Toxicity of Asbestos on Human Health

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TOXICOLOGY
SLE312 Toxicology Final Report
1. Summary of the toxic substance(s)
Minerals are crystalline inorganic elements or compounds, available in nature, with
characteristic chemical compositions and crystal structures. The term asbestos describes a
family of six
fibre- like
silicate
minerals extracted and processed for industrial and commercial purposes. These minerals
come in both fibrous and non-fibrous forms, but only the fibrous minerals are called asbestos
(Strohmeier et al, 2010). Table 1 shows the source and composition of the six silicate
minerals.
Table 1 showing six regulated asbestos minerals
Variety Ideal Chemical
Formula
Major Sources Morphology
“chrysotile” “Mg6Si4O10(OH)8” US, Canada curly, pliable
“crocidolite” “Na2(Fe2+,Mg3)Fe3+2Si8O22(OH)2” Western
Australia, South
Africa
Rod-like
“amosite” “(Fe2+,Mg7)Si8O22(OH)2” South Africa Rod-like
“anthophyllite
”
“(Mg,Fe2+)7Si8O22(OH)2” Finland Rod-like
“tremolite” “Ca2Mg5Si8O22(OH)2” Canada Rod-like
actinolite “Ca2(MgFe2+)5Si8O22(OH)2” Mining not done
An important difference between amphibole asbestos and chrysotile is that the first can
contain significant amounts of iron. In addition, while the amphiboles are rod-like chrysotile
has a unique structure. Serpentine minerals are composed of almost flat sheets of silica
(Si2O5)n2n- interspersed with cationic sheets.
Name of the Student
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Author Note:

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The fibres can stay in the body for years and the reaction develops very slowly. In addition,
asbestos fibres made from amphibole, which are comparatively more length and straight
compared to chrysotile fibres, are probably present in the lung for years. Intake of asbestos
fibres was present in drinking water or food because the dust discharged from the industrial
air mixed directly into the atmosphere. The fibres came into the water through metal pipes
from waste of piled asbestos, which contain cement and were used for drinking purposes.
Most people who get exposure to asbestos fibres through drinking water had higher average
death rates from cancer of the oesophagus, stomach and intestines.
Exposures and Outcomes
Mcculloch (1986) shows that asbestos is a carcinogen to individuals living in industrialized
states (LaDou et al., 2010) if exposure occurs. The exposure of large numbers of people had
been those who worked in buildings construction and the mines. However, it has been found
that exposure to asbestos not only affects workers directly linked to the production of
asbestos products but also their family members. The users of asbestos products are also
affected as well as those who are exposed to building materials, and other systems where
asbestos is used.
It is now universally accepted that those who are exposed to asbestos fibres can, in certain
circumstances, be affected with mainly three deadly diseases like lung cancer, asbestosis and
mesothelioma . In some cases, it may lead to other types of cancer, including cancers of the
gastrointestinal tract, the larynx and kidney and other types.
2. Conclusion
Some studies on the effects of asbestos on people with cancer show different outcomes. But it
is generally thought that asbestos causes cancer. It is reported that more than 20 million
people in the United States, and even more in other countries, exposed to asbestos, are at risk

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of mesothelioma, deadly cancer that covers the lung and the abdomen and is resistant to
current treatment methodologies. Moreover, continued exposure to asbestos may increase the
risk of being affected with lung cancer. Over the past 50 years, researchers have tried to
understand what is the background behind cause of cancer due to asbestos The answer is
featured in a study published in the edition of “Proceedings of the National Academy of
Sciences, USA, Doctor Haining Yang and Doctor Michele Carbone from the University of
Hawaii Cancer Research Centre in charge of a research team including employees”
(EurekAlert!, 2019).
These researchers were able to solve the paradox of how asbestos fibres could kill cancer
cells, could be responsible for the growth of a tumour on a dead cell. They discovered that
when asbestos can kill cells, this anomaly is possible through a process called "programmed
cell necrosis," which assist in releasing a molecule called "high mobility group box1 protein"
(HMGB1). HMGB1 starts a certain type of inflammatory response that causes mutagenic
release and factors that promote tumour growth. The researchers discovered that patients
exposed to asbestos have high level of HMGB1 in their serum. That is why they say that
HMGB1 can be aimed at preventing or treating mesothelioma and identifying asbestos
cohorts via the HMGB1 serological test (EurekAlert!, 2019).
3. Management Strategies
As per recent statistical data, the yearly production of asbestos throughout the world is
around two million tons, less than half of the annual production of 1977 (4.8 million tons).
This decrease is largely due to Canada stopping production of Asbestos or Asbestos related
products. Currently, around ninety percent of world asbestos are supplied by four countries:
China, Brazil Russia, and Kazakhstan. Around fifty per cent of the world's asbestos is
consumed by two highly populated countries, India China followed by Indonesia, Brazil and