Rainforests are the biggest source of oxygen, wood and medicines on this earth. Amazon rainforest is known for alluvial gold deposits. Gold is found both in river channels and at the banks of the river after floods (floodplains). Hydraulic mining techniques are used for mining gold. The method involves blasting at the banks of the river. This has caused irreversible damage to trees, birds and animals. While separating the sediment and mercury from the gold-yielding gravel deposits, small-scale miners who are less equipped than industrial miners, may ignore release of some mercury into the river. This mercury enters the food chain through aquatic animals and their predators. Highly poisonous compound ‘cyanide’ is also used to separate gold from sediment and rock. In spite of all precautionary measures, it sometimes escapes into the surrounding environment. Those who eat fish are at greater risk of ingesting such toxins.
Effect on Land
Deforestation: Mining requires large areas of land to be cleared so that the earth could be dug into by the miners. For this reason, large-scale deforestation is required to be carried out in the areas where mining has to be done. Besides clearing the mining area, vegetation in the adjoining areas also needs to be cut in order to construct roads and residential facilities for the mine workers. The human population brings along with it other activities that harm the environment. For example, various activities at coal mines release dust and gas into the air. Thus, mining is one of the major causes of deforestation and pollution.
Loss of Biodiversity: The forests that are cleared for mining purposes are home to a large number of organisms. Indiscriminate clearing of the forests leads to loss of habitat of a large number of animals. This puts the survival of a large number of animal species at stake. The cutting down of trees in itself is a big threat to a number of plants, trees, birds and animals growing in the forests. Pollution: Despite measures being taken to release the chemical waste into the nearby rivers through pipes, a large amount of chemicals still leak out onto the land. This changes the chemical composition of the land. Besides this, since the chemicals are poisonous, they make the soil unsuitable for plants to grow. Also, the organisms that live in the soil find the polluted environment hostile for their survival.
Effect on Water
Pollution: Chemicals like mercury, cyanide, sulfuric acid, arsenic and methyl mercury are used in various stages of mining. Most of the chemicals are released into nearby water bodies, and are responsible for water pollution. In spite of tailings (pipes) being used to dispose these chemicals into the water bodies, possibilities of leakage are always there. When the leaked chemicals slowly percolate through the layers of the earth, they reach the groundwater and pollute it. Surface run-off of just soil and rock debris, although non-toxic, can be harmful for vegetation of the surrounding areas. Loss of Aquatic Life: Release of toxic chemicals into the water is obviously harmful for the flora and fauna of the water bodies. Besides the pollution, mining processes require water from nearby water sources. For example, water is used to wash impurities from the coal. The result is that the water content of the river or lake from which water is being used gets reduced. Organisms in these water bodies do not have enough water for their survival.
River dredging is a method adopted in case of gold mining. In this method, gravel and mud is suctioned from a particular area of the river. After the gold fragments are filtered out, the remaining mud and gravel is released back into the river, although, at a location different from where they had been taken. This disrupts the natural flow of the river that may cause fish and other organisms to die. Previously buried metal sulfides are exposed during mining activities. When they come in contact with the atmospheric oxygen, they get converted into strong sulfuric acid and metal oxides. Such compounds get mixed up in the local waterways and contaminate local rivers with heavy metals.
Spread of Diseases
Sometimes the liquid waste that is generated after the metals or minerals have been extracted is disposed in a mining pit. As the pit gets filled up by the mine tailings, they become a stagnant pool of water. This becomes the breeding ground for water-borne diseases causing insects and organisms like mosquitoes to flourish.
Examples of the Environmental Impact of Mining
1. Environmental Impact of Mining In Guyana
In 1995, in Guyana, more than four billion liters of waste water that contained cyanide, slipped into a tributary of the Essequibo; when the tailings dam, which was filled with cyanide waste, collapsed. All the fish in the river died, plant and animal life was completely destroyed, and floodplain soils were heavily poisoned, making the land useless for agriculture. The main source of drinking water for the local people was also polluted. This was a major set-back for the eco-tourism industry on the river. When trees are cut (forest clearing for the construction of roads and mines, wood for the immigrated people, workers, etc.) and water sources are contaminated, animal populations migrate or die. Moreover, hunters are hired to feed the people working at the mining sites.
2. Mining in Goa
Illegal mining in Goa is being projected as a bigger scam than Bellary. While revenue losses from illegal mining has been estimated at about Rs 3,000 crore, the loss by way of damage to the environment and loss of livelihood has not been estimated. | |
Take the instance of Caurem village in Quepem taluka in south Goa. It has 2,000 families whose farms have been destroyed by illegal mines operating in the area. The silt from mining has entered the fields which now resemble a large quagmire. Tukaram Velip, a resident says that the perennial stream that irrigated the village fields is polluted and agriculture has been completely destroyed. People are left with no means of earning their living, he says.Most of the mines in the state are concentrated in four talukas—Bicholim in north Goa, and Sattari, Sanguem and Quepem talukas in south Goa. Activists say that an estimated 100,000 people living in the villages in these four talukas are affected. Besides loss of livelihood, they are also suffering from the adverse effects of air noise and water pollution.
“Mining has caused irreversible damage to forests, agriculture, fisheries and water aquifers,” says Abhijit Prabhudesai, member of Goyencha Xetkarancho Ekvott (GXE), a non-profit in Margaon city. He says the government has allowed mining even in forest areas despite the presence of wildlife. The mining has also affected the Salaulim dam on the Salaulim river in Sangeum taluka, which supplies drinking water to half the state’s population, besides providing water for irrigation and to industries. Over 20 mines are operating in the vicinity of the dam. Heavy silt has settled in the dam reservoir because of mining.
An official in the state water resources department admits that mining has damaged the state’s water resources and says the department is now reassessing the life span of the Salaulim dam. The dam was commissioned in the 1970s with an expected life span of 100 years. A study conducted by The Energy Resources Institute (TERI) in 1994 showed excess iron and manganese levels in the Salaulim reservoir water. “This was when mining was at a much lower scale as compared to present level of mining. We have repeatedly asked the government to conduct a study on water availability and quality, but nothing has been done till date,” says Prabhudesai.
3. Environmental Impacts Of Mining On Bundelkhand Region
In the Bundelkhand region of Uttar Pradesh, mining has had a huge negative impact on the environment. A Study was done to quantitatively evaluate the extent of the impact and the results were disappointing. The desirable limit of Fe is 0.3 mg/l and maximum permissible limit is 1.0 mg/l as per Indian standards. If water content more than these limit gives brackish color and bitter or metallic taste, therefore may not be use for drinking purposes. Concentrations of Cu in GW and SW samples varies from 0.029 to 0.088 mg/l and 0.039 to 0.062 in all the three seasons indicates that samples have more than permissible limit of Cu (<0.05 mg/l).
High concentration of Cu in water causes digestive disturbance, liver and kidney damage and the source is industrial or mining waste. Similarly, the Cd contents also varies 0.027 to 0.064 mg/l and 0.013 to 0.059 mg/l in GW and SW in all the three seasons which have been found more than permissible limit of Cd (0.01 mg/l), in potable water. The digging, blasting and drilling of granite mine generated dust particles of various sizes into the immediate atmosphere. Most of this dust is usually made up of silica (occurring as silicon dioxide SiO2). Among all the contaminants of the atmosphere in the granite mining areas, dust is probably the most abundant and ubiquitous. Investigations revealed that several workers were not aware of the proper safety procedures.
4. Environmental damage by Mining: Vedanata
Vedanta has been criticised by human rights and activist groups, including Survival International and Amnesty International and Niyamgiri Surakshya Samiti due to their operations in Niyamgiri Hills in Orissa, India that are said to threaten the lives of the Dongria Kondh that populate this region. The Niyamgiri hills are also claimed to be an important wildlife habitat in Eastern Ghats of India as per a report by the Wildlife Institute of India as well as independent reports/studies carried out by civil society groups. In January 2009, thousands of locals formed a human chain around the hill in protest at the plans to start bauxite mining in the area. The Union Environment Ministry in August 2010 rejected earlier clearances granted to a joint venture led by the Vedanta Group company Sterlite Industries for mining bauxite from Niyamgiri hills. Vedanta’s Alumina Refinery in Lanjigarh was critiqued by the Orissa State Pollution Control Board (the statutory environmental regulation body) for air pollution and water pollution in the area.
According to Amnesty International, local people reported dust from the plant settling on clothes, crops and food. Vedanta officials claimed there was no dust pollution from the plant at all. An environmental inspection of the plant reported water pollution by the plant including increasing the pH value of the river Vamshadhara below the refinery and a high level of SPM in the stack emissions. In October 2009 it was reported that the British Government has criticised Vedanta for its treatment of the Dongria Kondh tribe in Orissa, India. The company refused to co-operate with the British Government and with an OECD investigation. They have rejected charges of environmental damage, saying it may be related to the increased use of fertiliser by farmers. Safety concerns
2007 Mining Deaths
Unsafe mining operations led to 1,247 injuries and 26 deaths involving own employees and contractors. Balco, Korba, ChhattisgarhA chimney under construction by Gannon Dunkerley & Company at the Balco smelter in Korba, Chhattisgarh collapsed on 23 September 2009 killing at least 40 workers. Balco and GDCL management have been accused of negligence in the incident.
“Most of the mineral concentrations are in areas of the south, central and northeastern states of Orissa, Madhya Pradesh, Chattisgarh and Jharkhand, areas that are home to a majority of India’s 90 million tribal peoples. More than three quarters of the 2.6 million people displaced by mining from 1950 to 1991 have yet to be rehabilitated”.