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** Note: This page represents
information from an Infosheet produced by the California Department
of Health Services Environmental Health Investigations Branch, 1515 Clay
Street (Suite 1700), Oakland, CA 94612 April 1997.
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Stachybotrys chartarum (atra):
A mold that may be found in water-damaged homes.
Fungi:
Fungi are common in nature and serve a central
role as breakdown agents for organic matter. They contain fragments, or
spores, which are found in virtually every home and building (Jarvis).
Stachybotrys chartarum:
Stachybotrys chartarum
(SC) is a greenish black fungus that grows on material with a high
cellulose and low nitrogen content, such as fiberboard, gypsum board, paper,
dust, and lint, that becomes chronically moist or water damaged due to
excessive humidity, water leaks, condensation, water infiltration, or flooding.
No one knows how often this fungus is found since buildings are not routinely
tested for its presence. However, one study in Southern California found
it in 2.9% of 68 homes (Kozak) S. chartarum may (under specific environmental
conditions) produce several toxic chemicals called mycotoxins. These chemicals
are present on the spores and the small fungus fragments that are released
into the air. Although spores and other parts of this fungus are usually
trapped in a wet, slimy mass of fungal growth, many health officials are
concerned that spores may become airborne when the fungus dies and dries
up. Because S. chartarum spores are very small, some may be drawn into
the lungs when airborne spores are inhaled.
Health Effects:
The health effects of Stachybotrys chartarum
were first noted as diseases in Russian and Eastern European farm animals
that ate moldy hay. The first reported human effects were seen in agricultural
workers who handled the moldy straw or hay that was affecting the farm
animals (Jarvis). After consuming contaminated cereal grains, people experienced
symptoms included burning sensations in the mouth, nausea, vomiting, diarrhea
and abdominal pain (Schiefer). SC in humans is much less common than in
animals, and no lethal cases have been reported (Jarvis).
Much less is known about SC when it occurs in indoor environments, such
as homes or office buildings. In general, the intensity of exposure and
health effects from SC in such environments are much less severe than those
in farm animals and workers handling contaminated hay or straw (New York
Panel).
If SC spores are released into the air, there is a potential for humans
to develop symptoms such as coughing, wheezing, runny nose, irritated eyes
or throat, skin rash, or diarrhea. There are a few reports in the scientific
literature of improvement of symptoms when people left an area where SC
(Croft, Johanning) or other molds (Auger) were found, or after moldy materials
were removed from a dwelling or workplace.
It is theorized that the above symptoms may result from an allergic
response to the SC, or from toxins produced by SC or from another environmental
agent (New York panel). However, it is difficult to show that these types
of symptoms are due to SC for several reasons:
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1) When buildings are sampled, usually several other molds are found
in addition to SC, and these molds could also cause symptoms;
2) These symptoms are very nonspecific and can be related to other allergens
(such as dust mites, animal hair, pollen, etc.), or to infectious agents
such as bacteria or viruses;
3) Currently, research has not clarified what level of SC is necessary
to produce symptoms.
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A task group of the World Health Organization (WHO) concluded that "an association
between trichothecenes (the type of mycotoxins produced by SC and some
other molds) and human disease is possible, however only limited data is
available . . . conclusive evidence in humans has not been shown" (WHO).
Laboratory Tests for SC:
An antibody test for SC has been
used by a few physicians. However, this laboratory test is not always positive
in the presence of SC. In one study of 48 people possibly exposed to SC,
only 4 had an elevated antibody test for it (Johanning). In addition, since
we do not know how long the antibody may remain positive after SC exposure,
it is also possible that a positive test may be evidence of an earlier
encounter with SC, not a current one.
A New York expert panel on SC concluded "Laboratory tests for immune
markers associated with SC exposure are not helpful at this time. Research
should be pursued to refine such tests and characterize them more fully"
(New York panel, 1993).
Prevention of Mold in Dwellings:
As part of routine building
maintenance, buildings should be inspected for evidence of water damage
and visible mold. Conditions causing mold (such as water leaks, condensation,
infiltration, or flooding) should be corrected.
Correction of Visible Mold:
Visual identification of black
mold in a chronically wet area is considered to be a possible indicator
of SC or other mold. The New York City Department of Health convened an
expert panel on SC in May 1993, which recommended different methods of
mold removal depending on the size of the mold problem. Their recommendations
are summarized here:
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1) Level I : If the area of mold is 2 square feet or
less.
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A) The area can be cleaned by individuals who have received training
on proper clean up methods, protection and potential health hazards. These
individuals should be free from asthma, allergy and immune disorders. Gloves
and a half face respirator should be worn.
B) Contaminated material should be placed in a sealed plastic bag before
taking it out of the building. This will prevent contamination of other
parts of the building.
C) Surrounding areas should be cleaned with household bleach.
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2) Level II: If the area of mold is more than 2 square
feet but less than 30 square feet. The recommendations are the same
as Level I, with the added precaution that moldy materials should be covered
with plastic sheets and taped before any handling or removal is done. For
instance, a moldy panel of gypsum board (measuring 4 feet by 8 feet) wall
would need to have plastic sheeting taped over the affected area on the
wall before the wallboard is cut to remove the contaminated section. Once
cut from the wall, that section should be placed within another layer of
plastic before it is carried through the building for disposal.
3) Level III: If the area of mold is more than 30 square
feet. Personnel trained in handling of hazardous materials (such as
asbestos) are necessary. Specific recommendations for hazardous materials
workers can be found in the New York document.
4) Level IV: If SC is shown to be present in the heating,
ventilation, or air conditioning system. Recommendations are the same
as for Level III.
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Summary:
In summary, SC and other molds may cause health
symptoms that are nonspecific. At present there is no test that proves
an association between SC and particular health symptoms. Individuals with
persistent symptoms should see their physician. However, if SC or other
molds are found in a building, prudent practice recommends that they be
removed. The simplest and most expedient remediation that properly and
safely removes mold should be used.
Partial Bibliography
Andrassy K, Horvath I, Lakos T, Toke Z. "Mass incidence of mucotoxicoses
in Hajdu-Bihar County." Mykosen 1979;23:130-133.
Auger PL, Gourdeau P, Miller D, "Clinical experience with patients suffering
from a chronic fatigue-like syndrome and repeated upper respiratory infections
in relation to airborne molds". Am. J. of Indust. Medicine 1994; 25:41-42.
Corrier DE. "Mycotoxicosis: mechanism of immunosuppression." Vet Immunol
Immunopathol 1991; 30:73-87.
Croft WA, Jarvis BB, Yatawara CS. "Airborne outbreak of trichothecene
toxicosis", Atmosph Environ 1986; 20:549-552.
Flannigan B, McCabe EM, McGarry F. "Allergenic and toxigenic micro-organisms
in houses." J Appl Bact Symp (Suppl) 1991; 70:61S-73S.
Jarvis BB. "Mycotoxins and Indoor Air Quality." In: Biological Contaminants
in Indoor Environments (ASTM STP 1071). Phillip R. Morey, James C. Feeley,
James A. Otten (eds.). Philadelphia: American Society for Testing and Materials,
1990: 201-213.
Johanning E, Morey PR, Jarvis BB. "Clinical Epidemiological Investigation
of Health Effects caused by Stachybotrys Atra Building Contamination",
Proceedings of Indoor Air, 1993; Vol. 1: 225-230.
Johanning E, Biagini R, Hull DL, et al. "Health and immunology study
following exposure to toxigenic fungi (Stachybotrys chartarum) in
a water-damaged office environment" Int Arch Occup Environ Health 1996,
68:207-218.
Kozak PP, Garvins J, Cummins L H, Gillman SA. "Currently available methods
for home mold surveys." Ann Allergy 1979; 45:167-176.
New York City Department of Health. Guidelines on Assessment and
Remediation of Stachybotrys Atra in Indoor Environments, May 7, 1993.
Samson, RA. "Occurrence of molds in modern living and working environments."
Eur J Epidemiol 1985 March; 1: 54-61.
Schiefer HB and Beasley VR. Effects on the digestive system and energy
metabolism. in Trichothecene Mycotoxicosis: Pathophysiologic Effects, Vol.
1. Ed:VR Beasley. CRC Press, Boca Raton, FL, 1994 pp.61-89.
Summerbell RC, Stabi F, Dales R. et.al. "Ecology of fungi in human
dwellings."
J Med Vet Mycol. 1992 (Suppl 1); 30: 279-285.
"Selected mycotoxins, other toxins, trichothecenes, ergot". Environmental
Health Criteria 105. WHO, Geneva,. 1990: 71-163.
Ueno Y. In "Trichothecenes - Chemical, Biological and Toxicological
Aspects." Ueno (editor) Elsevier Science Publishing Co., Inc. New York,
NY. 1983. 135-146.
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