Black lung, also known as coal workers’ pneumoconiosis, describes a lung disease caused by the inhalation of coal dust or graphite. Initially, coal dust in the lungs causes few problems. Over time; however, the dust accumulates in the lungs, becoming visible by X-ray as small black dots. As the dust accumulates in the bronchioles, small airways that run through the lungs, they become obstructed. The obstructed airways interfere with the intake of air and the exchange of oxygen into the blood which results in the common symptoms of the disease.
Cough
Symptoms of black lung disease typically take years to develop. The presence of other respiratory diseases, such as bronchitis, which is inflammation of the bronchial tubes, or emphysema, a disease caused by smoking, can exacerbate symptoms. Black lung disease can cause a chronic cough. Coughing is an airway reflex triggered to remove foreign objects and excess mucus from the lungs.
Shortness of Breath
The accumulation of coal dust in the lungs can restrict the inhalation and exhalation of air, resulting in shortness of breath, a symptom medically known as dyspnea. Patients often describe shortness of breath as feelings of intense chest tightening or suffocation, according to MayoClinic.com.
Caplan Syndrome
The combination of black lung disease and rheumatoid arthritis, an autoimmune disease caused by the cells in the body attacking the membranes of the joints, can produce the symptoms of Caplan syndrome. Patients with Caplan syndrome develop inflammation of the airways which can lead to the formation of small bumps on the lungs known as nodules. These nodules restrict the airflow, causing symptoms similar to asthma including difficulty breathing, wheezing and cyanosis—turning blue due to lack of oxygen.
Progressive Massive Fibrosis
Some patients with black lung disease will develop scar tissue leading to a more serious symptom known as progressive massive fibrosis. The scars are typically large, measuring ½ inch in diameter. These large scars destroy lung tissue and blood vessels in the lungs which reduces the amount of oxygen reaching the bloodstream, leading to disabling episodes of shortness of breath.
Progressive massive fibrosis can lead to complications including increased blood pressure in the pulmonary artery that carries oxygenated blood from the lungs to the heart. The increase in pressure can cause cor pulmonale—right-sided heart disease. The scar tissue in the lungs can interfere with their ability to fully exhale, leading to a buildup of carbon dioxide and the onset of respiratory failure.
