Surface Mining: Air Pollution And Health Hazards

Mining is a significant contributor to the world economy, but it also has a large environmental footprint. One of the most pressing issues is air pollution, which is caused by the release of toxins and greenhouse gases during the extraction and processing of minerals. This has a detrimental impact on the health of people living near mines and the planet. This is especially true for surface mining, which involves clearing large areas of land, deforestation, and the removal of vegetation, which can lead to soil erosion and the pollution of waterways.

Particulate matter and methane emissions

Particulate matter (PM) is one of the primary pollutants produced by surface mining operations. PM is released into the atmosphere during the drilling, blasting, loading, transport, and unloading of minerals in surface mines. These activities generate harmful particles of varying sizes, which can have adverse effects on both human health and the surrounding environment.

The health impacts of particulate matter from surface mining are significant. Studies have linked the inhalation of PM to various adverse health outcomes, including restricted airways, reduced lung capacity and function, increased cardiovascular disease, pneumoconiosis, cancer, and neurotoxic effects. The size of the particles plays a crucial role in their health effects. Coarse particles larger than 30 μm, also known as total suspended particulate matter (TSPM), settle close to the emission point and are less concerning from a health perspective. On the other hand, particles smaller than 10 μm are responsible for reduced air quality and adverse health effects as they can be inhaled and reach the respiratory tract.

To address the issue of particulate matter emissions, various mitigation strategies and best practices for air quality monitoring at mining sites have been proposed. Real-time air quality monitoring is essential to detect and notify workers of air pollution spikes. Additionally, technologies such as diesel particulate matter (DPM) controls, sufficient ventilation, and dust suppression systems can help reduce particulate matter levels. Surface miners, mist sprayers, wet drilling, and wind screens can limit dust generation and movement within the mine. Regular vehicle maintenance and the use of energy-efficient vehicles with clean diesel fuel or alternative energy sources can also contribute to reducing particulate matter emissions.

Methane gas is another significant emission associated with surface mining, particularly in coal mining operations. Methane is a byproduct of coal mining and can pose safety risks due to its explosiveness in concentrated amounts. In 2021, methane emissions from active and abandoned coal mines accounted for about 7% of total U.S. methane emissions and 1% of total U.S. greenhouse gas emissions. To mitigate the risks and environmental impact of methane, green mining practices such as methane capturing techniques can be employed. For example, fans can be used to extract methane from mines and convert it into carbon dioxide and water vapour, which are less harmful when released into the atmosphere.

Air pollution and health

Air pollution is one of the leading causes of environmental health problems globally. The World Health Organization (WHO) estimates that air pollution is responsible for 7 million premature deaths annually. The production and processing of minerals and metals contribute significantly to this issue.

Mining operations, for example, release fine particles and gases into the air during blasting, excavation, and transportation. These particles may contain heavy metals and other pollutants, affecting air quality and the respiratory health of nearby residents. Additionally, the removal of vegetation and deforestation required for surface mining alter the landscape, impacting biodiversity and scenic beauty.

The smelting process in metal mining is a primary source of arsenic emissions and other toxins. Aluminum smelters, for instance, release carbon dioxide and perfluorocarbons (PFCs) during production. PFCs have a heat-trapping potential up to 9,200 times that of carbon dioxide and can persist in the atmosphere for tens of thousands of years.

Coal mining, in particular, has been associated with air pollution and mortality impacts. The production and handling of coal generate pollution through wind erosion, oxidation, and transportation processes. Studies have shown that suspensions of coal mining lead to reduced mortality rates in the affected regions.

To address these health concerns, air quality monitoring and management are essential. Advancements in sensor technology have made it more accessible and cost-effective to control air quality. By adopting clean energy models and environmentally friendly production processes, the impact of mining on air pollution can be minimized.

Environmental impact of coal mining

Coal is the most abundant and inexpensive fossil fuel, and it is the most widely used energy source, accounting for almost 40% of global electricity generation. However, coal mining, particularly surface mining, has significant environmental impacts, including air pollution and climate change.

Surface mining involves the use of large machinery to remove soil and rock layers and expose underground coal seams. This process can alter the landscape, removing vegetation, creating large cavities, and causing erosion. For instance, mountaintop removal, a destructive form of surface mining, uses explosives to remove mountain tops, dumping excess rock and soil into adjacent valleys, burying headwater streams, and causing irreversible damage to wildlife habitats and water sources.

Air pollution is a significant concern in coal mining. Fine particles released during blasting, excavation, and transportation of coal can contain heavy metals and other pollutants, degrading air quality and posing health risks to nearby communities and miners. Additionally, coal mining contributes to greenhouse gas emissions, with coal combustion emitting carbon dioxide, nitrogen oxide, sulfur dioxide, and methane, all of which contribute to global climate change.

Water pollution is another adverse effect of coal mining. The clearing of forests and vegetation for surface mining can lead to sedimentation in nearby waterways, killing fish and plants and disrupting aquatic ecosystems. Furthermore, coal mining activities can result in acid mine drainage, where exposed sulfide minerals react with oxygen and water to produce sulfuric acid, contaminating water bodies and harming aquatic life. Selenium pollution in water from coal mining has been linked to the decline of sensitive fish populations and deformities in fish and birds.

The environmental impacts of coal mining extend beyond local issues, and restoration efforts alone may not be sufficient to correct the damage. The extensive harm caused by coal mining underscores the importance of transitioning to renewable energy alternatives to preserve the environment and wildlife for future generations.

Mercury emissions from gold mining

Surface mining, a method of coal mining, involves clearing forests and stripping away the earth to expose underground coal deposits. This process has been associated with air pollution and climate change, as it degrades air quality and contributes to greenhouse gas emissions. Additionally, the removal of vegetation and the creation of large cavities during surface mining can negatively affect biodiversity and the natural landscape.

Now, let's focus on mercury emissions from gold mining:

To address this issue, organizations like the United Nations Environment Programme (UNEP) and the United States Environmental Protection Agency (EPA) have developed initiatives to reduce mercury emissions from gold mining. The Minamata Convention on Mercury, ratified in 2017, aims to control the trade, use, and emissions of mercury. It requires signatories to take steps to reduce or eliminate mercury use and emissions in mining processes. Additionally, the EPA has partnered with the Argonne National Laboratory (ANL) to create the Gold Shop Mercury Capture System (MCS), a low-cost and easily constructible technology to capture mercury emissions at the source.

By implementing mercury-reducing technologies and transitioning towards mercury-free mining practices, the global community is working towards minimizing the environmental and health impacts of mercury emissions from gold mining. These efforts are crucial to protect both human health and the planet.

Landscape and biodiversity changes

The extent of the impact on landscape ecology varies depending on the type of surface mine. For instance, a study on the impact of surface mining on semi-arid grassland landscape ecological health found that open-pit mines had the most significant impact, followed by dumping landscapes and mining area industrial squares. The construction of roads and infrastructure to accommodate mining activities and employees can also contribute to landscape changes and biodiversity loss.

The destruction or drastic modification of the original site during mining activities can have a major impact on biodiversity. This includes the loss of vegetation cover and wildlife habitats, as well as direct and indirect poisoning of animals, vegetation, and microorganisms by mine-extracted materials. Endemic species are especially vulnerable to habitat modifications, such as changes in pH and temperature, as they require very specific environmental conditions to survive.

Mining activities can also lead to land-use changes, with agricultural lands being rendered useless, causing food insecurity and an increase in the cost of living for local communities. The development of surrounding infrastructure, such as camps for miners and transportation networks, can further alter the landscape and lead to increased human-caused disturbances to local ecological systems.

The impact of surface mining on landscapes and biodiversity can be mitigated through the implementation of conservation strategies and the use of less invasive mining techniques. Environment-friendly and cost-effective land reclamation practices can help restore mined lands to their original state or higher use, preventing the release of contaminants and increasing the available land size.

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