Maria Luísa Ferreira Matos

Bio: Maria Luísa Ferreira Matos is an academic researcher. The author has contributed to research in topics: Noise & Drill. The author has an hindex of 1, co-authored 5 publications receiving 6 citations.

Whole Body Vibration in open pit mining—a short review

Abstract: The main objective of this study was to synthesize scientific knowledge in order to characterize Whole Body Vibration (WBV) in open pit mining: sources, measurements methodologies and main effects on health. A review based on PRISMA Statement was done. Inclusion criteria were research on WBV in mining, published after 1990 and written in English. Thirty-three studies were included in the review. Rock drills, shovels and dumpers are strongly present in this industry. They are potential sources of workers exposure to WBV. All bibliography followed methodological recommendations of ISO 2631-1:1997. For WBV characterization routine works, individual tasks, occurrence records, pavement features, were topics considered. Dumper is the equipment that can be the more dangerous; it has the highest Root Mean Square (RMS) acceleration values. Back pain is the main complaint in workers due to WBV exposure. All identified studies were screened initially by title and abstract, and then more carefully in full text. 3 RESULTS AND DISCUSSION 3.1 Research results Literature search has produced 607 potentially relevant papers. Following screening process steps shown in Figure 1. Thirty-three articles were included in the review. Most of them were discarded due to violating the inclusion criteria, although many duplicates were also excluded. Figure 1. Flow diagram of studies selected for review. 3.2 Sources of vibration in mining Classes of equipment and their open pit mining operations (WBV producers) were studied (Table 1). Table 1. Equipment and operations associated with WBV. Machine Activity Rock drill Positioning Drilling Travelling Shovel Trenching/excavating Swinging and loading Travelling Dumper Travelling Loaded by shovel Unloading Kunimatsu and Pathak (2012) 3.2.1 Rock drills Rock drills are, according to several authors, the equipments that produce lower Root Mean Squared (RMS) acceleration values over the occupational exposure. Howard, Sesek et al. (2009) reached an acceleration of 0,30 m·s -2 and Van Niekerk, Heyns et al. (2000) 0,16 m·s -2 on vertical axis (zz). According to these authors, at this workplace, the operator will be safeguarded from the risk of exposure to WBV. These studies were the only ones to analyze WBV in rock drills. 3.2.2 Shovels Due to its flexibility, low-cost operations, maintainability and multifaceted operating capability, shovels are widely used in surface mines (Frimpong, Galecki et al. 2011). The studies aiming the characterization of WBV exposure in shovels, in open pit mining, found very different values for RMS. Some studies point to WBV values below 0.5 m.s -2 (Howard, Sesek et al. 2009; Aye & Heyns 2011; Dentoni & Massacci 2013). However, authors like Vanerkar, Kulkarni et al. (2008) call attention to the risk conditions that may be subject these workers, with WBV values reaching 2.3 m.s -2 . The same happens with the predominant axis, there is no a clear definition. The vertical (zz) and the longitudinal (xx) are presented as the main axis according Aye & Heyns (2011) and Dentoni & Massacci (2013). Thus, the discrepant characterization of exposure to WBV in these equipments is notorious. This is probably due to the multiple operations carried by shovel, which lead to different situations. 3.2.3 Dumpers Dumpers are strong vehicles widely used in open pit mining environments to transport large quantities of rock to crushing plants or dump locations. Their capacity range is from 7 to 350 tonnes (Mandal & Srivastava 2010; Eger, Stevenson et al. 2011). The majority of studies analyzed (Van Niekerk, Heyns et al. 2000; Kumar 2004; Eger, Stevenson et al. 2008a; Howard, Sesek et al. 2009; Mandal & Srivastava 2010; Smets, Eger et al. 2010) assigns to these machines considerable vibration values, above 0.5 m.s -2 . The predominant axis is the vertical (zz). The dominant frequencies are set below 4 Hz. 3.2.4 Synthesis Table 2 shows the analyzed studies towards the characterization of WBV exposure in rock drills, shovels and dumpers in open pit mines. It is focused the RMS acceleration value, main axis and dominant frequencies. In open pit mines, in terms of WBV exposure were highlighted by its relevance, rock drills, shovels and dumpers (Howard, Sesek et al. 2009). Rock drill workers had the lowest exposition to WBV (only office workers are below). They are followed by the Shovels and Dumpers operators by increasing degree of risk. This ranking is consistent with the values collected in this review. Thus the dumper will be the workplace targeted for priority intervention. Table 2. Summary of studies characterizing exposure to WBV in rock drilling, shovel and dumper in open pit mining. Machine Authors (year) RMS [m.s] Main axis Dominant frequencies

Dispersion of quarry's dust - pilot study

Abstract: The mining industry involved, among other factors, exposure to dust, which affects workers, and also the surrounding populations. In this article, the dispersion of dust in the air environment was studied and the dust sampling was based on the French standard NFX 43 007:2008. The dust flux deposition was determined in twenty-four sampling points located inside and around the quarry. It was verified that the points with higher level of dust correspond to the operating area access, crushing plant, and a national road, with the average of 369.49 mg.m -2 .day -1 , 337.70 mg.m -2 .day -1 and 152.65 mg.m -2 .day -1, respectively. The lowest value of dust flux deposition corresponded to a point located in a limit of the quarry, with the value of 14.37 mg.m -2 .day -1 . Through this study it was concluded that the surrounding population could be affected by the dust quarry, although, the dispersion will greatly depends on the meteorological conditions, among other factors. prevailing wind direction, mainly in what concerns the storage in the open air, these circuits present a strong potential to produce dust. Another element of this system is the sand washing. However, due to the use of water, this unit is not responsible for the dust production. In this quarry there is also a decantation unit for sludge and a filter press. For exploitation activities, in a general view, there is some equipment operating on a defined place and with appropriate functions, such as: Rock / mining area / drilling and blasting Dumper / mining area – primary crushing plant / transportation of material to the crushing plant Wheel Loader / mining area and stock zones / transportation of material with different dimensions to the stock location or trucks loading Track excavator / mining area / excavation and, trucks and dumpers loading The main objective of this work was focused on the analysis of the dispersion of dust, which affect the workers and the surrounding population, by environmental air, in the neighborhood of a quarry, and the variation of dust flux deposition over time. 2 MATERIALS AND METHODS The general procedure used to achieve the main objective was based in the following tasks: to measure the total dust flux deposition in different sampling points within the quarry and its surroundings; to record the meteorological conditions during the several sampling periods in order to evaluate their influence on dust dispersion; to assess how local residents are affected by dust coming from the quarry; to study the effect of tree cover in the quarry surroundings; to compare the levels found within the quarry and its surroundings with the values obtained for the closer communication infrastructures (national road and municipal roads). 2.1 Sampling procedure Through the analysis of dust flux deposition in the quarry’s surroundings, this study tried to understand the dispersion plume in the study area and thus, to assess if the workers/population are affected by particles coming from the quarry. The methodology for collecting dust samples was based on the French standard NFX 43 007:2008 Air quality – Ambient air – Determination of the mass of dry atmospheric depositions – Sampling on deposit plates Preparation and treatment, which details the placement of plates, coated with resin, the locals to analyze and subsequent treatment of the samples collected. This standard seemed to be the most suitable for the results that this study was seeking. In a first step the twenty-four sites were selected in order to evaluate the total dust flux deposition (Fig. 1). This selection was made aiming to cover four types of areas: surrounding the quarry, quarry zone, stocks zone and national road. The four groups of sites correspond to the following points: Surrounding the quarry: 1, 2, 3, 4, 5, 6, 7, 23, 24; Quarry itself: 8, 9, 10, 11, 12, 13, 17, 18, 19, 20, 21; Stock zone: 14, 15, 16; National road: 22. The second step was to clean the plates with alcohol and then with dichloromethane to remove all the impurities and then, put them in an oven at 105°C for one hour. When the cleaning phase is finished, the plates should be adequately numbered and stored in separate containers for subsequent transport to the sampling site. Although the cleaning procedure is not described in the standard NFX 43 007:2008, the previous version of it, in the year 1973, it is referred that the plates should be dried in the oven at 105oC. The plates are made of stainless steel, with the dimensions of 5 x 10 cm. Figure 1. Location of sampling points within and surrounding

Relationship productivity with noise patterns found in cycles of loading and transport in open quarries

Abstract: Durante a avaliação de ruído ocupacional feita no interior da cabine de uma Pá Carregadora e de um Dumper numa pedreira a céu aberto para a produção de agregados para a construção civil, foram detetados alguns padrões de comportamento nas medições efetuadas. Pretende-se com este estudo relacionar a produtividade com os padrões de ruído associados aos ciclos de carga e transporte típicos da indústria extrativa a céu aberto. Será através da análise dos padrões encontrados que se poderão perspetivar estratégias de auxílio à tomada de decisão e melhoria de procedimentos em áreas como a segurança e higiene ocupacionais e a produtividade. A metodologia de recolha de dados de níveis sonoros, seguiu e teve em conta as principais etapas, sugeridas pela legislação e normalização em vigor, acompanhado pela análise do conteúdo do trabalho desenvolvido nos postos de trabalho em análise. Foi feita a identificação pormenorizada das diferentes tarefas dentro de cada período de amostragem, com o apoio de ficha de levantamento de dados/protocolos criadas para o efeito, de modo a também permitir que passassem a ser tratados de uma forma individualizada. Assim a deteção de padrões de propagação de ruído nas diferentes tarefas resulta da análise dos gráficos em cada uma das bandas de frequência de oitavas pré-definidas (63 Hz a 8 KHz). Da análise dos dados provenientes das medições e respetivo tratamento, foi possível relacionar os padrões de ruído encontrados com a produtividade nas operações de carga e transporte levadas a efeito relativamente, pela Pá Carregadora e pelo Dumper.

Whole-body vibration in drilling, loading and transport operations in quarry

Abstract: The mining work is done with exposure to multiple risks related to the production process, being vibration one of those risks. The aim of this study is to contribute to the study of occupational exposure to whole-body vibrations (WBV) in open pit mining, evaluating and comparing different workplaces/equipments. The experimental work was conducted in 2013 in a north Portugal open pit mine. Three equipments were studied: rock drill, shovel and dumper. WBV measurement and analysis was conducted in accordance with ISO 2631-1 (1997). It was used a device SVANTEK (Poland), SV 106, enabling the measurement of vibration in three axes (longitudinal xx, lateral yy and vertical zz). It was studied three WBV transmission ways: seat surface, seat backrest and cabin floor (feet). The monitoring of the WBV was taken at each workplace with measuring times between 2 and 3 hours. Data were processed and it was determined the dominant axis, the worker exposure RMS, A(8) and the maximum peak. The daily exposure to WBV in rock drill and shovel is below the legislated action value (0.5 m·s). The worker in these workplaces is protected from physical risk of WBV. In dumper, the daily exposure to WBV in this workplace is above the legislated action value. Thus, it is proposed to maintain the quarry roads more regularly. Big differences were found when the WBV is transmitted through the three-way transmission of WBV.

Patterns of whole-body vibrations in open pit mining

Abstract: The main objective is to detect Whole-Body Vibration (WBV) patterns in different mining equipments along their working cycles. Three activities / equipment were studied (rock drill, shovel and dumper) in a north Portugal quarry. The WBV measurement and analysis was conducted in accordance with ISO 2631-1 (1997). It was studied three WBV transmission ways: 1) seat surface, 2) seat backrest and 3) cabin floor (feet). Rock drill shown a WBV pattern, where there was an extensive drilling phase, with residual accelerations values, and a short phase when the vehicle have to move to do another hole. In shovel, was not detected any associated pattern. In dumper, can be distinguished all tasks: loading, loaded and unloaded travel, dumping. Big differences were found when WBV is transmitted through the seat backrest, with the longitudinal x-axis dominating. Rock drill and dumper shown WBV patterns, as opposed to shovel. Table 1. Features of the equipment under study. Equipment Rock drill Shovel Dumper Brand Atlas Copco CAT Terex Model Rock D7 374 D TR 45 Year of manufacture 2007 2011 2005 2.2 Measurement of Whole-Body Vibration WBV exposure measurements were conducted in accordance with the protocol defined by International Standards Organization (ISO) standard 2631-1 (1997). An SV 106 tri-axial accelerometer manufactured by SVANTEK, Poland was used. It measured vibration in three translational axes (longitudinal = xaxis; lateral = y-axis; vertical = z-axis). In order to measure vibration at the operator/seat and operator/floor interface, the accelerometer was mounted in a rubber seat pad and fixed in three different ways: (1) supporting seat surface; (2) seat backrest and (3) cabin floor. This is shown in Figures 1, 2 and 3, respectively. It was possible to study three-way transmission of WBV in the sitting position: input through the buttock, back and feet of the operator. The rubber pad was well fixed with tape trying to stay as close as possible to the surface. Figure 1. Placement of the whole-body accelerometer in the supporting seat surface a) rock drill, b) shovel and c) dumper. Figure 2. Placement of the whole-body accelerometer in the seat backrest of the a) rock drill, b) shovel and c) dumper. Figure 3. Placement of the whole-body accelerometer in the cabin floor of the a) rock drill, b) shovel and c) dumper, d) Orientation of the coordinated axis (fig.1, 2 and 3). 2.3 Data collection procedure For each workplace, typical work duty cycles were monitored. In rock drill, it included (1) Drilling; (2) Vehicle movement and positioning. In shovel, (1) Loading trucks or dumpers; (2) Material shifting and placing. In dumper, (1) Loading the bucket with rock; (2) Driving with loaded bucket to a dumping zone; (3) Dumping the loaded bucket; (4) Driving with an empty bucket back to the development heading to load another bucket. The time spent performing each task in the cycle was dependant on the skill of the operator, layout of the quarry and environmental factors (e.g. road conditions). Therefore, the total data collection time per workplace varied between 1 and 3h. The tasks were timed and the vibration measurements were accompanied by an observation and occurrences registration, sometimes with the aid of video recordings. 2.4 Analysis of Whole-Body Vibration exposure WBV analysis was conducted in accordance with ISO 2631-1 (1997) and carried out with SVAN PC ++, 1.5.10 version, developed by SVANTEK Poland. The analysis included a graphical monitoring, establishing a pattern of instantaneous acceleration versus time. The work duty cycle and each task were identified.

Whole-body vibration exposure of heavy earthmoving machinery operators in surface coal mines: a comparative assessment of transport and non-transport earthmoving equipment operators

Abstract: Purpose. Two groups of heavy earthmoving equipment operators, transport equipment (dumper) operators and non-transport equipment (drill and shovel) operators, in coal mines are assessed comparatively for their vibration magnitude and possible health consequences. Methods. Whole-body vibration exposure measurements were recorded according to Standard No. ISO 2631-1. Measurements were carried out at the operator-seat interface with a tri-axial seat pad accelerometer using a vibration analyser, followed by a questionnaire survey. The binary logistic regression model was used to comparatively assess the two groups of operators. Results. The binary logistic regression analysis revealed that the risk of lower back pain is 4.06 times greater (95% confidence interval [1.36, 12.08]) in transport equipment operators compared to non-transport operators. The daily vibration dose value of the transport equipment operators was 2.92 times greater than their counterparts (95% confidence interval [0.94, 9.09]). However, non-transport equipment operators belonging to the high driving experience category presented a value 5.26 times higher than the transport equipment operators. Conclusion. Transport equipment operators are more vulnerable to vibration hazards than their counterparts, as is evident from the vibration magnitude as well as from the symptoms of lower back pain.

Whole Body Vibrations: Experimental Assessment Of Anthropometric Differences On The Effects Of WBV Exposure In Quarry Workers

Abstract: The human biomechanical response to whole body vibrations (WBV) is affected by the inertial characteristics of the body itself, among which the anthropometric parameters of the subject, such as body mass and shape, are the most relevant. Although human exposure to mechanical vibration is universally recognized as a significant risk factor for workers, Directive 2002/44/EC indicates the minimum health and safety requirements regarding the exposure to risks arising from physical agents, stating that risk assessment may be essentially based on appropriate information available from the manufacturer without the obligation of carrying out any measurements. For this reason, information such as the machine type and model, operating conditions, driving style, soil type, and workplace characteristics are declared together with the manufacturer’s vibration measurements carried out in accordance with specific ISO EN Standards. Clearly, these data do not refer to the specific operating conditions and they do not consider the inertial and geometric parameters of the driver himself (as if these factors could not affect the exposure results). This study aims to evaluate the relationship between the WBV exposure values of loader vehicle drivers and their main anthropometric characteristics, i.e., height and weight. In this case study, the responses of drivers to vibrations from the same vehicle are analysed by means of several sampling campaigns. A correlation study is then presented along with some considerations which are proposed in order to quantify the observed differences and to predict exposure values from anthropometric data.

Assessment of dust pollution related to granite quarry operations in Kef Bouacida, Annaba (Algeria)

Abstract: Purpose. Assessment of dust pollution and analysis of aero­particles generated during operations at the quarry of Kef Bouacida aggregates, located in Oued El Aneb Annaba north­eastern of Algeria. Methodology. Measurement and monitoring of dust fallen, taken from the quarry site allowed identifying the forms and characteristics of the collected particles. These measurements were performed according to the French AFNOR NF X 43­007 standards on measurement of dry atmospheric deposition by the method of platelet deposition. findings. The results obtained during the dust fall show that these measures (83.34 g/m2/month) are much high­ er than the reference values of 30 g/m2/ month in the AFNOR NF­X43­007, to the German standard TA­LUFT (10.5 g/m2/month) and the Swiss OPair law (6 g/m2/month). For this reason, containment methods and measures intended to limit, prevent and eliminate the consequences of the production on the environment are suggested. originality. The evaluation of the adverse effects related to mining production, in particular the nuisance of dust, which can contribute to sensitizing the fight against these negative impacts on the environment, health and safety of the local population, and also increase environmental preservation actions and sustainable development. Practical value. The reduction of fine particle emissions is the greatest environmental challenge that the Algerian mining faces. The effects assessment of mining of granite on the environment, and the description of the difficulties of dust propagation, can be maintained by reduction measures to fight this nuisance, which poses safety and health problems for staff, accelerates the wear of equipment, and affects the quality of materials, not to mention the incon­ venience to residents and farmers. This study is part of the development of environmental protection and conservation of natural resources. keywords: Algeria, dust pollution, impact, environment, Kef-Bouacida quarry