Some Common
Questions about Asbestos
What is Asbestos?
Asbestos is a
natural mineral, mined from rock found in many countries, including Russia,
Canada, Australia and South Africa. It is made up of tiny fibres that are as
strong as steel, but can be woven like cotton, and are highly resistant to
heat and chemicals. Asbestos was dubbed the `Magic Mineral' because of its
unique properties and from the 1860s onwards it was used in thousands of
products and buildings all over the world. There are three main types of
asbestos that have been used in this country: brown asbestos (amosite); blue
asbestos (crocidolite) and white asbestos (chrysotile).
From the late
1880s it was realised that this `Magic Mineral' had a damaging effect on
health, but the truth about the dangers of asbestos was hidden by employers,
and successive Governments failed to act to protect workers. It was not until
the mid-1980s that blue and brown asbestos were banned in the UK, and not
until November 1999 that white asbestos was finally banned.
How does Asbestos damage health?
Asbestos damages
health when asbestos fibres are breathed (inhaled) into the lungs. Because
asbestos fibres are so fine, they can penetrate deep into the smallest airways
of the lungs so that they cannot be easily breathed or coughed out. Once the
fibres are inside the lungs, the body's defence mechanism tries to break them
down and remove them. Each fibre is a foreign body, like a splinter in a
finger. As the body tries to neutralise and break down the irritating fibres,
inflammations develop.
These processes
lead to the development of asbestos-related diseases. Asbestos fibres are so
strong that they can also penetrate through tissue into the sensitive lining
of the lungs (the pleura) causing illness. Once fibres are in the body, they
can move around, not only into the pleura, but also the lymph nodes and other
parts of the body.
Fibres can also
be swallowed (ingested). For example, when mucous and sputum that contain a
lot of fibres are swallowed, some of these fibres can stick in the intestinal
track and from there they can move into the lining of the abdomen
(peritoneum). Fibres can penetrate the skin and cause irritation and
reddening. Because of this, some people think that asbestos can grow inside
the body like a tree, but this does not happen.
Does exposure to asbestos
always damage health?
It is possible to
be exposed to high levels of asbestos for long periods of time and not to
develop any of the asbestos-related diseases. However, it is generally thought
that the more asbestos you have been exposed to, the more likely it is that
you will develop an asbestos-related disease such as asbestosis. This may mean
that you have been exposed to smaller doses of asbestos over a long period of
time, perhaps ten years, or to larger doses over a shorter period of time. It
is possible to develop mesothelioma, a cancer caused almost exclusively by
asbestos, because of a brief exposure to asbestos.
There is usually
a long latency period between exposure and actually developing an asbestos
disease. It usually takes at least 10 years, but can take much longer. It can,
for instance take up to 40 or more years to develop mesothelioma.
What are "asbestos bodies"
in lung tissue?
The body's
defence mechanisms often coat the asbestos fibres with a layer of protein and
they are then called "asbestos bodies". Finding asbestos bodies in lung tissue
suggests heavy occupational exposure to asbestos, but this does not
necessarily mean that you are suffering from an asbestos disease.