The National Institute for Occupational Safety and Health
(NIOSH) requests assistance in preventing silicosis and deaths in
construction workers exposed to respirable crystalline silica.
Construction workers, coworkers, managers, and equipment
manufacturers urgently need information about the hazards of
breathing respirable crystalline silica. Your assistance in this
effort will help prevent silicosis-related death and disease, a
national goal for health promotion and disease prevention stated in
Healthy People 2000 [PHS 1990].
This Alert describes six case reports of construction workers
who have died or are suffering from silicosis. In addition, the
Alert cites examples of five construction operations that used poor
dust controls and two operations that used good dust controls.
NIOSH requests that editors of trade journals, safety and
health officials, labor unions, owners, and employers bring the
recommendations in this Alert to the attention of all workers who
are at risk.
BACKGROUND
Types of Silica
Crystalline silica may be of several distinct types. Quartz, a
form of silica and the most common mineral in the earth's crust, is
associated with many types of rock. Other types of silica include
cristobalite and tridymite.
Potential for Exposure During Construction
Concrete and masonry products contain silica sand and rock
containing silica. Since these products are primary materials for
construction, construction workers may be easily exposed to
respirable crystalline silica during activities such as the
following:
- Chipping, hammering, and drilling of rock
- Crushing, loading, hauling, and dumping of rock
- Abrasive blasting using silica sand as the abrasive
- Abrasive blasting of concrete (regardless of abrasive used)
- Sawing, hammering, drilling, grinding, and chipping of
concrete or masonry
- Demolition of concrete and masonry structures
- Dry sweeping or pressurized air blowing of concrete, rock, or
sand dust
Even materials containing small amounts of crystalline silica may
be hazardous if they are used in ways that produce high dust
concentrations.
HEALTH EFFECTS OF CRYSTALLINE SILICA EXPOSURE
Description of Silicosis
When workers inhale crystalline silica, the lung tissue reacts by
developing fibrotic nodules and scarring around the trapped silica
particles [Silicosis and Silicate Disease Committee 1988]. This
fibrotic condition of the lung is called silicosis. If the nodules
grow too large, breathing becomes difficult and death may result.
Silicosis victims are also at high risk of developing active
tuberculosis [Myers et al. 1973; Sherson and Lander 1990; Bailey et
al. 1974].
A worker's lungs may react more severely to silica sand that has
been freshly fractured (sawed, hammered, or treated in a way that
produces airborne dust) [Vallyathan et al. 1988]. This factor may
contribute to the development of acute and accelerated forms of
silicosis.
Types of Silicosis
A worker may develop any of three types of silicosis, depending
on the airborne concentration of crystalline silica:
Chronic silicosis, which usually occurs after 10 or more
years of exposure to crystalline silica at relatively low
concentrations
Accelerated silicosis, which results from exposure to high
concentrations of crystalline silica and develops 5 to 10 years
after the initial exposure
Acute silicosis, which occurs where exposure
concentrations are the highest and can cause symptoms to develop
within a few weeks to 4 or 5 years after the initial exposure
[Peters 1986; Ziskind et al. 1976]
Complications
Initially, workers with silicosis may have no symptoms. As
silicosis progresses, there may be difficulty in breathing and other
chest symptoms such as cough. Infectious complications may cause
fever, weight loss, and night sweats. Severe mycobacterial or fungal
infections can complicate silicosis and may be fatal [Ziskind et al.
1976; Owens et al. 1988; Bailey et al. 1974]. Fungal or
mycobacterial infections are believed to result when the lung cells
(macrophages) that fight these infections are overwhelmed with
silica dust and are unable to kill mycobacteria and other organisms
[Allison and Hart 1968; Ng and Chan 1991]. About half of the
mycobacterial infections are caused by Mycobacterium tuberculosis
(TB), with the other half caused by M. kansasii and M.
avium-intracellulare [Owens et al. 1988]. Nocardia and Cryptococcus
may also cause infections in silicosis victims [Ziskind et al.
1976].
Medical evaluations of silicosis victims usually show the lungs
to be filled with silica crystals and a protein material [Owens et
al. 1988; Buechner and Ansari 1969]. Pulmonary fibrosis (fibrous
tissue in the lung) may or may not develop in acute cases of
silicosis, depending on the time between exposure and onset of
symptoms.
Furthermore, evidence indicates that crystalline silica is a
potential occupational carcinogen [NIOSH 1988; IARC 1987; DHHS
1991], and NIOSH is reviewing the data on carcinogenicity.
CURRENT EXPOSURE LIMITS
Occupational Safety and Health Administration (OSHA)
The current OSHA permissible exposure limit (PEL) for respirable
dust containing crystalline silica (quartz) for the construction
industry is measured by millions of particles per cubic foot (mppcf)
and is calculated using the following formula [29 CFR* 1926.55]:
250 mppcf
PEL† = ___________
% silica +5
_________________________________________________
*Code of Federal Regulations. See CFR in references.
†8-hour time-weighted average (TWA).
|
The current OSHA PEL for respirable dust containing
crystalline silica (quartz) for general industry is as follows [29
CFR 1910.1000]:
10 mg/m3 or 250 mppcf
PEL = ___________ ___________
% silica +2 % silica +5
|
NIOSH
The NIOSH recommended exposure limit (REL) for respirable
crystalline silica is 0.05 mg/m3 (50 µg/m3) as
a TWA for up to 10 hours/day during a 40-hour workweek [NIOSH 1974].
CASE REPORTS
Silicosis Cases
Case No. 1--Sandblaster
A 39-year-old man was diagnosed with silicosis (progressive
massive fibrosis) and tuberculosis in April 1993 after working 22
years as a sandblaster. He had noticed a gradual increase in
shortness of breath, wheezing, and discomfort from minimal exertion.
Tissue taken from his lungs showed extensive fibrosis.
The sandblaster was first diagnosed with silicosis in 1991 when a
coworker had developed tuberculosis and the State health department
had administered chest X-rays and skin testing to the entire crew.
He was one of 20 workers who sandblasted welds during water tank
construction to prepare the metal for painting. While sandblasting,
he wore a charcoal filter respirator. During a 10- to 11-hour day,
he spent 6 hours sandblasting.
Two brothers and three nephews who worked with him all tested
positive for tuberculosis. A brother-in-law had also worked at the
company for 20 years but had died from progressive silicosis in 1984
at age 42.
Case No. 2--Tile Installer
A white male nonsmoker was diagnosed with advanced silicosis,
emphysema, and asthma at age 49 after working 23 years as a tile
installer. He had reported shortness of breath and pneumonia.
His work included polishing and drilling tile, and he was exposed
to grout dust and sandblasting (though he did not do sandblasting).
He did not use a respirator. Information about dust controls was not
available.
Case No. 3--Brick Mason
A white male nonsmoker was diagnosed with silicosis, emphysema,
and lung cancer at age 70 after working 41 years as a mason laying
brick. The diagnosis was made after an open lung biopsy (a chest
X-ray had shown no evidence of silicosis).
This worker spent part of his time around coke ovens doing fire
brick work. He wore a respirator when he was working in dusty
conditions. Information about dust controls was not available.
Case No. 4--Rock Driller
A 47-year-old man was diagnosed with severe silicosis after
working 22 years as a rock driller. He was diagnosed in 1992 after
he was brought to a hospital with respiratory failure and right
heart failure. In the Spring of 1994, while he was on a ventilator,
he died from respiratory failure. His autopsy confirmed advanced
silicosis.
Before this worker's diagnosis, he had never seen a doctor and
had never had a chest X-ray. The drills he used were equipped with
dust controls, but they were routinely inoperable.
Case No. 5--Tunnel Worker
A white male worker died of silicosis at age 69 after working 2
years as a tunnel construction worker and 40 years as a nurse. He
had been a smoker until age 59 and was exposed to silica during his
2-year employment in tunnel construction. Information about
respirator use and dust controls was not available.
His nursing assignments included 5 years with the U.S. Public
Health Service, 27 years with an automobile manufacturer, 1 year
with a paper manufacturer, 6 years with various hospitals, and 1
year with a magazine publisher.
Case No. 6--Building Renovation Mason
A 55-year-old man was diagnosed in 1994 with simple silicosis
after working 30 years as a building renovation mason. Although a
lung biopsy revealed silicotic nodules, he was still working as of
1995.
This mason used an air-supplied respirator while sandblasting
during the past 25 years. Sand (or occasionally coal slag) was the
usual abrasive. The frequency of sandblasting was reported to be 12
times per year in the past and twice per year currently.
Periodically, the mason used a handheld masonry saw with no water on
the blade (though he did wear a disposable particulate filter
respirator).
EXAMPLES OF SILICA EXPOSURES AT CONSTRUCTION SITES
Exposures at Sites with Poor Dust Controls
Exposures to respirable crystalline silica at the following
construction sites exceeded the NIOSH REL of 0.05 mg/m3
for up to 10 hours/day during a 40-hour workweek [NIOSH 1974].
New Building Construction, April 1992
At the site of a new building under construction (Figure 1), a
sandblaster was employed to blast the surface of a poured concrete
structure using silica sand. The sandblaster wore a supplied-air,
Type CE continuous-flow respirator, but his helper used no
respiratory protection. The amount of air flow through the
supplied-air respirator was not determined. Other workers nearby
(some only 20 to 25 feet from the sandblasting at various times)
were either using disposable particulate respirators or had access
to them. For the sandblaster, 60-minute personal air samples
indicated a respirable quartz concentration of 0.68 mg/m3
inside and 1.83 mg/m3 outside the Type CE continuous-flow
respirator. For the blaster helper, a 57-minute personal air sample
indicated a respirable quartz concentration of 0.52
mg/m3. A 65-minute area air sample indicated a respirable
quartz concentration of 0.26 mg/m3.
Bridge Demolition, May 1992
At the demolition site of a small bridge, handheld drills and a
concrete saw were used to weaken the structure. The commercial-type
saw consisted of a steel diamond-tipped blade in a large portable
circular-saw housing. The saw used water to prevent wear of the
blade. Respiratory protection was not used by any of the workers
present. For a worker using a handheld drill, a 45-minute personal
air sample indicated a respirable quartz concentration of 0.78
mg/m3. For a concrete saw operator, a 45-minute personal
air sample indicated a respirable quartz concentration of 1.64
mg/m3. Area air samples indicated concentrations of 0.0,
0.65, 1.96, and 2.15 mg/m3 respirable quartz.
Multistory Building Renovation, August 1992
During renovation of a high-rise office building (Figure 2), a
plumber cut the concrete floor on each of the 16 floors to install
rest room floor drains. He wore a disposable particulate respirator
and used a floor-stand fan to direct dust out the window. A
350-minute personal air sample indicated a respirable quartz
concentration of 14.2 mg/m3. Area air samples indicated
3.2, 3.36, and 4.1 mg/m3 respirable quartz. Other workers
in the area (such as elevator mechanics) were exposed without
respiratory protection.
New Building Construction, November 1992
At the site of a building under construction (Figure 3), a
hillside was drilled and blasted to give access to the building
site. A drill operator stood at the controls of a drill without a
cab; he wore a half-face respirator with pesticide cartridges, which
he had purchased himself at an auto parts store. During air
sampling, the dust collection system for the drill was not operable,
and water was not used as a dust suppressant. A 324-minute personal
air sample indicated a respirable quartz concentration of 0.80
mg/m3.
Interstate Highway Repair
During interstate highway repair, four workers drilled horizontal
holes in concrete pavement after a rectangular portion of damaged
concrete was removed (Figure 4). Two of the workers operated
backhoes fitted with a special drill attachment, and the other two
workers positioned the drill and drilled the holes. No dust
collection system or water suppressant was in use. One of the
backhoe operators wore a disposable particulate respirator, and the
other wore a half facepiece particulate cartridge respirator. One
drill operator wore a disposable particulate respirator, and the
other wore a quarter-facepiece particulate filter respirator.
Personal air samples (approximately 200 minutes each) were taken on
two different days. Air concentrations were above the REL for one of
the backhoe operators on the first day (0.08 mg/m3) and
for both drill operators on both days (0.81 and 0.41
mg/m3 on day 1, and 0.42 and 0.32 mg/m3 on day
2).
EXPOSURES AT SITES WITH GOOD DUST CONTROLS
Exposures to respirable crystalline silica at the following
construction sites were below the NIOSH REL of 0.05 mg/m3
for up to 10 hours/day during a 40-hour workweek [NIOSH 1974]. These
examples illustrate that exposures to silica can be controlled in
the construction industry through the use of engineering
controls‡ and work practices.§
______________________________
‡Engineering controls are hazard controls designed
into equipment and workplaces.
§Work practices are procedures followed by employers
and workers to control hazards.
Highway Construction with Hillside Drilling and
Blasting
At a highway construction site, a hillside was drilled and
blasted to make room for a new, wider highway (Figure 5). The drill
operator was seated in an enclosed, air-conditioned drill cab. Two
shifts were sampled without detecting respirable quartz in air
samples from the driller's cab or from a personal sampler on the
driller--even though bulk dust samples of the drill cuttings
indicated 60%, 71%, 55%, and 60% quartz.
Highway Construction with Pavement Sawing
At a new highway construction site, the concrete pavement was
sawed to provide expansion joints for the concrete (Figure 6). Two
workers operated commercial-type pavement saws, and one operated a
water truck. The water truck provided water for the blades of the
two saws (gravity feed). Personal air samples were collected for the
three workers during a 4-hour shift and a 9-hour shift. Respirable
quartz was not detected in any of the samples even though bulk dust
samples indicated that the concrete samples contained 18%, 19%, 21%,
22%, and 24% quartz.
CONCLUSIONS
This Alert illustrates the variety of conditions in the U.S.
construction industry that can lead to the development of silicosis.
Efforts to prevent silicosis may be inadequate if any of the five
following conditions exist:
- A lack of awareness about the sources of silica exposure, the
nature of silicosis, and the causes of the disease
- Failure to substitute abrasive blasting materials less toxic
than those containing silica
- Inadequate engineering controls and work practices
- Inadequate respiratory protection programs for workers
- Failure to conduct adequate surveillance programs, including
exposure and medical monitoring
RECOMMENDATIONS
NIOSH recommends the following measures to reduce exposures to
respirable crystalline silica in the workplace and to prevent
silicosis and deaths in construction workers:
- Recognize when silica dust may be generated and plan ahead to
eliminate or control the dust at the source. Awareness and
planning are keys to prevention of silicosis.
- Do not use silica sand or other substances containing more
than 1% crystalline silica as abrasive blasting materials.
Substitute less hazardous materials.
- Use engineering controls and containment methods such as
blast-cleaning machines and cabinets, wet drilling, or wet sawing
of silica-containing materials to control the hazard and protect
adjacent workers from exposure.
- Routinely maintain dust control systems to keep them in good
working order.
- Practice good personal hygiene to avoid unnecessary exposure
to other worksite contaminants such as lead.
- Wear disposable or washable protective clothes at the
worksite.
- Shower (if possible) and change into clean clothes before
leaving the worksite to prevent contamination of cars, homes, and
other work areas.
- Conduct air monitoring to measure worker exposures and ensure
that controls are providing adequate protection for workers.
- Use adequate respiratory protection when source controls
cannot keep silica exposures below the NIOSH REL.
- Provide periodic medical examinations for all workers who may
be exposed to respirable crystalline silica.
- Post warning signs to mark the boundaries of work areas
contaminated with respirable crystalline silica.
- Provide workers with training that includes information about
health effects, work practices, and protective equipment for
respirable crystalline silica.
- Report all cases of silicosis to State health departments and
OSHA.
These recommendations are discussed briefly in the following
subsections.
Dust Control
The key to preventing silicosis is to keep dust out of the air.
Dust controls can be as simple as a water hose to wet the dust
before it becomes airborne. Use the following methods to control
respirable crystalline silica:
- Use the dust collection systems available for many types of
dust-generating equipment. When purchasing equipment, look for
dust controls. Use local exhaust ventilation to prevent dust from
being released into the air. Always use the dust control system,
and keep it well maintained. Do not use equipment if the dust
control system is not working properly.
- During rock drilling, use water through the drill stem to
reduce the amount of dust in the air, or use a drill with a dust
collection system. Use drills that have a positive-pressure cab
with air conditioning and filtered air supply to isolate the
driller from the dust.
- When sawing concrete or masonry, use saws that provide water
to the blade.
- Use good work practices to minimize exposures and to prevent
nearby workers from being exposed. For example, remove dust from
equipment with a water hose rather than with compressed air. Use
vacuums with high-efficiency particulate air (HEPA) filters, or
use wet sweeping instead of dry sweeping.
- Use abrasives containing less than 1% crystalline silica
during abrasive blasting to prevent quartz dust from being
released in the air.
- Use containment methods such as blast-cleaning machines and
cabinets to prevent dust from being released into the air.
Personal Hygiene
The following personal hygiene practices are essential for
protecting workers from respirable crystalline silica and other
contaminants such as lead, particularly during abrasive-blasting
operations [NIOSH 1991a]:
- Do not eat, drink, or use tobacco products in dusty areas.
- Wash hands and face before eating, drinking, or smoking
outside dusty areas.
- Park cars where they will not be contaminated with silica and
other substances such as lead.
Protective Clothing
Take the following steps to assure that dusty clothes do not
contaminate cars, homes, or worksites outside the dusty area:
- Change into disposable or washable work clothes at the
worksite.
- Shower and change into clean clothes before leaving the
worksite.
Air Monitoring
Air monitoring is needed to measure worker exposures to
respirable crystalline silica and to select appropriate engineering
controls and respiratory protection. Perform air monitoring as
needed to measure the effectiveness of controls. Collect and analyze
air samples according to NIOSH Method Nos. 7500 and 7602 [NIOSH
1994] or their equivalent.
RESPIRATORY PROTECTION
Use of Respirators
Do not use respirators as the primary means of preventing or
minimizing exposures to airborne contaminants. Instead, use
effective source controls such as substitution, automation, enclosed
systems, local exhaust ventilation, wet methods, and good work
practices. Such measures should be the primary means of protecting
workers. However, when source controls cannot keep exposures below
the NIOSH REL, controls should be supplemented with the use of
respirators.
Respiratory Protection Program
When respirators are used, the employer must establish a
comprehensive respiratory protection program, as outlined in the
NIOSH Guide to Industrial Respiratory Protection [NIOSH 1987a] and
as required in the OSHA respiratory protection standard [29 CFR
1910.134 and 1926.103]. Important elements of this standard are
--periodic environmental monitoring,
--regular training of personnel,
--selection of proper NIOSH-approved respirators,
--an evaluation of the worker's ability to perform the work
while wearing a respirator,
--respirator fit testing, and
--maintenance, inspection, cleaning, and storage of respiratory
protection equipment.
The respiratory protection program should be
evaluated regularly by the employer.
Type CE Abrasive-Blasting Respirators
Type CE abrasive-blasting respirators are the only respirators
suitable for use in abrasive-blasting operations. Currently, four
Type CE abrasive-blasting respirators are certified by NIOSH [NIOSH
1996]:
1. A continuous-flow respirator with a loose-fitting
hood and an assigned protection factor (APF) of 25
2. A continuous-flow respirator with a tight-fitting facepiece
and an APF of 50
3. A positive-pressure respirator with a tight-fitting,
half-mask facepiece and an APF of 1,000
4. A pressure-demand or positive-pressure respirator with a
tight-fitting full facepiece and an APF of 2,000
NIOSH recommends that workers wear a Type CE, pressure-demand or
positive-pressure, abrasive-blasting respirator (APF of 1,000 or
2,000) during abrasive-blasting operations that involve crystalline
silica.
Other Respirators
For operations other than abrasive blasting, Table 1 lists the
minimum respiratory equipment required to meet the NIOSH REL for
crystalline silica under given conditions. Use the most protective
respirator that is feasible and consistent with the tasks to be
performed. For additional information about respirator selection,
consult the NIOSH Respirator Decision Logic [NIOSH 1987b]. Workers
should use only respirators that have been certified by NIOSH and
MSHA [NIOSH 1991b] according to 30 CFR 11, or respirators certified
by NIOSH according to 42 CFR 84 (effective July 10, 1995).
Table 1.--NIOSH-recommended respiratory
protection for workers exposed to respirable crystalline
silica
| Condition |
Minimum respiratory protection required
to meet the
NIOSH REL (0.05 mg/m3) |
< 0.5 mg/m3*
(10 x REL) |
Any half-mask, air-purifying respirator
with a
high-efficiency particulate filter† |
Table 1. NIOSH-recommended respiratory protection for workers
exposed to respirable crystalline silica
__________________________________________________________________________________________
Condition Minimum respiratory protection required to meet
the NIOSH REL (0.05 mg/m3)
__________________________________________________________________________________________
<=0.5 mg/m3* Any half-mask, air-purifying respirator with a high-efficiency
(10 x REL)‡ particulate filter†
------------------------------------------------------------------------------------------
<=1.25 mg/m3 Any powered, air-purifying respirator with a
(25 x REL) high-efficiency particulate filter, or
Any supplied-air respirator equipped with a
hood or helmet and operated in a continuous-flow
mode (for example, type CE abrasive-blasting
respirators operated in the continuous-flow mode)
------------------------------------------------------------------------------------------
<=2.5 mg/m3 Any air-purifying, full-facepiece respirator
(50 x REL) with a high-efficiency particulate filter, or
Any powered, air-purifying respirator with a
tight-fitting facepiece and a high-efficiency
particulate filter
------------------------------------------------------------------------------------------
<=50 mg/m3 Any supplied-air respirator equipped with a half-mask
(1,000 x REL) and operated in a pressure-demand or other positive-pressure
mode (for example, a Type CE abrasive-blasting respirator
operated in a positive-pressure mode)§
------------------------------------------------------------------------------------------
<=100 mg/m3 Any supplied-air respirator equipped with a full
(2,000 x REL) facepiece and operated in a pressure-demand or other
positive-pressure mode (for example, a Type CE
abrasive-blasting respirator operated in a
positive-pressure mode)
------------------------------------------------------------------------------------------
Planned or emergency Any self-contained breathing apparatus equipped with a full
entry into environments facepiece and operated in a pressure-demand or other
containing unknown positive-pressure mode, or
concentrations or con-
centrations >100 mg/m3 Any supplied-air respirator equipped with a full facepiece
(2,000 x REL) and operated in a pressure-demand or other positive-pressure
mode in combination with an auxiliary self-contained breathing
apparatus operated in a pressure-demand or other positive-
pressure mode
------------------------------------------------------------------------------------------
Firefighting Any self-contained breathing apparatus equipped with a full
facepiece and operated in a pressure-demand or other
positive-pressure mode
------------------------------------------------------------------------------------------
Escape only Any air-purifying, full-facepiece respirator with a high-
efficiency particulate filter, or
Any appropriate escape-type, self-contained breathing apparatus
__________________________________________________________________________________________
*<= is less than or equal to;> is greater than.
† The new NIOSH respirator certification regulation (42 CFR 84) became effective
July 10, 1995, and replaces the old regulation (30 CFR 11). High-efficiency is the
appropriate filter for respirable crystalline silica under 30 CFR 11; N100, R100, and
P100 are the appropriate filters for respirable crystalline silica under 42 CFR 84.
‡ Assigned protection factor (APF) times the NIOSH REL. The APF is the level of
protection provided by each type of respirator.
§ Type CE abrasive-blasting respirators are the only respirators suitable for
use in abrasive-blasting operations. Instruction about the purpose and set-up of regulated
areas marking the boundaries of work areas containing crystalline silica
Medical Monitoring
Medical examinations should be available to all workers who may
be exposed to respirable crystalline silica. However, examinations
should always supplement effective dust monitoring and
controls--never substitute for them. Such examinations should
occur before job placement or upon entering a trade, and at least
every 3 years thereafter [NIOSH 1974]. Examinations should include
at least the following items:
- A medical and occupational history to collect data on
crystalline silica exposure and signs and symptoms of
respiratory disease
- A chest X-ray classified according to the 1980 International
Labour Office (ILO) International Classification of Radiographs
of Pneumoconioses [ILO 1981]
- Pulmonary function testing (spirometry)
- An annual evaluation for tuberculosis [ATS/CDC 1986].
Warning Signs
Warning signs should be posted to mark the boundaries of work
areas contaminated with crystalline silica. These signs should
warn workers about the hazard and specify any protective equipment
required (for example, respirators). The sample sign in Figure 7
contains the information needed for a silica work area where
respirators are required.
Training
Workers should receive safety training and education that
includes the following [29 CFR 1926.21]:
- Information about the potential health effects of exposure
to respirable crystalline silica
- Material safety data sheets for silica, masonry products,
alternative abrasives, and other hazardous materials [29 CFR
1926.59]
- Instruction about the purpose and set-up of regulated areas
marking the boundaries of work areas containing crystalline
silica
- Information about safe handling, labeling, and storage of
toxic materials
- Discussion about the importance of substitution, engineering
controls, work practices, and personal hygiene in reducing
crystalline silica exposure
- Instruction about the use and care of appropriate protective
equipment (including protective clothing and respiratory
protection).
Surveillance and Disease Reporting
NIOSH encourages reporting of all cases of silicosis to the
State health departments and OSHA. To encourage uniform reporting,
NIOSH has developed reporting guidelines and a surveillance case
definition for silicosis (see Appendix). This definition and these
guidelines are recommended for surveillance of work-related
silicosis by State health departments and regulatory agencies
receiving reports of cases from physicians and other health care
providers [CDC 1990].
ACKNOWLEDGMENTS
The principal contributors to this Alert were Kenneth D. Linch;
Dennis W. Groce; Karl J. Musgrave; Ruth A. Jajosky; Steven R.
Short; and John E. Parker. Please direct comments, questions, or
requests for additional information to Dr. Gregory Wagner,
Director, Division of Respiratory Disease Studies, NIOSH, 1095
Willowdale Road, Morgantown, West Virginia 26505-2888; Telephone:
(304) 285-5749.
NIOSH would also like to thank the Silicosis SENSOR Program
States for their work in preventing silicosis:
Illinois [Celan Alo and Roy Maxfield, (217)
785-1873]
Michigan [Ken Rosenman and Mary Jo Reilly, (517)
353-4979]
New Jersey [Martha Stanbury, (609) 984-1863]
North Carolina [Bill Jones and Susan Randolph,
(919) 715-3625]
Ohio [Ed Socie and Nan Migliozzi, (614) 466-4183]
Texas [Teresa Willis and Dennis Perrotta, (512)
458-7269]
Wisconsin [George Gruetzmacher and Henry
Anderson, (608) 266-1253]
We greatly appreciate your assistance in protecting the lives
of U.S. workers.
Linda Rosenstock, M.D.,
M.P.H.
Director
National Institute for
Occupational
Safety and Health
Centers for Disease
Control
and Prevention
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IARC [1987]. IARC monographs on the evaluation of the
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silicates. Vol. 42. Lyon, France: World Health Organization,
International Agency for Research on Cancer, pp. 49, 51, 73-111.
ILO (International Labour Office) [1981]. Classification of
radiographs of the pneumoconioses. Med Radiogr Photogr 57(1):2-17.
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