Asbestosis is a breathing
disorder caused by inhaling asbestos fibers. Prolonged accumulation of
these fibers in your lungs can cause scarring of lung tissue and
shortness of breath. Asbestosis symptoms can range from mild to severe,
and usually don't appear until years after exposure.
Asbestos is a natural mineral product that's resistant to heat and
corrosion. It was used extensively in the past in products such as
insulation, fire-retardant materials, cement, and some vinyl floor
Most people with asbestosis acquired it on the job before the federal
government began regulating the use of asbestos and asbestos products in
the mid-1970s. Today, its handling is strictly regulated. Acquiring
asbestosis is extremely unlikely if you follow your employer's safety
procedures. Treatment focuses on relieving your symptoms.
The effects of long-term exposure to asbestos typically don't show up
for at least 20 to 30 years after initial exposure, and sometimes
longer. Signs and symptoms develop when damage and scarring caused by
the asbestos fibers lead to stiffness in your lung tissue so that your
lungs can't contract and expand normally (a form of pulmonary fibrosis).
Once exposure to asbestos is stopped, however, the fibrosis stops
progressing in the majority of cases.
Some asbestosis symptoms include:
* Shortness of breath, initially only with exertion, but eventually even while resting
* Decreased tolerance for physical activity
* Chest pain
* Finger deformity (clubbing) in some cases
Although most of these signs and symptoms are similar to those of other
breathing disorders, such as asthma, the way in which they develop is
different. In asbestosis the effects of the disease occur over months
When to see a doctor
If you have a history of exposure to asbestos and you're experiencing
increasing shortness of breath, talk to your doctor about the
possibility of asbestosis. If it is asbestosis, your doctor may be able
to prescribe treatment to relieve your symptoms. It's unlikely that the
disease will progress after removal from exposure.
When you inhale, air travels through your nose or mouth, down your
throat, through your larynx to your trachea — the main passageway for
air to your lungs. Your trachea splits into two branches called bronchi,
one carrying air to the left lung, one to the right. Within each lung,
the bronchi branch off over a dozen times into smaller and smaller
airways. Some of the smallest of these airways (bronchioles) lead into
tiny ducts (alveolar ducts) that end in microscopic air sacs (alveoli).
Alveoli have very thin, elastic walls that allow an exchange of gases
vital to your health — oxygen flows from the alveoli into your
bloodstream to nourish your body, and carbon dioxide flows from your
bloodstream into the alveoli and on into your bronchi, to be expelled.
A natural screening system
Normally, microorganisms, dust and other foreign particles in the air
you breathe are removed by microscopic hairs on the surface of your
airways that beat hundreds of times a minute (cilia). The cilia sweep
the particles into your upper airway, where the particles are swallowed
into your digestive system, trapped in your nose hairs or expelled when
Even when unwanted particles do get into your lungs, immune cells
destroy most of them. Alveoli, for example, house their own special
cleanup crew — immune cells called macrophages, which are attracted to
and ingest foreign substances, such as smoke particles, dust and
Fibers resist breakdown
Unfortunately, asbestos fibers are difficult to destroy, even for
macrophages. When a macrophage attempts to ingest an asbestos fiber, it
often fails because the fiber is too long and partially resistant to
breakdown. In the process, however, the macrophage leaks out substances
that were supposed to destroy the foreign body, but these substances can
also harm the alveoli. This causes the alveoli to become inflamed and
eventually scar, a process referred to as fibrosis.
If many fibers are inhaled over a long period, the cumulative scarring
of alveoli reduces their ability to exchange oxygen and carbon dioxide.
The result is that your lung capacity diminishes, oxygen exchange is
diminished, and you feel increasingly short of breath. Also, because the
lungs are stiff, like a dried sponge, it takes a great deal of muscular
effort to breathe.
For unknown reasons, not everyone exposed to asbestos for long periods develops asbestosis. Genetic factors may play a role.
Because asbestos occurs naturally in the environment, everyone breathes
in some asbestos fibers. Usually, these are expelled before they reach
the deeper areas of your lungs, but even if they do, a few fibers won't
create signs and symptoms of asbestosis.
People most at risk of developing asbestosis are those who are exposed
to high concentrations of asbestos for long periods of time, such as
workers who were involved in the mining, milling, manufacturing,
installation or removal of asbestos products. Most cases of asbestosis
occur at least 10 years after the person's first exposure to asbestos.
Brief exposure to asbestos a few times in your life won't cause harm.
However, it's always best to avoid direct exposure. Removal of asbestos
products is generally considered a major project. If you decide to have
it done, seek the help of a professional.
If you live, work or study in a building where existing asbestos has
been contained and sealed, you're not at risk of asbestosis.
The severity of asbestosis is generally related to the amount and
duration of exposure to asbestos. Effects of the disease may be so mild
as to cause almost no symptoms. Or the condition may create such a
reduced flow of oxygen as to be disabling or even fatal. Asbestosis may
lead to the following conditions:
* High blood pressure in your lungs. Asbestosis-related scar tissue
may eventually compress or obliterate your lungs' small blood vessels,
causing high blood pressure in your lungs' arteries (pulmonary
* Heart problems. Pulmonary hypertension can lead to enlargement and
failure of your heart's right ventricle (cor pulmonale). Your heart
consists of four chambers — two upper chambers called atria and two
lower chambers called ventricles. Your right ventricle assists in
pumping oxygen-poor blood from your organs and tissues to your lungs,
where your blood receives a new boost of oxygen. As your pulmonary
arteries narrow, your heart's right ventricle must work harder to pump
blood through your lungs. Initially, your heart tries to compensate by
thickening its walls and dilating the right ventricle to increase the
amount of blood it can hold. But this measure only works temporarily,
and eventually — after a period of a few years — the right ventricle
weakens and fails from the extra strain.
* Lung cancer. If you smoke and have asbestosis, your chance of
developing lung cancer increases greatly, especially if you smoke more
than a pack of cigarettes a day. Tobacco smoke and asbestos both
contribute to each other's cancer-causing (carcinogenic) effects, so
that the combination of both risk factors together is more dangerous
than the effects of either risk factor alone.
* Other lung damage. Exposure to asbestos can lead to other health
complications, including changes in the thin membranes covering your
lungs and lining your chest cavity (pleural membranes). Pleural changes
may be the first signs of asbestos exposure and may include pleural
thickening, the formation of calcium deposits in the pleura (plaques),
and an abnormal accumulation of fluid between the membranes (pleural
effusion). Pleural effusion itself is benign and doesn't increase your
risk of asbestosis or malignant mesothelioma.
* Other cancer. People exposed to asbestos at an early age, for a
long period of time or at high levels are at increased risk of malignant
mesothelioma. Diagnosis and treatment of this cancer is often
difficult. Malignant mesothelioma takes many years to develop. Most
people with this condition were first exposed to asbestos at least 20
years — and sometimes as long as 50 years - prior to their diagnosis.
While asbestos exposure is the primary risk factor for malignant
mesothelioma, asbestosis itself doesn't increase your risk of this
cancer, nor does malignant mesothelioma increase your risk of
Preparing for your appointment
You're likely to start by first seeing your family doctor or a general
practitioner. However, in some cases when you call to set up an
appointment, you may be referred immediately to a lung disorders
specialist called a pulmonologist or to an occupational medicine
If you work for a manufacturer where exposure to asbestos products is
known, you may be required to have routine, yearly visits with a
pulmonologist or occupational medicine specialist.
Because appointments can be brief and because there's often a lot of
ground to cover, it's a good idea to be well prepared for your
appointment. Here's some information to help you get ready and on what
to expect from your doctor.
What you can do
* Be aware of any pre-appointment restrictions. At the time you make
the appointment, be sure to ask if there's anything you need to do in
advance. This might include writing down a detailed history of your jobs
since you first started working.
* Write down any symptoms you're experiencing. For asbestosis, it
will help your doctor to have as many details as possible about when
your symptoms first appeared and how they may have changed or worsened
* Write down key personal information, especially related to
possible environmental exposure to asbestos, even as long as 20 or more
years ago. Take the time to think about jobs, remodeling projects,
school environments or other experiences in your past when you may have
been exposed to asbestos. For example, your doctor will want to know if
you were in the military — especially the navy, where asbestos was
formerly used extensively in shipbuilding.
* Make a list of your key medical information, including other
conditions you're being treated for and the names of the medications
that you're taking. Include on your list every prescription and
over-the-counter drug you use, as well as any vitamins and supplements.
* Take film from any chest X-rays you've had in the last 20 years.
It will help your doctor make a diagnosis if he or she can compare an
old chest X-ray with the results of a current scan. The actual X-ray
film is more important to your doctor than is the report.
* Take a family member or friend along, if possible. Sometimes it
can be difficult to soak up all the information provided to you during
an appointment. Someone who accompanies you may remember something that
you missed or forgot.
* Write down questions to ask your doctor.
Your time with your doctor is limited, so preparing a list of questions
will help you make the most of your time together. List your questions
from most important to least important in case time runs out.
For asbestosis, some basic questions to ask your doctor include:
* What is likely causing my symptoms or condition?
* Do I have pulmonary asbestosis?
* Are there any other possible causes for my symptoms or condition?
* What kinds of tests do I need?
* Is my chest X-ray abnormal? Has it changed since the last one?
* Are there treatments that can help?
* What is my risk of long-term complications?
* How will you monitor my condition over time?
* Can I continue to work?
* Will it help if I stop smoking now?
* If the people I live with smoke, will it aggravate my condition?
* Do you know if I might qualify for workers' compensation, based on my symptoms?
* I have these other health conditions. How can I best manage them together?
* Are there any restrictions that I need to follow?
* Should I see a specialist? What will that cost, and will my insurance cover seeing a specialist?
* Are there any brochures or other printed material that I can take home with me? What Web sites do you recommend visiting?
In addition to the questions that you've prepared to ask your doctor,
don't hesitate to ask questions during your appointment at any time that
you don't understand something.
What to expect from your doctor
Your doctor is likely to ask you a number of questions. Think about your answers ahead of time. Your doctor may ask:
* When did you first begin experiencing symptoms?
* Have your symptoms stayed the same or gotten worse?
* What kind of work have you done in your career, starting from a young age through to the present?
* Have you been involved in any home-remodeling projects or other building renovations?
* Have any current or former colleagues been diagnosed with asbestos-related lung conditions?
* Have any close relatives, friends, or people with whom you've
shared long-term projects or hobbies been diagnosed with a related
* Do you or did you smoke? If so, how much?
* Have you been diagnosed or treated for any other medical conditions? When?
What you can do in the meantime
If you smoke or share a home with people who smoke, try to cut back on
your exposure to smoke while you wait for your appointment. The symptoms
of any heart or lung condition are made worse by inhaling smoke. No
matter what your diagnosis, if you smoke, work with your doctor to make a
plan for stopping.
Tests and diagnosis
To help your doctor make an accurate diagnosis, provide him or her with a
detailed history of your work activities and any other sources of
possible exposure to toxic dusts. Tell your doctor about the
availability of dust masks and other respiratory-protection devices in
your workplace. Your doctor may also ask if you know of any fellow
employees who have been diagnosed with a condition caused by exposure to
Your doctor may detect a dry, crackling sound when listening to your
lungs with a stethoscope. You may also undergo these diagnostic tests:
* Pulmonary function tests. These tests determine how well your
lungs are functioning and may help in the diagnosis. Pulmonary function
tests measure how much air your lungs can hold and the airflow in and
out of your lungs. For example, you may be asked to blow as hard as you
can into an air-measurement device called a spirometer. Some pulmonary
function tests measure the amount of gas exchanged across the membrane
between your alveoli and capillary blood vessels.
* Chest X-ray. A chest X-ray can often detect abnormalities in your
lungs before you experience any symptoms. On an X-ray, areas of scar
tissue that appear as small, scattered, opaque areas on the lining of
your lungs are called pleural plaques. Although they indicate previous
exposure to asbestos, they are not a predictor of asbestosis or
malignant mesothelioma, a cancer that can occur in the tissue that
surrounds the lungs. Asbestosis appears as excessive whiteness in your
lung tissue. If the asbestosis is advanced, your entire lung may be
affected, giving it a honeycomb appearance.
* Computerized tomography (CT) scan. In some cases, your doctor may
request a computerized tomography (CT) scan of your lungs. These scans
generally provide greater detail than does a usual chest X-ray. This may
help detect asbestosis in its early stages, even before it shows up on
the chest X-ray.
If you have ever had these tests in the past, try to get copies of those
reports — and of actual X-ray films, if possible — to share with your
doctor. These will provide critical information to help diagnose your
Treatments and drugs
There's no treatment to reverse the effects of asbestos on the alveoli.
Treatment focuses on preventing progression of the disease and relieving
symptoms. The most important factor in keeping the condition from
worsening is to eliminate exposure to asbestos. For most people,
scarring of lung tissue doesn't begin or progress once exposure has
The following may be components of asbestosis treatment:
* Smoking cessation. If you smoke, it's important to stop,
particularly because of the extremely heightened risk of lung cancer. In
addition, smoking may cause emphysema, which further reduces your lung
* Vaccinations. Because of your impaired lung condition, treat a
cold or a bout of the flu promptly to avoid complications. Your doctor
may advise you to receive flu and pneumonia vaccines.
* Medications. The complication of pulmonary hypertension is often
treated with medications to expand or relax blood vessels, and
blood-thinning medications to prevent blood clots from forming and
obstructing narrowed vessels.
To ease difficulty breathing, your doctor may prescribe supplemental
oxygen or drain fluid from around your lungs, if necessary.
Occasionally, severe cases of asbestosis may be treated with lung
Reducing the level of exposure to asbestos is the best prevention
against asbestosis. In the United States, by law, a worker's exposure to
asbestos may not exceed 0.1 fiber per cubic centimeter of air. Federal
law requires employers in industries that work with asbestos products,
such as construction and shipyard industries, to monitor exposure
levels, create regulated areas for asbestos work, and provide their
employees with appropriate training, protective gear such as face masks,
and decontamination hygiene areas.
Many homes built before the 1970s contain asbestos products, such as
building insulation, insulation for hot-water and steam pipes,
soundproofing and decorative material sprayed on walls and ceilings,
older stove-top and ironing board pads, as well as some types of
textured paint, patch compounds, roofing and siding shingles, and vinyl
Generally, there's no cause for concern being around these products as
long as they're in good condition and you don't disturb them or cause
them to disintegrate. It's when they're damaged that there's a danger of
asbestos fibers being released into the air. If you need repair or
removal of an asbestos product, it's best to have it done by a