Safety & Health in the Stone Crushing Industry - Occupational ...

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A.3 Keeping Workers Healthy
Stone crushing produces a lot of dust. Dust consists of particles,
which are dispersed in the air and remain there for a while. It is
generated from mechanical actions, such as stone crushing, truck
movement, etc. Although most dust particles can be seen with the
naked eye, some cannot be seen without the help of a microscope.
These fine dust particles can travel deep into the lungs and have
the potential to cause the most damage. A "dusty lung"
(pneumoconiosis in medical terms) or severe chronic lung disease
(called "chronic-obstructive pulmonary disease", COPD in medical
terms) is a common hazard caused by to much exposure to dust.
Several rocks such as granite and normal sand contain a
substance called "silica" in varying degrees, typically about 10 or
20%. This substance causes even more severe lung disease when
inhaled as fine, man-made particles ("silicosis" in medical terms).
These fine particles are typically found in the stone crushing
process. Scar tissue forms deep in the lungs and makes the lungs
less efficient and less strong. Over time, even AFTER work in stone
crushing and the dust exposure has stopped, this destruction
process in the lungs continues and the worker will eventually die
from the damage.
Typical signs of lung damage by dust include difficulty breathing,
shortness of breath, wheezing, constant coughing, reddish or bluish
color of ears and/or the lips. This difficulty in breathing is often
combined with fatigue, loss of appetite, weakness.
Stone dust cannot be avoided in stone crushing. It is produced by
the crushing itself, the sorting, the transport of gravel and also by
vehicle movements over dusty roads. We can however reduce the
amount of dust that reaches the lungs. By engineering controls, the places where dust is generated
can be encapsulated so the dust is not easily carried off by the wind. Only after engineering and other
controls have been used in all areas, personal protective equipment such as appropriate masks should
be used. So-called Particulate Respirators Masks offer various amounts of protection depending on the
type of filter and the fit provided. Using a cloth to cover the nose and mouth is NOT really protecting
the worker.
There is no good short-term solution to the problem.
Appropriate masks that protect workers from dust are often
hard to find in developing countries. Even if they were
available, the very high amount of dust would force the
workers to change the masks or filters several times per
day. In addition, the masks are often uncomfortable,
specifically when one works in a hot climate.
The best solution is therefore to REDUCE the amount of
dust that is being released into the ambient air. This can be
done by:
• Enclosing the dust sources and processes
• Ventilate with a local exhaust system near the
generating source
• Spraying water at the source of dust dispersion