More than 1 million U.S. workers are
exposed to crystalline silica. Each year, more than 250 American workers
die with silicosis. There is no cure for the disease, but it is 100
percent preventable if employers, workers, and health professionals work
together to reduce exposures.
In addition to silicosis, inhalation of
crystalline silica particles has been associated with other diseases, such
as bronchitis and tuberculosis. Some studies also indicate an association
with lung cancer.
Who Is at Risk?
Working in any dusty environment where
crystalline silica is present potentially can increase a person's chances
of getting silicosis. If a number of workers are working in a dusty
environment and one is diagnosed with the silicosis, the others should be
examined to see if they might also be developing silicosis.
Some examples of the industries and activities that pose the greatest
potential risk for worker exposure include:
- construction (sandblasting, rock
drilling, masonry work, jack hammering, tunneling)
- stone cutting (sawing,
abrasiveblasting, chipping, grinding) glass manufacturing
- mining (cutting or drilling
through sandstone and
- agriculture (dusty conditions
from disturbing the soil, such as plowing or harvesting)
- foundry work (grinding,
moldings, shakeout, core
- shipbuilding (abrasive
- ceramics, clay, and
- railroad (setting and laying
- manufacturing of soaps and
- manufacturing and use of
More than 100,000 workers in the United
States encounter high-risk, silica exposures through sandblasting, rock
drilling, and mining. Workers who remove paint and rust from buildings,
bridges, tanks, and other surfaces; clean foundry castings; work with
stone or clay; etch or frost glass; and work in construction are at risk
of overexposure to crystalline silica.
What Are the Types, Symptoms and
Complications of Silicosis?
There are three types of silicosis,
depending upon the airborne concentration of crystalline silica to which a
worker has been exposed:
- Chronic silicosis
usually occurs after 10 or more years of overexposure.
- Accelerated silicosis
results from higher exposures and develops over 5-10 years.
- Acute silicosis occurs
where exposures are the highest and can cause symptoms to develop
within a few weeks or up to 5 years.
Chronic silicosis, the most common form
of the disease, may go undetected for years in the early stages; in
fact, a chest X-ray may not reveal an abnormality until after 15 or 20
years of exposure. The body's ability to fight infections may be
overwhelmed by silica dust in the lungs, making workers more susceptible
to certain illnesses, such as tuberculosis. As a result, workers may
exhibit one or more of the following symptoms:
- shortness of breath following
How Can Workers Determine If They
A medical examination that includes a
complete work history and a chest X-ray and lung function test is the
only sure way to determine if a person has silicosis. Workers who
believe they are overexposed to silica dust should visit a doctor who
knows about lung diseases. The National Institute for Occupational
Safety and Health (NIOSH) recommends that medical examinations occur
before job placement or upon entering a trade, and at least every 3
How Can Silicosis Be Prevented?
Workers and employers will be able to get
a package of free materials on how to prevent silicosis by calling a
toll-free telephone information service operated by NIOSH in the U.S.
Department of Health and Human Services (1-800-35-NIOSH; select option
2, then option 5). The package contains a tip sheet of ideas for
preventing silicosis, a guide for working safely with silica, and
stickers for hard hats to remind workers that, If it's silica,
it's not just dust. Spanish - language versions of materials
also will be available soon.
Department of Labor staff will distribute silica materials when they
inspect mines, construction sites, and other affected industries.
Source: U.S. Dept. of Labor