A Glossary of Interpreting Mold Data
There are no published regulatory standards to interpret mold results or assess health risks related to mold exposure. Even though fungi and
bacteria have been linked to various health problems, sensitivity varies from person to person. Therefore it is impossible to reach a
suitable conclusion for those exposed to mold.
Mold is found everywhere moisture and air are present. Ordinarily, the most severe mold species are Stachybotrys, Cladosporium, and
Fusarium because they produce toxins. Among such species, Stachybotrys (black mold) is the worst. Once discovered,
it needs to be remediated (abated).
Alternaria, Aspergillus, Basidiospores, Curvularia, Epicoccum, and Penicillium form the next group to be watched closely for
people with compromised immune system or with allergies. The indoor concentration of these spores will affect residents depending on their
Comparing outside and inside readings, when spore counts outside are greater than inside, one can assume that spores could be migrating from
outside. If inside spore count readings are greater than outside, then mold could be growing inside.
Relative humidity (RH) is an indication of the amount of water in the room. The American National Standards Institute
(ANSI) and the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) developed ANSI/ASHRAE Standard 55-2004,
“Thermal Environmental Conditions for Human Occupancy”. Since prolonged humidity levels above 60% allow molds, spores, and fungi to propagate
(grow), ANSI/ASHRAE recommends that indoor relative humidity (RH) levels not exceed 60%. ASHRAE states that “Relative Humidity in habitable
spaces preferably should be maintained between 30% and 60% to minimize growth of allergenic or pathogenic organisms”.
In conclusion, measurements of indoor air quality parameters are indicators of environmental conditions, at a specific moment in time, and
these often change rapidly.
“Most molds, even if you can smell them, are not harmful,” says the UC Berkley Wellness Letter. However, each complaint needs to be
handled separately, considering each employee experiencing upper respiratory ailments and chemical sensitivities with great care and caution.
Limited Glossary of Molds
- In decaying wood, plants, food, soil, and outdoor air. Found in house dust, carpet, damp area on window
frames and where condensation occurs indoors. Chief fungal cause of hay fever. Important allergen. Phaeohyphomycosis (causing
cystic granulomas in the skin and subcutaneous tissue), nasal lesions, nail infections; the majority of infections reported from
persons with underlying disease or in those taking immunosuppressive drugs. In immunocompetent patients, Alternaria colonizes the
paranasal sinuses, leading to chronic hypertrophic sinusitis.
- Saprophytes and plant pathogens. Found everywhere in nature. Dependent on genus and species, but the vast
majority does not cause disease.
- Found indoors in water-damaged buildings. Most people are immune to it. Possible lung infection for people
with lung disease.
- Bipolaris/Drechslera Group: Found in plant debris, soil. Plant pathogens of numerous plants, particularly
grasses. Occasionally a cause of phaeohyphomycosis, including keratitis, sinusitis, and osteomyelitis. These infections usually occur
in immunocompromised persons, although infections also occur in normal hosts. One case of brain abscess reported in an
- Bipolaris/Drechslera Group
- Bipolaris species are common, and are most closely related to Drechslera and Exserohilum.
- Found in soil, seeds, cellulose substrates, dung, woody and straw materials. Uncommon agent of onychomycosis
- Frequently found outdoor. Found indoor in water-damaged buildings. Only occasionally associated with
diseases in humans (Pulmonary infections, sinusitis, edema, keratitis, onychomycosis).
- May cause infection for people with compromised immune system. (cerebral abscess, endocarditis, mycetoma,
ocular keratitis, onychomycosis, pneumonia, sinusitis)
- Found in plant debris, soil. Secondary invader of damaged plant tissue. Can grow in conditions of low
humidity, is a known allergen that can be isolated from human skin and sputum.
- Common on food. Mycotoxin producers.
- Other Brown
- Generic category which is not classifiable and insignificant contributable to heath issues.
- Indoor air samples, on dust, carpet, or wall paper. Human pathogenic species are rare. May cause diseases
for people with compromised immune system.
- Smuts, Periconia, Myxomycetes
- Found on cereal crops, grasses, weeds, other fungi, and on other flowering plants. No reports of human
infection by the plant parasitic forms.