In a world where consumerism is pre-eminent and majority of products fail to be recycled, the mining industry remains vital in providing resources to help economies grow and improve standards of living. However, is this causing us to dig ourselves a deeper hole in environmental issues? We’ll examine different environmental issues caused by mining.
Deforestation
In 50 years of operation, the industry has stripped 5,099 hectares of land of trees, including some 3,218 hectares of forest. Bauxite is Jamaica's second largest foreign exchange earner after tourism. Bauxite is extracted by open-cast mining which requires the complete removal of vegetation and topsoil. Jamaica Bauxite Institute (JBI) and watershed management maps have shown significant degradation of forests and watersheds in mining areas in the parishes of Trelawny and St. Ann on the island’s north coast and St. Elizabeth, Manchester, Clarendon and St. Catherine on the south coast. Most affected are the parishes of St. Ann and Manchester mined by Kaiser and Alumina Partners (Alpart).
Additionally, The Ministry of Agriculture’s Forestry Department, which is administering the Trees for Tomorrow project, believes that firewood and charcoal production are perhaps responsible for the largest amount of trees reaped here annually. Alcan’s Farm Manager, Silvan McDonald says the company is dedicated to easing as much as possible the problems associated with its operations. In a move to protect some of the island’s biodiversity Alcan established two sanctuaries to relocate and preserve wild orchids found inside its mining areas. A plan to plant one million food and timber trees in mainly marginal areas is halfway complete. The tree planting is in addition to the company’s land restoration programme. Bauxite companies are required by law to return the land to a productive state, once a mine closes. Land restoration involves filling the cavities and laying some 38 centimetres of topsoil. So far, the land recovered has been suitable only for housing, the planting of food crops such as vegetables and for pasture for cattle.
Waste Disposal
Since 1985, considerable progress has been made in the bauxite/alumina industry. Before 1985 the disposal of red mud was in some cases done in unlined pits, which resulted in sodium contamination of surface and groundwater resources. But due to new technologies, such as dry mud stacking, thick mud stacking and the use of sealed ponds, the potential for sodium contamination of the aquifer has been significantly reduced. The issue of the disposal of hazardous materials has been a vexing one for environmentalists. Formerly, asbestos-a cancer causing material when inhaled, was the insulating material used in the industry. Over time, however, as technology has advanced, other materials became available and have been replacing asbestos. There are cases in the industry where specifications regarding the disposal of this waste have exceeded US standards. “In these cases, the procedure is to put the waste in plastic bags and then pack them in steel wall containers or drums after which they are buried up to six feet deep,” says Mr Worrell Lyew You, Director of Process Monitoring and the Environment at the JBI. A concern for the industry, which members of the public know very little of, is PCBs. PCBs are components of the oil which were previously used in transformers and other electrical equipment. Since 2000, all PCB-contaminated material has been removed and shipped to France for incineration.
Farming
Bauxitic soils in Jamaica store water, forest trees extract water held in soils to depths of at least 11-18 metres. For farmers, this deeply stored water in the soil means that crops can survive and grow even when the rain doesn’t fall for weeks. This eliminates the need for artificial irrigation. When deep, moisture-holding bauxitic soils are mined out, not only do we lose that storage capacity but rain falling on the land will reach the underground limestone more rapidly. This creates the risk of more intense discharge rates at river heads and/or temporary flooding in upland depressions. In 1947, the framers of The Mining Act failed to appreciate the significant role of soil in the water cycle. They instead focused on the top 15 centimetres (six inches) of soil, where nutrient recycling occurs. But by the 1970s, companies such as Alcan learned from experimental research that unless the reclaimed lands were intended to be used for “growing grass in perpetuity”, successful production of other crops required at least 30 centimetres of soil (and with their caveat that fertiliser dressings also were required).
Mining Pollution
There have been many documented instances of environmental pollution caused by mining operations, which are often caused by leakages of mining tailings. Mining tailings are the materials left behind after the economically valuable fraction of material has been extracted. These materials are often stored in large tailings dams to prevent environmental damage as tailings are often radioactive, toxic or acidic. Tailings consist of valuable substances used in the extraction process such as cyanide, mercury or arsenic; therefore, modern mining programmes often aim to remove these harmful but valuable chemicals to reuse for further mineral separation. In addition to improving efficiency and cutting costs, this minimises the risk of environmental damage by reducing the toxicity of the tailings. As a result of strict international regulations, pollution caused by mining has been dramatically reduced; however, it is still an ongoing problem in many developing countries where illegal small-scale operations known as ‘artisanal mining’ occur. These low-tech, subsistence mining operations are often unsafe, and the poor management of sites leads to environmental pollution in the region. The problems associated with artisanal mining remain complex as it is difficult to identify and shut down all of these small operations. Furthermore, although artisanal mining can result in dangerous environmental pollution, it does help to alleviate the estimated 40 million people who participate in this industry from poverty.
Water Use in Mining
Mining and mineral processing operations often have high water footprints as many stages require the use of water. Examples include dust mitigation, removing soluble particles and separation processes, and creating tailings dams for waste management. Although some stages, such as the separation of minerals, can reuse and recycle the water, other stages such as spraying to remove airborne dust will lead to pollution of the water, preventing water from being recycled. High water use in mining operations can lead to reduced access for local people to uncontaminated freshwater supplies and can result in a local area suffering from water stress. Mining has a relatively small water usage and often a large fraction of the water used is saline so does not have much use in other industries or domestically. For example, the US has one of the highest rates of mineral production in the world after China and Australia; however, the water used for mining only makes up about 1% of the total national water use with 47% of this water being low-quality saline water.
Air Pollution
Ore dust and gases released by the mining process are bad for the health of miners as well as the environment. Over time, exposure to the dust created by mining operations can lead to disease and the buildup of scar tissue in the lungs. Diesel-powered equipment, which naturally creates carbon emissions, further contributes to the air pollution produced by mining. Heavy metals and other air pollutants first deposited on the soil hurt root development and prevent plants from effectively utilising soil resources. The allocation of resources to the various plant structures will vary as a result of these decreases in resource capture, which include the generation of carbohydrates through photosynthesis, mineral nutrient intake, and water uptake from the soil. The effect on development when air pollution stress co-occurs with other stresses, such as water stress, depends on a complex interplay of activities within the plant. Air pollution has the potential to alter the competitive dynamics within an ecosystem, which could modify the composition of the plant community. These alterations in agroecosystems may show up as a decreased economic yield.
Conclusion
Mining continues to be a huge component of the local and global economy — and will likely only grow larger as demands for raw materials increase. It is important to weigh up the social and environmental damages caused by extracting the minerals against the benefits gained from the use of the final product. This is troubling for those who care about the environment. Mining can often be devastating — causing air and water pollution, soil erosion and the degradation of ecosystems. While some methods have less impact than others, it almost always has a serious and lasting environmental impact. It is vital that governments and companies continue to create clean mining technologies with strict environmental regulations which will enable the mining industry to pave the way for a sustainable and hopeful future.
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