By Edgardo Alarcón León
The negative effects of the mining industry on the environment are manifested mainly by the contamination of surface and groundwater, air, soil, vegetation and biota. Lately, based on scientific evidence, the mining industry, especially the coal extractive industry, have been notified that since its inception they are also an active contributor to the consequences of climate change.
Despite the fact that the extractive activity of mineral resources is of economic, social and industrial importance, the problems associated with environmental aspects and their relationship with climate change have not yet been seriously evaluated. The negative effects of the mining industry on the environment are manifested mainly by the contamination of surface and groundwater, air, soil, vegetation and biota.
Although debatable and according to the place where the mining takes place, the activity generates other environmental health problems, such as noise pollution, and cultural and social conflicts. Lately, based on scientific evidence, the mining industry, especially the coal extractive industry, have been notified that since its inception they are also an active contributor to the consequences of climate change.
Although it is known that climate changes over the millennia have always existed and occur in a natural and cyclical way, it is now confirmed that climate change and its environmental effects as a result of human activities accelerated since the beginning of the industrial revolution. (IPCC 2007). With the exception of skeptics like Bjorn Lomborg (2004) who argues that climate changes are natural events and that the climatological data available are not properly analyzed and interpreted, most scientists (eg Flannery 2005) assert that production of greenhouse gases as a result of industrialization worsened in the last 60 years. The most notable agents that affect climate balance are increases in atmospheric concentrations of greenhouse gases (GHG) and aerosols (microscopic particles in suspension in the air) (Table 1), and variations in solar activity. Both of them
phenomena can alter the Earth's radiation balance and therefore the climate (IPCC 2007). The most abundant GHGs are carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) and the rare gases chlorofluorocarbons and hydrofluorocarbons (CFCs and HFCs) (Table 1).
Table 1 shows the main emission sources that contribute substantially to the production of gases, salts and solid and liquid particles (water vapor) other than those usual in the atmosphere. Industries that massively use fossil fuels, intensify forest clearing, adopt land use changes, and soil degradation (eg mining, agriculture, and livestock) are primary contributors to the production of gases such as carbon dioxide, methane and nitrous oxide (Table 1 and Table 2). Medium and / or small industries such as those related to automotive mechanics, refrigeration, petrochemical industry, etc., are secondary contributors in the production of gases including chlorofluorocarbons, ozones and others (eg powders, salts) (Table 1 and Table 2 ). In certain cases, the latter generate localized pollution, but in relation to the movement of the winds, the extension, frequency and lifetime of transported pollutants, environmental pollution can be regional and / or national and / or intercontinental. It is obvious that according to the index of industrial and economic development, third world countries such as Peru do not produce the same amount of gases, particles and salts as those countries that are in an accelerated process of industrialization (eg China, India) and / or industrialized countries (eg United States of America, Japan, European countries, Australia and New Zealand).
The mining industry and related industries, as shown in Table 1 and Table 2, emit the main gases, solid particles and heat-retaining liquids into the atmosphere. While solid pollutants include dusts originated by the action of blasting and / or solid waste disposal in dumps and / or tailings (Figure 1), gaseous pollutants with organic and inorganic chemical traces derive especially from thermochemical (explosive) processes, transformation and mineral processing, oxidation and / or decomposition of solid waste and liquid waste, vehicle exhausts and those released during processes such as the burning of slag and / or toxic waste and / or non-toxic waste.
Due to these processes, many private and public institutions related to the mining industry, especially in developed countries (eg European countries, New Zealand), have proposed, elaborated and enforced legislation to mitigate and / or reduce gas emissions and solid or liquid particles into the atmosphere. In Peru, although the government has improved its legislation regarding environmental pollution, the regulations are not specific when they refer to climate change. As a consequence, the mining, iron and steel industries and refineries have not become objective when it comes to these problems that affect humanity as a whole. For example, recently the environmental damage in the cities of La Oroya and Ilo as a result of the emanation of gases and urban pollution by lead dust from the deposits of mineral concentrates in Callao have been classified as critical and the programs remedies are only reactive to consequences.
Many researchers (eg Gittleman et al. 1999, Shotyk et al. 1998) indicate that air pollution by trace minerals such as lead has occurred for more than two thousand years and they are mostly related to the first lead smelters and its use in other services such as printing, manufacture and repair of batteries and its use in gasoline. However, in the case of La Oroya, which has been declared one of the ten most polluted cities in the world by the Blacksmith Institute, and other towns such as Ilo and Cerro de Pasco, the content of traces of lead and sulfur in the air they are directly related to emissions in metallurgical complexes and mining activity. Other studies (eg Ubillus Limo 2003, Boon et al. 2001) indicate that traces of other metals of a toxic and carcinogenic nature such as cadmium, arsenic and antimony also have a substantial presence in the atmosphere that covers Oroya, Ilo and Pasco and These also lead to metallurgical and mining complexes.
Figure 1 Contamination and dust suppression during iron extraction.
The management and sustained availability of water is also another problem that results from global warming. Based on its observations and predictions, the Intergovernmental Group of Experts on Climate Change (IPCC) has detected that globally there is substantial fluctuation in the distribution of water masses (IPCC 2007). For example, it has been observed that there is an increase in the atmospheric concentration of water vapor, changes in the precipitation cycles, reduction of areas covered by snow and accelerated thaw, and changes in the water content of soils and runoff. Changes in rainfall are substantially variable in space and time. Due to the variability of precipitation, it has been noted that waters in high latitudes and in certain humid tropical areas have increased while in low and middle latitudes and dry tropical areas they have skimmed (IPCC 2008).
The predictions also infer that droughts and episodes of intense rainfall will be more numerous and frequent. Within this context and due to the demand for water that the mining industry has, in certain countries, water consumption and management policies have also recently been revised and better legislated.
Mining development and related industries mainly impact the behavior and quality of surface and groundwater (Figure 2).
Depending on the type of extraction and the hydrogeological processes that control the area where the industries are located, the negative effects on groundwater can be expressed especially in the variation of surcharge and discharge, change of flows and changes with the water table. For example, if the drop in groundwater levels during the extraction of aquatic resources is not adequately monitored and controlled, it may affect the geotechnical stability of the place and the flow of rivers, wetlands and springs that are interconnected to aquifers or aquitares. Likewise, depending on the amount of water extracted, the hydrogeological structure of the area of influence and the division of aquifers can be compromised, generating changes in the position of aquifers or generating unnecessary interconnection between superficial and deep aquifers, deriving unnecessary contamination of these water bodies. The contamination of these waters is sometimes accelerated due to the lack of programs for the prevention and control of infiltrations that transport pollutants and derive in waste fields, tailings and leaching piles. The circulation of water through sulphide-mineralized bodies also generates serious environmental problems such as acid mine drainage (AMD). DAM originates from the interaction between oxygen, water, bacteria, and sulfur mineral and is a common problem in base metal and coal mining. In Peru, recently, there have been extensive reports on the contamination of rivers (eg Rió Mantaro), streams, lakes (eg Lake Junín) and other sources of fresh water such as springs due to pollutants from the centers. miners and / or metallurgists. Another problem, equally important, is that many of the mining, refining and metallurgical industries are normally located
in dense or moderately populated areas. The need for water and energy use to develop their operations increases according to the productive capacity of the centers and this places significant pressure on the water and energy needs of the adjacent populations.
Figure 2 Excess surface / groundwater evaporation reservoir at Ranger uranium mine, Australia (semi-tropical environment).
In ecological systems, flora and fauna also have cycles determined by climatic, terrestrial and aquatic conditions and their physical-chemical conditions. When these conditions are altered, flora and fauna begin to change, migrate, and the ecological balance is disrupted with unpredictable consequences. An example is the degradation of the soil that originates due to the movement of soils to develop open pit mining and the construction of solid waste fields, dumps and tailings. This process is totally negative since the water-soil-plant-biota ecological balance is altered to the detriment of the survival of each of the living elements that share the system. Likewise, due to the extraction of water and the development of acidic and alkaline liquid effluents, soils, vegetation and biota are affected to a great extent, bringing with it the migration, death and / or loss of species.
In sum, in recent decades the mining industry has contributed negatively to climate change. The relationship between the exploitation of mining resources and the environmental implications and its relationship with climate change are complex and not adequately considered. It is also overwhelming that some means of production of mineral resources and industries of mineral transformation processes must substantially change methodologies and technologies and / or be eliminated. The current scientific and technological advances are in the ability to provide better methods to recover and process mineral resources. Likewise, in recent times better methodologies have been developed for the proper management of solid, liquid and gas waste. For example, the coal mining and utilization industry has proposed clean coal technology. This technological process includes the chemical treatment of coal to transform it into gas and thus reduce the amount of carbon dioxide it emits into the atmosphere. Another technology that is under investigation is the sequestration of carbon dioxide and other greenhouse gases. The technology consists of the capture and injection or burial of gases in deep strata, deep saline water tables, salt caverns or caverns abandoned by mining and abandoned oil fields. Finally, the wise political will of the government through its environmental monitoring and control institutions can also help prevent future dangers of environmental pollution and effectively regulate the emission of gases and others that affect climate stability. Likewise, the economic contribution, both from the government and that of the mining-industrial community, can contribute to attempts to rehabilitate and close closed mining sites and / or assist with the deepening of investigations between the relationship: mining industry - the environment. - climate changes.
Edgardo Alarcón Leon PhD - Geoenvironmental / Geotechnical Scientist - ENVIROAndes
Boon, R.G.J., Alexak, A., Herrera Beccerra, E., (2001) The Ilo Clean Air Project: a local response to industrial pollution control in Peru. Environment and Urbanization, Vol 13, No 2. 18 pp
Flannery, T. (2005) The weather makers: How man is changing the climate and what it means for life on earth. Grove Press, New York. 357 pp
Gittleman, JL, Billig, P., Ault, SK, Hernández-Avila, M. (1999) Activity Report, No. 47: Options for Monitoring Biological and Environmental Lead during the Phase-out of Lead in Gasoline in Latin America & the Caribbean. Prepared for the Office of Health and Nutrition, Global Bureau and the Environment Team, Office of Regional
Sustainable Development, Bureau for Latin America and the Caribbean U.S. Agency for International Development under EHP Activity No. 250-CC. September 1999.
IPCC (2008) Climate change and water. Technical Paper of the Intergovernmental Panel on Climate Change prepared in response to a decision of the Panel. June 2008. 214 pp
IPCC, (2007) Climate Change 2007: Synthesis Report. Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Lead Drafting Team: Pachauri, R.K. and Reisinger, A. (editors of the publication)]. IPCC, Geneva, Switzerland, 104 pp.
IPCC, (2007) Climate change 2007: Summary for policymakers. An Assessment of the Intergovernmental Panel on Climate Change. 12-17 November 2007. 22 pp
Lomborg, B. (2004) The skeptical environmentalist: Measuring the real state of the world. Cambridge University Press. 515 pp
Shotyk, W., Weiss, D., Appleby, P. G., Cheburkin, A. K., Frei, R., Gloor, M., Kramers, J. D., Reese, S., Van Der Knaapm W. O. (1998). History of Atmospheric Lead Deposition Since 12,370 14C yr BP from a Peat Bog, Jura Mountains, Switzerland. Science, Vol. 281. pp 1635-1640
Ubillus Limo, J. (2003) Study on the presence of lead in the environment of Talara in 2003.
Monograph to choose the professional title of Chemical Engineer. 146 pp