Particulate Matter and Coal Dust

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Why this Information Is Important: Coal dust particles are tiny pieces of coal in the air and that has settled on surfaces. Coal dust is released into the air when wind blow over coal piles or coal is moved, such as during train transport. Know where coal dust comes from, document coal dust pollution in your home and neighborhood.

Attention: Residents, activists and advocates, researchers

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Listen to Kim Williams, interviewed by Adrian Wood

Airborne Particles

Airborne particles—also known as particulate matter (PM), particulates, or aerosols—refer to any mixture of solids and liquid droplets in the atmosphere. Particles can be directly released into the air or formed through chemical reactions of gaseous pollutants.

Particles are often distinguished by their size. The terms PM1, PM2.5, and PM10 are common ways particles are described, measured, and regulated, with the number indicating the size of particles based on their diameter in micrometers. Particles can also be discussed in the terms of very-fine (PM1), fine (PM2.5), and coarse (PM10) particles, with PM10 generally referring to dust. Particle size, composition, and shape affect how particles are regulated under the U.S. Clean Air Act and their health impacts.

Coal Dust

Coal dust is a type of particulate matter that contains coal. Coal dust particles tend to be larger in size, including PM2.5 and PM10, as well as even bigger PM that is visible with the unaided eye.[1] Coal dust is lost from the atmosphere through settling and deposition, leaving black dust films on outdoor and indoor surfaces. Coal dust contains toxic heavy metals that have serious health impacts at ambient concentrations and exposures below the U.S. Environmental Protection Agency (EPA) PM10 National Ambient Air Quality Standards (NAAQS).

Coal Dust Emissions

Coal dust is produced through physical processes, like the friction, that occurs when coal pieces bumping against each other or coming into contact with surfaces like conveyor belts, train cars and truck beds, that wear on the brittle coal rocks during mining, movement and transport, and exposure to weather. These processes generate coal particles that are uplifted to the air and carried by winds. The distance traveled by coal dust in the atmosphere depends on the size of particles, with smaller particles generally reaching farther distances as they settle more slowly because they are less affected by gravity.

Wind and Weather

Wind: Coal stockpiles and railcars are susceptible to wind erosion, with coal particles easily becoming airborne. Wind speeds over the coal piles and railcars influence how much coal dust is emitted to the air. As wind speeds increase, more particles are emitted.[2]
Higher airborne particulate matter and black carbon levels have been measured when winds blow from CSX Curtis Bay Piers in Baltimore, Maryland into a neighboring community .[3]
Clouds, Rain, and Fog: Coal dust emissions are reduced on cloudy, rainy, foggy, and humid days. This is similar to the effects of water sprayers for wet dust suppression.
Relative humidity also influences coal dust particle size, with higher humidities leading to larger particles because dust particles clump together, and lower humidities increasing the overall concentrations and the amount of smaller dust particles emitted.[4]

Coal Transporting and Handling

Transportation of Coal: Transport of coal in uncovered railcars releases significant amounts of coal dust to the air by the jostling of coal rocks in the railcars as they travel. The railroad company BNSF has conducted studies that indicate 500 pounds (lbs) to 1 ton of coal can escape from a single coal car during travel along a railway.[5]
Coal Handling: Loading and unloading coal from railcars into storage piles can unsettle dust particles and release them into the air. Equipment at the terminals that move coal piles, such as bulldozers and conveyor belts, can release coal dust into the air. The transfer of coal onto ships can similarly unsettle dust particles. In 1989, the Virginia Air Pollution Control Board (APCB) set limits on the emissions from each ship unloading operation, conveyor belts, bucket elevators, silo air slides, and the truck load-out system to 0.3 pounds per hour for PM2.5 and PM10 for each respective coal handling operation. In July 1994, this emission limit was increased to 1.6 pounds per hour.
Handling Size and Frequency: The amount of dust varies with the amount material passing through the coal terminals. More coal means more dust. The age of the coal in the pile is also important. When new material is loaded onto a storage pile, its potential for dust emissions is at a maximum, and particles are easily created and released. As the coal weathers, the potential for dust is reduced. Some particles are already lost by winds, and exposure to moisture causes the aggregation and cementation of particles to bulk coal surfaces.[6]

Evidence of Coal Dust Deposition in Lambert's Point, Norfolk

Soil samples soils collected in Lambert's Point, Norfolk had elevated arsenic levels.[7][8] This research reported that soils at a depth of 4 centimeters were 7.1 percent by weight un-combusted coal with a mean arsenic concentration of 13.3 milligrams per kilogram soil (mg/kg). The percent by weight of coal decreased with increasing distance away from the Norfolk Southern Pier 6 Terminal.[7]

Resources and Materials: See for Yourself and Dig Deeper

  • Photograph: Coal dust residues in Southeast Newport News. Photograph from the Repair Lab.
    Photograph: Coal dust residues in Southeast Newport News. Photograph from the Repair Lab.
  • Photograph: Coal dust residues in Southeast Newport News. Photograph from the Repair Lab.
    Photograph: Coal dust residues in Southeast Newport News. Photograph from the Repair Lab.
  • Photograph: Coal dust residues in Southeast Newport News. Photograph from the Repair Lab.
    Photograph: Coal dust residues in Southeast Newport News. Photograph from the Repair Lab.
  • Photograph: Coal dust residues in Southeast Newport News. Photograph from the Repair Lab.
    Photograph: Coal dust residues in Southeast Newport News. Photograph from the Repair Lab.
  • Photograph: Coal dust residues in Southeast Newport News. Photograph from the Repair Lab.
    Photograph: Coal dust residues in Southeast Newport News. Photograph from the Repair Lab.
  • Photograph: Coal dust residues in Southeast Newport News. Photograph from the Repair Lab.
    Photograph: Coal dust residues in Southeast Newport News. Photograph from the Repair Lab.

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The Front Porch and Community Action

Have a question? Want to start a conversation or share an observation? Join the discussion: Front Porch

Do you have photographs or stories to add to this page? Add Your Voice

You can also email the Repair Lab at editor@voicesinthedust.org or call, text, or send a voice memo to (757) 317-0356. If you prefer, a Repair Lab team member can record your story in person or collect physical materials to digitize and then return them to you.

Do you suspect there is coal dust on your property? The Repair Lab is collecting dust samples from inside the homes of residents in Southeast Newport News. Read more: Got Dust?

Elected and government officials respond to sustained pressure from their constituents. If you suspect there is coal dust on your property, take photographs, videos, and describe your experience in a complaint to the Newport News City Council or Norfolk City Council, your elected House Representative and Senator in Virginia General Assembly, the Virginia Department of Environmental Quality (VA DEQ) Tidewater Office, Virginia Air Pollution Control Board (APCB), and U.S. Environmental Protection Agency (EPA) Region 3 Office. Contact information and sample language for your call or email are available on these pages.

About the Audio on this Page

You are listening to Kim Williams, Lambert's Point resident and activist, discuss local community organizing against coal dust pollution over the last decade and the contributions of Joe Cook of the Sierra Club Virginia Chapter and Mr. Charles Corbett of New Virginia Majority. Kim Williams also describes her frustrations with VA DEQ's Tidewater Air Monitoring Evaluation (TAME) study, her fears about the impacts of coal dust exposure on her children's and her health, and what she loves about living in Lambert's Point. The interviewer is the Repair Lab's Adrian Wood on May 11, 2023. The Audio and Transcript are available. So are many more interviews:

Sources

  1. ↑ Li, et al., Experimental Research of Particle Size and Size Dispersity on the Explosibility Characteristics of Coal Dust, Powder Technology, 292, 290–297, 2016.
  2. ↑ Deng et al., Characteristics of Atmospheric Dustfall Fluxes and Particle Size in an Open Pit Coal Mining Area and Surrounding Areas, Scientific Reports, 15, 9597, doi:10.1038/s41598-025-94161-4, 2025.
  3. ↑ Deanes et al., Relation of Wind Direction and Coal Terminal Activity Patterns with Air Pollution Burden in a Community Bordering a Coal Export Terminal, Curtis Bay, Maryland, USA, Air Quality, Atmosphere & Health, 18, 2805–2821, 2025.
  4. ↑ Peng et al., The Effect of Moisture on Particulate Matter Measurements in an Ultra-Low Emission Power Plant, Fuel, 238, 430–439, doi:10.1016/j.fuel.2018.10.140, 2019.
  5. ↑ Coal Dust Frequently Asked Questions, BNSF, 2011.
  6. ↑ Compilation of Air Pollution Emission Factors, EPA Office of Air, Noise and Radiation, and the Office of Air Quality Planning and Standards, January 1984.
  7. ↑ 7.0 7.1 Bounds et al., Arsenic Addition to Soils from Airborne Coal Dust Originating at a Major Coal Shipping Terminal, Water, Air, and Soil Pollution, 185, 195–207, 2007.
  8. ↑ Bounds, The Distribution of Airborne Coal Dust in Soil Profiles of Norfolk, VA and Its Implication for Arsenic Loading to These Soils, Thesis, Old Dominion University, ODU Digital Commons, 2001.
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