Environmental Health Investigations Branch,
Department of Health Services,
chartarum (SC) is a greenish
black mold that grows on material with a high cellulose content, such as
fiberboard, the paper covering of gypsum wallboard, wallpaper, dust, and
wood when these become chronically water damaged. This
mold requires very wet conditions for days or weeks in order to grow. Excessive indoor humidity resulting in water vapor
condensation on walls, plumbing leaks, spills from showering or bathing,
water leaking through foundations or roofs may lead to growth of many
types of mold, including Stachybotrys.
No one knows how frequently this mold is found indoors since
buildings are not routinely tested for its presence.
chartarum is one of many molds that are capable of producing one or
more mycotoxins (chemicals produced by molds that may be able to cause
symptoms or illness in people). It
has recently gained notoriety as some strains are capable of producing a
very potent toxin. However, finding Stachybotrys
within a building does not necessarily mean that occupants have been
exposed either to allergens (pieces of the fungus or spores that can cause
allergic symptoms in people prone to allergies) or toxins produced by this
fungus. Laboratory studies
indicate that molds such as Stachybotrys
that have the ability to produce toxins do not always do so.
Whether a mold produces a toxin while growing in a building may
depend on what the mold is growing on, conditions such as temperature, pH,
humidity or other unknown factors. When
mycotoxins are present, they occur on spores and the small mold fragments
that may be released into the air. While
Stachybotrys is growing, a wet
slime layer covers its spores, preventing them from becoming airborne. However,
when the mold dies and dries up, air currents or physical handling can
cause spores to become airborne. There
are no commercial laboratory tests currently available that can detect
mycotoxins in a building where molds are present.
Health problems associated with Stachybotrys chartarum were first noted in Russian and Eastern
European farm animals that ate moldy hay in the 1930’s and 1940’s.
Horses eating heavily SC-contaminated fodder experienced immune system suppression,
infection and bleeding that was fatal with high doses.
The first reported human health effects were seen in agricultural
workers who handled the moldy straw or hay. These high level exposures were associated with coughing,
runny nose, burning sensations in the mouth or nose, nose bleeds,
headache, fatigue and skin irritation (rashes and itching) at the site of
moldy hay contact.
Much less is known about health effects of SC
when it occurs in indoor environments, such as homes or office
buildings, where the most likely route of exposure is inhalation. If
large numbers of SC spores are
released into the air, some people may develop symptoms such as coughing,
wheezing, runny nose, irritated eyes or throat, skin rash, fatigue or
diarrhea. Researchers have
theorized that these symptoms may result from toxins produced by SC
or exposure to a combination of several molds or bacteria and the
chemicals they produce. Most
people who experience health effects associated with moldy buildings fully
recover following removal and clean-up of the mold contamination.
Much of the concern about
toxin-producing indoor molds and especially Stachybotrys
followed its identification in the mid-1990s in the homes of a small
number of Cleveland infants with an unusual form of lung bleeding. The
original investigation, cosponsored by the U.S. Centers for Disease
Control and Prevention (CDC) suggested that very wet homes and Stachybotrys growth played a role in these lung hemorrhage cases.
However, after reviewing the methods used to conduct the original
study, the CDC concluded in May, 2000 that a possible association between
the lung bleeding in the Cleveland infants (now called “acute idiopathic
pulmonary hemorrhage”) and exposure to molds, specifically Stachybotrys
chartarum, was not proven. However,
both the CDC and other research groups are continuing to examine the role
of indoor molds in both child and adult health, particularly for those
molds that may produce toxins.
How can I tell if my health
problems are caused by Stachybotrys?
It is currently difficult to prove that individual
health symptoms are due to SC exposure
for several reasons:
1) When buildings are
sampled, usually several other molds or bacteria (some capable of
producing chemicals such as endotoxin) are found in addition to SC,
and these may also contribute to symptoms;
2) These symptoms are very nonspecific and may be related to
exposure to other sources (such as dust mites, animal dander, pollen or
other allergens) or to infectious agents such as viruses that cause common
colds or flu;
Research has not identified how much Stachybotrys exposure is necessary to produce symptoms;
There is no test that can determine if a person was exposed to this
fungus or its toxins.
Tests for Human Exposure to SC
mold or toxins
A few physicians have used a blood antibody test to
determine whether their patients have been exposed to the SC mold or its toxins. However,
this procedure has not been proven to be valid.
In one study of 48 people exposed to SC,
only 4 had elevated antibodies. The
Stachybotrys antibody test can
also be positive when an individual is exposed to other types of mold
altogether (i.e., cross-reaction). Therefore
this test cannot be used to definitively determine whether someone has
been exposed to the Stachybotrys
mold or its toxins. In
addition, since we do not know how long antibodies remain elevated after SC exposure, it is also possible that a positive test may be
evidence of a previous encounter with SC
or a cross-reacting mold, not a current one.
of Mold in Dwellings
As part of routine building maintenance, buildings should be inspected
for evidence of water damage and visible mold.
Water damage should be corrected early (within 48 hours) and
building surfaces or furnishings dried to prevent mold growth.
If any type of visible mold growth is found, whether Stachybotrys
or any other mold, the water damage leading to it should be corrected and
visible mold removed by appropriate methods as described below.
of Visible Mold
Visible mold should be removed by the simplest and
easiest method that is proper and safe. Common
household molds found around bathtubs or between shower tiles should be
removed with a household cleanser. For
building components like walls or ceilings showing any type of fungal
growth, including Stachybotrys,
specific methods for removal are based on the extent of visible
contamination and underlying water damage.
New York City Department of Health produced a set of voluntary
guidelines in April, 2000 that incorporate the best available knowledge on
removing mold contaminated building components.
Their recommendations are summarized here, but the full text should
be consulted before deciding on a remediation strategy.
Text is available at the New York City Department of Health website
listed at the end of this document.
I : If the area of
mold is small and isolated (10 square feet or less) – e.g., ceiling
tiles, small areas on walls
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, eye
protection and an N95 disposable respirator (available at neighborhood
hardware stores) should be worn.
B) Contaminated material that
cannot be cleaned should be removed and placed in a sealed plastic bag
before taking it out of the building.
This will prevent contamination of other parts of the building.
C) The work area and areas
used by the remediation workers while exiting the building should be
cleaned with a damp cloth or mop. All
areas should be left dry and visibly free of mold contamination and
isolated areas (10-30 square feet) – e.g., a wallboard panel
The recommendations are the same as
Level I, with the added precaution that
A) Moldy materials should be covered with plastic sheets and taped
before any handling or removal is done.
For instance, a moldy panel of gypsum wallboard should have plastic
sheeting taped over the affected area on the wall before it is cut to
remove the contaminated section. Once
cut from the wall, that section should be placed inside another layer of
plastic and sealed up with tape before it is carried through the building
B) Following removal of contaminated material, the work area and exit
areas should be HEPA vacuumed (a vacuum equipped with a High-Efficiency
Particular Air filter) in addition to cleaning with a damp cloth or mop.
III, IV, V: Large
area (more than 30 square feet) – e.g., several wallboard panels or more
A health and safety professional with experience performing microbial
investigations should be consulted prior to any cleaning activities to
provide oversight for the project. See the specific recommendations in “Guidelines on
Assessment and Remediation of Molds in Indoor Environments”, New York
City Department of Health, on their website (see Additional Resources). If you do not have access to the Internet you may request a
copy through the California Department of Health Services Indoor Air
Quality Assistance Line at (510) 540-2476.
Exposure to high levels of Stachybotrys chartarum and other mold spores may cause health
symptoms in some individuals. Therefore,
any fungal growth on building materials should be cleaned off or removed
as rapidly as possible to maintain a healthy indoor environment. New
York City Department of Health guidelines provide detailed information on
mold remediation strategies and are available from their website (see
At present there is no environmental test to
determine whether Stachybotrys growth found in buildings is producing
toxins. There is also no
blood or urine test that can establish if an individual has been exposed
to Stachybotrys chartarum spores or its toxins. Anyone
with persistent health problems that they believe may be related to indoor
molds should consult their physician.
York City Department of Health. Guidelines
on Assessment and Remediation of Molds in Indoor Environments.
Full text document available at http://www.ci.nyc.us/health.
For further information about
this document contact New York City Department of Health at (212)
U.S. E.P.A. Indoor Air Quality Web Site – Mold Links and General
U.S. E.P.A. Indoor Air Quality Information Clearinghouse:
For information on many
types of indoor air contaminants.
Centers for Disease Control and Prevention.
Questions and Answers
on Stachybotrys chartarum and
other molds http://www.cdc.gov/nceh/asthma/factsheets/molds/default.htm.
Centers for Disease Control and Prevention. Update:
Pulmonary Hemorrhage/Hemosiderosis Among Infants – Cleveland, OH,
1993-1996. Morbidity and Mortality Weekly Report 49(09):180-4 March 10,
2000. Full text available:
More Environmental and Mold Sources of