Silicosis
Silicosis
Silicosis is a respiratory disease caused by inhalation of silica
dust, which leads to inflammation and scarring
of the lung tissue.
Three types of silicosis
are seen:
Simple chronic silicosis: Results from long term exposure (more than 20 years) to low amounts of silica dust. Nodules
of
chronic inflammation and scarring
provoked by the silica
dust form in the lungs and chest lymph nodes.
This disease may feature
breathlessness and may resemble chronic
obstructive pulmonary disease (COPD).
Accelerated silicosis: Occurs after exposure to larger amounts
of silica over a shorter period
of time
(5 - 15 years). Inflammation, scarring and symptoms
progress faster
in accelerated silicosis than in simple silicosis.
Acute silicosis: Results from short-term exposure
to very large amounts
of silica. The lungs become
very inflamed and may fill with fluid, causing
severe shortness of breath and low blood oxygen levels.
Causes of Silicosis
Silica is a common, naturally-occurring crystal. It is found in most rock beds and forms dust during mining, quarrying, tunnelling and work with many metal ores. Silica is a main component of sand, so glass workers
and sand-blasters also receive heavy exposure
to silica.
·
Caused by breathing small particles
of crystalline silica.
·
Afflicts thousands of miners
and millions of other workers engaged in hazardous dusty occupations
·
One of the most dangerous
occupational health problems
in the world.
Mechanism of Silicosis
·
Airborne silica dust enters the body primarily by inhalation.
·
The inhaled air passes
through the upper airways,
the trachea, bronchi
and smaller branches eventually reaching the bronchioles and in the alveoli
(or small airways)
·
These particles cause “fibrosis” or scar tissue formation in the lungs.
·
It then causes the lung tissue to form nodules.
·
As the disease
progresses, the silicotic
nodules merge and form a continuous
mass
of fibrotic tissue called progressive massive fibrosis.
·
These are responsible for cancer.
·
This also reduces the lung’s ability to extract oxygen from the air.
Symptoms:
·
Shortness of breath
with exercise, usually in patients
who have progressive massive fibrosis.
·
Chronic cough
Additional symptoms that may be associated with this disease, especially in acute silicosis:
·
Fever
·
Cough
·
Weight loss
·
Severe breathing difficulty
Respirable Concrete Dust – Silicosis Hazard
in Construction Industry
Activity studied:
·
Abrasive Blasting
·
Concrete pavement Sawing and Drilling
. Asphalt or concrete milling
Recommendations:
·
Power tools and equipment
used to disturb
silica containing materials must be designed to allow workers
to operate them safely.
·
Need to eliminate the abrasive
blasting of concrete.
·
In concrete drilling
water should be used through the drill stem and high velocity dust collection systems should be used.
·
Similarly in asphalt
or concrete milling water spray system should be used.
·
Tools and equipment
should be developed
to effectively capture the dust generated.
·
Provide appropriate personal
protective equipment (PPE) such as Respirators
·
Workers should wear washable or disposable protective clothes
and should shower and change before leaving
the worksite.
·
Medical examinations, including periodic
x-rays, should
be provided to all workers who are potentially exposed.
·
Workers should practice
good personal hygiene
to prevent unnecessary exposure.
Workers should wash their hands before
eating, drinking etc.
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