A total of 27 samples collected from two boreholes (RGCF-1and RGCF-2) were thoroughly analyzed. The average REE concentration in RGCF-1 was 724 ppm, while for RGCF-2, it was 658 ppm with a distribution pattern of Ce>La>Nd>Y>Pr>Sc>Sm>Gd>Dy>Yb>Er>Eu>Ho>Tb>Tm>Lu. Quartz, feldspar, sanidine, magnetite, hematite, anatase/titanate and illite were deduced to be the major mineral phases in these coal ash samples prepared at 815°C. In RGCF-1, REEs were associated with magnetite, whereas in RGCF-2, they were primarily with aluminosilicate and titanate minerals. The overall concentration of critical REEs varied from 122.5 to 387.8 ppm with an outlook co-efficient (C outl) of 0.58–1.26, indicative of the suitability of the chosen coal block for future exploration. Such an exploration-based investigation on abundance of REEs in the Indian subcontinent coupled with the knowledge of their mineralogical association is beneficial in not only understanding their enrichment but also coining a suitable extraction strategy for these valuables.

An assessment of environmental impacts in mining areas of Paschim Bardhhaman district, West Bengal, India

Mining is the most significant economic action in the Paschim Bardhaman district of West Bengal, India. Simultaneously, it has an enormous figure of negative influences on the natural, environmental, ecological, and social environment. The land use and land cover (LULC) alteration, coal mining effect (open-cast) on the LULC, and the local environmental influences are deliberated. The Paschim Bardhhaman’s LULC area is examined for the period of 30 years i.e., since the year like 1991 to 2021. Furthermore, alteration examination and spatial–temporal dynamics of LULC quantification are also deliberated. Analysis discloses that the water body marginally increased from 0.64% in 1991 to 0.96% in 2021. Mining area increased from 0.00% (1991) to 8.97% (2021) respectively. Instead, vegetation has decreased from 40.17% (1991) to 31.20% (2021) continuously. Similarly, settlement increased from 5.02% to 13.77% in the year 1991 to 2021 respectively. Agricultural land progressively decreased from 44.47% (1991) to 39.73% (2021) respectively. Raniganj Coalfield area, Eastern Coalfield Limited (ECL), and Coal India Limited (CIL) are the triggers for open cast mining. Land surface temperature (LST) increased by 7.96 ˚C (summer) and 10.24 ˚C (winter) between 30 years. The LST, LULC, and vegetation limitations are substantial factors in the universally changing climate investigations. Thermal infrared remote sensing demonstrated its competence for observing temperature and moving micro-climate in urban regions. The outcomes indicate that the outside temperature influences self-heating surfaces (hotspots) regions. The examination likewise shows that the outside temperature influences the self-heating surfaces (hotspots) regions.

Influence of surface mining on seasonal hydrology response to storms across eastern Kentucky, USA

ABSTRACT Mountain Top Removal and Valley Fill (MTR/VF) practices have drastically altered the surface cover, topography and hydrology of many watersheds across the Appalachian region of the US. These practices strip the bedrock from the ridges and peaks of watersheds, before removing the coal seams and depositing the waste fill into adjacent valleys. Existing research has generated conflicting outcomes as to the resulting hydrological impacts in response to storms. This creates potential issues for subsequent mitigation projects seeking to recreate prior hydrological conditions and riparian ecosystems. Our study focused on the potential influence of MTR/VF practices for a series of mined and unmined watersheds across the Eastern Coalfield of Kentucky. We analyzed rainfall-runoff response, focusing on how quickly rainfall was converted to quickflow and how much water left the catchment during storms for the 2022 water year. Lag times were shortened for the mined watersheds while quickflow coefficients reduced when vegetation cover increased. Valley fill-in mined watersheds also appears to create a delayed secondary release of quickflow from headwater locations during more extreme storms. These findings may assist future reclamation/mitigation practices for mined watersheds across Eastern Kentucky aiming to correctly recreate the hydrologic conditions that resemble those of unmined landscapes.

First record of Marecastrepera (Linnaeus, 1758) from an abandoned coal mined lake of Eastern Coal Fields, India

Here we report occurrence of the migratory species Marecastrepera (Linnaeus, 1758) commonly known as Gadwall from a freshwater pitlake of Eastern Coal Fields, India. The very first pictures (in recent times) are presented with a note on potential threatto its new habitat and possibilities of future research on this speciesin abandoned coal mined lakes.

Reporting of Bar Headed Goose (Anserindicus, Lathum 1790) from pitlakes of Eastern Coal Fields, India

Here we report occurrence of the species Anserindicus from a freshwater pitlake of Eastern Coal Fields, India. The very first pictures (in recent times)of 62+ individuals are presented with a note on conservation measures of its new habitat and scope of future research on Anserindicus in this region of eastern part of India.

Application of alternative organic wetland media for acid mine drainage treatment: Insights on reformations of microbial community structure

Acid mine drainage (AMD) discharge, particularly from the North Eastern Coalfield (NEC), Assam, has been a major persistent ecological threat. A lab-scale constructed wetland (CW) deriving organic wastes as the wetland media was implemented to treat high acidity (724 mg L–1 as CaCO3) AMD loaded with sulfate (1000–1300 mg L–1). Metal contents in mine wastewater comprised iron, aluminium, manganese, zinc, cobalt, nickel and chromium as 104, 25, 6.2, 5.1, 1.1, 1.1 and 1.1 mg L–1, respectively. CW operated continuously at a hydraulic loading rate (HLR) of 0.03 m3 m–2 d–1 for 282 days. Effluent water quality was monitored, and resulting shifts in microbial diversity were identified. Results demonstrated 771 mg L–1 (as CaCO3) alkalinity in effluent and metal removal (87–100%), except Co and Mn, which surpassed effluent discharge criteria. Further, the high-throughput sequencing results revealed significant reformations in bacterial assemblages throughout the operational period. Proteobacteria (45%) and Bacteroidetes (26%) represented the major bacterial groups at the start-up of CW, which later declined due to the elimination of aerobic strains under anaerobic conditions. Additionally, methanogenic archaea suppressed greatly due to the competition from sulfate and iron-reducers. An increase in the relative abundances of key functional bacteria (Firmicutes, Bacteroidetes, Actinobacteria and Acidobacteria) in the treatment phase indicated stable operation. Sulfate reduction (62%) was partial, evidenced by the prominence of sulfate-reducing bacteria (SRB) (Thermodesulfobium, Syntrophobacter, Desulfomonile and Desulfovibrio). This study offers insights into the microbial dynamics within an organic-media-amended CW, which directly influences AMD treatment.

Electrical resistivity tomography technique coupled with numerical modelling: A case study for stability analysis

AbstractCavity due to underground old mine workings is one of the major threats to the coal mines and the overlying subsurface and surface properties, which need to be protected. The detection of old mine workings and stability assessment of overlying strata are common problems in most of the Indian coalfields. Several coal mines in India are loss‐making, mainly due to different types of mine hazards. Khandra mine is one such mine at Raniganj Coalfield, Eastern Coalfields Ltd., a subsidiary of Coal India Limited. In the present study, 2‐dimensional and 3‐dimensional electrical resistivity tomography were carried out for detailed subsurface characterization. It supports delineating underground workings, including the nature of voids/cavities (air or water‐filled). Excessive distortions were reported in electrical resistivity tomography application, especially at the near‐surface, owing to large resistivity variations. Refinement of the model by half‐unit electrode spacing was attempted here to reduce the distortions with minimum possible absolute errors. 3‐Dimensional resistivity volumetric model was also developed with the help of five electrical resistivity tomography parallel profiles for better apprehension of the subsurface. Analysis provided important inputs for stability analysis using 3‐dimensional numerical modelling. The physico‐mechanical properties of the overlying strata, pre‐excavation in situ stresses, boundary conditions and the mine geometry simulation were incorporated for understanding the stability analysis. Stability analysis was carried out using the finite difference technique. The analysis of 3‐dimensional numerical modelling indicated that two distinct layers comprising (i) laterite/part of the course to medium‐grained sandstone and (ii) developed galleries of R‐IX seam exhibited a very low safety factor below 1.0, indicating potholing/subsidence susceptibility. The other three layers comprising parts of fine‐grained sandstone exhibited a relatively higher safety factor of around 2.0, indicating moderately stable zones, but not on a long‐term basis. Parts of Siduli stream embankments need suitable retaining walls to avoid water inundation for the stability of the area.

Mercury in coal from south eastern coalfield and mercury partitioning at sub-critical coal-fired power plant

Mercury in coal from south eastern coalfield and mercury partitioning at sub-critical coal-fired power plant

Comparison of model study with field implementation of gravity blind backfilling method to control subsidence induced disaster in abandoned underground coal mines

Blind hydraulic backfilling technique is used for subsidence control in underground coal mines. A laboratory size model of underground working was developed to understand backfilling process. Observations from model were utilized for backfilling process in one of the underground mines. This study describes the results obtained in the field investigation at an old abandoned waterlogged underground coal mine of Eastern Coalfields Limited (ECL), a subsidiary of Coal India Limited and their verification with the findings obtained in the laboratory scale model study carried out on a model of underground coal mine worked by board and pillar method. The relative influence of slurry concentration and flow rates on the areas of filling from a single inlet borehole has been discussed. The relative spread of sand in different directions has also been measured using a remotely operated underground vehicle mounted camera. The empirical relationships developed under field conditions have been found to be similar to those of laboratory model.

Underground mine deformation monitoring using Synthetic Aperture Radar technique: A case study of Rajgamar coal mine of Korba Chhattisgarh, India

Coal mines are the major source of energy in industries and are important indicators of the economic growth of a country. Excessive withdrawal of coal from underground coal mines without stowing leads to surface deformation. In this study, Synthetic Aperture Radar Technology has been used to identify the surface deformation in the Korba Coal Mines of India. Korba coal mines are major coal-producing mines in India that come under South Eastern Coalfields Limited (SECL). It covers three underground mines. Depillaring has been done through the caving method, which may lead to the deformation of the area and its surroundings. Deformation may have devastating consequences if overlooked. So, it requires continuous monitoring of the area. Space-based SAR interferometry is the most preferred technique to monitor any mining area over a period of time. In this technique, known as the DInSAR technique, a deformation map can be generated from images of the same area acquired over different points of time. In the present study, images of the month of February of the years 2015, 2016, 2017, and 2019 have been successfully utilized for DInSAR analysis over the Rajgamar area. The Interferogram allows analysis of an entire mine site including pits and their surrounding area. High precision monitoring over wide coverage enables to bring out accurate deformation results due to the presence of coherent targets and monitoring risk across the study area. Maps generated from data were scrutinized and interpreted. Consequentially, 2015–2016 shows greater deformation than the other two corresponding maps generated 2015–2017 and 2015–2019 data. Results were validated through ground observations. Overall the area of the Rajgamar coal mine is getting deformed at a slow rate.

Profiling and occupational health risk assessment study on coal ashes in terms of polycyclic aromatic hydrocarbons (PAHs)

Profiling and cancer risk assessment on the polycyclic aromatic hydrocarbons (PAHs) content of coal ashes produced by the major coal combustion plants from the eastern coalfield region in India was conducted. Thirteen PAHs were detected on coal ashes collected from ash deposition sites of major thermal power plants and the profiling of the PAHs was done. Benzo[a]pyrene equivalents (BaPeq) for individual PAHs were calculated and applied to the probabilistic assessment model from US EPA (1989). Monte Carlo simulations were conducted to assess the risk of inhabitants exposed to PAHs through the dust of the coal ash deposition site. In fly ash, the range of total amount of carcinogenic PAHs was from 3.50 to 6.72 µg g−1 and for the bottom ash, the range was 8.49 to 14.91 µg g−1. Bottom ashes were loaded with ample amounts of 5- and 6-ring carcinogenic PAHs, whereas fly ashes were dominated by medium molecular weight PAHs. The simulated mean cancer risks from fly ashes were 2.187 E–06 for children and 3.749 E–06 for adults. For the case of bottom ash, the mean risks were 1.248 E–05 and 2.173 E–05 respectively for children and adults. Among all the three exposure routes, dermal contact was the major and caused 81% of the total cancer risk. The most sensitive parameters were exposure duration and relative skin adherence factor for soil, which contributed the most to total variation. The 90% risks calculated from the bottom ashes (2.617 E–05 for children and 4.803 E–05 for adults) are marginally above the acceptable limit (>1.000 E–06) according to US EPA. In this study, a comprehensive risk assessment on carcinogenic PAHs present in coal ashes was done for the first time that may be helpful to develop potential strategies against occupational cancer risk.

Community resilience, Corporate Social Responsibility and local economic development: The case of coal mining in India

Corporate social responsibility (CSR) in the mining sector is believed by its proponents to be a critical element of responsible business practice, providing strategic economic advantages while helping to minimize environmental damage. In the midst of the current COVID-19 crisis, this study presents a paradigm for assessing the development of local communities through CSR initiatives by the mining sector. For the purpose of the study, data were gathered from 1209 beneficiaries living in the vicinity of Eastern Coalfield Limited (ECL). According to the findings of the study, CSR initiatives result in enhanced livelihood activities, skills, knowledge, empowerment, and community participation for the community affected by COVID-19. This study has significant implications for academics and corporate executives in the context of India's mandatory CSR laws, as it uses structural equation modelling (SEM) to evaluate the efficacy of CSR initiatives in terms of local community development and to unravel the complexity of the relationship between corporations and society. In addition, community resilience is employed to mediate various CSR initiatives and local community development as an innovative approach to managing the COVID-19 pandemic.

Reclamation of Coal Mined Land with Integrated Biological Approach

A pilot study was conducted at a backfill area of coal mine overburden dump (OBD) in Tikak Colliery, North Eastern Coal Field, Margherita, Assam, India, to evaluate the performance of 42 native plant species in a revegetation experiment with integrated biological approach during 2018-2021. The plantation was done with application of lime @ 15 gm per pit and farm yard manure (FYM) @ 2 kg per pit and planting nursery raised inoculated seedlings with arbuscular mycorrhizal fungi (AMF) and plant growth promoting rhizobacteria (PGPR) after a series of pot experiments. Pot culture experiments were done to obtain the best treatment combination for the field trails. The seed ball technology was also adopted in the initial year to stabilize the area with green herbaceous cover and to improve soil parameters. The result revealed that herbaceous species growing from seed ball sowing could survive in the OBD area. The best performed treatment combination was AMF + PGPR + Lime + FYM. Out of a total of 42 native plant species 17 were recorded for 60- 70 % survival after 2 years of planting on the OBD site. These practices completely replaced the application of topsoil in the revegetation programme of coal mine site and may be replicated for reclamation of OBD site for successful plantation programme.

Design of blasting patterns to induce effective caving in continuous miner depillaring panel – a case study

ABSTRACT An innovative scheme of induced caving by blasting was adopted in the depillaring continuous miner panel CM1 of Jhanjra Colliery of Eastern Coalfields Limited, a subsidiary of Coal India Limited. Initially, the blasting pattern was designed with respect to underground workings and later with respect to the surface, vertically above the panel, to facilitate effective caving. The natural caving was delayed due to the presence of three hard-rock beds of more than 5000 cavability index in the immediate roof of the R-VI seam in addition to the oversized left-out standing pillars kept during coal extraction in the panel, which provided extra supports to the hanging roof-rock in the goaf. To mitigate the situation, the design parameters were meticulously planned and implemented for successful blasting operations, which led to effective caving in the goaf and enabled successful extraction of the coal from the panel maintaining the required level of safety and productivity.

An Analysis of Financial Performance of the Coal Mining Industries: A Case Study of Raniganj Coalfield of Eastern Coalfield Limited

The leading coalfield of India, the Raniganj coalfield under Eastern Coalfield Limited is recognised as the birth place of the Indian coal mining industry and one of the most prominent coalfields not only in India but also in the world. It is also the second largest supplier of superior quality of coal in the nation at present subsequent to Jharia coalfield. Raniganj and Jharia Coalfields (RCF &amp; JCF) can be recognised as mirror image in the history of coal mining in India. Both the coal mining areas are witnessing mining of coal for more than 230 years. With the shifting of economic structure of the country, the cold filed region has registered quite a lot of ups and down in its financial performance. From this point of view the current paper is an attempt to assess the financial performance in the field of mining segment of Raniganj Coal Field, the most important coal producer in West Bengal. The whole study is entirely based on secondary data. A period of five year from 2014-15 to 2019-20 has been determined for the study. The data have been tabulated, analysed and interpreted with the help of Z Score Model and Economic Value Added (EVA) based on financial ratios. It is observed from the analysis of various financial ratios that the revenue earning capability, liquidity condition and long-standing solvency situation of RCF, is to a certain extent good during the entire study period and the level of bankruptcy situation is also very low.