In the mid-1970s the sad truth about asbestos become known: it
is a killer. This mineral has great fire and heat resistance
properties and was widely used in building insulation products
including those for homes and schools. Countless thousands of people
were exposed and the effects are still being felt. Although asbestos
has been removed from most buildings and banned for many uses, it is
still present in some products as well as being a naturally
occurring substance. For the sake of your health, it's important to
know where it is found and how it works within the body.
What is asbestos?
Asbestos refers to a group of naturally occurring silicate minerals
with the ability to separate into fibers. These long thin fibers are
strong and flexible enough to be woven into cloth and are valued for
their heat and fire resistant qualities. There are several types of
asbestos, three of which have been widely used:
Chrysotile or white asbestos comes mainly from Canada (there is
even a town in Quebec named Asbestos). This type is found in
Amosite, or brown asbestos, comes from southern Africa.
Crocidolite, or blue asbestos, comes from Australia and southern
Africa. In the twentieth century, an estimated 30 million tonnes
of asbestos were used in United States alone.
Where is it found?
Few people know that asbestos is still in use today in many
products. These include: building insulation, carpet underlay,
roofing materials, brake pads and linings, pot holders, hair dryers,
floor tiles, insulated electrical wire, textured paints, toasters
and other household appliances. Manufacturers are not required to
declare the presence of asbestos in component parts on their labels.
Asbestos is used primarily for heat insulation and fire
resistance. It is typically combined with a binding agent so that
asbestos will not be released into the air. Problems arise when
these dangerous fibres become airborne as can easily happen during
renovation projects such as removing old flooring or insulation.
The natural state of asbestos can also create problems since
people usually aren't aware of the dangers. Chrysotile is found in
serpentine rocks particularly common in California and Canada. This
rock is typically greyish-green to bluish-black in colour and may
have a shiny appearance. Although asbestos is not found in all
serpentine rock, when it does occur it is usually found in amounts
ranging from 1% up to 25%. These amounts are high enough to cause
problems if the rock is broken or crushed thus releasing asbestos.
This can happen at quarries, when digging building foundations, or
when driveways are surfaced with serpentine rock. It can also be
released through natural weathering and erosion.
Asbestos is a known cancer-causing agent. The only acceptable
environmental level is none at all. If the microscopic particles or
fibers of asbestos are inhaled they can penetrate deeply into the
lungs and eventually into other parts of the body. Our immune system
response is to coat these foreign particles with a special protein
to render them harmless. Unfortunately, for reasons that medical
science does not fully understand, these proteins-coated molecules
can trigger cancer. In fact, for years after being exposed, the body
continues to try to neutralize the asbestos, which means that people
continue to be in danger of developing disease. Common ailments
include asbestosis, cancer of the lungs, stomach, colon, ovaries and
esophagus, as well as another form of cancer called mesothelioma.
How asbestos affects our bodies
What makes asbestos so dangerous to human health is that the fibres
are extremely small and do not easily break down in the body.
Normally when we inhale dust particles the automatic response is to
cough so that much of it is removed in our exhaled breath or in
mucus. Asbestos is insidious because many of the particles are so
small that they travel deep within our lungs without triggering the
cough response. In the second or so that it takes to inhale, these
particles can travel down the trachea, bronchi and into hundreds of
thousands of alveoli (air sacs). It is here in the alveoli where
oxygen enters our bloodstream upon inhaling and carbon dioxide is
expelled upon exhaling.
The irritation caused by foreign fibres stimulates the body to
attempt to neutralise the invader. The result can be filerosis or
scar tissue in the spaces between the air sacs and the small airways
(bronchi). This scarring hinders the body's ability to absorb oxygen
and remove carbon dioxide. Sometimes a victim suffers only shortness
of breath but the cumulative, long-term effects can lead to cancer.
One of the ailments directly related to the penetration of asbestos
into the alveoli is mesothelioma. A similar type of ailment is
pleural mesothelioma which is cancer of the cells of the pleura, the
lining around the outside of the lungs and the inside of the ribs.
Asbestos in your home
If you suspect that there may be asbestos in buildings where you
live or work, contact the Ministry of Environment. Do not attempt to
remove old insulation or flooring. Without the proper protective
gear including masks specially designed to block microscopic
particles, the results can be deadly. Professional flooring and
insulation installers should be aware of asbestos-containing
products and be able to remove them safely.