749
CHAPTER NINETEEN
Respiratory System
Symptoms of berylliosis
typically begin about a decade
after the F
rst exposure. It is distin-
guished from other lung ailments
with a blood test that detects
antibodies to beryllium. Affected
individuals and those who do not
have symptoms but know that
they were exposed to beryllium
can have periodic blood tests and
chest radiographs to detect the
condition early. The steroid drug
prednisone is used to control
symptoms.
A Disorder with Many
Names
Repeatedly inhaling dust of
organic origin can cause a lung
irritation called extrinsic allergic
alveolitis. An acute form of this
reaction impairs breathing and
causes a fever a few hours after
encountering dust. In the chronic
form, lung changes occur gradu-
ally over several years. The con-
dition is associated with several
occupations and has a variety of
colorful names, including bathtub refinisher’s
lung, maple bark stripper disease, popcorn work-
er’s lung, and wheat weevil disease.
9/11-Associated Air Pollution
When more than a million tons of dust and debris
fell on lower Manhattan as the World Trade Center
collapsed on September 11, 2001, the dust and
debris presented a mixture of chemicals that no
T
he lungs are exquisitely sensitive to the
presence of inhaled particles. Such expo-
sures can cause a variety of symptoms,
both acute and chronic, that range from a persis-
tent cough to cancer.
Asbestos
Asbestos, a naturally occurring mineral, was once
widely used in buildings and on various products
because it resists burning and chemical damage.
Asbestos easily crumbles into F
bers, which, when
airborne, can enter human respiratory passages.
Asbestos-related problems include asbestosis
(shortness of breath resulting from scars in lungs),
lung cancer, and mesothelioma (a rare cancer of
the pleural membrane).
Asbestos fibers longer than 5 micrometers
(0.0002 inch) and thinner than 2 micrometers
(0.00008 inch) can cause illness when inhaled,
but asbestos clearly causes respiratory illness
only if the fibers are airborne. Experts must
determine whether it is safer to encapsulate
asbestos in a building and leave it in place or
remove it. Table 19A indicates how risk of becom-
ing ill rises with duration of exposure to asbestos.
Berylliosis
Beryllium is an element used in fluorescent
powders, metal alloys, and in the nuclear power
industry. A small percentage of workers exposed
to beryllium dust or vapor develop an immune
response, which damages the lungs. Symptoms
include cough, shortness of breath, fatigue, loss
of appetite, fevers and night sweats, and weight
loss. Radiographs show granuloma scars in the
lungs, and pulmonary function tests and listen-
ing to breath sounds with a stethoscope reveal
impaired breathing.
human respiratory system had ever encountered
(F
g. 19C). Particles spewed into the air from paint,
plaster, foam, glass, ceramics, concrete, vermicu-
lite, wood, soot, and textiles. Particle size was
important. Although the human respiratory tract
easily ejects particles greater than 10 microm-
eters in diameter in coughs or sneezes, particles
with diameters between 2.5 and 10 micrometers
can enter the upper airways, and the F
nest partic-
ulates, with diameters from 0.09 to 0.24 microm-
eters, pass the respiratory system’s initial barriers
and may make it as far as the alveoli. These F
nest
particles included sulfur compounds, tiny bits
of silicon and metals, including vanadium and
nickel from fuel oil; titanium from concrete; and
iron, copper, and zinc.
±ortunately, asbestos and dangerous organic
compounds were very scant in the debris, and
more than 95% of the particulates were large
enough to sneeze out. However, some of the
workers in the area developed “World Trade
Center cough” from inhaling alkaline large par-
ticles, mostly from F
berglass. We will be learning
about the e²
ects of this disaster on air quality and
the human respiratory system for many years.
19.2
CLINICAL APPLICATION
Lung Irritants
TABLE
19A
|
Asbestos-Related Respiratory Illness
Situation
Level of Exposure
(F
bers/cubic centimeter)
Cancer Cases per
Million Exposed People
Asbestos workers with twenty years’
exposure
10 F
ber/cc
200,000
Permissible upper limit in buildings
today
0.1 F
ber/cc
2,000
Child in school with asbestos
six hours/day
0.0005 F
ber/cc
6
Most modern buildings
0.0002 F
ber/cc
4
FIGURE 19C
Urban aerosols compromise lung function
(temporarily, we hope). This image highlights the sources
of some of the debris that covered lower Manhattan after
the September 11, 2001 attacks. Red and yellow represent
concrete dust, and purple indicates a mineral, gypsum,
found in wallboard.
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