Black Lung Disease (aka Coal Workers’ Pneumoconiosis)

Please add the profiles of those who have died from Black Lung Disease

Coal workers' pneumoconiosis (CWP), also known as black lung disease or black lung, is caused by long-term exposure to coal dust. It is common in coal miners and others who work with coal. It is similar to both silicosis from inhaling silica dust and to the long-term effects of tobacco smoking. Inhaled coal dust progressively builds up in the lungs and cannot be removed by the body; this leads to inflammation, fibrosis, and in worse cases, necrosis.

Black lung is the common term for several respiratory diseases that share a single cause: breathing in coal mine dust. Even wearing a mask is often not enough. Coal dust is not as fibrogenic as in silica dust. You can’t see the dust that really hurts you. Coal dust that enters the lungs can neither be destroyed nor removed by the body. The particles are engulfed by resident alveolar or interstitial macrophages (a type of white blood cell) and remain in the lungs, residing in the connective tissue or pulmonary lymph nodes. Coal dust provides a sufficient stimulus for the macrophage to release various products, including enzymes, cytokines, oxygen radicals, and fibroblast growth factors, which are important in the inflammation and fibrosis of CWP. Aggregations of carbon-laden macrophages can be visualized under a microscope as granular, black areas. In serious cases, the lung may grossly appear black. These particles of not just coal dust but also silica, provoke the body’s immune response. However, because the invaders are mineral, rather than bacterial or viral, the response spirals causing inflammation and fibrosis, as well as the formation of nodular lesions within the lungs. The centers of dense lesions may become necrotic due to ischemia, leading to large cavities within the lung. Over time, the lungs actually turn black & stiffen, preventing them from properly expanding when inhaling. This in turn damages the air sacs, thus impeding oxygen from being exchanged with carbon dioxide.

History

Georgius Agricola, a German mineralogist, first described lung disease in coal miners in the 16th century, and it is now widely recognized. It may be the best known occupational illness in the United States.

See: Brit.J. industr. Med., 1952, 9,93. - History of Lung Disease of Coal Miners in Great Britain: Part II, 1875-1920. by Andrew Meiklejohn

Black lung is actually a set of conditions and until the 1950s its dangers were not well understood. The prevailing view was that silicosis was very serious but it was solely caused by silica and not coal dust. The miners' union, the United Mine Workers of America, realized that rapid mechanization meant drills that produced much more dust, but under John L. Lewis they decided not to raise the black lung issue because it might impede the mechanization that was producing higher productivity and higher wages. Union priorities were to maintain the viability of the long-fought-for welfare and retirement fund, which would be sustained by higher outputs of coal. After the death of Lewis, the union dropped its opposition to calling black lung a disease and realized the financial advantages of a fund for its disabled members.

In the Federal Coal Mine Health and Safety Act of 1969, the US Congress set up standards to reduce dust and created the Black Lung Disability Trust. The mining companies agreed to a clause, by which a ten-year history of mine work, coupled with X-ray or autopsy evidence of severe lung damage, guaranteed compensation. Equally important was a "rate retention" clause that allowed workers with progressive lung disease to transfer to jobs with lower exposure without loss of pay, seniority, or benefits. Financed by a federal tax on coal, the Trust by 2009 had distributed over $44 billion in benefits to miners disabled by the disease and their widows. A miner who has spent 25 years in underground coal mines has a 5–10% risk of contracting the disease.

After the Federal Coal Mine Health and Safety Act of 1969 became law in the United States, the percentage of American miners suffering from black lung disease decreased by about 90 percent. More recently, however, rates of the disease have been on the rise. The National Institute for Occupational Safety and Health (NIOSH) reported that close to 9 percent of miners with 25 years or more experience tested positive for black lung in 2005–2006, compared with 4 percent in the late 1990s.

Symptoms:

• Chronic coughing
• Increased mucus production
• Shortness of breath
• Pulmonary hypertension (high blood pressure in your lungs)

There are two forms: simple & complicated -- the differentiation between is based on the severity of the condition. Although it is very rare for this condition to progress past the simple stage, when it does so, complicated black lung disease often has a poor prognosis.

The severity of the condition will depend on how long the person was exposed to the coal mine dust and the amount of coal mind dust inhaled during that time.

Onset of the disease is gradual; the symptoms usually appear only after 10–20 years of exposure to coal dust, and the extent of disease is clearly related to the total dust exposure. It is not clear, however, whether coal itself is solely responsible for the disease, as coal dust often is contaminated with silica, which causes similar symptoms.

There is strong evidence that tobacco smoking aggravates the condition.

The early stages of the disease (when it is called anthracosis) usually have no symptoms, but in its more advanced form it frequently is associated with pulmonary emphysema or chronic bronchitis and can be disabling; tuberculosis is also more common in victims of black lung.

Diagnosis

There are three basic criteria for the diagnosis of CWP:

• Chest radiography consistent with CWP
• An exposure history to coal dust (typically underground coal mining) of sufficient amount and latency
• Exclusion of alternative diagnoses (mimics of CWP)

Symptoms and pulmonary function testing relate to the degree of respiratory impairment but are not part of the diagnostic criteria. As noted above, the chest X-ray appearance for CWP can be virtually indistinguishable from silicosis. Chest CT, particularly high-resolution scanning (HRCT), are more sensitive than plain X-ray for detecting the small round opacities.

The advanced form, referred to as complicated, is also known as progressive massive fibrosis. The accumulation of the dust particles in the lungs causes breathing complications. Those diagnosed with the simple form of the disease may not notice any symptoms, but as the disease progresses, a cough and shortness of breath develops, as well as moderate to severe airway obstruction, decreasing quality of life.

Epidemiology

Due to the introduction of stringent coal dust control measures, black lung disease was all but eliminated by the 1970s. Recently, however, its prevalence has dramatically increased, possibly due to a relaxation of safety standards in the mining industry.

In 2013 CWP resulted in 25,000 deaths down from 29,000 deaths in 1990. Between 1970–1974, prevalence of CWP among US coal miners who had worked over 25 years was 32%; the same group saw a prevalence of 9% in 2005–2006. In Australia, CWP was considered to be eliminated in the 1970s due to strict hazard control measures. However, there has been a resurgence of CWP in Australia, with the first new cases being detected in May 2015.

From: Smithsonian - Why Black Lung Disease Is Deadlier Than Ever Before. By Maya Wei-Haas, 15 May 2017; updated 8 Feb 2018

• These diseases (such as coal workers' pneumoconiosis, emphysema and progressive massive fibrosis, referred to as black lung) are progressive, and they have no cure. More than 76,000 miners have died of black lung since 1968, according to statistics from the U.S. Department of Labor.
  • See: US Dept. of Labor - MSHA issues final rule on lowering Miners’ exposure to respirable coal dust. MSHA News Release on 4/23/2014 (As of January 20, 2017, information in some news releases may be out of date or not reflect current policies.)
    • According to NIOSH estimates, more than 76,000 miners have died since 1968 as the result of the disease, and more than $45 billion in federal compensation benefits have been paid out to coal miners disabled by black lung and their survivors. Evidence indicates that miners, including young miners, are continually being diagnosed with the disease.
    • Since February 2017, NIOSH has published new results in the Journal of the American Medical Association documenting the largest cluster yet of advanced black lung cases. In just three clinics that treat miners in Virginia, Kentucky and West Virginia, 416 new cases of black lung were reported.
  • On-the-job mine safety has improved drastically in recent decades, with deaths due to accidents now counted in the tens, not hundreds, as they were in the 1970s and 80s. Long-term health, however, is a different story. As the administration seeks to fulfill the campaign promise to send miners in coal country back to work, black lung has made a comeback. Today, the disease sickens roughly 1 in 14 underground miners with more than 25 years experience who submit to voluntary check ups—a rate nearly double that from the disease’s lowest point from 1995 to 1999.
  • Even more worrisome, the disease is striking miners earlier and in a more deadly form than ever before. Though experts are still working out the causes for the rise in disease, many believe it is a combination of both longer hours on the job and new methods of rock extraction.
• Increases in cases of progressive massive fibrosis (PMF) are occurring despite measures to control coal dust that were put into place decades ago.
  • The finding stems from an analysis of U.S. Department of Labor data on former coal miners who applied for benefits from the Federal Black Lung Program between its start in 1970 and 2016. The program's launch coincided with use of modern dust control measures.
  • Over 46 years, more than 4,600 coal miners were diagnosed with black lung. Half of the cases occurred since 2000, the data showed.
  • The researchers found that most people with PMF last mined in West Virginia (29 percent), Kentucky (20 percent), Pennsylvania (20 percent) and Virginia (15 percent).
  • Several theories might explain the resurgent epidemic. Affected miners appear to have worked in smaller mines that might have invested less in dust reduction systems. In addition, today's mines produce higher levels of crystalline silica, which is more damaging to the lungs than coal dust. Also, miners may be working longer hours on more days each week. That leaves less time for their lungs to clear the inhaled dust.

Treatment:

There is no cure for black lung disease, so treatment usually focuses on relieving symptoms and improving quality of life.

A black lung treatment regimen will vary based on whether a person has a simple or complicated form of CWP and what specific symptoms are being experienced. Generally speaking, medications and supplemental oxygen may be used to improve breathing and control co-existing symptoms from related conditions, such as chronic obstructive pulmonary disease (COPD). Lung transplantation may be recommended for patients with very severe cases of black lung.

Autologous cellular therapy is an alternative black lung treatment that is showing encouraging results in some patients. This treatment involves using the patient’s own cells to promote the body’s natural healing processes, which may in turn help reduce lung inflammation and ease unpleasant symptoms like coughing and shortness of breath. Because cells are found naturally in the body and are not a drug, most patients don’t experience any negative side effects.

Why is it coming back?

• Government And Industry Failures:
  • Strict limits on coal dust exposure were set in 1969, but loopholes permit companies to expose miners to excessive dust. Compliance depends on the industry's self-policing, but enforcement is mixed and many miners report routine manipulation of sampling that fools federal inspectors.
• Increased Hours And Production Pressure
  • Greater demand and higher coal prices forced miners to work harder and longer. The average workweek grew 11 hours in the last 30 years. In 2010, production was triple what it was when new coal dust limits were put in place.
• Efficient Technology
  • Mining machines are more powerful and efficient, cutting through coal seams laced with the more toxic silica-bearing quartz and sandstone.

References & Additional Reading:

• Wikipedia - Coalworker’s pneumoconiosis
• NPR - Black lung returns to coal country
• NPR- Black-Lung Rule Loopholes Leave Miners Vulnerable. by Howard Berkes. 10 Jul 2012
• NPR - What is Black Lung? Alyson Hurt, Howard Berkes, Alicia Cypress. 9 Jul 2012
• WebMD - Coal Miners Facing New Wave of Black Lung Disease. 25 May 2018 (Health Day News)
• Lung Institute Blog - Is Black Lung Treatable? Posted by Jessica Sandoe. 8 Aug 2017
• Lung Institute - Black Lung Disease Facts
• Lung Institute - Prognosis for Black Lung Disease
• Encyclopaedia Britannica - Black lung disease
• Disabled World - Black Lung Disease
• List of Miner’s Related Diseases & Terminology
• NCBI – Respiratory Diseases Caused by Coal Mine Dust. By: A Scott Laney PhD & David N Weissman, MD, Oct 2014

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