Thursday, August 13, 2009

090326003 Asbestos


ASBESTOS


Depending on various
factors, matter and materials can have their virtues and vices.
Mainly this depends on the duration one remains exposed to them. For
example, a required quantity of some mineral like salt can be good
for health but an excessive amount can become a cause for some
diseases. Health Risk Assessment studies do not tell us if an
individual has been exposed to some chemical but they are carried out
to find out what amount of exposure will pose a health risk for a
wider range of people, like a city or a community
(Office of Environmental Health Hazard Assessment, 2003).


Asbestos occurs in
nature with unique physical and chemical properties. Though it is
widely used in industry, there are many risks associated with it
concerning issues of health safety. Exposure to asbestos has been
established as a cause of pleural and pulmonary diseases. In a review
of asbestos related diseases Pneumoconiosis Committee of the College
of American Pathologists and the National Institute for Occupational
Safety and Health in 1982 noted that “the association of lung
cancer with exposure to asbestos has been established by
epidemiological studies conducted in a number of different population
groups” (Dodson, Brooks, O'sullivan, &
Hammar, 2004).


In an another study
carried out on rats it was observed that rats who were given higher
concentrations of asbestos in water for twelve weeks had mesothelial
proliferation. Asbestos taken by the rats found its way to the lungs
from gastrointestinal system via lymph hematological route. This
could become a cause of malignancies (Hasan Oglu,
Bayram, Hasanoglu, & Demirag, 2008).


Asbestos is commonly
used in construction material of buildings, defense technology,
manufacturing of cars, enamels and paints, etc. Prolonged exposures
to asbestos fibers has been established to cause lung disease by
inhaling asbestos particles, asbestosis. It can remain passive for as
long as thirty years and then develops into lung cancer or
mesothelioma which is an inoperable cancerous disease (Asbestos,
2008).


Environmental
Protection Agency had proposed a complete ban on use of asbestos
during the next decade but this was turned down by the Court of
Appeals which allowed the use of asbestos except for floorings and
new products which use asbestos (Asbestos, 2008).
Treatment of lung diseases caused by inhaling asbestos particles can
only relieve the symptoms of these diseases. Besides medication,
other options of treatment include removing individuals away from the
environment, dust control, ventilation and use of dust masks.


State, Federal and
International agencies have declared asbestos as a human carcinogen,
which means that there is enough evidence to establish that the
effect of exposure to asbestos causes cancer. In 1986, Air Resources
Board (ARB) identified asbestos as a toxic air pollutant. All
categories of asbestos are officially considered hazardous. Moreover,
there is no safe exposure level of asbestos for residential
communities. This risk of being effected depends on for how much and
how long you have been exposed to asbestos particles. Once penetrated
through the body tissue, they can remain there on the lungs and the
membrane surrounding it. The fibers that remain in the body become
the cause disease of diseases. There are possibilities that the
diseases such caused may not become apparent immediately and might
take as long as twenty to thirty years to appear.


Amongst the serious
diseases, following three are the most common diseases caused by
exposure to asbestos.



  • Asbestosis, which
    causes coughing and shortness of breath. People with heavy exposure
    to asbestos become affected by this disease.


  • Mesothelioma is a
    form of cancer which affects the lung membrane.


  • Lung cancer,
    smokers exposed to asbestos have a higher risk of being effected by
    lung cancer (Office of Environmental Health Hazard
    Assessment, 2003).



Concern with use of
ultramafic or serpentine rock material


Serpentine and
ultrafamic rock materials generally contain asbestos. Ultrafamic
roads were commonly put to use in paving of certain kinds of roads,
parking lots and in floorings of many such open areas. Some schools
might have areas which contain asbestos. Children in such schools are
at a risk of being exposed to asbestos.


Steps taken to
curtail exposure to ultramafic rock asbestos


Air Resource Board
(ARB) in June 2000 revised a regulation which now prohibits the use
of asbestos contained ultramafic rock and serpentine in paving areas
subject to vehicular, non-vehicular and pedestrian use. Prior to this
a school advisory was released in 1990 and 1999. Moreover, another
regulation in 2001 requires control of dust emission in industrial
areas.


Environmental Heath
Agency has recommended the following measures to minimize mixing of
asbestos in air in construction and roadways projects.
































































































































Dust Source



Mitigation
Measure



Application
Frequency



Relative
Effectiveness
1



Excavation



Water wetting



as needed



2-3



Excavate during
calm periods



when possible



1



Mobile
Construction Equipment



Water wetting
of roads surfaces



as needed



2-3



Rinse vehicles /
equipment



as needed



3



Wet loads of
excavated material



each load



3



Cover loads of
excavated material



each load



2-3



Wet and cover
loads



each load



4



Exposed
Ultramafic or Serpentine Areas



Water wetting



as needed



3-4



Cover with 6 to
12 inches of non-asbestos material



end of project



4



Wind breaks /
berms



where needed



1-2



Chemical
sealants / dust suppressants



3 mos. - 1 yr.



3



Vegetative
reclamation



end of project



3



Asphalt cement
paving



as needed



4



Roads



Water wetting



as needed



3-4



Speed control



always



1-3



Wind breaks /
berms



where needed



1-2



Cover with 2 to
4 inches of non-asbestos rock



as needed



3-4



Chemical
sealants / dust suppressants



3 mos. - 1 yr.



2-3



Single-coat
chip/seal



as needed



4



Triple-coat
chip/seal



as needed



4



Petroleum
sealants



as needed



4



Asphalt cement
paving



as needed



4



(Office of
Environmental Health Hazard Assessment, 2003)



Bibliography


Asbestos.
(2009). Encyclopædia Britannica . Chicago.


Dodson,
R., Brooks, D., O'sullivan, M., & Hammar, S. (2004, August).
Quantitative Analysis of Asbestos Burden in a Series of Individuals
with Lung Cancer and a History of Exposure to Asbestos. Inhalation
Toxicology
, 16 (9), pp. 637-647.


Encarta
Book of Quotations. (1999). Human Society and Racism. (M.
Corporation, Ed.) Bloomsbury Publishing Plc.


Hasan
Oglu, H., Bayram, E., Hasanoglu, A., & Demirag, F. (2008). Orally
Ingested Chrysotile Asbestos Affects Rat Lungs and Pleura. Archives
of Environmental & Occupational Health
, 63 (2), pp.
71-75.


Office
of Environmental Health Hazard Assessment
. (2003). Retrieved
March 29, 2009, from OEHHA Web Site:
http://oehha.ca.gov/air/toxic_contaminants/asbes_f.html











1
Subjective rating; where 1 is least effective and 4 is most
effective.




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