Topic Overview
What is black lung disease?
Black lung disease is a common name for any lung disease that develops from
inhaling coal dust. This name comes from the fact that those with the disease
have lungs that look black instead of pink. Medically, it is a type of
pneumoconiosis called coal workers' pneumoconiosis (CWP).
There are two forms: simple CWP
and complicated CWP, which also involves progressive massive fibrosis
(PMF).
The inhalation and accumulation of coal dust into the lungs
increases the risk of developing
chronic
bronchitis and chronic obstructive pulmonary disease (COPD).
What causes coal workers' pneumoconiosis (CWP)?
The inhalation and accumulation of coal dust causes coal workers'
pneumoconiosis (CWP). This stems from working in a coal mine, coal trimming
(loading and stowing coal for storage), mining or milling graphite, and
manufacturing carbon electrodes (used in certain types of large furnaces) and
carbon black (a compound used in many items, such as tires and other rubber
goods). Because CWP is a reaction to accumulated dust in the lungs, it may
appear and get worse during your exposure to the dust or after your exposure
has ceased.
The severity of CWP depends on the type of coal dust, how much dust was in the air, and how long you have been exposed to it.
Is CWP the same thing as chronic obstructive pulmonary disease (COPD)?
No. Although CWP may share many of the symptoms of
emphysema and/or chronic bronchitis (which are also known as
COPD), CWP is not COPD and is not treated like
COPD.
What is the course of CWP?
CWP starts with the inhalation and accumulation of coal dust in the
lungs. For many, there are no symptoms or noticeable effect on quality of life.
There may be a cough and sputum (mucus) from inhalation of coal dust, but this
may be more a matter of dust-induced bronchitis. As CWP progresses and is complicated by
PMF, a cough and shortness of breath develop, along with sputum and moderate to
severe airway obstruction. Quality of life decreases. Complications of CWP
include
cor pulmonale.
Smoking does not increase
the prevalence of CWP, nor does it affect the development of CWP. But it may
add to lung damage and contribute to the development of COPD. Coal workers who
smoke are at much greater risk of developing COPD than nonsmoking coal
workers.
How does CWP affect your lungs?
When coal dust accumulates in the lungs, a coal
macule may form. A coal macule is a combination of coal dust and
macrophages. As the disease progresses, macules can
develop into a coal nodule, an abnormality of the lung tissue. In time, a type
of emphysema and fibrosis may develop.
Lung nodules wider than
1 cm (0.4 in.) have been
accepted as evidence of progressive massive fibrosis (PMF), although some
organizations say a minimum width of
2 cm (0.8 in.) is necessary.
Nodules may grow to a large size and hinder or stop the airflow in the lungs'
airways.
How is CWP diagnosed?
CWP is diagnosed through an occupational history and chest X-rays. Lung
function tests may be used to determine how badly the lungs are damaged.
Occupational history is very important to the diagnosis of CWP-if
a person has not been exposed to coal dust, he or she cannot have CWP. The
occupational history should include not only recent and past full-time
employment, but also summer jobs, student jobs, military history, and
short-term jobs.
The diagnosis of CWP has legal public health
implications, since some states require that all cases be reported.
Can CWP be prevented?
CWP can be prevented by controlling dust and having good ventilation in the workplace.
How is it treated?
There
is no proven effective treatment for CWP, although complications can be
treated.
There are several U.S. laws regarding CWP and its
treatment, and the government may help pay for treatment. But to be eligible,
you must be totally and permanently disabled by this disease. Most miners aren't eligible for federal black lung benefits. For information on organizations
dealing with mining and black lung disease, see the Other Places to Get Help
section of this topic.