| Causes of Scleroderma (MAIN MENU) |
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| Causes
of Scleroderma: Silica Exposure |
| This page
was written by Shelley
Ensz and has not yet been medically edited. |
|
| Overview of Silica
Exposure |
| Silica exposure can cause autoimmune
diseases such as lupus, scleroderma,
and vasculitis.
It can also cause silicosis,
kidney disease, lung cancer, tuberculosis, and other airways
diseases. Environmental
exposure to silica can occur in workers and bystanders
in many industries, including agriculture, construction, and
potters. |
| Materials
Containing Silica |
| Silica occurs in the following
materials, but there is a potential for danger ONLY when
crystalline silica particles are in the air. If you can
answer YES to any of these, then it is likely that Silica
is used at your work and that it is airborne. |
Abrasives
Coal Dust
Concrete
Dirt
Filter Aids
Graphite, natural
Mica
Mineral Products
Paints
Pavement |
Perlite
Plant Materials
Plastic Fillers
Polishing Compounds
Portland Cement
Sands
Silicates
Slag
Soapstone
Soil |
Source:
Occupational Safety & Health Administration (OSHA).
Read
more... |
|
| Silica occurs
as a natural component of many materials used or encountered
in construction activities. Crystalline silica is present in
substantial quantities in sand, sandstone and granite, and
often forms a significant proportion of clay, shale and slate.
It can also be found in chalk, limestone and other rock and
soil. Products such as concrete and mortar also contain crystalline
silica. 2003, Health and Safety Executive. |
Silica
Exposure
can occur to workers and bystanders in the following
type of industries: |
abrasives (manufacturing
and use)
agriculture
ceramics, clay, pottery
construction
detergent manufacturing
foundry work
glass manufacturing |
masonry work
mining
railroad construction
sandblasting
shipbuilding
soap making
stone cutting |
| Source:
National Institute for Occupational Health and Safety. Read
more... |
|
| Silica. At
least 1.7 million U.S. workers are exposed to respirable crystalline
silica in a variety of industries and occupations, including
construction, sandblasting, and mining. Occupational exposures
to respirable crystalline silica are associated with the development
of silicosis, lung cancer, pulmonary tuberculosis, and airways
diseases. These exposures may also be related to the development
of autoimmune disorders, chronic renal disease, and other adverse
health effects. CDC National Institute for Occupational
Health and Safety. |
| Health
Effects of Occupational Exposure to Respirable Crystalline
Silica Occupational exposures to respirable crystalline
silica are associated with the development of silicosis,
lung cancer, pulmonary tuberculosis, and airways diseases.
These exposures may also be related to the development of
autoimmune disorders, chronic renal disease, and other adverse
health effects. Publication No. 2002-129, April 2002,
NIOSH Hazard Review. |
| Silica
Flour The risk of developing silicosis may be very high
for workers exposed to silica flour. Silica flour is used
industrially as an abrasive cleaner and as an inert filler.
It is found in toothpaste, scouring powder, and metal polish,
paint, wood fillers, road surfacing mixtures, and foundry
processes. Workers in industries that use silica flour may
be unaware that it is a hazardous material because of either
the absence of labelling or the mislabelling of silica flour
containers. 1987 Bulletin, NIOSH. |
| Silica and Silicosis |
| Understanding
a complex killer. Respirable silica, a material present
in cement construction products, including roof tiles, has
been a known occupational health hazard for more than a century.
Silicosis has been associated with other connective tissue
diseases such as rheumatoid arthritis, scleroderma, lupus
and sarcoidosis. In addition, it has been linked with various
kidney disorders. Professional Roofing Magazine. August
2005. |
| Silicosis
Epidemics The worst epidemic of silicosis occurred in
1930-1931, during the construction of Gauley Bridge tunnel
in West Virginia; more than 400 of the estimated 2000 men
who drilled rocks died of silicosis, and almost all the survivors
developed silicosis. eMedicine. |
| Silica and Lupus |
| Silica
accelerated systemic autoimmune disease in lupus-prone New
Zealand mixed mice. Lungs of the silica-exposed mice
had increased inflammatory infiltrates as well as fibrotic
lesions characterized by excess collagen deposition. Silica
exposure significantly exacerbated the course of disease. PubMed.
Clin Exp Immunol 2003 Mar;131(3):415-21. (Also see: Lupus) |
| Silica and Scleroderma |
| What
is Scleroderma? ISN. |
| Brochure:
What is Scleroderma? (PDF Format) Includes a symptom
checklist for systemic scleroderma. International Scleroderma
Network. |
| Genetic basis for systemic sclerosis. Investigations into the genetics of systemic sclerosis may shed light on the complex pathophysiology of this disease, help to identify factors that predict organ involvement, and suggest new treatment strategies. Science Direct. Oct 2007. (Also see: Causes of Scleroderma: Genetics, Solvents, and Environmental Factors) |
| Silica
and the immune system. In view of the double involvement
of the Innate and the Adaptive Immune Systems and their cooperation
in the stimulation of fibrosis, Silicosis can be considered
as a "Collagen" Disease, related to other diseases
of that group like rheumatoid arthritis, lupus erythematosus
and scleroderma. PubMed. Acta Biomed Ateneo Parmense.2005;76
Suppl 2:38-44. |
| Silicone
Breast Implants and Scleroderma. Are some cases of connective
tissue disease, such as scleroderma, related to artificial
joints or silicone breast implants? Contradictory findings
continue to plague research into this area. ISN. |
| Silicosis,
usually a nodular pulmonary fibrosis, is the disease most associated
with exposure to respirable crystalline silica. Although the
reported mortality associated with silicosis has declined over
the past several decades, many silicosis associated deaths
still occur. An unknown number of workers also continue to
die from silica-related diseases such as pulmonary tuberculosis
(TB), lung cancer, and scleroderma. Publication No.
2002-129, April 2002, NIOSH Hazard Review. |
| Interim
Report to the Workers' Compensation Board on Scleroderma. The
repeated occurrence of a very rare disease, at least three
times more common in women, in males occupationally exposed
to silica is suggestive of a causal association. What is
striking in the literature on scleroderma reviewed for this
report is the repetition of the association between this
disease and an occupational history of exposure to free silica
and/or vibratory tools. 03-31-92, Industrial Disease Standards
Panel (ODP), IDSP Report of Findings No. 8, Toronto, Ontario. |
| In
a hospital-based case-referent study of systemic sclerosis
(SSc) and occupational risk factors (55 cases and 171 referents),
an excess risk for SSc was observed in men with previous
occupational exposure to solvents and certain chemicals (vinyl
chloride, formaldehyde). SSc was associated, even though
not significantly, with occupational exposure to solvents
and silica among women. PubMed. G Ital Med Lav Ergon.
2003 Jul-Sep;25 Suppl(3):46-7. |
| Occupational
silica exposure and risk of various diseases: an analysis
using death certificates from 27 states of the United States. A
matched case-control design was employed to examine each
of several diseases (including silicosis, lung cancer, stomach
cancer, oesophageal cancer, COPD, pulmonary tuberculosis,
sarcoidosis, systemic lupus erythematosus, systemic sclerosis,
rheumatoid arthritis, and various types of renal disease). PubMed.
Occup Environ Med 2003 Feb;60(2):122-129. |
| Silica and Vasculitis |
| Exposure
to silica and risk of antineutrophil cytoplasmic antibodies
(ANCA)-associated vasculitis. Long-term silica exposure
may be one of the exogenous factors contributing to ANCA
production, however, silica exposure alone, without typical
silicosis, was not associated with ANCA positivity. PubMed.
Am J Ind Med. 2006 May 11. (Also see: Vasculitis and Antibodies) |
| Silica
exposure and systemic vasculitis. I present the case
of a 63-year-old male who worked in DOE (Department of Energy)
facilities for 30 years as a weapons testing technician.
In addition to silica, other workplace exposures included
beryllium, various solvents and heavy metals, depleted uranium,
and ionizing radiation. The patient's diagnoses included
microscopic polyangiitis, systemic necrotizing vasculitis,
leukocytoclastic vasculitis, and glomerulonephritis. PubMed.
Environ Health Perspect. 2003 Dec;111(16):1933-8. (Also see: Vasculitis) |
| Silica Environmental
and Occupational Exposures |
Silica
Exposure
can occur to workers and bystanders in the following
type of industries: |
abrasives (manufacturing
and use)
agriculture
ceramics, clay, pottery
construction
detergent manufacturing
foundry work
glass manufacturing |
masonry work
mining
railroad construction
sandblasting
shipbuilding
soap making
stone cutting |
| Source:
National Institute for Occupational Health and Safety. Read
more... |
|
| Silica-dust-exposed
mine workers with scleroderma (systemic sclerosis). There
was a significant increase in the prevalence of tuberculosis
in the past in the group with scleroderma, compared with
a group of men with silicosis from the same population. The
nature of the association of tuberculosis with scleroderma
has not been defined. Chest, Vol 92, 260-262, 1987. |
| Study
Looks at Possible Link Between Skin Exposure to Silica and
Autoimmune Disorders. While the link between occupational
exposure to silica and autoimmune disorders has been well-established,
most studies have focused on inhalation exposure. This hypothesis
is that "skin exposure to fine and ultrafine silica
– probably crystalline silica – can result in a susceptible
or predisposed individual developing an autoimmune disorder
such as SLE, rheumatoid arthritis or scleroderma." Occupational
Hazards. 10/11/05. |
| Determining
Silica Exposure Because silica is so abundant in our
natural resources, it's possible that you use silica and
don't even know it! There is potential for danger ONLY when
crystalline silica particles are in the air. There may be
materials that contain silica but if the operations on those
materials do not generate dust, there is little chance of
inhaling the silica. Likewise, there may be silica particles
in the air even though you don't see any dust. |
| Deaths
from Silica in the Workplace The first column is the
occupational title. The second column (PMR) is the observed
number of deaths from silicosis per occupation divided by
the expected number of deaths. U.S. Department of Labor,
Occupational Safety & Health Administration. |
| Scleroderma
from silica is listed as a an occupational disease, recognized
by the U.S. Worker's Compensation Bureau guidelines.> |
| From the "Interim Report to
the Worker's Compensation Board on Scleroderma" (Ontario,
Canada): |
| "Scleroderma was recognized
as an occupational disease in the former German Democratic
Republic. Its status after reunification is unclear. Dr. U.
Haustein of Karl Marx University, Leipzig, has described the
adjudication process as case-by-case (19). Each patient is
discussed by a committee of experts (Obergutachtenkommission).
Careful consideration is given to all facts such as occupational
exposure time to silica, working conditions, interval until
the manifestation of the disease, association with silicosis,
etc. |
| "In South Africa, scleroderma
is mentioned in the Occupational Diseases in Mines and Works
Act (78 of 1973). This act originated in 1911 and was aimed
at improving working conditions in all South African mines.
Many aspects of the Act relate to "risk work" and "compensatable
disease". Risk work, in practice, is all work below the
natural surface of the earth and certain surface operations
(work in crusher houses, reduction plants, and on slime dams)." |
| Silicosis:
Medical/Legal Pitfalls To evaluate disability due to
silicosis, one must document a reduction in pulmonary function
that is sufficient to prevent the person from engaging in
gainful employment or activities of daily living. 2004
eMedicine. |
| Silica Research |
| Immunoglobulin
and lymphocyte responses following silica exposure in New
Zealand mixed mice. These studies begin to provide possible
mechanisms for environmentally induced autoimmune diseases
that have been reported in many epidemiological studies. PubMed.
Inhal Toxicol. 2004 Mar;16(3):133-9. |
