may show symptoms after relatively short periods
of exposure and often improves when exposure
ceases. Asbestosis may develop after relatively
short exposure though symptoms typically do not
become apparent for decades after exposure. The
diagnostic path focuses on occupational history
and exposure patterns. Diagnostic examination
typically includes AUSCULTATION, chest X-RAY, pul-
monary function tests, and imaging procedures
such as ULTRASOUND, COMPUTED TOMOGRAPHY (CT)
SCAN, orMAGNETIC RESONANCE IMAGING (MRI). The
pulmonologist may also perform BRONCHOSCOPY,
BRONCHOALVEOLAR LAVAGE, or lung biopsy to rule
out other causes of symptoms.
Treatment Options and OutlookThe first and most important element of treatment
is to end the exposure. Nearly all forms of pneu-
moconiosis improve with this measure. Perma-
nent damage to the lungs that has already
occurred, such as fibrosis, does not reverse though
its progression may stop. The disease process of
asbestosis is such that damage continues long after
exposure ceases. The outlook depends on the form
of pneumoconiosis, the length or extent of expo-
sure, and whether the person also smokes. Ciga-
rette smoking significantly worsens both the
disease process and the outlook.
Risk Factors and Preventive MeasuresOccupational pneumoconiosis develops with
exposure to substances that enter and remain in
the lungs. Avoiding such exposure is the only cer-
tain means of prevention. Workplace measures to
reduce exposure to the lowest possible levels
include environmental controls to filter or other-
wise contain dusts and fibers. Personal protective
equipment may include clothing, masks, and res-
pirators.
See also ASTHMA; BRONCHITIS; CHRONIC OBSTRUC-
TIVE PULMONARY DISEASE(COPD); INDOOR AIR QUALITY;
OCCUPATIONAL HEALTH AND SAFETY.pneumonectomy See THORACOTOMY.pneumonia INFLAMMATIONof the LUNGS, usually
the result of an INFECTION, that causes the alveolar
sacs to fill with fluid or pus. Pneumonia is the
most serious consequence of INFLUENZA, and in
combination with influenza is the seventh leading
cause of death in the United States. Pneumonia
may be lobar, affecting the entire lobe of the lung,
or bronchial, affecting diffuse areas of lung. The
more of the lung that is involved, the more seri-
ous the consequences. People most vulnerable to
infection resulting in pneumonia and complica-
tions from pneumonia are the very young, the
very old, and those who have immunodeficiency
disorders such as HIV/AIDSor other serious health
conditions such as CANCER. About two million peo-
ple in the United States develop pneumonia each
year, and about 60,000 die as a result of the infec-
tion or its complications.220 The Pulmonary System
FORMS OF PNEUMOCONIOSISForm of Pneumoconiosis Causative Substance Occupational Exposure
anthracosis coal dust coal mining
asbestosis asbestos fibers and dust insulation, aerospace components, brake lining,
shipbuilding
berylliosis beryllium dust electronics, aerospace manufacturing, metal working,
metal reclamation processing
byssinosis raw cotton fibers and dust raw cotton processing, textile production
silicosis silica dust sandblasting, sand and gravel mining