Comparative assessment of the vertical distribution of respirable particulate matter in surface coal and metal mines using unmanned aerial vehicle mounted low-cost sensor

Trucks are the primary means of haulage in surface coal, metal, and nonmetal mining operations. The number of fatal accidents involving trucks is higher when compared to all other mining equipment. The Mine Safety and Health Administration (MSHA) reports that 137 fatalities were haul truck- related in the United States between 1995 and 2011. A total of 12 truck-related accidents, including 13 fatalities, were recorded in surface coal mining operations in West Virginia (WV) during this period. The objectives of this research were to (i) analyze the root causes of these accidents, and (ii) develop effective intervention strategies to eliminate these fatalities. The Fault Tree Analysis (FTA) technique was used to systematically analyze truck related fatalities. Data on truck-related injury accidents in West Virginia surface coal mines during 2012 and 2013 were also analyzed in this study. Results of the study indicate that inadequate or improper pre-operational check and poor maintenance of trucks were the two most common root causes of these accidents. A total of eight accidents occurred on haul roads, while 10 accidents occurred while the trucks were moving forward. The two most violated provisions of Code of Federal Regulations were 30 CFR§77.404 - Machinery and equipment; operation and maintenance (six times), and 30 CFR§77.1606 - Loading and haulage equipment; inspection and maintenance (five times).;A total of 223 reported injuries were recorded at West Virginia surface coal mines. With the exception of two missing data, a total of 178 accidents were equipment-related and 43 accidents occurred without equipment being involved. The equipment categories accounting for the most number of injuries were: truck (57 times) and bulldozer/dozer/crawler tractor (43 times). The majority of the truck-related injuries occurred within the worker's first five years at the mine and within the first five years at their current job title. Workers between ages 25 and 39 had the greatest percentage of injuries. Most injuries were recorded during "Section I" (6:00 a.m. - 2:00 p.m.), and the fall season has the greatest number of truck-related injuries of all four seasons. Regarding the nature of injury, "sprains and strains" made up about 32%, topping all other types of injuries. The most commonly injured body part in truck-related injuries was the "Multiple parts.".;A two-pronged approach to accident prevention was used: one that is fundamental and traditional (safety regulations, training and education, and engineering of the work environment); and one that is innovative and creative (e.g.,

Spatio-temporal distribution and transport of particulate matter in the eastern tropical North Atlantic observed by Argo floats

During 1991 and 1995, the Italian National Program for Antarctic Research carried out two oceanographic campaigns in the framework of the International (Strait of) Magellan Project. In this paper, we describe the distribution, biochemical composition, and mineralogical characteristics of particulate matter and the characteristics of the water masses defining microbasins in the Strait of Magellan. The data analyses highlighted differences in quality and quantity of the suspended matter and its organic component in the basins that make up the Strait and the Pacific Ocean. The westernmost basin is subject to an eastward flow from the Pacific Ocean, and continental runoff in the surface layers, which are consequently rich in organic matter with a high C:N ratio. The central basin, Isla Carlos III–Segunda Angostura, is characterized by the mixing of Sub-Antarctic Pacific waters, continental runoff, and glacio-fluvial waters: The basin has the lowest particulate matter concentration, but at Paso Ancho showed high concentrations of organic matter with a lower C:N ratio. The easternmost basin, Segunda Angostura-Atlantic entrance, is characterized by the mixing of the water column due to strong Atlantic tides and showed high concentration of particulate matter with a high detritic component. Generally, the organic matter concentrations showed significant differences during the cruises, being higher in 1991. Using the multivariate discriminant factor analysis to determine whether statistically significant differences existed between defined sampling areas, we determined that temperature, particulate organic carbon, and total particulate matter were the variables most important for the difference between areas.

Assessment of vertical and horizontal distribution of respirable particulate matter in and around a surface coal mine

Knowing the vertical distribution of ambient particulate matter (PM) will help port authorities choose the optimal dust-suppression measures to reduce PM concentrations. In this study, we used an unmanned aerial vehicle (UAV) to assess the vertical distribution (0–120 m altitude) of PM in a dry bulk port along the Yangtze River, China. Total suspended particulates (TSP), PM10, and PM2.5 concentrations at different altitudes were measured at seven sites representing different cargo-handling sites and a background site. Variations in results across sites make it not suitable to characterize the vertical distribution of PM concentration at this port using simple representative distributions. Bulk cargo particle size, fog cannon use, and porous fence all affected the vertical distribution of TSP concentrations but had only minor impacts on PM10 and PM2.5 concentrations. Optimizing porous fence layout according to weather conditions and cargo demand at port have the most potential for mitigating PM pollution related to port operation. As ground-based stations cannot fully measure vertical PM distributions, our methods and results represent an advance in assessing the impact of port activities on air quality and can be used to determine optimal dust-suppression measures for dry bulk ports.

In the United States, an unexpected and severe increase in coal miners’ lung diseases in the late 1990s prompted researchers to investigate the causes of the disease resurgence. This study aims to scrutinize the effects of various mining parameters, including coal rank, mine size, mine operation type, coal seam height, and geographical location on the prevalence of coal worker's pneumoconiosis (CWP) in surface and underground coal mines. A comprehensive dataset was created using the U.S. Mine Safety and Health Administration (MSHA) Employment and Accident/Injury databases. The information was merged based on the mine ID by utilizing SQL data management software. A total number of 123,589 mine-year observations were included in the statistical analysis. Generalized Estimating Equation (GEE) model was used to conduct a statistical analysis on a total of 29,707, and 32,643 mine-year observations for underground and surface coal mines, respectively. The results of the econometrics approach revealed that coal workers in underground coal mines are at a greater risk of CWP comparing to those of surface coal operations. Furthermore, underground coal mines in the Appalachia and Interior regions are at a higher risk of CWP prevalence than the Western region. Surface coal mines in the Appalachian coal region are more likely to CWP development than miners in the Western region. The analysis also indicated that coal workers working in smaller mines are more vulnerable to CWP than those in large mine sizes. Furthermore, coal workers in thin-seam underground mine operations are more likely to develop CWP.

The benefits of sensor based computer control in the international mining industry are many. Consequently, the industry expends considerable effort researching and developing automated systems. These efforts span the total industry including exploration, extraction, processing, and refining. All of the major segments of the mining industry: underground and surface, industrial minerals, metal, non-metal, and coal have participated in these developments. The result is a large body of information that is impossible to cover completely in a conference paper. To provide interesting information to the conference audience, this paper focuses on efforts to automate mobile production equipment. Most of the efforts apply to international underground metal and coal mines. Mobile mining and construction equipment presently utilize mechanization and remote control. For example, remote controlled equipment, where an operator is stationed some distance from the machine, but within line-of-sight, is found on many continuous mining machines in underground coal mines and LHD'S in underground metal mines. Teleoperated equipment where operators can be stationed further away, beyond-line-of-sight, is currently being tried at mines in the USA, Canada, Australia, and Sweden. Research projects currently focus on intelligent analysis of data from sensors to produce control algorithms which will be termed "mining robotics" to distinguish it from simpler closed ioop control termed "automation." The reason current research focuses on intelligent analysis of sensor data to produce control algorithms is that mining takes place in the geological environment where conditions are highly variable and unpredictable. As a result, mining systems must have substantial cognitive abilities to recognize and deal with these unpredictable variations. Robotics has been described as the intelligent connection between perception and action. It may provide the greatest benefits in productivity and safety since it incorporate artificial-intelligence-based algorithms that show promise for adapting to the dynamic mining environment. Many mines have purchased the latest available technology from equipment manufacturers. These large, expensive, advanced machines have high production capabilities and are very reliable. For these machines to provide the highest cost effectiveness, they should be fully utilized; however this is not always the case. For example, underground coal continuous miners are only utilized 17% of the shift (Suboleski and King, 1990, and King and Suboleski, 1991). These problems occur in surface and underground mines, but underground mining has the most opportunity for improvement. In addition, maintaining an artificial environment 348 / SPIE Vol. 1613 Mobile Robots VI (1991) 0-8 194-0750-X/92/$4.00 in an underground mine that is conducive to optimal work performance is expensive. By its nature, underground mining can be hot or humid, in addition, the equipment produces dust, noise, fumes, and other hazards. Explosive or toxic gases and the constant danger of rock falls add to the increasing list of health and safety concerns that have initiated volumes of federal and state regulations for maintaining safe work places for humans in underground mines. These regulations cause tremendous capital and operating expenditures that prevent many mineral deposits from being mined profitably. For example, in both underground coal and metal mines, miners excavate many more entries or drifts than necessary to produce and remove the ore or coal in order to provide a safe environment for humans. These difficulties will increase as mines deplete nearsurface reserves that have the best working conditions. As a result, some areas are not mined because of the expense of providing an adequate environment for human operators. A good example is narrow ore veins in metal mines that would normally require cut and fill stoping methods to provide adequate ground support. With teleoperated or robotic equipment, less expensive open stoping practices can be used. Another example is automated longwall systems that can be operated more freely in a bi-directional cutting mode because they eliminate respirable dust exposure on the face.

Operators of mobile equipment at surface and underground coal mines are exposed to whole-body vibration. Long term exposure to high amplitude whole-body vibration is associated with the subsequent development of back pain, and has also been linked to multi-system health related issues. The issue has been recognised by the mining industry, however, the management of the hazard has been hampered by difficulties obtaining whole-body vibration measurements during normal operations. The research utilises a novel measurement technique to gather extensive whole-body vibration data from surface and underground mining equipment during normal operation in order to identify the principal sources of hazardous whole-body vibration exposures, and to explore potential control measures.The accuracy of an iOS application (WBV) installed on an iPod Touch was assessed against gold standard measurements (SV106) via ninety-six simultaneous measurements obtained across a range of surface mining equipment during normal operations. The results indicated a 95% confidence interval of +/- 0.077ms-2 r.m.s. for vertical whole-body vibration. The validity of the application has subsequently been confirmed by two independent groups.A total of 172 long duration whole-body vibration measurements were collected from three surface coal mines from August 2014 to May 2016. An initial survey (64 measurements) of a variety of equipment types in operation at one site, revealed that while the majority of measurements were within, or above the ISO2631.1 health guidance caution zone; track-mounted tractors fitted with a blades and rippers, (commonly referred to as “dozers”) were highlighted as being associated with very high, and in some case, extreme whole-body vibration levels. Dozers were the subsequent focus of further work at the three sites, and the prevalence of very high amplitude whole-body vibration measurements was confirmed at each. The data gathered from individual dozers during different shifts demonstrated considerable variability across the measurements obtained which suggested that the variability seen was a function of some combination of task and/or operator characteristics, rather than equipment characteristics. Although information was gathered regarding tasks, location and ground conditions in which the equipment operated, no consistent relationships between these variables and the vibration levels measured could be discerned.The deployment of whole-body measurement equipment is normally very difficult within underground coal mines because of the precautions required to eliminate ignition sources. However, three low-methane coal mines were identified where these precautions were not required. A total of 265 long duration measurements were obtained over 16 weeks of data collection between November 2015 and March 2019. 274 short duration measurements were also obtained during investigations of whole-body vibration that correlates with speed and roadway maintenance.An initial survey of mobile equipment operated at the underground coal mines revealed that shuttle cars, load-haul-dump equipment, and personnel transport vehicles returned elevated whole-body vibration levels. Shuttle cars in particular were associated with very high whole-body vibration amplitudes. These equipment were targeted with a range of control measures during normal mining operations. A positive impact of roadway maintenance on vertical whole-body vibration amplitude was recorded, with reductions in vertical whole-body vibration amplitudes for both driver and rear passenger. The effect of increasing vehicle speed on increasing vertical vibration amplitudes was consistent regardless of seating position, and the effect on the rear passenger was much greater. Vertical vibration measurements well exceeded the health guidance caution zone for speeds greater than10 km/hr, and were extremely high for higher speeds. The small sample size of measurements from shuttle car seat changeout precluded meaningful statistical comparison, however the vertical whole-body vibration amplitudes measured after change were lower for both shuttle cars measured.The relatively low cost of the iPod Touch hardware, and the accuracy and simplicity of the WBV application, provides the opportunity for site-based workplace safety and health staff to routinely collect long duration whole-body vibration exposure data. This information, when correlated with secondary information such as the activity being undertaken, operating conditions and equipment characteristics, has the potential to assist sites in the identification of appropriate control measures and evaluate the effectiveness of those measures as part of a whole-body vibration risk management program.

When developing strategies aimed at mitigating air pollution in densely populated urban areas, it is vital to accurately investigate the vertical distribution of airborne particulate matter (PM) and its primary influencing factors. For this study, field experiments were conducted to quantify the vertical distribution and dispersion processes of PM at five vertical heights related to trees—including at street level near vehicular emission sources (0.3 m), pedestrian breathing height (1.5 m), beneath the canopy (6 m), mid-canopy (9 m), and the top of the canopy (12 m)—within a street-facing building in Wuhan, China. Comparing the vertical dispersion patterns of PM with six particle sizes (PM1, PM2.5, PM4, PM7, PM10, and total suspended particulates—TSPs), larger particles exhibited more pronounced variations with height, notably TSPs (correlation coefficient of −0.95) and PM10 (−0.84). The findings consistently revealed a downward trend in PM concentrations across various particle sizes with increasing height, indicating a negative linear correlation between particle concentrations and altitude within the street canyon. For every 1% increase in vertical height, the PM2.5 concentration decreased by approximately 5.44%, the PM10 concentration decreased by 132.1%, and the TSP concentration decreased by 180.6%. These findings show potential for guiding building designers in developing effective strategies, such as optimal vent placement, in order to mitigate the intrusion of outdoor air pollution—particularly PM2.5—into indoor environments. Furthermore, this research provides novel insights for residents living in street-facing buildings and individuals with respiratory diseases, aiding them in the selection of residential floors to minimize health risks associated with exposure to respirable PM.

Coal is a low-cost commodity and coal miners profit margins are slim, such that mining companies must maintain tight cost control to achieve acceptable returns. The challenge to coal geophysics is to adapt to these economic constraints and provide cost-effective, reliable methods for exploration and mining requirements. The geophysical methods which have been used in the reconnaissance, pre-development, and operational stages of coal exploration and mining are reviewed in terms of their exploratory function and their typical frequency of application. Borehole logging is the one method which is highly utilised for both surface and underground coal mining exploration, although seismic methods (mainly high-resolution reflection, and in-seam), are also frequently applied in underground coal-mining investigations. Because surface coal mining is constrained to shallow seams, most exploration is achieved by drilling methods, with geophysics playing a supporting but subordinate role. Also surface mining is less sensitive to seam disturbances such as faulting, rolls and intrusions, and can afford to set less strict requirements for prediction and resolution. The trend in underground mining is towards high-production longwall methods, which are much less tolerant of disturbance, and demand survey reliability and resolution standards which often stretch the limits of current exploration technology. A Workshop on Underground Coal Mining Exploration Techniques was conducted by the Australian Coal Association in 1991 to identify the strategies and priorities for future research and development. Most of the recommendations coming from the Workshop incorporated geophysical technologies, particularly the development of borehole logging methods which can be applied to in-seam drillholes. The recommendations also identified the need to selectively import and adapt analogous but more advanced technology from other areas, such as seismic reflection expertise from the petroleum industry, and to consolidate on the promising beginnings shown by techniques such as the radio-imaging method and in-seam seismic. The future also holds opportunities for geophysics to assist in the development and application of innovative mining systems. High-wall mining, continuous surface miners, and the increasing trend towards high-production automated mining equipment, bring with them the need to provide geophysical monitoring sensors and guidance systems.

Hydrology, circulation and distribution of particulate matter in Thermaikos Gulf (NW Aegean Sea), during September 2001–October 2001 and February 2002

Coal remains a very important source of energy for the global economy. Surface and underground coal mining are the two major methods of coal extraction, and both have benefits and drawbacks. Surface coal mining can have a variety of environmental impacts including ecosystem losses, landscape alteration, soil destruction, and changes to surface and groundwater quality and quantity. In addition, toxic compounds such as heavy metals, radioactive elements, polycyclic aromatic hydrocarbons (PAHs), and other organic contaminants are released in the environment, ultimately affecting the health of ecosystems and the general population. Underground mining has large impacts on underground water supplies and water quality, but generally has less visual surface impacts such as leaving waste and tailings on the surface and subsidence problems. In response to the concern about these environmental issues, many strategies have been developed by scientists and practitioners to minimize land degradation and soil pollution due to mining. Reclamation laws passed in numerous countries during the past 50 years have instituted practices to reduce the impacts of soil pollution including burying toxic materials, saving and replacing topsoil, and vegetating the land surface. While modern mining practices have decreased the environmental impacts, many sites are inadequately reclaimed and present long-lasting soil pollution problems. The current review summarizes progress in comprehending (1) coal mining impacts on soil pollution, (2) the potential risks of soil pollution associated with coal mining, and (3) different types of strategies for remediating these contaminated soils. Research and prospective directions of soil pollution in coal mining regions include refinements in assessing pollutant levels, the use of biochars and other amendments, phytoremediation of contaminated soils, and the release of toxic elements such as mercury and thallium.

The distribution and composition of suspended particulate matter in the sea is very complex and not well understood. In this study, 3 different approaches were used to estimate the quantity and quality of suspended particulate matter in 34 samples from the euphotic zone of 9 stations in the Gulf of California. The results from electronic, microscopic and chemical analyses showed that most parameters measured were significantly correlated, e.g. the total particulate volume from particles of 2 to 150 μ diameter, as obtained from the Coulter Counter, proved to be significantly related to such parameters as seston, particulate nitrogen, particulate carbon, phytoplankton carbon and chlorophylla. It can be concluded from this study that the Coulter Counter can be a very useful instrument to determine, with little effort, the size, distribution, and volume of particulate suspended matter in the sea. These data can then be used to calculate some important biological parameters which are necessary to establish meaningful models of phytoplankton production. More detailed studies are necessary to prove the above mentioned relationships in depth, space and time.

The vertical distribution of fine particulate matter (PM2.5) is a vital link in understanding the transport and evolution of haze. However, existing ground stations cannot provide sufficient vertical observations of PM2.5, especially at fine scales regarding space and time. This study deployed a six-rotor unmanned aerial vehicle (UAV) equipped with portable monitors to observe the vertical distributions of PM2.5 and meteorological parameters within 1000 m lower troposphere. By comparing with ground-based monitoring station and tethered balloon platform for PM2.5 measurements, the UAV was improved and then used to perform a field observation experiment in the Qingpu district of Shanghai, China. The UAV-based observations showed a decreasing vertical profile of PM2.5 in the experimental day, with a decrease of more than 50% at 0–1000 m height. PM2.5 had a vertical pattern that declined rapidly after 700 m in the afternoon, but the morning PM2.5 had a rapid decline from 200 to 500 m compared with other height intervals in this period. A temperature inversion at a lower height in the morning blocked newly formed PM2.5 at ground to disperse upward, and PM2.5 above the temperature inversion was composed of residuals in last night. The temperature inversion gradually climbed up in the afternoon, which was beneficial to the dispersion of near-ground PM2.5. The difference of relative humidity above and below 700 m height implies different geographical origins that were well identified and explained by a cluster analysis. This study generally highlights the significance of using a lightweight UAV to understand air pollution and governance environments in the urban area.

Emission from field burning of agricultural crop residue is a common environmental hazard observed in northern India. It has a significant potential health risk for the rural population due to respirable suspended particulate matter (RSPM). A study on eight stage size segregated mass distribution of RSPM was done for 2 wheat and 3 rice crop seasons. The study was undertaken at rural and agricultural sites of Patiala (India) where the RSPM levels remained close to the National Ambient Air quality standards (NAAQS). Fine particulate matter (PM(2.5)) contributed almost 55% to 64% of the RSPM, showing that, in general, the smaller particles dominated during the whole study period with more contribution during the rice crop as compared to that of wheat crop residue burning. Fine particulate matter content in the total RSPM increased with decrease in temperature. Concentration levels of PM(10) and PM(2.5) were higher during the winter months as compared to that in the summer months. Background concentration levels of PM(10), PM(2.5) and PM(10-2.5) were found to be around 97 ± 21, 57 ± 15 and 40 ± 6 μg m(-3), respectively. The levels increased up to 66, 78 and 71% during rice season and 51, 43 and 61% during wheat crop residue burning, respectively. Extensive statistical analysis of the data was done by using pair t-test. Overall results show that the concentration levels of different size particulate matter are greatly affected by agricultural crop residue burning but the total distribution of the particulate matter remains almost constant.