Mining in the Tropicsby Carrie HartleyNortheastern State University


Mining activities in the tropics has become increasingly popular as prices for natural resources continue to rise. Gold prices, for example, have increased 360% over the last decade (Swenson 2011). Many developing countries are allowing these activities in spite of the known damages to the environment caused by mining processes because of global demand for the resources. As more road ways are being paved throughout the Rain Forrest, many illegal mining operations are popping up alongside these roadways adding to the environmental damage. Gold mining, in particular, is environmentally destructive because of the toxic metals used during processing the mineral. Mining, in general, results in deforestation, large quantities of waste, changes to the landscape, and water pollution.

In lesser developed countries, such as those that are home to the rain forests, many lack operational environmental control policies and the ability to supervise the mining operations in their countries. Smaller mining operations that are abundant throughout the tropics do not have the resources to utilize mining practices that are environmentally safe. In addition, they often lack the knowledge and understanding of the impact they are having on the environment with their current mining techniques that results in large amounts of waste and pollution. Poverty is usually higher in lesser developed countries adding to the attraction of mining profits despite the environmental factors associated with mining activities. Larger mining companies tend to have operations in effect that reduce pollution and waste from their mining techniques but still result in deforestation and changes to the landscape where they are operating. Many governments in the tropics have given tax incentives to draw in mining activities to their countries that has facilitated in the increased mining activities.

The mining process starts out by removing trees and vegetation at the site and clearing for access roads resulting in deforestation. Explosives are then used to create a pit or break up rock to be crushed into smaller pieces. The pits can fill with water and create breeding grounds for mosquitoes causing an increase in malaria illnesses. Sometimes the top soil is removed and heavy machinery and drills are used to create holes where the mineral can be extracted. The soil is often times replaced but savannas may grow instead of the original forests that inhabited the area. During gold mining, alluvial deposits are found along river banks where the dirt and gravel is sucked up and put back in a different spot resulting in destruction of the riverbed. This creates major problems for the river and its inhabitants. Although there are different mining processes, all of them can permanently alter the landscape and create negative effects on the wildlife.


Acid Drainage
Acid drainage is a very serious concern when it comes to mining. Acid drainage most often appears from copper, coal, zinc, lead, and pyrite mining activities (Wahlberg 2000). It occurs when rock is broken up during the mining process to obtain the ore. The excess rock is held somewhere on the mine site. The ore-bearing rock is crushed into fine pieces called tailings, once the minerals have been removed. The surface area of the rock that contains sulfide minerals, such as pyrite, is exposed to oxygen or water creating a chemical reaction thus producing sulfuric acid. The acidic water then runs into streams or becomes ground water impacting the ecosystem. Even after mining operations have ceased, acid drainage pollution can create problems long after because it is very difficult to stop. Peru declared a state of emergency at a mine near Lima over fears that its tailings dam, weakened by seismic activity and subterranean water filtration, could release arsenic, lead, and cadmium into the main water supply for the capital in July 2008 (Bebbington and Williams 2008).

Many fish species are highly sensitive to acidic water affecting their reproduction habits and physical functions often times resulting in death. Many studies suggest that acid drainage affects ion regulation through the gills of fish resulting in impaired respiration mechanisms. Some metals even adhere to the gills and clog the openings resulting in death. Food sources for some fish are also affected by the increase in acidity resulting in inadequate food supplies and a deficient quality of food. Because some metals coat the riverbed and results in increase sediment, reproductive success of fish is also negatively affected. Fish tend to avoid waters that are acidic when possible which results in an overall change to the ecosystem and biodiversity because animals that feed on fish will have to find food sources elsewhere.

Soil and sediment erosion into water sources negatively affecting surface water quality is another problem associated with mining operations. Mine sites involve moving and disturbing a large amount of land. When it rains, erosion of this land can cause sediment to build up in nearby bodies of water or floodplains. This sediment build up can cause alterations and loss of habitat in the water bodies and floodplains. Minerals from the mine sites are often washed into these habitats along with sediment causing toxicity problems as well. Sedimentation not only affects water sources but also the land surrounding them because the increase in sediment can alter the landscape and vegetation. Vegetation and aquatic life is often times lost or decreased as a result of increased sedimentation.

Waste Rock and Tailings
Waste rock and tailings can have impacts on the environment by contamination of groundwater beneath the mine site itself. Toxicity of the groundwater results from leaching of substances within the exposed rock that then seep into the ground. Some mining companies place an impermeable liner under these piles that helps to control the damage. Tailings are disposed of by mixing them with large amounts water in a pond built by the mining company. The tailing ponds release contaminated water into the surrounding environment and some have even been known to affect water supplies for miles downstream.
Morro do Ouro Gold Mine, Paracatu, Brazil - Overview

Overview of the Morro do Ouro ("Mountain of Gold") gold mining operation in the town of Paracatu, Minas Gerais state, eastern Brazil. The mine is operated by Canada-based Kinross Gold Corporation. Mine workings are the gray area at left; mine tailings are dumped in the large impoundment on the right, contained by a 13,000-foot-long rock and earth embankment (light brown). Image was taken on September 22, 2003 by Sky Truth.

Air Pollution
Air pollution occurs especially during operational activities of the mine. Rock is crushed into fine pieces, called tailings, to extract the ore during the mining process and large waste piles accumulate with these small rock pieces. These waste piles are easily dispersed to other areas by the wind because of the small size of those pieces. This creates air pollution that can cause harm to a person’s health and the surrounding environment. This is most frequent in open pit mining where blasting and transportation of materials occurs the most.

Biodiversity and Habitat
Because wildlife species depend on each other for survival, mining causes effects to the tropical habitat that extends far away from the mine site itself. Removal and clearing of vegetation for construction of roads and the mine site impacts the availability of resources for wildlife such as shelter provided by the canopy cover and food sources which in turn changes the structure of species altering the biodiversity of that area. Some species do however, benefit from the modifications by mining such as big horn sheep, species of algae that are tolerant to acidic waters, and certain weedy plants. Some of these species may thrive and become dominant in the modified habitat while others cease to exist all together affecting the biodiversity that tropical rainforests are known to have. Smaller segments of tropical forest, such as fragmented forests, that are altered suffer the greatest impact compared to larger segments.

Mined sites can take many years to recover while most in the tropical rainforest never revert back to its original undisturbed state. A Study evaluating mine sites in the Amazon found that regeneration of tropical forest is slow with very little vegetation ever matching its original fauna. Large areas of mined sites remained bare with very little grass and forest development after several years of the mine being closed. Bare land and open stagnate ponds of water from the mining activities were found routinely throughout the study. Where open pit mining was concerned, no vegetation was found within the pit itself suggesting soil infertility. The study concluded that additional research needs to be done; however, it will take years before a mine site regenerates forest growth if it ever does. This can be detrimental to the rain forest habitat and ecology of the area. (Peterson and Heemskerk 2000)

Economic and Social Impact
Lesser developed countries often seek ways of earning revenue for its citizens and mineral resources are often an avenue used. Papua New Guinea for example, receives almost two thirds of its export earnings from mineral deposits (GoPNG, 2002). Mineral exports may contribute to a country’s poverty in some ways instead of increasing its’ wealth. Competition with agricultural segments, government corruption, and mismanagement of operations are some reasons why mining operations do more to hurt an economy that help it. Mining jobs are typically limited in duration and they often pull people away from their farming operations leaving abandoned farm sites. Entire communities may be displaced during a large scale mining operation contributing to conflict and resentment. This is especially true in indigenous communities where they have strong cultural and spiritual ties to the land and resources. Mining also tends to prompt negative social behavior such as alcoholism, prostitution, and sexually transmitted diseases (Miranda et al., 1998).

Mining has impacts on other economic activities as well. When a mine is not properly managed and allowed to pollute and affect the surrounding environment, farming and fishing livelihoods are negatively impacted. This also poses a threat to public health and can consequently have a negative impact resulting in higher health care costs. Mining activities can directly impact food and water sources from chemical pollution and food availability due to habitat loss. Mining processes often use a large amount of water which can limit the amount available for use by local communities which adds to resentment and conflicts in the area. Air pollution from heavy metals released into the air at the mine site can cause an increase of asthma and respiratory problems increasing health care costs. Because mining camps tend to have negative social behavior as described above, violence escalates leading to an increased need for medical attention.

Government Regulations
Environmental laws and regulations establishes framework and guidance for mining companies as to what is acceptable and what is not allowed when working in that country. Many countries have rules governing environmental policy and are a part of international efforts to save certain habitats. The World Heritage Convention, for example, has been signed by 176 countries which commits to protecting natural and cultural sites (UNESCO 1972). Executing and managing laws are often difficult for lesser developed countries due to political conflicts or lack of funds to pay anyone to oversee the compliance of those laws. The Brazilian government, for example, proposed a new regulation last year that actually allows for more forest to be cleared for mining and logging activities instead of passing stricter regulations to save forest (Hudson 2011). In Papua New Guinea, the government relies on the mining company reports rather than conducting site visits to determine whether compliance standards with environmental regulations are being followed due to a lack of resources available as described above. In the tropics, numerous mining activities are being done illegally at the cost of the environment and those who inhabit it with no real enforcement upon those illegal miners. Funding and staffing are the main obstacles for these tropical countries when it comes to enforcing and regulating mining activities.

Countries often solicit their natural resources for profit and gain, especially when global demand is high. Mining can have a tremendous impact on the environment and its inhabitants as discussed. In an area such as the tropical rainforest where biodiversity is high and dependent on one another for survival, we need to take a close look at how our actions are going to impact the environment. Monitoring programs including water, air, and soil need to be put in place and practices routinely to evaluate the impact on the environment. Regulations and boundaries need to be set to decrease the impact mining has to the environment as much as possible. We also need to evaluate whether mining in certain areas is truly going to be profitable factoring in the environmental and economic impacts mining activities produce. Regulations and guidelines need to be enforced and have consequences if they are not adhered to properly. Conserving the rain forest and its natural resources should be of utmost importance as we gain so much knowledge from them. Hopefully, we can find a balance between harvesting and conserving natural resources while not inducing negative consequences in the process.


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