Coal's Pollution Legacy: Understanding Coal's Environmental Impact

Coal is a major source of pollution and has been linked to severe environmental and public health impacts. In 2022, coal combustion for energy accounted for about 19% of total US energy-related CO2 emissions and 55% of total CO2 emissions from the electric power sector. Coal-fired power plants emit harmful substances such as sulfur dioxide, nitrogen oxides, heavy metals, and fine particulate matter (PM2.5), which have been associated with increased mortality and health issues such as asthma, cancer, heart disease, and respiratory illnesses. The environmental impact of coal extraction methods, such as mountaintop removal, also contributes to pollution and landscape alteration. While efforts to reduce emissions through regulations and pollution control technologies have shown success, transitioning to cleaner energy sources is essential to mitigate coal's worst effects on the planet and human health.

Coal-fired power plants emit mercury, lead, and other heavy metals

Coal-fired power plants emit a range of harmful substances, including mercury, lead, and other heavy metals, which have been linked to severe environmental and public health impacts. Mercury, a potent neurotoxin, can cause irreparable harm to human health, especially the brain development of young children. It is released through the smokestacks of coal-fired power plants and can travel significant distances, affecting both nearby residents and those farther away. Lead, another toxic heavy metal, is also emitted from these plants, posing risks to human health and the environment.

Mercury is a significant concern due to its ability to bioaccumulate, meaning its concentration increases as it moves up the food chain. It falls onto soils and washes into waterways, where bacteria convert it into methylmercury, a highly toxic organic form. This methylmercury is then consumed by organisms, leading to a buildup of mercury in their flesh. As larger organisms or humans consume these contaminated organisms, they ingest higher doses of mercury, posing severe health risks.

Coal-fired power plants also release other harmful pollutants, including carbon monoxide, volatile organic compounds (VOCs), arsenic, sulfur dioxide, and nitrogen oxides. These emissions contribute to air pollution, smog, respiratory illnesses, and lung disease. Additionally, the coal industry's mining practices, such as mountaintop removal, can alter landscapes and contaminate waterways, causing further environmental damage.

To address these issues, the U.S. Environmental Protection Agency (EPA) has implemented regulations, such as the Mercury and Air Toxics Standards (MATS), to reduce mercury emissions from coal-burning power plants. The Clean Air Act and the Clean Water Act also mandate industries to reduce pollutants released into the air and water. However, the effectiveness of these measures depends on the widespread adoption of pollution controls, and the future of these protections remains uncertain.

While coal-fired power plants contribute significantly to pollution, it is important to note that coal accounts for roughly one-quarter of all energy-related carbon emissions in the United States. In 2022, coal combustion for energy accounted for about 19% of total U.S. energy-related CO2 emissions and 55% of CO2 emissions from the electric power sector. The transition to cleaner energy sources and the implementation of pollution-control technologies are crucial steps toward mitigating the environmental and health impacts associated with coal-fired power plants.

Coal power plants cause air pollution, linked to asthma, cancer, and heart disease

Coal-fired power plants emit air pollutants, including mercury, sulfur dioxide, nitrogen oxides, and particulate matter. These pollutants have been linked to asthma, cancer, and heart disease, among other serious health issues.

Mercury, for example, can damage the nervous, digestive, and immune systems. Sulfur dioxide and nitrogen oxide emissions contribute to the formation of smog and haze, which can aggravate respiratory conditions. Particulate matter, or "soot," is linked to chronic bronchitis, aggravated asthma, cardiovascular issues such as heart attacks, and premature death. Additionally, carbon monoxide, released from coal plants, can cause headaches and place additional stress on individuals with heart disease.

Studies have shown that residents living near coal-fired power plants experience higher rates of respiratory and cardiovascular disease, cancer, and premature death. In one study, researchers found that when coal-fired power plants shut down or upgraded their emission controls, rescue inhaler use, emergency room visits, and hospitalizations for asthma decreased among nearby residents. This was particularly evident in Louisville, Kentucky, where a project called AIR Louisville recruited people with asthma to use digital sensors attached to their asthma inhalers. The data showed a direct correlation between reduced coal plant emissions and improved asthma symptoms, with a decrease in hospitalizations and emergency room visits.

While carbon capture and storage technologies (CCS) are emerging as potential solutions to capture CO2 released from coal plants, these technologies are still expensive and unproven on a large scale. Additionally, CCS does not address other harmful pollutants produced by coal combustion. Therefore, it is crucial to continue developing and implementing effective emission controls and regulations to reduce the air pollution and associated health risks posed by coal-fired power plants.

Coal combustion releases carbon dioxide, a primary driver of global warming

Coal is an abundant and inexpensive fuel source that has long been a reliable source of energy in the US. However, its production and use have significant environmental impacts, particularly air and water pollution, and it is a primary driver of global warming.

When coal is burned, it releases airborne toxins and pollutants, including mercury, lead, sulfur dioxide, nitrogen oxides, particulates, and various other heavy metals. These emissions have severe environmental and public health impacts, including asthma, breathing difficulties, brain damage, heart problems, cancer, neurological disorders, and premature death. In addition, coal-fired power plants produce more than 100 million tons of coal ash annually, which can contaminate waterways and drinking water supplies.

The combustion of coal releases carbon dioxide, a heat-trapping gas that is the primary driver of global warming. Carbon dioxide is produced when the chemical bonds holding carbon atoms in coal are broken during combustion, releasing energy and carbon dioxide into the atmosphere. The amount of carbon dioxide released depends on the type of coal, with some coals containing up to 60-80% carbon. For every gram of carbon burned, nearly 4 grams of carbon dioxide are produced.

Carbon dioxide acts like a blanket, warming the Earth's surface and causing global warming. The consequences of global warming driven by carbon dioxide emissions include rising temperatures, accelerating sea level rise, drought, heat waves, heavy rainfall, intensified storms, and species loss.

In 2022, coal combustion for energy accounted for about 19% of total US energy-related carbon dioxide emissions and 55% of carbon dioxide emissions from the electric power sector. Coal is a significant contributor to the increasing atmospheric carbon dioxide levels, which are higher than at any point in human history. If the global energy demand continues to be met primarily with fossil fuels, human emissions of carbon dioxide could reach 75 billion tons per year or more by the end of the century.

Coal mining affects landscapes and contaminates water sources

In 2022, coal accounted for roughly one-quarter of all energy-related carbon emissions in the United States. Coal mining affects landscapes and contaminates water sources in several ways.

Firstly, surface mining involves clearing forests and stripping away the earth to expose underground coal deposits. This process leaves behind desolate lands incapable of supporting wildlife. Excessive logging destroys wildlife habitats and their inhabitants, and it also accelerates erosion. Without vegetation to anchor the soil, precipitation can carry away loose topsoil into nearby waterways.

Mountaintop removal is an especially destructive form of surface coal mining. Explosives are used to blast off the mountaintop, and the excess rock and soil are then dumped into adjacent valleys. These "valley fills" permanently bury headwater streams, causing critical losses in wildlife habitat, clean water sources, and natural benefits such as nutrient regulation and flood control. More than 2,000 miles of headwater streams have been buried due to mountaintop removal, leading to severe impacts on water quality that can persist long after mining has ceased.

Underground mines generally affect the landscape less than surface mines, but they are not without their risks. The ground above mine tunnels can collapse, and acidic water can drain from abandoned mines. Additionally, methane gas that occurs in coal deposits can explode if it becomes concentrated in underground mines.

Water sources are also contaminated by coal mining. Acid mine drainage (AMD) occurs when water reacts with sulfur-bearing minerals in rocks, resulting in highly acidic water containing toxic heavy metals. AMD poses a severe threat to wildlife and renders affected waterways unusable for drinking and recreation. Coal mining and power plants also produce coal ash, which can end up in ponds, lakes, and landfills, eventually contaminating waterways and drinking water supplies. In 2000, a coal slurry impoundment in Kentucky failed, contaminating hundreds of miles of rivers and streams with thick black sludge.

Coal pollution control technologies reduce harmful emissions

In the United States, coal accounts for roughly a quarter of all energy-related carbon emissions. The combustion of coal releases harmful substances that contribute to air pollution, acid rain, and greenhouse gas emissions. These emissions include toxins and pollutants such as mercury, lead, sulfur dioxide, nitrogen oxides, particulates, and various other heavy metals.

Coal pollution control technologies, also known as coal pollution mitigation, are systems and technologies that aim to reduce these harmful emissions and mitigate the health and environmental impacts of burning coal for energy. These technologies can be divided into pre-combustion and post-combustion approaches. Pre-combustion approaches include cleaning coal physically and chemically. Physically cleaning coal involves gravimetric processes, often in conjunction with froth flotation, to remove minerals and other non-combustible components. Chemical cleaning treats crushed coal with acids or bases to remove deleterious components, leaving only the combustible material behind.

Post-combustion approaches include flue-gas desulfurization, selective catalytic reduction, electrostatic precipitators, and fly ash reduction. Flue-gas desulfurization, or scrubbers, are used to clean sulfur from the smoke before it exits the smokestacks of power plants. Selective catalytic reduction and electrostatic precipitators are advanced technologies that can remove multiple pollutants as a single unit. Fly ash, a byproduct of coal combustion, can be captured and stored near power plants, placed in landfills, or reused to produce products such as cement and synthetic gypsum for wallboard.

Another example of coal pollution control technology is carbon capture and storage (CCS), which captures CO2 and acid rain-producing pollutants, separates them, and compresses the CO2 into a liquid. While this technology is not considered a final solution for CO2 reduction, it provides an achievable near-term solution while more desirable alternative solutions to power generation are developed. The development and implementation of these coal pollution control technologies are crucial in reducing the harmful emissions associated with coal combustion and mitigating their environmental and health impacts.

Frequently asked questions