http://dx.doi.org/10.15446/dyna.v81n186.39771

Occupational injuries in the mining sector (2000-2010). Comparison with the construction sector

Las lesiones por accidente de trabajo en el sector de la minería (2000 - 2010). Comparación con el sector de la construcción

 

José Juan de Felipe-Blanch ^a, Modesto Freijo-Álvarez ^b, Pura Alfonso ^c, Lluís Sanmiquel-Pera ^d & Carla Vintró-Sánchez ^e

 

^a Escuela Politécnica Superior de Ingeniería de Manresa, Universidad Politécnica de Cataluña (UPC), España. felipe@mmt.upc.edu
^b Escuela Politécnica Superior de Ingeniería de Manresa, Universidad Politécnica de Cataluña (UPC), España. freijo@ee.upc.edu
^c Escuela Politécnica Superior de Ingeniería de Manresa, Universidad Politécnica de Cataluña (UPC), España. pura@emrn.upc.edu
^d Escuela Politécnica Superior de Ingeniería de Manresa, Universidad Politécnica de Cataluña (UPC), España. sanmi@emrn.upc.edu
^e Escuela Politécnica Superior de Ingeniería de Manresa, Universidad Politécnica de Cataluña (UPC), España. carla.vintro@upc.edu

 

Received: September 4^th, 2013. Received in revised form: May 14^th, 2014. Accepted: June 5^th, 2014

 

---

Abstract
This paper compares the incidence of fatal and non-fatal occupational injuries of workers in the mining and construction sectors in Spain between 2000 and 2010. Data on work injuries were obtained from the Spanish Ministry of Labour and Immigration and the denominators were obtained from the available statistics on Social Security registration. We calculated the incidence of fatal and nonfatal occupational injuries, the relative risk (RR) and odds ratio (OR) for a 95% of confidence interval (CI) for the mining workers compared to the construction workers. The obtained results indicate that mining workers have a higher risk of occupational injuries and lost more working days than the construction workers.

Keywords: mining: construction; work injuries; lost working days; fatal injuries

Resumen
El presente trabajo realiza una comparación entre la incidencia de las lesiones por accidentes laborales mortales y no mortales de los trabajadores del sector de la minería con los trabajadores de la construcción en España entre los años 2000 y 2010. Los datos de lesiones por accidentes de trabajo procedieron del Ministerio de Trabajo e Inmigración y los denominadores se obtuvieron de las estadísticas disponibles sobre afiliación a la Seguridad Social. Se calculó la incidencia de lesiones mortales y no mortales por accidente de trabajo, el riesgo relativo (RR) y la probabilidades relativas (OR) en el intervalo de confianza del 95% (IC 95%) para los trabajadores ambos sectores. Los resultados obtenidos indican que los trabajadores de la minería tienen un mayor riesgo de lesiones por accidentes laborales y de perder jornadas de trabajo respecto a los trabajadores de la construcción.

Palabras clave: minería; construcción; lesiones laborales; jornadas perdidas; lesiones mortales

---

 

1.  Introduction

The construction sector has been one of the most dynamic in the Spanish economy between 2000 and 2007 and the most studied sector by its occupational accidents [1]. Thus, in 2004 around 106,500 new jobs were created, representing nearly a quarter (23%) of all jobs created in Spain. In this period of time it was common that the amount of buildings that were built in Spain annually exceeded the number of buildings that were built in the whole of Germany, France and the UK [2].

During the period 2000-2010, 2 million people worked in the construction industry, both in buildings and civil engineering works, and specialized construction activities. This amount represents about 10% of the total of the employed population and 7.3% of the gross domestic product [3]. At the same time, the Spanish construction sector had the highest number of accidents resulting in injury with a total of 213,531 cases with time off work [4], excluding in itinere accidents. About 98.9% of them were classified as minor injuries, and caused an equivalent loss of 4.5 million days, or of about 21 days per worker. Musculoskeletal disorders and physical symptoms are common to both activities [5, 6]. Serious injuries caused about 300,000 days of losses [7].

With regard to the mining sector (coal, crude oil, natural gas and non-energetic minerals), the number of employees in the period under consideration was about 60,000. The accidents with time off work were approximately 9,500, producing a loss of 250,000 days, resulting in about 26 days per accident. The incidence of occupational accidents in the Spanish mining sector has been declining throughout the period 2000-2010. However, it continues to have very high values, despite the adoption of several general laws [8,9], and other specific ones for the mining sector to ensure safer working conditions [10,11].

The work in the mining and construction sectors implies a greater risk of death compared to other industries; it is 9 and 3 times higher, respectively [12].

There are many studies on deterministic evaluation of mining and construction sector accidents [13-20] separately. The aim of this study is to evaluate the difference in the risk of fatal and nonfatal occupational injuries of the construction workers compared with workers of mining in Spain between 2000 and 2010.

 

2.  Methods

The assessment of this comparison was based on a study of fatal and nonfatal work injuries occurred in the mining and construction sectors in Spain between 2000 and 2010. Only those injuries in which the injured worker lost at least one day of work were considered. 102,817 non-fatal accidents in mining and 2,348,841 nonfatal in construction and 176 fatal accidents in mining and 2,739 fatalities in construction were found, not including those in itinere [21].

The analysis was performed both for the total work injuries occurred in the construction (National Economic Activity Classification, CNAE 45) and mining sectors. Subsectors of mining considered were: Extraction and agglomeration of anthracite, hard coal, and lignite (CNAE 10), extraction of crude petroleum and natural gas (CNAE 11), mining of uranium and thorium ores (CNAE 12), mining of metal ores (CNAE 13) and non-metallic mining and quarrying (CNAE 14).

The average population per year was calculated as the arithmetic mean of the population at risk that the different surveys (LFS) provided for the years 2000-2010 for each year [22].

The incidence rate of fatal accidents per 100,000 workers, (FR), was calculated according to the formula used by Haile et al. (1) [23].

Where, FR is the incidence rate of fatal accidents per year in the period 2000-2010, FN, number of fatal accidents in the construction / mining during 2000-2010; ETC, total number of workers in the construction or mining sectors during 2000-2010.

The incidence rate of non-fatal accidents per 1000 workers, (IR), was calculated according to the formula (2).

Where, IR is the incidence rate of non-fatal accidents per year in the period 2000-2010, IN, the number of non-fatal accidents in the sector under study, and ITC, the total number of workers in the construction or mining sectors during the period 2000-2010.

To calculate the incidence of accidents, we used the number of employees in these economic activities according to the Surveys of Labour Force from 2000 to 2010 and fatal and nonfatal accidents occurred during these 11 years presented by the Spanish Ministry of Labour and Social Affairs [5].

We compared incidence rates of fatal and nonfatal injuries for mining workers respect that of construction workers to determine whether the presence of the risk factor is associated with a higher frequency of lesions (relative risk, RR).

We have contrasted the number of days off work due to nonfatal injuries of mining workers respect to the construction workers. It has been estimated the risk of loss days of work (OR) as follows (3):

 

3.  Results

Injuries in mining accidents were quantified by using the incidence rate of accidents of coal mining (CNAE10), petroleum (CNAE11) and non-energetic minerals (CNAE12, 13 and 14). Workers in the coal mines had the largest number of fatalities during 2000, 2007, 2008 and 2009, reaching in year 2000 a total of 17 accidents, having an incidence rate of 73.91 per 100,000 workers (Fig. 1). For all other years higher incidence rates were recorded for workers of the non-energetic mineral extraction, which in 2003 had the maximum of 20 fatal accidents with an incidence rate of 52.22. Oil extraction was the only activity in which for seven consecutive years there have been no fatalities and the highest incidence rate took place in 2006, with 2 deaths, which represented an index of 20.83, although this sector has accounted for 8 to 13% of the total workforce of the mining sector. These data suggest that there is a high degree of occupational safety in this activity (Fig. 1).

Similarly, workers of the coal mining sub-sector, in comparison with the other branches of mining, had a higher rate of fatal injuries for occupational accidents during the 11 years analyzed, peaking in 2008 with 581 accidents. In the oil and non-energy minerals, injuries from accidents are significantly lower than in coal mining.

If we compare the construction and mining sectors, the relative risk of occupational injuries, year by year, on average, it was higher in mining workers, as in the case of non-fatal injuries (1.66, 95% CI: 1.62 to 1.68) as for fatal injuries (2.39, 95% CI: 1.45 to 4), although there are differences in the analysis of the each year (Fig. 2).

The risk of non-fatal injuries by occupational accident was higher for mining workers than for those of the construction sector. This risk was particularly high in 2000 and 2004. Moreover, in 2009, and relatively in 2010, the risk was significantly lower among mining workers. In reference to fatal injuries, every year relative risks occur in mining worker, this was the significant difference in 2000, 2003 and 2006, when these risks exceeded 2.50. Moreover, in the years 2008 and 2009 the risk of fatal injury was almost equal between the two groups of workers. It is noteworthy that in any year the risk of occupational injury among mining workers was lower than that for construction workers (Fig. 2).

To detect if there are common or similar causes in the variation in the accidents rates in non-fatal injuries, these values in the construction and the mining sectors were compared. The evolution of both rates is almost linear, with a Pearson coefficient of 0.84; this suggests that the causes of the temporal evolution of them are similar.

In the case of fatal accidents, despite the linearity of the evolution of both rates, these show a lower Pearson coefficient than in the case of non-fatal accidents (0.78), suggesting the existence of different causes that affect in the evolution of each indicator.

We calculated the incidence rate of accidents of not worked days by occupational accident, as the number of not worked days for this reason, and the population at risk in the related sector. In comparing the days not worked as a result of  injuries (Table 1) it can be appreciated that mining workers are at greater risk of losing working days, (1.51, 95% CI: 1.50 to 1.52) almost double that than those in the construction sector, with the consequent economic costs [23-31].

Also we can see that there is a strong linearity between the evolutions of both indicators of workday loss (Table 1), which indicates common driving causes for both indicators.

 

4.  Discussion

This study has been possible solving the common problem in quantitative research of work injuries in the construction and mining sectors in Spain. It is difficult to obtain the number of workers covered by social security, with which to compare properly the number of injuries. This problem is not exclusive of Spain [32]. However, the study is limited, because minor accidents are not reported by the companies, as happens in other countries [33-35], and are not taken into account, so the incidence rates obtained in the present study are lower than the real ones.

The employment in mines is similar to the construction sector; the maximum employment in mines took place in 2006 and in the construction sector in 2007. From these two years the occupation began to decrease in both sectors. In all the mining sub-sectors the fatal occupational injuries have a downward trend, although there is a long way to go to the total elimination of fatal accidents. In coal mining, the rates of fatal accidents are down over the course of the years; the rates of non-fatal accidents decrease rather slowly, from an index of 458 in 2000 to 445 in 2010.

The incidence rate of nonfatal accidents per 1,000 workers has been declining in the two sectors considered, through in construction from 129 in 2000 to 60 in 2010 and in the mining sector it decreased from 220 in 2000 to 105 in 2010.

The relative risk (RR) of nonfatal injury for occupational accidents in the eleven years studied was higher in miners, decreasing slightly from year to year, from 1.88 (95% CI; 1.85 to 1.91) in 2000 to 1.71 (95% CI 1.66 to 1.76) in 2010.

Labor legislation and preventive initiatives implemented in the two sectors for the prevention of accidents at work have largely contributed to the reduction of occupational injuries. However, further work is needed on measures to reduce temporary employment or of outsourcing business in Spain, which present higher values than in other European Union countries [36]. Also, the different events that occurred before the occupational injury should be analyzed [37].

Comparing the two sectors it can be appreciated that the relative risk of a fatality is always higher in the mining sector, being almost triple in 2000, with a relative risk of 2.90 (95% CI, 1.98 to 4.30), to nearly equal 1.07 (95% CI 0.34 to 3.35) in 2009. This may be due to the specific characteristics of jobs in the mines, which have worse environmental conditions (high temperatures, presence of gas and dust, high rock-fall hazard in underground mining) and the use of more dangerous machinery and work equipment.

By comparison with the United States of America (Table 2) and analyzing the year 2010 from the queried data of the Bureau of Labor Statics [38], we find that in that year 751 fatal injuries occurred in the construction sector in the USA, respect to 172 in Mining. The employed population in those two sectors was 5,645,000 and 694,000 workers, respectively.

Comparing these data with those from Spain, we can appreciate that in this year the incidence rate of accidents with fatal injuries in the construction sector in Spain was lower than in USA, 8 and 13.3 respectively. Similarly, in mining the rate per 100,000 workers was 17 in Spain, compared to 24.8 in the U.S. The relative risk (RR) of a fatal injury in the USA in construction or mining is higher than in the same sectors in Spain (1.66 in the construction and 1.45 in mining). This suggests that during the Spanish economic crisis, temporary jobs have been reduced, leaving the better informed and trained workers.

The days not worked due to injuries caused by non-fatal accidents have decreased in the two studied sectors throughout the study period. The ratio of days lost in mining per worker was twice the ratio of days lost in construction per worker, over the 11 years studied. This indicates that the non-fatal injury accidents in mines are more serious than in construction and workers need more days to recover.

We also suggest that it is necessary to measure the degree of alcohol and drugs consumed by workers in the workplace as an effective method to reduce accidents, both in construction and in mining, keeping in mind that the reduction of drugs in the workplace has proven to be an effective preventive measure [39].

 

5.  Conclusions and recommendations

The trend of fatal and non-fatal work accidents, both in mining and in construction has declined in Spain during the 11 years analyzed.

The results of the present study confirm an increased risk of work injuries in mining workers with respect to those from construction. This risk may be higher than that observed if all injuries that occurred were registered.

Within the mining sector, the incidence rate of fatal accidents in coal mining remains high, and constant, regarding the extraction of: oil, metal ores, non-metallic and non-energetic sub-sectors.

The relative risk of a fatal or nonfatal injury in 2010 was higher for workers in the mining and construction in the United States of America than for Spanish workers in equivalent sectors.

Workplace accidents, both in mining and in construction, need to continue being studied in greater detail and with quality data. These studies will make this important health problem visible to the public and, therefore, it will be the first step for prevention.

Both mining and construction companies are required to assess the risks of occupational safety, but often these assessments are not accurate. Consequently, the causes of accidents are not really the same that commonly can be used in other productive sectors. It is imperative to analyze the real causes and get all the information to make a good assessment of risks.

For a better understanding of the nature of the accidents in the analyzed sectors, management should adopt a statistical methodology of accidents nationwide, in each of the sub-sectors of mining and construction. Thus, the studies could be done for each subsector with its own peculiarities, to facilitate planning preventive measures for each [40].

 

References

[1] Mariscal, M.A, Garcia S, Garcia, J. and Ritzel, D., The impact of occupational hazard information on employee health and safety: An analysis by professional sectors in spain. International Electronic Journal of Health Education, 15, pp. 83-98, 2012.         [ Links ]

[2] Ministerio de Educación. El sector de la construcción en España. Available: http://www.educacion.gob.es/exterior/ro/es/materiales/MODULO18.doc. [citado el 21 de octubre 2012]         [ Links ] .

[3] Ministerio de Trabajo y Asuntos Sociales. Instituto Nacional de Seguridad e Higiene en el Trabajo. Obsevatorio de la construcción. 2002 Available: http://www.insht.es/Observatorio/Contenidos/EstudiosTecnicos/SectorConstr/Informe%20construcci%C3%B3n%202002.pdf. [citado el 02 de noviembre de 2010]         [ Links ] .

[4] Benavides, F.G., Giráldez, M.T. and Castejon, E., Analysis of the mechanisms of minor occupational injuries in the construction industry in Spain. Gaceta Sanitaria, 17 (5), pp. 353-359, 2003.         [ Links ]

[5] García, S., Mariscal, M.A., García, J. and Ritzel, D.Working conditions, psychological/physical symptoms and occupational accidents. Bayesian network models Safety Science, 50, pp. 1760-1774, 2012.         [ Links ]

[6] Sanmiquel, L.L., Vintró, C. and Freijo, M., Characteristics of the 3 most commo types of occupational accident in spanish sub-surface and surgace mining, from 2003-2008, DYNA, 79 (172), pp. 118-125, 2012.         [ Links ]

[7] Ministerio de Trabajo y Asuntos Sociales. Estadísticas de accidentes de trabajo. Available: http://www.mtas.es/Estadisticas/EAT/Eat00/Index.htm. [Citado el 8 de setiembre de 2012]         [ Links ] .

[8] Ley de Prevención de Riesgos Laborales. L. Nº 31/1995 (8 noviembre 1995).         [ Links ]

[9] Real Decreto de las disposiciones mínimas de seguridad y salud en las obras de construcción. R.D. Nº 1627/1997 (14 de octubre de 1997).         [ Links ]

[10] Real Decreto del Reglamento General de Normas Básicas de Seguridad Minera. R.D. Nº 863/1985 (2 de abril de 1985).         [ Links ]

[11] Real Decreto de disposiciones mínimas destinadas a proteger la seguridad y la salud de los trabajadores en las actividades minera R.D. Nº 1389/1997 (5 de septiembre de 1997).         [ Links ]

[12] Sorock, G. S., Smith, E. and Goldofi, M., Fatal occupational injuries in the New Jersey construction industry, 1983 to 1989. Journal of Occupational Medicine, 35, pp.916-921, 1993.         [ Links ]

[13] Sari, M., Selcuk, A., Karpuz, C., Sebnem, H. and Duzgum, B., Stochastic modeling of accident risks associated with an underground coal mine in Turkey. Safety Science, 47, pp. 78-87, 2009.         [ Links ]

[14] Groves, W., Kecojevic, V. and Komljenovic, D., Analysis of fatalities and injuries involving mining equipment. Safety Research, 38, pp. 461-470, 2007.         [ Links ]

[15] Onder, S., Evaluation of occupational injuries with lost days among opencast coal mine workers through logistic regression models. Safety Science, 59, pp. 86-92, 2013.         [ Links ]

[16] Coleman, P. and Kerkering, J., Measuring mining safety with injury statistics: Lost workdays as indicators of risk. Safety Research, 38, pp. 523-533, 2007.         [ Links ]

[17] Lenné, M., Salmon, P., Liu, C. and Trotter, M., A systems approach to accident causation in mining: An application of the HFACS method. Accident, Analysis and Prevention, 48, pp. 111-117, 2012.         [ Links ]

[18] Komljenovic, D., Groves, W. and Kecojevic, V., Injuries in U.S. mining operations - A preliminary risk analysis. Safety Science, 46, pp. 792-801, 2008.         [ Links ]

[19] Marhavilas, P.K., Koulouriotis, D.E. and Spartalis, S.H., Harmonic analysis of occupational-accident time-series as a part of the quantified risk evaluation in worksites: Application on electric power industry and construction sector. Reliability Engineering & System Safety, 112, pp. 8-25, 2013.         [ Links ]

[20] Cameron, I., Hare, B. and Davies, R., Fatal and major construction accidents: A comparison between Scotland and the rest of Great Britain. Safety Science, 46 (4), pp. 692-708, 2008.         [ Links ]

[21] Ministerio de Trabajo e Inmigración. Accidentes en jornada de trabajo con baja, según gravedad, por sector y rama de actividad. Available: http://www.mtin.es/estadisticas/anuario2001/HTML/ATE/ate04.html. [Citado el 14 de diciembre 2011]         [ Links ] .

[22] Instituto Nacional de Estadística. Encuesta de Población Activa. Available: http://www.ine.es/daco/daco42/daco4211/epa0100.pdf. [Citado el 8 de marzo 2011]         [ Links ] .

[23] Haile, G., Hendricks, S. and Stanevich, R., Fatal occupational falls in the U.S. construction industry, 1980-1989. Accident Analysis & Prevention, 28, pp. 647-654. 1996.         [ Links ]

[24] López-Lasaola R. ¿Es rentable la Prevención?. Dyna Ingeniería e Industria, 83 (2), pp. 119-122, 2008.         [ Links ]

[25] Bentley, T.A. and Haslam, R.A.. Identification of risk factors and countermeasures for slip, trip and fall accidents during the delivery of mail. Applied Ergonomics, 32 (2), pp. 127-134, 2001.         [ Links ]

[26] Kemmlert, K. and Lundholm, L., Slips, trips and falls in different work groups with reference to age and from a preventive perspective. Applied. Ergonomics, 32 (2), pp. 149-153. 2001.         [ Links ]

[27] Lehane, P., and Stubbs, D., The perceptions of managers and accident subjects in the service industries towards slip and trip accidents. Applied. Ergonomics, 32 (2), 119-186, 2001.         [ Links ]

[28] Haslam, R.A., Hide, S.A., Gibb, A.G.F., Gyi, D.E., Pavitt, T., Atkinson, S. and Duff, R., Contributing factors in construction accidents. Applied. Ergonomics, 36 (4), pp. 401-415, 2005.         [ Links ]

[29] Bentley, S., Hide, D., Tappin, D., Moore, S., Legg, L., Ashby, L., Parker, R., Investigating risk factors for slips, trips and falls in New Zealand residential construction using incident-centred and incident-independent techniques. Ergonomics, 49, pp. 62-77, 2006.         [ Links ]

[30] Gard, G. and Berggard, G., Assessment of anti-slip devices from healthy individuals in different ages walking on slippery surfaces. Applied Ergonomics, 37, pp. 177-186, 2006.         [ Links ]

[31] Bentley, T., The role of latent and active failures in workplace slips, trips and falls: an information processing approach. Applied Ergonomics, 40, pp. 175-180, 2009.         [ Links ]

[32] Ruser, J.W., Denominator choice in the calculation of workplace fatality rates. American Journal of Industrial Medicine, 33, pp. 151-156, 1998.         [ Links ]

[33] Snashall, D., Occupational health in the construction industry. Scaninavian, Journal of Work, Environment & Health, 31, pp. 5-10, 2005.         [ Links ]

[34] Kines, P., Spangenberg, S. and Dyreborg, J., Prioritizing occupational injury prevention in the construction industry: injury severity or absence?. Jounal of Safety Research, 38, pp. 53-58, 2007.         [ Links ]

[35] Jorgensen, K., A systematic use of information from accidents as a basis of prevention activities. Safety Science, 46, pp. 164-175, 2008.         [ Links ]

[36] Massarelli, N. and Wozowczyk, M., European Union Labour Force Survey. Annual results 2009. [en línea] . Theme 3. Population and Social Conditions. 35/2010. Statistcs in focus. Eurostat [Bruxelles, Bélgica] Available: http://epp. Eurostat.ec.europa.eu/cache/ITY_OFFPUB/KS-QA-10-035/EN/KS-QA-10-035-EN.PDF. [Citado el 23 de abril 2013]         [ Links ]

[37] Sanmiquel, L., Freijo, M. and Edo, J., Analysis of work related accidents in the Spanish mining sector from 1982-2006. Journal of Safety Research, 41, pp. 1-7, 2010.         [ Links ]

[38] Bureau of Labor Estatistics. Fatal occupational injuries by industry and selected event or exposure, 2011 (US); Available: http://www.bls.gov/news.release/cfoi.t02.htm. [Citado el 4 de setiembre de 2012]         [ Links ] .

[39] Wickizer, B., Do drug-free workplace programs prevent occupational injuries? Evidence from Washington State. Health Services Research, 39, pp. 91-110, 2004.         [ Links ]

[40] Pérez-Alonso, J., Carreño-Ortega, A., Vázquez-Czabrera, F.J. and Callejón-Ferre, A.J.. Accidents in the greenhouse-construction industry of SE Spain. Applied Ergonomics, 43, pp. 69-80, 2012.         [ Links ]

 

J. J. de Felipe-Blanch, PhD, Full Associate professor in Heat Engine Department in the Escuela Politécnica Superior de Ingeniería de Manresa of University Polytechnic of Catalonia, Spain. He graduated 1991, Engineer Naval Machines, Faculty of Nautical, University Polytechnic of Catalonia. Master of Educational Formation 1995. Ph.D. 2004, Simples models with indicators, Faculty of Engineering, University Polytechnic of Catalonia. Major fields of scientific and professional activities are operations research and dynamics systems in urban problems, with vision integrated different dimension of sustainability and expert in the field of energy applicable mining. He served as a key expert-reviewer for the FP6 INSURE (Contract no 505358). He published articles in several journals and participates in several projects.

M. Freijo-Alvarez, holds a PhD from the Polytechnic University of Catalonia and a Superior technician Degree in Prevention of Labor Risks in the specialties of Security, Hygiene, Ergonomic and Psycho-Sociology. Has been a Senior Professor at the .Polytechnic University of Catalonia for the last 27 years. He as 9 years professional experience in the industry and has published a several articles on labour security in mining in Spanish magazines, apart from writing communications and attending and speaking at International Congresses of mining.

P. Alfonso, she has a Ph.D. in Geology from the University of Barcelona. Her research in materials processing and ore deposits has been developed in several research centers, as the Institute of Geology and the Institute of Chemistry and Technology of Sofia (Bulgaria), the Scottish Research and Environmental Centre, Scotland, the "Consejo Superior de Investigaciones Científicas", in Spain. Between 1987 and 1990 she worked for the International Organization for Migration (IOM) as advisor of the Nicaraguan Institute of Mining, INMINE, in issues related to physico-mechanical tests and gold deposits. Since 2010 she is Associate Professor in the Department of Mining Engineering and Natural Resources Engineering School of Manresa, Polytechnic University of Catalonia.

L. Sanmiquel-Pera. holds a PhD from the Polytechnic University of Catalonia (UPC) and a Master in Prevention of Labour Risks in the specialties of Security, Hygiene, Ergonomic and Psycho-Sociology for the Camilo José Cela University. Between 1990 and 2004 he was a mining Inspector for the Main directorate of Mines and Energy of Catalonia, (Spain). Since 1990, he is a professor of the department of Mining Engineering and Natural Resources of the Polytechnic University of Catalonia (UPC). He has collaborated in different training programs in subjects related to labor security for both underground and opencast quarries and exploitation plants.

Carla Vintró-Sánchez, PhD, Associate professor in Business Management Department in the Escuela Politécnica Superior de Ingeniería de Manresa of Polytechnic University of Catalonia, Spain. She graduated in 2004, Mechanical Engineering, and in 2007, Industrial Management Engineering, Polytechnic University of Catalonia, Spain. She is Master in Prevention of Occupational Risks, 2008, and she completed her PhD in 2011, in Polytechnic University of Catalonia, Spain. Her research interests include management systems and sustainable mining. She has published in national and international journals.