Environmental Impacts of Mining and Smelting

8/12/2019 Environmental Impacts of Mining and Smelting

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Environmental Impacts of Mining and Smelting

Background

The mining sector is responsible for some of the largest releases of heavy metals

into the environment of any industry. It also releases other air pollutants

including sulfur dioxide and nitrogen oxides in addition to leaving behind tons of

waste tailings, slag, and acid drainage. Occupational and environmental exposure

to heavy metals, silica, and asbestos can occur during mining and milling

operations. The smelting process (extracting the metal from the ore) is associated

with the highest exposures and environmental releases.

The hazards to human health caused by exposure to heavy metalsincluding

lead, cadmium and mercuryhave been thoroughly documented. These metals

are associated with a range of neurological deficits in both children and adults in

addition to a range of other systemic effects. Exposure to airborne silica and

asbestos can cause lung cancer, pneumoconiosis and numerous other health

effects.

While pollution controls can minimize exposures to workers and surrounding

communities, these safeguards are often absent in mining and smelting

operations in developing countries. Even relatively efficient mining operations

result in enormous waste, emissions to air and water, and a legacy of

environmental contamination in nearby communities. Around the world, unsafe

mining and smelting practices have been responsible for a continuing series of

environmental and human health disasters, which cause great human tragedy and

undermine social stability, economic development and sustainability goals.

For example, in 2010, more than 400 children died in Zamfara, Nigeria from acute

lead poisoning caused by unsafe mining and processing lead-containing gold ore.

People grinding the ore, often in and around their homes, contaminated at least

180 villages over a wide area.


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Even large-scale gold mining has significant mercury releases associated with ore

processing. It is now known that significant mercury emissions result from cyanide

leaching and even from mine tailings where no mercury has been added.6

More commonly, small-scale gold mining utilizes significant quantities of mercuryto extract gold from the ore. Exposure to mercury in these operations not only

endangers miners and their families, but is also detrimental to the environment

when deposited into the water supply. Artisanal gold mining employs an

estimated 10-15 million miners in more than 55 countries.7 Estimates are that

these small operations produce about 20% of the world's gold supply.

Many studies have documented significant mercury exposures in these gold

mining communities. In the Madre de Dios region of Peru, gold shops serving

small artisanal miners were found to have mercury levels that were more than 20

times the World Health Organization (WHO) occupational health standard for

mercury.8 This region of Peru alone has over 20,000 informal gold mining

operations.

The environmental impact of miningincludeserosion,formation ofsinkholes,loss ofbiodiversity,and

contamination of soil,groundwaterandsurface waterby chemicals from mining processes. In some

cases, additional forest logging is done in the vicinity of mines to increase the available room for thestorage of the created debris and soil.Besides creating environmental damage, the contamination

resulting from leakage of chemicals also affect the health of the local population.Mining companies in

some countries are required to follow environmental and rehabilitation codes, ensuring the area mined is

returned to close to its original state. Some mining methods may have significant environmental and

public health effects.

Children Are Most Susceptible

Children suffer a disproportionate share of the disease burden imposed by mining

pollution. The International Labour Organization (ILO) estimates that 250 million

children are involved in child labor and that over 70 percent of them face

hazardous conditions. Children in Asia, South America, and Africa participate in

the mining of gold, tin, and precious metals. According to the United Nations

Environment Program (UNEP), small-scale gold processing operations in
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developing countries employ one million children. Children, who are more

susceptible to the impacts of heavy metals, tend to have higher exposures and

generally account for the majority of deaths and disease associated with mass

poisoning incidents from these operations. Studies have documented that

children involved in mining have higher exposures to mercury, lead, and other

metals and suffer severe lead and mercury intoxication.

Assessing Hazards from Artisanal Mining in Nigeria

In 2012, OK International conducted an investigation of artisanal small-scale

mines (ASM) throughout Nigeria to assess health hazards in an effort to prevent

tragedies like the one in Zamfara. We visited gold mines, ore processing sites and

lead mines where we collected soil and water samples and completed a hazardevaluation for each site. We also worked with the Nigerian Ministry of Mines and

Steel Development (MMSD) in coordination with other government agencies to

conduct a three-day training session to increase the capacity within government

agencies to evaluate hazards in ASM.

Soil samples collected around gold ore processing at one site had lead

concentrations as high as 1% in a location where miners also slept and ate. These

concentrations pose a significant health risk to both the miners and surrounding

communities. Not surprisingly, lead concentrations were also very high around

artisanal lead mines where the ore had as much as 18% lead. We also found soil

to be contaminated with mercury at gold processing sites where children were

conducting amalgamation processes. In addition to the hazards of toxic metals in

the ore, we noted very high silica dust exposures in ore processing.

Although some resources have been devoted to environmental remediation and

medical treatment of poisoned children in Zamfara, little attention is being paid

to the extent of the problem in other areas of Nigeria. There is no national or

state level database of artisanal mines in Nigeria and information about the metal


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content in ore is lacking. Raising awareness among miners of the hazards and

safer mining practices is desperately needed at ASM sites throughout Nigeria in

order to prevent the occurrence of more lead and mercury contamination and

silicosis. We are also recommending that the Nigerian authorities conduct a more

thorough investigation of gold mines outside Zamfara to characterize locations

with significant lead exposure.

Outsourcing Hazardous ProcessingA Growing

Problem

In recent years we have witnessed a growing shift to export the most polluting

aspects of the mining industry to developing countries. The U.S. exports millionsof tons of mined ore to countries with more lenient environmental and

occupational regulations and little enforcement. For example, in 2010, 50% of the

lead ore mined in the U.S. was exported to China and South Korea for processing

(see below). Only 25% of the lead ore mined in the U.S. is now processed at the

nation's one remaining primary smelter.

The graph below shows that lead ore exports from the U.S. to China grew by 50

percent between 2005 and 2010. China has reported more than 30 serious lead

poisoning incidents around lead smelters and battery recyclers since 2009.

Moreover, changes in the global economy threaten to increase the harm caused

by unsafe mining and smelting practices. Growing demand for metals and

increasing commodity prices are encouraging expansion of both formal and small-

scale mining and recycling around the world.

In addition, initiatives aimed at reducing global carbon emissions can have the

unintended consequence of increasing lead poisoning in developing countries. Forexample, the adoption of solar, wind power and electric vehicles is increasing

demand for lead batteries. The development of new applications for larger

lithium ion batteries is significantly increasing the demand for lithium, cobalt,

manganese and other metals. This trend may continue if plans to accelerate the

production of electric and hybrid vehicles are realized.


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U.S. LEAD ORE EXPORTS TO CHINA:

Global Campaign to End Hazardous Mining Activities

The response to the reported mass poisoning incidents surrounding mining and

smelting operations is predictably similar from country to country: shock upon

discovery of the problem, medical treatment of survivors (to the extent that

resources are available), and a call for huge sums to remediate environmental

contamination. In most cases no one is left to cover the costs of environmental

cleanup or even to compensate workers harmed on the job. A new approach is

needed to prevent these human health impacts and environmental

contamination before the damage is done.

OK International is therefore calling for a global campaign to end dangerous

mining, smelting and recycling practices that poison children, workers, and

families in developing countries and leave adjacent communities devastated by

widespread contamination. These efforts will instead encourage the adoption of

improved practices in the most hazardous mining and smelting operations. This

campaign would engage technical experts, create multistakeholder partnerships,

develop and promote consensus standards, and link safety, health and

environmental concerns with economic development. The campaign's goal is to

change the norms of practice to prevent environmental contamination before

medical treatment and costly cleanup operations are needed.

Issues

WATER POLLUTION

Mining can have adverse effects on surrounding surface and ground water if protective measures are not

taken. The result can be unnaturally high concentrations of some chemicals, such as arsenic,sulfuric

acid,andmercuryover a significant area of surface or subsurface.Runoff of mere soil or rock debris -

although non-toxic- also devastates the surrounding vegetation. The dumping of the runoff in surface

waters or in forests is the worst option here.Submarine tailings disposalis regarded as a better option (if
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the soil is pumped to a great depth).Mere land storage and refilling of the mine after it has been depleted

is even better, if no forests need to be cleared for the storage of the debris. There is potential for massive

contamination of the area surrounding mines due to the various chemicals used in the mining process as

well as the potentially damaging compounds and metals removed from the ground with the ore. Large

amounts of water produced from mine drainage, mine cooling, aqueous extraction and other mining

processes increases the potential for these chemicals to contaminate ground and surface water. In well-

regulated mines, hydrologists and geologists take careful measurements of water and soil to exclude any

type ofwater contaminationthat could be caused by the mine's operations.

Heavy metals[edit]

Dissolution and transport of metals andheavy metalsby run-off and ground water is another example of

environmental problems with mining, such as theBritannia Mine,a former copper mine nearVancouver,

British Columbia.Tar Creek,an abandoned mining area in Picher, Oklahoma that is now

anEnvironmental Protection Agencysuperfundsite, also suffers from heavy metal contamination. Water

in the mine containing dissolved heavy metals such asleadandcadmiumleaked into local groundwater,

contaminating it.[6]

Long-term storage of tailings and dust can lead to additional problems, as they can be

easily blown off site by wind, as occurred at Scouriotissa,an abandoned copper mine inCyprus.

Deforestation[edit]

Withopen cast miningthe overburden, which may be covered in forest, must be removed before the

mining can commence. Although thedeforestationdue to mining may be small compared to the total

amount it may lead to species extinction if there is a high level of local endemism.

Mitigation

To ensure completion ofreclamation,or restoring mine land for future use, many governments and

regulatory authorities around the world require that mining companies post a bond to be held in escrow

until productivity ofreclaimed landhas been convincingly demonstrated, although if cleanup procedures

are more expensive than the size of the bond, the bond may simply be abandoned. Since 1978 the

mining industry has reclaimed more than 2 million acres (8,000 km) of land in the United States alone.

This reclaimed land has renewed vegetation and wildlife in previous mining lands and can even be used

for farming and ranching.

Responsible miningResponsible miningrefers to advocacy to reformminingactivity, as well a marketing strategy used by

mining companies to promote their operations as environmentally or socially sound. Goals may vary by

group.Responsible mining first began to appear in an article entitled "Re-inhabitory Mining"[1]

and next as

"Ecological Mining".[2]

The term "Responsible Mining" was formulated by Ranil Senanayake of

theInternational Analog Forestry Networkand Brian Hill of the Institute for Cultural Ecology

Groups

'Responsible mining' advocacy is carried out by severalnon-governmental organizations(NGOs):

The Alliance for Responsible Miningis an independent, mission-driven initiative that supportsartisanal

and small-scale (ASM) minersglobally. Established in 2004, the organizations mission is to enhance

social and economic wellbeing, strengthen environmental protection and establish fair governance in
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ironmental_impact_of_mining#cite_note-6http://en.wikipedia.org/wiki/Cadmiumhttp://en.wikipedia.org/wiki/Leadhttp://en.wikipedia.org/wiki/Superfund_(environmental_law)http://en.wikipedia.org/wiki/United_States_Environmental_Protection_Agencyhttp://en.wikipedia.org/wiki/Picher,_Oklahomahttp://en.wikipedia.org/wiki/Vancouverhttp://en.wikipedia.org/wiki/Vancouverhttp://en.wikipedia.org/wiki/Britannia_Beach,_British_Columbiahttp://en.wikipedia.org/wiki/Heavy_metalshttp://en.wikipedia.org/w/index.php?title=Environmental_impact_of_mining&action=edit&section=4http://en.wikipedia.org/wiki/Water_pollution


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ASM communities by formalizing the ASM sector. To achieve its mission, ARM has created an

exceptional set of social and environmental standards known as the Fairmined certification. ARM offers

extensive and continuous support and training to ASM communities to help them reach the standards,

achieve the Fairmined certification and invest in community development. Furthermore, ARM serves as

an intermediary for ASM communities, which gives them the opportunity to respond to international

markets demanding ethical metals and jewelry. Since 2004, ARM has facilitated the positivetransformation of multiple ASM communities in Latin America and is currently expanding its efforts to

Africa and Asia.

Description/Abstract

As coal is considered as a substitute for other fuels, more serious attention is being given to theenvironmental impacts of the whole coal fuel cycle: mining, transport, storage, combustion andconversion. This book presents an account of these environmental impacts and the recentdevelopments to control them. In addition to the experience and developments in North America andWestern Europe the book presents information on the developments in the socialist countries of

Eastern Europe. The book covers elements and chemical compounds; coal in the internationalenergy scene; land disturbance and reclamation after mining; resource demands of coal production;environmental impacts of coal transportation; coal combustion; coal conversion technologies;application of the exposure commitment model to coal utilization emission problems; theenvironmental significance of trace elements from coal combustion and conversion processes; theenvironmental significance of coal-derived carbon compounds; occupational and environmentalhealth problems from coal utilization and conversion; and the effect of coal utilization emissions onnatural and man-managed terrestrial and freshwater ecosystems.

Documents

Environmental Impacts of Mining and Smelting