PENICILLIUM:
Penicillium species have been shown to be fairly common indoors, even in
clean environments, but can be problematic when indoor spore levels are
higher than outdoors (Burge, 1986; Miller et al., 1988; Flannigan and
Miller, 1994). Spores have the highest concentrations of mycotoxins,
although the vegetative portion of the mold, the mycelium, can also contain
the poison. The viability of spores is not essential to toxicity. In other
words, a dead spore can still be a source of toxin.
ASPERGILLUS:
Aspergillus species are also fairly prevalent in problem buildings. This
genus contains several toxigenic species, among which the most important
are, A. parasiticus, A. flavus, and A. fumigatus. Aflatoxins produced by the
first two species are among the most extensively studied mycotoxins. They
are among the most toxic substances known, being acutely toxic to the liver,
brain, kidneys and heart, and with chronic exposure, potent carcinogens of
the liver. They are also teratogenic (Smith and Moss, 1985; Burge, 1986).
Symptoms of acute aflatoxicosis are fever, vomiting, coma and convulsions
(Smith and Moss, 1985). A. flavus is found indoors in tropical and
subtropical regions, and occasionally in specific environments such as
flowerpots. A. fumigatus has been found in many indoor samples. A more
common aspergillus species found in wet buildings is A. versicolor, where it
has been found growing on wallpaper, wooden floors, fibreboard and other
building material. A. versicolor does not produce aflatoxins, but does
produce a less potent toxin, sterigmatocystin, an aflatoxin precursor
(Gravesen et al., 1994). While symptoms of aflatoxin exposure through
ingestion are well described, symptoms of exposure such as might occur in
most moderately contaminated buildings are not know, but are undoubtedly
less severe due to reduced exposure. However, the potent toxicity of these
agents advise that prudent prevention of exposures are warranted when levels
of aspergilli indoors exceed outdoor levels by any significant amount. A.
fumigatus has been found in many indoor samples. This mold is more often
associated with the infectious disease aspergillosis, but this species does
produce poisons for which only crude toxicity tests have been done (Betina,
1989). Recent work has found a number of tremorgenic toxins in the conidia
of this species (Land et al., 1994). A. ochraceus produces ochratoxins (also
produced by some penicillia as mentioned above). Ochratoxins damage the
kidney and are carcinogenic (Smith and Moss, 1985).
STACHYBOTRYS:
Stachybotrys chartarum (atra) has been much discussed in the popular press
and has been the subject of a number of building related illness
investigations. It is a mold that is not readily measured from air samples
because its spores, when wet, are sticky and not easily aerosolized. Because
it does not compete well with other molds or bacteria, it is easily
overgrown in a sample, especially since it does not grow well on standard
media (Jarvis, 1990). Its inability to compete may also result in its being
killed off by other organisms in the sample mixture. Thus, even if it is
physically captured, it will not be viable and will not be identified in a
cultured sample media, even though it is present in the environment and
those who breathe it can have toxic exposures. For that reason, it is
prudent to take a surface sample, such as tape or bulk, whenever evidence of
black mold is found. This organism has a high moisture requirement, so it
grows vigorously where moisture has accumulated from roof or wall leaks, or
chronically wet areas from plumbing leaks. It is often hidden within the
building envelope and inside wall cavities. When Stachybotrys is found in an
air sample, it should be searched out in walls or other hidden spaces, where
it is likely to be growing in abundance. This mold has a very low nitrogen
requirement, and can grow on wet hay and straw, paper, wallpaper, ceiling
tiles, carpets, insulation material (especially cellulose-based insulation).
This information was quoted from an article called “Is Indoor Mold
Contamination a Threat to Health?” by Harriet M. Ammann, Ph.D., D.A.B.T. -
Senior Toxicologist at Washington State Department of Health, Olympia,
Washington.
For a full copy of
her report in PDF format CLICK HERE
For a
full copy of her report in Plain Print format CLICK HERE
Stachybotrys is a specific family (genus) of mold that is present in the
environment. Out-of-doors stachybotrys molds help to decay organic matter. One
particular species known as stachybotrys atra (sometimes known as stachybotrys
chartarum) is prone to growth indoors. This mold is normally dark brown or black
in color. It can look slimy, sooty, or even like grayish white strands depending
on the amount of moisture available and the length of time it has been growing.
It is important to remember that many other common indoor molds can look similar
to stachybotrys (including cladosporium, aspergillus, alternaria, and
drechslera), so testing is critical to conclusively identify stachybotrys in a
building. Stachybotrys mold needs the proper conditions in order to grow,
including moisture, a nutrient source, temperature, and time. Standing water or
a relative humidity of 90% or higher is necessary for stachybotrys to start
germination and grow. However, once the stachybotrys begins to grow it can
continue to propagate even if the surface water source dries up and the relative
humidity falls to 70%. The nutrient sources that best support stachybotrys are
those with a high cellulose content. As such, stachybotrys thrives on natural
materials such as hay, straw, and wood chips, as well as building materials such
as ceiling tile, drywall, paper vapor barriers, wallpaper, insulation backing,
cardboard boxes, and paper files. Stachybotrys survives a wide variation in
temperature and grows most proficiently in temperatures that humans consider
warm to moderately hot. It tends to develop more slowly than many other
molds—one to two weeks after moisture intrusion as compared to one to two days
for molds like aspergillus, penicillium, or cladosporium. Despite its slow
start, stachybotrys usually develops into the dominant mold if the conditions
are favorable, eventually crowding out other mold types that may have colonized
the material first.
Like many other molds, stachybotrys can spread both through the generation of
spores and the growth of root-like structures called mycelia. Stachybotrys
spores grow in clusters at the end of stem-like structures known as hyphae. The
spores do not easily disperse into the air if the colonized material is wet, as
the spores are held together by a sticky/slimy coating. Distribution through the
air is possible when the mold dries out or is disturbed. Because of this danger
of the airborne dispersion of spores, all cleaning and removal of stachybotrys
mold should be done using appropriate controls.
Stachybotrys has a high moisture requirement, so it grows vigorously where
moisture has accumulated from roof or wall leaks, or chronically wet areas from
plumbing leaks. It is often hidden within the building envelope. When S.
chartarum is found in an air sample, it should be searched out in walls or other
hidden spaces, where it is likely to be growing in abundance. This mold has a
very low nitrogen requirement, and can grow on wet hay and straw, paper,
wallpaper, ceiling tiles, carpets, insulation material (especially
cellulose-based insulation). It also grows well when wet filter paper is used as
a capturing medium.
S. chartarum has a well-known history in Russia and the Ukraine, where it has
killed thousands of horses, which seem to be especially susceptible to its
toxins. These toxins are macrocyclic trichothecenes. They cause lesions of the
skin and gastrointestinal tract, and interfere with blood cell formation.
(Sorenson, 1993). Persons handling material heavily contaminated with this mold
describe symptoms of cough, rhinitis, burning sensations of the mouth and nasal
passages and cutaneous irritation at the point of contact, especially in areas
of heavy perspiration, such as the armpits or the scrotum (Andrassy et al.,
1979).
One case study of toxicosis associated with macrocyclic trichothecenes produced
by S. chartarum in an indoor exposure, has been published (Croft et al., 1986),
and has proven seminal in further investigations for toxic effects from molds
found indoors. In this exposure of a family in a home with water damage from a
leaky roof, complaints included (variably among family members and a maid)
headaches, sore throats, hair loss, flu symptoms, diarrhea, fatigue, dermatitis,
general malaise, psychological depression. (Croft et al, 1986; Jarvis, 1995).
SUMMARY:
Stachybotrys has a different make up than most other molds and does not
produce airborne spore as easily as other molds. If you were to physically
touch a spot of black mold, it would feel slimy and would smear on the area.
Areas and substances where black mold can be found include water soaked
wood, ceiling tiles, wall paneling, cardboard, even items made of cotton.
Black mold can grow on drywall and insulation and can infest areas in the
floors, walls and ceilings.
Moisture is essential to the growth of black mold, and when it is wet it is
shiny in appearance.
If and when you are contemplating clean up of black mold, there are two
important considerations:
1. Know what you are dealing with.
If you were told you have an animal in your house, your first question
would be, “What kind of animal?” Based on the answer, you will know
the best way to “suit up” for the encounter. If you know you have a kitty-cat, you
may need a pair of gloves to keep from getting scratched. If you know you have a lion, you
might want a whip, a chair, and a pistol just in case. Same with mold. If you are going to clean up some
common allergenic molds you will need a cheap dust mask and a pair of rubber
gloves. If you are going to clean up toxic mold, you will need an expensive
respirator and other protective gear. Perhaps you will want to set up a
containment area to keep toxic mold spores from contaminating other areas of
your home. Taping off vents and duct work can help prevent the spread of
toxic spores into the HVAC system as well.
2. Verify the extent of the problem.
Many of the indoor mold problems you will encounter are the direct
result of water intrusion, i.e. improper drainage and irrigation, plumbing
leaks, rain and condensation issues. After discovering the root of the problem
and correcting it, you may be able to clean the area with bleach depending
on the scope of the contamination. In the even you choose to do the clean up
yourself, it is
important to understand that bleach is only good for cleaning mold off of a
surface. It should not be used for cleaning mold that is deeply
embedded. Bleach dries too quickly to penetrate deep enough into wood or drywall
to reach embedded mold, therefore, it does not always reach mold that is embedded beyond
the surface. For that reason, after or instead of cleaning with bleach, use a mildewcide
(not a fungicide) disinfect cleaner to penetrate deep into contaminated
construction materials to kill embedded mold. After this you must take care to thoroughly dry the
cleaned area. If there is any trace of mold left behind, it is only a matter
of time before you will repeating the entire process. One way to be sure
your clean up is effective is to have the cleaned materials re-tested by your
inspector.
For more information on cleaning mold CLICK
HERE.
3. Hiring a Contractor
If you choose to have a contractor clean up the contamination, there are
a couple of important matters for you to consider:
a) Only hire experience Mold Remediation Contractors. There are many fine
and well established remodeling companies around who do great remodeling
work but are not well experienced in mold remediation. Remodeling
contractors who are not remediation specialist can make a bad situation
absolutely horrible with their lack of mold experience.
b) Insist on references of customers who's jobs are at least one year old. A
mold clean up job can look really great right after its finished. But if it
isn't done correctly the problem can come back much worse than before within
six months to a year.
c) Never allow your contractor to conduct his own post-remediation clearance
testing.
For more information about hiring a
contractor CLICK HERE.
RESEARCH / STUDIES
A COLLECTION OF WHITE PAPERS
Below is an extensive library of research and studies by independent
sources from both the medical and scientific communities as well as
governmental agencies in and outside of the United States. AMI makes no
claim or warranty regarding the reliability, accuracy or current
relevance of any of the data.
Click on any of these links to scroll down to the topic:
Stachybotrys Induced Hemorrhage in the Developing Lung
The Immunopathology of Hypersensitivity Reactions
Hypersensitivity Pneumonitis from Toxic Mold Exposure
Cognitive Impairment Associated with Exposure to Toxigenic Fungi
Building-Related Illness in Occupants of Mold-Contaminated Houses
Prevention
and Treatment of Skin Lesion of T-2 Toxin
Diagnosing the Cause of
a "Sick Building:"
Effects
of Mycotoxins on Human Immune Functions in Vitro
Agonistic and Antagonistic effects of Zearalenone, an Etrogenic Mycotoxin,
Human Cancer Cell lines
Trichothecenes
Toxigenic Fungi: Which
are Important?
Toxigenic Fungi and Mycotoxins
Exposure Biomarkers in Chemoprevention Studies of Liver Cancer
Mechanisms of
Aflatoxin B1 Lung Tumorigenesis
Relationship
Between Lung Cancer and Aflatoxin B1
Neuronal Effects of
Microbial Toxins
Health Effects, Pathology, Epidemiology
Ecology, Detection and Identification Problems of Moulds in Indoor
Environments
Occupational Exposure to Molds, Diseases and Diagnosis
Indoor Moulds:
a Public Health Problem in Belgium
Pilot Analysis of the Immune Response to Fungal Antigens in Subjects Working
in Humidity Damaged Houses
Can Microbial Volatile Metabolites Cause Irritation at Indoor Air
Concentrations?
Growth Conditions of Streptomyces Anulatus Regulate Induced Inflammatory
Responses and Cyto Toxicity in Macrophages
Clinical Findings Related to Indoor Fungal Exposure - Review of Clinic Data
of a Specialty Clinic
Pulmonary Hemorrhage Among Infants with Exposure to Toxigenic Molds
IAQ and
Human Toxicosis: Empirical Evidence and Theory
Cognitive Impairment Associated with Exposure to Toxigenic Fungi
Symptoms Associated to Work in a Water Damaged School Building
Sensory Irritation of Microbially Produced Volatile Organic Compounds in
Mice During Repeated Exposures
Immunological Biomonitoring in the Assessment of Exposure to Airborne Fungi
from Waste Handling
Chronic Toxic Encephalopathies Apparently Related to Exposure to Toxigenic
Fungi
Building-Related Illness in Occupants of Mold-Contaminated Houses
Diagnosing the Cause of a "Sick Building:" a Case Study of an
Epidemiological and Microbiological Investigation
Fungal Exposure and IGg-levels of Occupants in Houses with and without Mold
Problems
The
Immunopathology of Hypersensitivity Reactions
Exposure to Stachybotrys Chartarum Induces Immunoglobulin a Antibody
Response in Man
Sensitization to Molds and Respiratory Symptoms in School Children
Mycotoxin
Cytotoxicity Screening of Field Samples
The Effect-Inhaled Spores of Mycotoxin Producin Fungi on Animals
Trichothecenes as
a Potent Inducer of Apoptosis
Analysis for Stachybotrys
Toxins
Assessing
Bioaerosols in Elementary School Classrooms
Anatomy of a Fungal Problem
Prevalence of Fungi
in Carpet Dust Samples
Detection and Decontamination of a Facility Contaminated with Fungi
Including Stachybotrys chartarum
Airborne Concentrations of Trichoderma and Stachybotrys linked to
Mycotoxicosis
Exposure Measures for Studies of Mold and Dampness and Respiratory Health
Fungal Growth in Buildings: The Aerobiological Perspective
Why
are there Still Problems with Fungal Allergen Extracts?
Comparative studies of fungal media for the recovery of Stachybotrys
Chartarum from Environmental Samples
Heteroduplex DNA Fingerprinting of Penicillium Brevicompactum from House
Dust
The Trichodiene Synthase Gene from Stachybotrys Chartarum : A Potential
Diagnostic Indicator of Indoor Contamination
Microscopic Fungi and Metabolites in Dwellings-a Bioassay Study
Moisture, Mold and
Health in Apartment Homes
Toxigenic Microbes in Indoor Environment: Identification, Structure and
Biological Effects of the Aerosolizing Toxins
Evaluation of
Exposure to Environmental Bacteria
Cellular and Humoral Responses in an Animal Model Inhaling Penicillium
Chrysogenum Spores
Sporulation of the Hyphomycete Stachybotrys chartarum Under Three Light
Conditions
Mycotoxin Spectra as a Biochemical Parameter for Occupational and
Environmental Fungus Exposure
Membrane Toxic Substances in Water-damaged Construction Materials and Fungal
Pure Cultures
Different
Methods to Characterize Moldy Buildings
Comparative Studies of Collection Efficiency of Airborne Fungal using
Andersen Single-Stage Sampler and Air-O-Cell Cassettes
Trichothecene Mycotoxins in Some Water-Damaged Buildings
Immunochemical Detection of Mycotoxins Associated with Stachybotryotoxicosis
Mitigation of Visible Fungal Contamination in Buildings: Experience From
1993 - 1998
Microbes and Moisture Content of Materials from Damaged Building
Concentrations of Viable Spores of Fungi and Actinomycetes in Ventilation
Channels
Air
Quality Restoration in a Fungal Contaminated Building
Sampling,
Results & Remediation in 300 "Sick Houses"
Identifying and Preventing Fungal Contamination Problems in New Home
Construction
A Toxic Mold Cleanup Guide
Molds as an
Environmental Factor in Infant Leukemia?
Mechanisms of Adverse Health Effects of Moldy House Microbes: in vitro and
in vivo studies on toxic effects and inflammatory responses.
Exposure to Bioaerosols
Schools, Mould
and Health - An Intervention Study
Development of Methods to Monitor the Success of Repair Measures
Neurotoxic Effects of
Microbial Toxins
The Biological Activities of the Metabolites of Microbes Present in the
Indoor Air
Environment, Decision-Making and Well-Being - Insecurity, Uncertainty and
Crisis of Expertise
Radonsafe Foundation, Moisture Prevention and Air Exchange in a Healthy
Building
Adsorption, Desorption, and Chemical Reactions in the Particulate Matter
Collected on Air Filters and Ducts
Fungal Allergens and Antigens - Their Characterization and Biological
Effects in Mice after Inhalation Exposure
Indoor Air Quality Control
Mold and Moisture Transfer in Building Structures and Buildings with
Particular Regard to the Prevention of Health Hazards
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IS ALL BLACK MOLD TOXIC?