• Safety and Health at Work
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• v.12 no.4
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• pp.479-489
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• 2021

Background: During 2011, a study was undertaken to assess safety conditions in Serbian underground coalmines by analysis of injury data. The study covered all Serbian coalmines, identified week spots from the aspect of safety, and recommended possible courses of action. Since then, Serbia has made changes to safety and health legislation; all coalmines introduced new preventive measures, adopted international standards, and made procedures for risk management. After 10 years a new study has been performed to analyze the impact of these changes. Materials and methods: In this study, the injuries that have occurred in the Serbian underground coal mines over the last 20 years were analyzed. Statistical data analysis was performed by IBM SPSS Statistics v23. The injuries that occurred in the last ten years were compared with the results of the previous study (2000-2009). The average values of injury rates for both periods were compared for each of the categories (severity, age, body part, qualification), and the results were presented as absolute difference or percentile difference. Results: The results showed reduction in the number of injuries in the category of 20-30 years old workers, where the new training procedures for workers, which were set by mandatory legal regulations, certainly contributed. They also showed an increase in the number of injuries in the category of old workers, which indicates that the law did not have a positive effect on this category. Conclusion: The total number of injuries is still high; therefore, it is necessary to introduce mechanization and automation in mines and have a better policy for older workers who retire later nowadays.

• Safety and Health at Work
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• v.10 no.3
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• pp.377-383
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• 2019

Objectives: Exposure to fine particles in urban air has been associated with a number of negative health effects. High levels of fine particles have been detected at underground stations in big cities. We investigated the exposure conditions in four occupational groups in the Stockholm underground train system to identify high-exposed groups and study variations in exposure. Methods: $PM_1$ and $PM_{2.5}$ were measured during three full work shifts on 44 underground workers. Fluctuations in exposure were monitored by a real-time particle monitoring instrument, pDR, DataRAM. Qualitative analysis of particle content was performed using inductively coupled plasma mass spectrometry. Nitrogen dioxide was measured using passive monitors. Results: For all underground workers, the geometric mean (GM) of $PM_1$ was $18{\mu}g/m^3$ and of $PM_{2.5}$ was $37{\mu}g/m^3$. The particle exposure was highest for cleaners/platform workers, and the GM of $PM_1$ was $31.6{\mu}g/m^3$ [geometric standard deviation (GSD), 1.6] and of $PM_{2.5}$ was $76.5{\mu}g/m^3$ (GSD, 1.3); the particle exposure was lowest for ticket sellers, and the GM of $PM_1$ was $4.9{\mu}g/m^3$ (GSD, 2.1) and of $PM_{2.5}$ was $9.3{\mu}g/m^3$ (GSD, 1.5). The $PM_1$ and $PM_{2.5}$ levels were five times higher in the underground system than at the street level, and the particles in the underground had high iron content. The train driver's nitrogen dioxide exposure level was $64.1{\mu}g/m^3$ (GSD, 1.5). Conclusions: Cleaners and other platform workers were statistically significantly more exposed to particles than train drivers or ticket sellers. Particle concentrations ($PM_{2.5}$) in the Stockholm underground system were within the same range as in the New York underground system but were much lower than in several older underground systems around the world.

• Safety and Health at Work
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• v.9 no.1
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• pp.10-16
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• 2018

Background: A detailed evaluation of the underground mine climate requires extensive measurements to be performed coupled to climatic modeling work. This can be labor-intensive and time-consuming, and consequently impractical for daily work comfort assessments. Therefore, a simple indicator like a heat stress index is needed to enable a quick, valid, and acceptable evaluation of underground climatic conditions on a regular basis. This can be explained by the unending quest to develop a "universal index," which has led to the proliferation of many proposed heat stress indices. Methods: The aim of this research study is to discuss the challenges in identifying and selecting an appropriate heat stress index for thermal planning and management purposes in underground mines. A method is proposed coupled to a defined strategy for selecting and recommending heat stress indices to be used in underground metal mines in the United States and worldwide based on a thermal comfort model. Results: The performance of current heat stress indices used in underground mines varies based on the climatic conditions and the level of activities. Therefore, carefully selecting or establishing an appropriate heat stress index is of paramount importance to ensure the safety, health, and increasing productivity of the underground workers. Conclusion: This method presents an important tool to assess and select the most appropriate index for certain climatic conditions to protect the underground workers from heat-related illnesses. Although complex, the method presents results that are easy to interpret and understand than any of the currently available evaluation methods.

• Journal of Yeungnam Medical Science
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• v.15 no.2
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• pp.325-340
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• 1998

A cross-sectional study was conducted to evaluate the relationship between sick building syndrome(SBS) and the environmental factors affecting SBS on 130 underground workers and 60 controls. The study consisted of 1) a review of environmental condition 2) measurement of temperature, $O_2$, $CO_2$, CO, and formaldehyde and 3) a questionnaire survey of symptom prevalence and perception of environmental conditions using indoor Air Quality questionnaire recommended by National Institute for Occupational Safety and Health. Bronchitis and dust allergy were more prevalent in underground workers significantly(p < 0.05). Among the 18 symptoms related to the indoor air pollution, the experience rate of dry, itching or irritated eyes, sore or dry throat, chest tightness, tired or strained eyes and dry or itchy skin symptom was significantly different between the underground workers and controls. The diagnostic criteria of SBS was defined as at least 1 symptom is experienced 1-3 times a week during the last 1 month among 18 indoor air pollution related symptoms which can be relieved by moving out of the underground. Applying the criteria, the mean symptom score was significant higher in underground workers than controls significantly (p < 0.05). These resalts indicated that underground workers are under inappropriate ergonomic and physical condition and inadequate ventilation. Their experience rate of symptoms related to indoor air pollution and prevalence of SBS was significantly higher than controls. To reduce the prevalence of SBS of underground workers, the surveillance system of indoor air quality, restriction of using fuel in underground and legislative regulations for the environment are needed to establish a better indoor air quality. Early detection, treatment and prevention of SBS through medical attention is also needed.

• Journal of Korean Society for Atmospheric Environment
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• v.4 no.1
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• pp.23-32
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• 1988

The exposure level of respirable dust and silica for the coal workers of underground coal mines in Taebaek area was evaluated. Personal air samplers were attached to the coal workers-drillers, coal cutters, their helpers, haulers, and separators. Normality and lognormality of respirable dust and silica concentrations were tested by Kolmogorov-Smirnov one-sample test, differences of means of respirable dust and silica concentration were tested by group-t-test and paired t-test, and relation between respirable dust and silica concentration were tested by regression test.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.4
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• pp.48-58
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• 2009

In recent years, construction worker safety in construction site is important. Especially, the frequent collapse accidents have happened in tunnels, utility tunnel and underground structure, so that the importance of worker safety is greatly emphasized. It is difficult to communicate with other workers in underground space, using the current cable or wireless communicator. When the accident is occurred, it can't rescue workers. This is the reason that it has a deficiency to find a location of survivor and communicate rescure crew and field workers. In this paper we extract the optimal technical factors of USFSS(Underground Structure Field Support System) based on integrated technique of wireless communication and location awareness. And USFSS developed in this study is suited for bad environment of underground structure construction and able to track 3D position of laborer and communicate mutually.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.1 no.1
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• pp.47-55
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• 1991

Exposure level of respirable coal dust of underground coal mines in Taebaek area was evaluated. Personal air samplers with 10-mm nylone cyclones were attached to the coal workers including drillers, coal cutters, their assistants, haulers, and separators. Log-normality of respirable dust exposure concentration were tested by Kolmogorov-Smirnov one-sample test. Differences of means of respirable dust exposure concentration between work sites were tested by one-way ANOVA test and multiple comparison(Scheffe) test. And differences of respirable dust exposure concentration of principal and assistant workers in drilling sites and in coal faces were tested by paired t-test. Relation of respirable dust exposure concentration for the principal workers and their assistants in drilling sites and in coal faces were tested by regression analysis. The results were as follows : 1. All of the respirable dust concentration were log-normally distributed. 2. There were not only significantly different means of exposure concentration between drillers and coal cutters but between coal cutters and haulers. 3. Means of exposure concentration of drillers and drilling assistants were not significantly different. And means of exposure concentration of coal cutters and coal cutting assistants were not different.

• Journal of Preventive Medicine and Public Health
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• v.39 no.4
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• pp.325-330
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• 2006

Objectives: The aims of this study were to examine the level of airborne fungi and environmental factors in Seoul metropolitan subway stations and to provide fundamental data to protect the health of subway workers and passengers. Methods: The field survey was performed from November in 2004 to February in 2005. A total 22 subway stations located at Seoul subway lines 1-4 were randomly selected. The measurement points were subway workers' activity areas (station office, bedroom, ticket office and driver's seat) and the passengers' activity areas (station precincts, inside train and platform). Air sampling for collecting airborne fungi was carried out using a one-stage cascade impactor. The PM and CO2 were measured using an electronic direct recorder and detecting tube, respectively. Results: In the activity areas of the subway workers and passengers, the mean concentrations of airborne fungi were relatively higher in the workers' bedroom and station precinct whereas the concentration of particulate matter, $PM_{10}\;and\;PM_{2.5}$, were relatively higher in the platform, inside the train and driver's seat than in the other activity areas. There was no significant difference in the concentration of airborne fungi between the underground and ground activity areas of the subway. The mean $PM_{10}\;and\;PM_{2.5}$ concentration in the platform located at underground was significantly higher than that of the ground (p<0.05). Conclusions: The levels of airborne fungi in the Seoul subway line 1-4 were not serious enough to cause respiratory disease in subway workers and passengers. This indicates that there is little correlation between airborne fungi and particulate matter.

• Journal of the Society of Disaster Information
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• v.20 no.2
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• pp.302-314
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• 2024

Purpose: This study proposes a fall detection model based on a top-down deep learning pose estimation model to automatically determine falls of multiple workers in an underground utility tunnel, and evaluates the performance of the proposed model. Method: A model is presented that combines fall discrimination rules with the results inferred from YOLOv8-pose, one of the top-down pose estimation models, and metrics of the model are evaluated for images of standing and falling two or fewer workers in the tunnel. The same process is also conducted for a bottom-up type of pose estimation model (OpenPose). In addition, due to dependency of the falling interference of the models on worker detection by YOLOv8-pose and OpenPose, metrics of the models for fall was not only investigated, but also for person. Result: For worker detection, both YOLOv8-pose and OpenPose models have F1-score of 0.88 and 0.71, respectively. However, for fall detection, the metrics were deteriorated to 0.71 and 0.23. The results of the OpenPose based model were due to partially detected worker body, and detected workers but fail to part them correctly. Conclusion: Use of top-down type of pose estimation models would be more effective way to detect fall of workers in the underground utility tunnel, with respect to joint recognition and partition between workers.

• Proceedings of the KIEE Conference
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• 1997.07c
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• pp.803-806
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• 1997

The AC induced voltage on underground pipelines not only do harm to workers and instruments, but also cause big trouble in some case. This paper gives the mechanisms, examples, and countermeasure for the AC induced voltages which are caused by the resistive coupling between the grounding system of the 22.9kV distribution power system and the underground pipeline.