Coal's Dark Side: Air Pollution Explained

Coal is a fossil fuel that has been used as a source of energy for a long time. However, burning coal releases a variety of airborne toxins and pollutants, such as mercury, lead, sulfur dioxide, nitrogen oxides, particulates, and heavy metals, which have detrimental effects on both human health and the environment. These pollutants contribute to asthma, cancer, heart and lung ailments, neurological problems, acid rain, and global warming. Additionally, coal mining techniques can alter landscapes and cause water pollution, further impacting ecosystems and communities. As a result, there is a growing transition towards cleaner sources of energy to mitigate the adverse impacts of coal on the environment and public health.

Coal-fired power plants emit toxic soot and ozone, causing lung ailments

Coal-fired power plants emit toxic soot and ozone, which are extremely harmful to lung health for those living near and breathing in those pollutants. In 2011, the American Lung Association released a report titled "Toxic Air: The Case for Cleaning Up Coal-fired Power Plants," highlighting the dangerous air pollutants emitted from power plants.

The burning of coal releases small particles composed of a mixture of metals, chemicals, and acid droplets into the air. These particles, known as particulate matter or soot, are linked to chronic bronchitis, aggravated asthma, cardiovascular issues such as heart attacks, and even premature death. In 2014, US coal power plants emitted 197,286 tons of small airborne particles, with diameters of 10 micrometers or less, contributing to the respiratory health issues mentioned above.

The release of nitrogen oxides (NOx) from coal combustion is another significant contributor to air pollution. These oxides react with volatile organic compounds in the presence of sunlight, leading to the formation of ground-level ozone, the primary ingredient in smog. Smog irritates lung tissue, exacerbates asthma, and increases susceptibility to chronic respiratory diseases. Additionally, nitrogen oxides contribute to the formation of acid rain, which has further environmental consequences.

Mercury emissions from coal-fired power plants are also a critical concern. Coal plants are responsible for a significant proportion of US mercury emissions, a toxic heavy metal that can damage the nervous, digestive, and immune systems. Even small amounts of mercury deposited in bodies of water can render fish unsafe to eat, posing risks to both human health and the aquatic ecosystem.

To address these issues, pollution control technologies are available, but many power plants still lack the necessary pollution controls. The Clean Air Act and the Clean Water Act mandate industries to reduce pollutants released into the air and water, and efforts have been made to develop technologies that can remove impurities from coal or improve its energy efficiency, reducing the amount burned. However, the transition away from coal towards cleaner sources of electricity is essential to mitigating coal's worst impacts on human health and the environment.

Burning coal releases carbon dioxide, a primary driver of global warming

Global warming driven by carbon dioxide emissions from burning coal and other fossil fuels has significant environmental and public health impacts. These include rising temperatures, accelerating sea level rise, drought, flooding, extreme weather events, and species loss. The consequences of global warming are already being felt worldwide, and the severity of these impacts is directly tied to the amount of carbon dioxide released into the atmosphere.

Carbon dioxide is a greenhouse gas, one of several gases that contribute to global warming and climate change. Other greenhouse gases include methane and nitrous oxide. When released into the atmosphere, these gases trap heat, preventing it from escaping into space, and leading to an overall increase in the Earth's temperature.

Coal, in particular, has a high "carbon intensity," meaning it releases more carbon dioxide when burned compared to other fossil fuels like oil and gas. This is because coal has a higher carbon content than these other fuels. As a result, coal-fired power plants are significant contributors to carbon dioxide emissions and global warming.

To address the issue of carbon dioxide emissions from burning coal, scientists are researching methods such as carbon capture, which involves separating CO2 from emissions sources and injecting it underground for permanent storage. Additionally, transitioning to cleaner sources of electricity, such as hydrogen fuel, can help reduce carbon dioxide emissions and mitigate the impacts of global warming.

Coal plants are responsible for a high proportion of mercury emissions, a toxic heavy metal

Coal-fired power plants are the largest source of mercury emissions in the United States, accounting for approximately 8,800 pounds of mercury released into the atmosphere in 2017 alone. Mercury is emitted during the combustion of coal and other fossil fuels. However, coal has much higher mercury concentrations than other fossil fuels, which is why coal-fired power plants often emit larger quantities of mercury. Mercury pollution from coal plants is particularly severe in certain parts of the country, such as North Dakota, Texas, Appalachia, and the Midwest.

Mercury is a toxic heavy metal that poses significant dangers to human health and the environment. When released into the atmosphere, mercury can contaminate water bodies, making fish unsafe to eat. Indeed, just 1/70th of a teaspoon of mercury deposited on a 25-acre lake is enough to render its fish unsafe for consumption. Human exposure to mercury can occur through the consumption of contaminated fish or inhalation of polluted air, leading to severe health issues.

The toxic heavy metal has been linked to neurological and developmental damage in humans. It can cause brain damage in babies and is associated with heart disease, asthma, and other serious health issues. Additionally, mercury exposure can lead to damage to the nervous, digestive, and immune systems, posing a serious threat to child development.

To address the issue of mercury emissions from coal plants, the Environmental Protection Agency (EPA) has proposed regulating mercury pollution under the Clean Air Act. The EPA's proposal recognises the importance of reducing hazardous air pollution from power plants to safeguard public health. The implementation of the Mercury and Air Toxics Standards has helped reduce mercury pollution and mitigate the associated risks to human health and the environment.

Nitrogen oxides emitted by coal power plants cause smog and irritate lung tissue

Nitrogen oxides (NOx) are a product of burning coal. In 2014, US coal power plants emitted over 1.5 million tons of NOx. NOx emissions contribute to smog and irritate lung tissue, exacerbating asthma and making people more susceptible to chronic respiratory diseases like pneumonia and influenza. They are also linked to cardiovascular issues, such as heart attacks, and can even lead to premature death.

NOx emissions from coal-fired power plants have been declining in recent years. This is due to a combination of factors, including the increasing use of scrubbers (flue gas desulfurization equipment) to remove NOx from emissions, switching to lower-sulfur coal, and the adoption of selective catalytic reduction (SCR) and selective non-catalytic reduction (SNCR) technologies. In addition, the declining use of coal in favour of cheaper and cleaner natural gas has also contributed significantly to the reduction in NOx emissions.

Despite these efforts, coal-fired power plants still emit substantial amounts of NOx. In comparison to natural gas, coal-fired units produce over five times as much NOx per unit of electricity. This is due to the higher content of nitrogen, sulfur, and carbon in coal compared to natural gas. Older coal-fired units are particularly problematic, as fewer of them have installed modern emissions controls, which are designed to limit the formation of NOx or capture them after they are formed.

To further reduce NOx emissions from coal-fired power plants, a range of strategies can be employed. These include continuing to encourage the use of scrubbers and other pollution control technologies, as well as transitioning to lower-sulfur coal or alternative fuel sources with lower NOx emissions profiles. Additionally, retrofitting older coal-fired units with modern emissions controls can help reduce NOx emissions from these facilities, which have been found to emit pollutants at higher rates than newer units.

Coal mining techniques can cause streams to be polluted, harming aquatic wildlife

Coal is a fossil fuel that, when burned, releases a number of airborne toxins and pollutants. These include mercury, lead, sulfur dioxide, nitrogen oxides, particulates, and various other heavy metals. The consequences of these emissions include asthma, breathing difficulties, brain damage, heart problems, cancer, neurological disorders, and even premature death.

However, the environmental impacts of coal extend beyond air pollution and greenhouse gas emissions. Coal mining techniques, for instance, can cause significant harm to aquatic wildlife. Mountaintop removal, a type of coal extraction that involves removing the tops of mountains with explosives, has affected large areas of the Appalachian Mountains in West Virginia and Kentucky. This technique alters the landscape, and the resulting debris is often dumped into the valleys below, burying headwater streams. These streams are essential tributaries that mark the beginning of river networks.

More than 2,000 miles of headwater streams have been buried due to mountaintop removal, leading to critical losses in wildlife habitat, clean water sources, and natural benefits such as nutrient regulation and flood control. The water draining from these filled valleys may contain pollutants that can harm aquatic life downstream. Scientists analyzing central Appalachian streams impacted by coal mining found a 32% decline in species diversity and a 53% decline in the total number of invertebrates, fish, and salamanders compared to unaffected stream sites.

Additionally, coal mining can result in acid mine drainage, where highly acidic water containing heavy metals like arsenic, copper, and lead contaminates nearby rivers, lakes, and aquifers. This occurs when substances like iron sulfide are oxidized after exposure to air and water, changing the pH of streams. Selenium pollution, specifically, has been associated with the decline in sensitive fish populations and the occurrence of deformities in fish and birds in regions impacted by coal mining.

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