Coal is a mineral used in electricity generation, steel production, cement manufacturing, and the construction of synthetic materials. In the United States, it is primarily used as a fossil fuel in the production of electricity.

Coal is an extremely brittle mineral, and both the extraction and refinement processes produce a fine powder known as coal dust. Coal is deliberately pulverized for use as fossil fuel, and this process also produces a substantial output of coal dust. Finally, mining, transportation and even the mechanical handling of coal can create coal dust.

What is in coal dust?

Coal dust is a complex substance that contains at least 50 different elements and their oxides. These toxic substances include lead, mercury, nickel, tin, cadmium, antimony, and arsenic, as well as radio isotopes of thorium and strontium. The actual composition of the dust depends on the size of the particle and the specific coal seam which produced it.

What health issues can coal dust cause?

Respirable coal dust can significantly impact workers' health, particularly inside mines. Significant amounts of coal dust are produced in mines, and the environment tends to have less ventilation. These health effects can include increased risk for heart diseases and respiratory diseases such as asthma and lung cancer.

Chronic obstructive pulmonary disease (COPD) is another frequent result of exposure to coal dust. Silicosis can occur when the coal dust contains particles of crystalline silica. Many of these diseases are irreversible and can result in permanent disability or even death.

The finer the particles, the more dangerous they are. Tiny invisible bits of coal can embed themselves in the lungs. Long term exposure can also exacerbate the adverse health effects of coal dust exposure. Other factors that can influence the seriousness of coal dust exposure include the specific chemical composition and physical properties of the dust particles.

Black Lung Disease (Pneumoconiosis)

Black Lung Disease, also referred to by its scientific name Pneumoconiosis, is caused by inhaling respirable coal dust and has been responsible for the deaths of over 77,000 coal mine workers since 1968. According to one study, one in every five coal miners who have worked in central Appalachia for twenty years or more suffer from Black Lung Disease. There is also a high economic cost. Worker's compensation claims related to coal dust have cost the federal government over $45 billion.

Black Lung gets its name from the fact that the lungs of sufferers turn black rather than the usual pink color found in a healthy lung. It is both incurable and untreatable.

As workers inhale coal dust over a long time, years or even decades, dust particles embed in the lungs. The worker's immune system attempts to get rid of the foreign particles, which eventually results in inflammation and scarring, also known as fibrosis. As the disease progresses, the tissues around the air sacs and air passages become thick and stiff from scarring and breathing becomes increasingly difficult.

Because it can take many years for Black Lung to develop, the majority of workers diagnosed with it are over the age of 50 and nearing retirement. There are few warning signs, but when symptoms do appear, they can include:

  • Cough
  • Shortness of breath
  • Chest tightness
  • Black sputum

The Risk of Explosions

The dangers of coal dust extend beyond those related to exposure. Coal dust suspended in the air is also highly explosive and very susceptible to spontaneous combustion because it has more surface area per unit weight. Coal dust is the leading cause of many of the world's worst mining accidents.

Government Controls

On August 1, 2014, the Mine Safety and Health Administration's (MSHA) respirable dust rule went into effect. This final rule tightened the guidelines for sampling. It also increased sampling, expanded medical surveillance requirements and extended the ability of inspectors to cite and demand immediate correction for companies that do not comply. Finally, it provided the same rights to demand alternate work settings to surface workers suffering from Pneumoconiosis that were previously only extended to underground coal mine workers. A second phase of the rule in February 2016, mandated that coal mine workers wear coal dust monitors.

In August 2016, the third phase of the MSHA rule went into effect. This third phase substantially reduced the concentration limits for respirable coal mine dust. Specifically, those reductions mandate that:

  • The concentration limits for respirable coal mine dust are lowered from 2.0 milligrams of dust per cubic meter of air (mg/m3) to 1.5 mg/m3 at underground and surface coal mines
  • The concentration limits for respirable coal mine dust are lowered from 1.0 mg/m3 to 0.5 mg/m3 for intake air at underground mines and for part 90 miners (coal miners who have evidence of the development of Pneumoconiosis)

What Employers Can Do

In addition to adhering to federal and state rules regarding coal dust, employers can provide additional safeguards that can help protect their employees. Employers should start with appropriate training and education on both the dangers and ways to mitigate risks and ensure that all employees comply with the safety standards and measures that have been put into place. The Occupational Safety and Health Administration (OSHA) has provided additional safety standard recommendations for workers at risk of exposure to coal dust, which are as follows:

  • Wear a mask.
  • Wash dust off exposed skin.
  • Wash your face and hands before eating, drinking, or taking medicine.
  • Do not smoke.
  • Get regular chest X-rays.

Since viruses that affect the lungs can put your workers at further risk, it is also a good idea to encourage or provide access to virus prevention efforts such as yearly flu shots. There are also vaccines available for pneumonia, which may be of interest.