Mold Glossary Mold Glossary

ACGIH - American Conference of Governmental Industrial Hygienists

Allergy - an exaggerated or inappropriate immune response initiated by exposures to antigens such as mold spores, pollen, or certain drugs and foods

Amplification - the process of indoor growth leading to an increased indoor microbial concentration compared to the immediate outdoor environment 

Anderson sampler - a sieve-type air sampling device that uses a vacuum pump to draw air through a radial pattern of 300 small holes, impacting particles in each of the small streams of air onto the surface of microbial growth medium.  

ASHRAE - American Society of Heating Refrigerating and Air-Conditioning Engineers

Aspergillosis - a group of diseases caused by the fungus Aspergillus; affected tissues may include lungs, bronchial airways, sinus cavities, ears, and eyes

Asthma -an immediate hypersensitivity (allergy) resulting in respiratory symptoms such as wheezing, coughing, shortness of breath, and a feeling of constriction within the chest or bronchial airways

Bacteria - microorganisms with prokaryotic cell organization (lacking membrane-bounded nucleus and other specialized features); bacteria are also typically much smaller than fungi (molds)

Bioaerosol - an airborne dispersion of particles containing whole or parts of biological entities, such as bacteria, viruses, dust mites, fungal hyphae, or fungal spores.

Blastomycosis -a disease caused by the fungus Blastomyces dermatitidis; may infect lungs, skin, mucous membranes, bones, internal organs, and joints.

Brown-rot Fungi: - fungi that are capable of utilizing the cellulose and hemicellulose portions of wood but are incapable of decomposing brown lignin; rot characteristics include crumbly appearance and brown coloration.

BRI - building-related illness: a recognized disease that can be attributed to airborne building bioaerosols or chemical pollutants.

Cell -;the smallest and most fundamental unit of life.

CFUs - Colony Forming Units; individual regions of growth attributed to a single reproductive unit such as a spore or vegetative cell.

Coccidioidomycosis -&;a disease caused by the fungus Coccidioides immitis; may infect lungs, internal organs, bones, joints, and skin.

Colony a discrete growth usually discernable by the naked eye; this term is usually used in reference to growth originating from a single spore or cell

Cryptococcosis -a disease caused by the fungus Cryptococcus neoformans; may infect lungs, central nervous system, skin, and lining of body cavity.

Dermatophytes - a fungus that causes skin disease in humans or other animals

Dew point - the temperature at which water would condense from the air if the air mass were cooled. In general, when the relative humidity is high, the dew point will be close to the air temperature. At 100% relative humidity, the dew point is equal to the air temperature. When the relative humidity is low, the dew point is much lower than the air temperature.

Endotoxin - a lipopolysaccharide component of the membrane of gram-negative bacteria that is heat stable and toxic; a secreted toxin produced by bacteria is termed an "exotoxin"

Fungus - (pl. fungi) a kingdom of organisms (equal in rank to the Plant Kingdom or the Animal Kingdom) defined technically as a parasite or saprobeic, filamentous or single-celled eukaryotic organism, devoid of chlorophyll and characterized by heterotrophic growth, and the production of extracellular enzymes.  Fungi include yeasts, molds, mildews, and mushrooms.  

Fungicide -a chemical compound capable of inhibiting or destroying the growth of fungi

Genus a grouping of similar species according to taxonomic criteria, for example, humans (Homo sapiens) belong to the genus 'Homo' and the species 'sapiens'

HEPA filter - High Efficiency Particulate Air filters that have been tested to assure removal of 99.9% of particles 0.3 µm in size

Histoplasmosis - a disease caused by the fungus Histoplasma capsulatum; may infect lungs, skin, mucous membranes, bones, skin, and eyes

Hypersensitivity - an allergy; an exaggerated or inappropriate immune response categorized based on which part of the immune system that is involved and the onset of response (i.e. Types I, II, III, IV)

Hypha -;(pl. hyphae) a branching tubular structure that forms the vegetative body of a growing filamentous fungus

HVAC - Heating, Ventilating, and Air-Conditioning

Immunocompromised - any condition in which the immune system functions in a abnormal or incomplete manner; such conditions are more frequent in the young, the elderly, and individuals undergoing extensive drug or radiation therapy

Immunosuppression - suppression of the natural immune response (see immunocompromised)

Keratitis - microbial infections of the cornea (eye); when caused by a fungus, it is referred to as mycotic keratitis

Legionnaires' Disease (Legionellosis) - a form of pneumonia caused by the bacterium Legionellae ; first discovered in 1976 from infected persons attending the Legionnairs meeting in Philadelphia.

Microbe - a general or non-specific term for any microorganism such as bacteria, fungi (molds), algae, or protozoa.

Mildew - a common name for mold or fungi; often used in reference to fungal growth on bathroom tiles and fixtures 

Mold - a common name for fungi that grow in a filamentous fashion and reproduce by means of spores; all molds are fungi, but not all fungi are considered 'molds.

Mucormycosis - a group of disease caused by the fungi belonging to the group Mucorales (Class Zygomycetes); such fungi may infect lungs, sinuses, mucous membranes, central nervous system, internal organs, and eyes.

Mycellium - the collective mass of hyphae (filamentous cells) comprising the body of most fungi and molds  

Mycetoma - invasive fungal infection of subcutaneous tissues (under the skin)

Mycology - the scientific study of fungi (Kingdom Fungi or Mycota).

Mycosis - an infection caused by fungi (mold) (pl. mycoses).

Mycotoxicosis - any disease caused by fungal toxins (mycotoxins)  

Mycotoxins - a diverse class of poisonous compounds produced by certain mushrooms and other fungi; mycotoxins are produced on the surface of mold spores and remain toxic even after the spore is dead

Onychomycosis - invasive fungal infections of the nail

Otomycosis - a superficial fungal infection of the outer ear canal

Pathogen - a microorganism that causes a disease response.

Piedra - fungal infection of hair shafts resulting in the formation of dark (black piedra) or white (white piedra) nodules within the hair shaft.

Pneumonia a disease characterized by the inflammation of the lungs; often caused by bacteria or certain species of fungi.

Propagule - any disseminable microbial element that can give rise to new growth (e.g. spores, hyphal fragments, cells)

Pulmonary hemorrhage - a condition characterized by bleeding in the lungs caused by weakening of the lung vessels; often due to exposure to inhaled toxins produced by the mold Stachybotrys

RAST testing - radioallergosorbent test; a blood test for measuring antigen specific antibodies (allergic reactions).  Used primarily where skin testing is impractical or unreliable (i.e. extreme sensitivity, dermatitis, children).

Relative humidity - an expression of how much moisture is in the air as a percentage of the total moisture the air can contain at the current temperature. For example, if the air has all the water vapor that it can contain at a given temperature, the relative humidity is 100%; if the air has only half of the vapor that it can contain at a given temperature, the relative humidity is 50%.

Ringworm - fungal infections of the skin resulting in raised red swellings or lines that resemble burrowing worms; includes the diseases known as athlete's foot, jock itch, and ringworm or the scalp 

Saprobeany microorganism capable of obtaining nutrients from dead or non-living organic matter.

Serology- the medical science of serum; or the technique of determining antigens or antibodies in serum.

Serum- the clear or slightly yellowish liquid that remains after the plasma portion is allowed to clot; blood is comprised of a plasma portion (55%) and a cellular portion (45%); plasma contains water, salts, and plasma proteins (albumin, fibrinogen, antibodies) whereas the cellular portion contains red blood cells (erythrocytes), platelets, and white blood cells (leukocytes)

Sick Building Syndrome (SBS) ye, nose and throat irritations; fatigue; and skin disorders.

Soft-rot Fungi:fungi that are capable of decomposing the cellulose and hemicellulose portions of wood; most soft-rot also partially degrade lignin; these species are most common in moist hardwoods

Species- the most specific taxonomic classification; an interbreeding population of individual organisms; often abbreviated as 'sp.' in reference to a single species or 'spp.' when referencing several species

Spores- reproductive units or specialized cells that provide the primary means for dispersal and survival; many fungal (mold) spores are capable of long term dormancy and are therefore referred to as resistant spores or resting spores

Substrate- substance on or in which a microorganism is living

Toxigenic-  a substance or biological entity that has the property itself or can produce one or more compounds that have the property to harm humans or other animals.

Type I Hypersensitivity (anaphylactic reactions)- an immediate, usually localized response to allergens such as fungi, pollen, dust mites, or animal dander; examples of this type of disorder include insect stings, asthma, food allergies, drug reactions, and hives;  type of antibodies involved.

Type II Hypersensitivity (cytotoxic reactions)- a delayed response (usually within hours or days) involving reactions against antigens located on target cells which are then destroyed; examples of this type of disorder include blood transfusions reactions and hemolytic disease of newborns (involving Rh factors); type of antibodies involved: IgG, IgM

Type III Hypersensitivity (immune-complex reactions)- a delayed response (usually within hours or days) involving insoluble antigen-antibody complexes which cause tissue necrosis (death) and acute inflammation; examples of this type of disorder include Farmer's Lung (caused by fungi and other microorganisms), serum sickness, and malaria; type of antibodies involved IgG, IgM 

Type IV Hypersensitivity (cell-mediated response)- a delayed response to microorganisms, tissue transplants, or chemicals that cause cellular inflammation; examples of this type of disorder include contact dermatitis, and Tuberculosis reactions (Mantoux test); type of antibodies involved: none

VOCs- volatile organic compounds; some VOCs are of industrial origin whereas others are produced by microorganisms.

Water Activity - the water activity of a solution is equal to 1/100th the relative humidity when expressed as a percent. Water activity is also equivalent to the ratio of the solution's vapor pressure to the vapor pressure of pure water.

White-rot Fungi:fungi that are capable of utilizing lignin as well as cellulose and hemicellulose; most wood-decay fungi (especially many mushrooms) are of this type; these species are often associated with rot of building lumber.

Wood-decay Fungi- fungi that are capable of decomposing various components of wood; categorized as either soft-rot fungi, brown-rot fungi, or white-rot fungi.

Yeast a group of single-celled fungi characterized by the ability to reproduce by budding

Got a New Project You're Proud of?

Post it on Your Projects!