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Mining Mineral
Mining Asbestos
Asbestos
 Asbestos
is a gristly mineral that is in chemical nature inert with added
heat defiant properties. It has been utilized in over a wide spec
of products of more than 3,000 products, counting fire resisting
materials, cement, brake pads, plastics, paper products and textile
products.
There
are 2 forms of very usually used Asbestos, Serpentine and Amphibole.
The Serpentine range of asbestos is termed as Chrysotile, where
in turn the Amphibole range contains Crocidolite, Amosite, Anthophyllite,
Actinolite and Tremolite.
Archetypal
asbestos mining in the United States used open pit extraction
followed by the milling process. Max out manufacture of asbestos
in the United States was way over the 299 million pounds/year
capacity in the late 1960s and early 1970s. Production deceased
to 112 million pounds/year in 1987, to 37 million pounds/year
in 1989, it stepped down to 30 million pounds/year in 1993, even
to 15.4 million pounds/year in 1997, and as low as 13.2 million
pounds/year in 1998 and 1999.
Asbestos
are fibrous, naturally happening hydrated silicates that have
long been mined and used for their fire-retardant and insulating
properties as construction materials. Asbestos can be found in
amphibole and serpentine forms. 95% of the asbestos mined globally
is in a serpentine form of chrysotile type, with fibres that are
long and curly. Amphibole forms of asbestos may be of amosite,
crocidolite or anthophyllite types, and are shorter and straighter
than serpentine varieties. According to the Stanton Hypothesis,
amphibole fibres were originally thought to pose less risk, but
these fibres were then linked to increased rates of mesothelioma.
Dr. Montague Murray first recognized the negative
health effects of asbestos in 1899. However, dust control legislation
for mines was not enacted in North America until 1971. In the
middle years, mining and use of asbestos improved dramatically
by 120-fold, peaking upon the enaction of legislation in 1971,
and decreasing exponentially until the present. The current decreases
in the rate of mining are due to public health concerns and to
the increasingly more restrictive standards placed upon the level
of asbestos dust allowed in mines, from 5 fibres/cm3 in 1971 to
1 fibres/cm3 at present although the global levels of asbestos
mined have decreased significantly, Canada continues to be one
of the world's foremost producers. 2.4 × 105 tonnes were mined
in Canada in 2003, which accounted for much of the world's production
of asbestos.
What are the health effects of asbestos exposure?
Exposure to airborne friable asbestos may result in a potential
health risk because persons breathing the air may breathe in asbestos
fibers. Continued exposure can increase the amount of fibers that
remain in the lung. Fibers embedded in lung tissue over time may
cause serious lung diseases including: asbestosis, lung cancer,
or mesothelioma. Smoking increases the risk of developing illness
from asbestos exposure.
Adverse health effects from exposure to asbestos remain a serious
concern to miners, mining communities and residents of buildings
that contain asbestos. Miners and mining communities are at the
greatest risk from asbestos related diseases, but are better ready
to limit their exposure to asbestos than homeowners who are unknowingly
breathing in asbestos. There is a time lag of 15 to 40 years between
exposure and asbestos-caused disease for both residents and miners,
which often makes it difficult to relate historical exposure to
current symptoms. Asbestos has far-reaching and long-lasting impacts
for human health, both through occupational and environmental
exposure.
Three of the major health effects associated with asbestos exposure
include:
Asbestosis – Asbestosis is a grave, progressive, long-term
non-cancer disease of the lungs. It is caused by inhaling asbestos
fibers that irritate lung tissues and cause the tissues to scar.
The scarring makes it hard for oxygen to get into the blood. Symptoms
of asbestosis include shortness of breath and a dry, crackling
sound in the lungs while inhaling. There is no effective treatment
for asbestosis.
Lung Cancer – Lung cancer causes the largest number of
deaths related to asbestos exposure. People who work in the mining,
milling, manufacturing of asbestos, and those who use asbestos
and its products are more likely to develop lung cancer than the
general population. The most common symptoms of lung cancer are
coughing and a change in breathing. Other symptoms include shortness
of breath, persistent chest pains, hoarseness, and anemia.
Mesothelioma – Mesothelioma is a rare form of cancer that
is found in the thin lining (membrane) of the lung, chest, abdomen,
and heart and almost all cases are linked to exposure to asbestos.
This disease may not show up until many years after asbestos exposure.
This is why great efforts are being made to prevent school children
from being exposed.
Exposure to asbestos increases your risk of developing lung disease.
That risk is made worse by smoking. In general, the greater the
exposure to asbestos, the greater the chance of developing harmful
health effects. Disease symptoms may take several years to develop
following exposure. If you are concerned about possible exposure,
consult a physician who specializes in lung diseases (pulmonologist).
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