Coal Power Plants, Pollution and Death

Pollution from coal-fired power plants causes more deaths than previously thought.

New research shows that air pollution particles from coal-fired power plants are more harmful to human health than many experts thought and are more than twice as likely to cause premature death as air pollution particles from other sources.

In a study published in the journal Science, my colleagues and I determined how particles emitted by coal-fired power plants in the United States move through the atmosphere and then linked each plant's emissions to Medicare mortality data for Americans over 65 years of age.

Coal-fired power plants and their damage to health

Our findings show that air pollution from coal-burning power plants was linked to nearly half a million premature deaths in older Americans between 1999 and 2020.

It's an alarming number, but the study also offers good news: The number of deaths each year linked to coal-fired power plants in the United States has been declining since the mid-2000s, when federal regulations forced operators to install exhaust gas scrubbers and many utilities completely shut down coal-burning power plants.

We estimate that carbon pollution caused 55.000 deaths in the United States in 1999. By 2020, that number had dropped to 1.600.

Energy transition

In the United States, coal is being replaced by natural gas and renewable energy sources to produce electricity. However, global coal consumption is expected to increase in the coming years. This makes our results even more relevant for better understanding by policymakers around the world when developing future policies.

Carbon air pollution: why is it so bad?

A landmark study conducted in the 1990s, known as the Harvard Six Cities Study, linked fine particles in the air, known as PM2,5, to an increased risk of premature death. Since then, other studies have linked PM2,5 to lung and heart disease, cancer, dementia and other illnesses.

Following this investigation, the Environmental Protection Agency began regulating PM2,5 concentrations in 1997 and lowered the limits over time.

PM2,5 (particles small enough to be inhaled deeply into the lungs) come from a variety of sources, including gasoline burned in vehicles and smoke from wildfires and power plants.

Coal is also a mixture of many chemicals: carbon, hydrogen, sulfur and even metals. When coal is burned, all of these chemicals are released into the atmosphere in the form of gases or particles. There, they are transported by the wind and interact with other chemicals available in the atmosphere.

As a result, anyone downwind near a coal-fired power plant could be inhaling a complex cocktail of chemicals, each with potential health effects.

Monitor PM2.5 carbon dioxide emissions

To understand the risk that carbon emissions pose to human health, we tracked sulfur dioxide emissions from each of the 480 largest coal-fired power plants in the United States that have been operating continuously since 1999, flying with the wind and becoming fine particles: carbon PM2.5.

We used sulfur dioxide due to its known health effects and emissions were significantly reduced during the study period.

We then used a statistical model to link PM2,5 coal exposure to Medicare data for nearly 70 million people between 1999 and 2020. This model allowed us to estimate deaths related to PM2,5 dust from coal.

We included other sources of pollution in our statistical model and took into account many other known risk factors, such as smoking, local climate, and income level. We tried several statistical methods and they all gave consistent results.

We compared the results of the statistical model with previous results that examined the health effects of PM2,5 from other sources and found that PM2,5 from coal is twice as harmful as PM2,5 from all other sources.

The number of deaths associated with each power plant depends on many factors: the amount of coal released into the atmosphere, the direction of the wind and the number of people inhaling the pollutants. Unfortunately, American power companies have located many of their facilities downwind of major population centers on the East Coast. This arrangement increased the influence of these plants.

Using an interactive online tool, users can see our estimate of the number of annual deaths at each power plant in the United States. and also note how these numbers have decreased over time for most coal-fired power plants.

The American success story and the global future of coal

Engineers have been developing effective scrubbers and other pollution control devices that can reduce emissions from coal-burning power plants for several years.

The Environmental Protection Agency has regulations that specifically reward coal companies for installing scrubbers, and most companies that haven't installed them are closing their doors.

The results were surprising: sulfur dioxide emissions were reduced by approximately 90% in factories with scrubbers installed. Nationally, sulfur dioxide emissions have fallen 95% since 1999. We estimate a significant reduction in the number of deaths associated with each facility that installed or closed scrubbers.

As advances in fracking technology reduced the cost of natural gas and regulations made it more expensive to operate coal-fired power plants, utilities began to replace carbon by natural gas, natural resources and power plants that generate renewable energy.

The switch to natural gas – a fossil fuel that is cleaner than coal but is still a greenhouse gas that contributes to climate change – has helped reduce air pollution even further.

Today, coal provides about 27% of US electricity, up from 56% in 1999. However, the global outlook for coal is mixed. As the United States and other countries look toward a future that uses less coal, the International Energy Agency expects global coal consumption to increase at least through 2025.

Our study and others like it clearly show that increased use of coal will harm human health and the climate.
Making the most of emissions controls and switching to renewable energy sources are sure ways to reduce the negative impact of coal.

With information from: Lucas Henneman, assistant professor of engineering at George Mason University. The Conversation.