| Aw | Paul Aw is an abbreviation for water activity or equilibrium relative humidity (%ERH). Water activity is defined as the partial pressure of water relative to the vapor pressure of pure water at the same temperature or a measurement of the water that is available for biological and chemical reactions. The Aw scale starts from 0 (dry) and goes to 1.0 (pure water). Microbial growth can start as low as 0.6 Aw, which includes halophilic (live on substrates with high concentrations of salt) bacteria, osmophilic or osmotolerant (live on substrates with high osmotic pressure) yeasts, and xerophilic or xerotolerant (live on arid or dry substrates) fungi. |
| Acute | Refers to any disease which has a rapid onset and persists a relatively short period of time. (e.g. days, weeks), terminating either in recovery or death. The term is also used for exceptionally severe or painful condition. |
| Acute Toxicity | The concentration of a compound required to cause a poisonous effect (e.g. lethality) on a target organism, organ, or cell-type. |
| Adsorbtion | The removal of gasses or liquids in specialized filters whereby the gas or liquid adheres as a thin film to the surface of a solid substance. |
| Aerobe | Any organism that grows in the presence of oxygen. Obligate aerobes are organisms that require molecular oxygen to grow. Facultative organisms can grow with or without oxygen, and they shift in its presence to a respiratory metabolism. |
| Aerosol | Material finely divided and suspended in air or other gaseous environment, with compositions as varied as itself. |
| Aerosol Sampler | Device used to collect air samples to test hypothesis about indoor environments. Air samplers are used to detect and quantify bioaerosol presence, to identify aerosol release from sources, to assess human exposure to biological agents, and to monitor the effectiveness of control measures. Types of bioaerosol samplers include - gravitational sampler (collect by settling onto a collection surface); inertial or non-inertial samplers (impactors, impingers or centrifugal). |
| Aerotech 6 Sampler | Viable particle sampler, aluminum device held together by three spring clamps and sealed with o-ring gaskets. This single stage impactor contains 400 precision-drilled holes. Airborne particles are impacted onto the surface of an agar plate via a vacuum pump. |
| Agar | A gelatin like material obtained from seaweed and used to prepare culture media on which microorganisms are grown. Also used for electrophoresis of DNA and RNA. |
| Air Contaminant | An unwanted airborne constituent that may reduce acceptability of the air. |
| Air-O-Cell | A popular spore trap collection method. |
| Airborne Microorganisms | Biologically active contaminants suspended in the air either as free-floating particles surrounded by a film of organic or inorganic material, or attached to the surface of other suspended particulates. |
| Algae | A heterogeneous group of eukaryotic, photosynthetic, unicellular or multicellular organisms. |
| Allergen | Any substance or agent that causes an allergic reaction. |
| Allergic Dermatitis | Rash that occurs when the skin is exposed to certain allergens. |
| Allergic Rhinitis | Inflammation of the lining of the nose caused by allergies. Term used for hay fever and/or allergy to pollen, dust mites, and mold spores. |
| Allergy | An abnormal immune-mediated hypersensitive response to chemical and/or physical stimuli. Typical allergy symptoms can include any or all of the following hypersensitive responses - inflammation, rhinitis, sinusitis, dermatitis, hypersensitive pneumonitis, conjunctivitis and/or asthma. Allergic manifestations of major importance occur in about 10 percent of the population. |
| Alveoli | The inside end of the airway tree, consisting of tiny air sacs within the lungs, formed at the ends of bronchioles; through the thin walls of the alveoli, the blood takes in oxygen and gives up its carbon dioxide in the process of respiration. |
| Anaerobe | Obligate anaerobes are organisms that can grow only in the absence of oxygen. Facultative organisms can grow with or without oxygen, and they shift in its presence to a respiratory metabolism. |
| Andersen N-6/Aerotech 6 | Viable particle sampler, aluminum device held together by three spring clamps and sealed with o-ring gaskets. This single stage impactor contains 400 precision-drilled holes. Airborne particles are impacted onto the surface of an agar plate via a vacuum pump. |
| Antibiotic | A chemical substance, of microbial origin or synthetically produced, that has the capacity to inhibit or kill bacteria when applied in dilute solutions. |
| Antibody | An immune-response protein produced in warm-blooded animals in response to an injected foreign antigen and capable of reacting specifically with that antigen. |
| Antigen | Any substance, often proteins but occasionally complex lipids, carbohydrates, or some nucleic acids, (usually foreign) that, when introduced into the body of a warm-blooded animal, has the capacity to stimulate the formation of the corresponding antibodies; and the ability to react specifically with these antibodies. |
| ASHRAE | American Society of Heating, Refrigerating, and Air-conditioning Engineers, Inc. |
| Aspergillosis | One of a group of diseases of animals and humans caused by various species of Aspergillus. |
| Asthma | A lung disorder characterized by attacks of breathing difficulty, wheezing, coughing, and thick mucus coming from the lungs. Asthma attacks can be caused by breathing foreign substances (allergens) or pollutants, infection, vigorous exercise, or by emotional stress. Treatment includes eliminating the cause if possible. Sprays or wideners of the bronchi taken by mouth, and steroid drugs are also used. Repeated attacks often result in shortness of breath (emphysema) and permanent obstructive lung disease. Also called bronchial asthma. |
| Asthma Promoters | Conditions and substances, such as allergies, tobacco smoke, colds and respiratory infections, that can lead to lasting inflammation in the airways and leave them prone to react faster or more severely to an asthma trigger. |
| Bacteria | Microscopic organisms living in soil, water, organic matter, plants and animals. These prokaryotic organisms do not have a distinct nucleus, are single-celled, and lack photosynthetic abilities. |
| Bactericide | Any agent (chemical or physical) that is able to kill bacteria. |
| Bacteriocidal | Able to kill bacteria. |
| Bioaerosol | An aerosol comprised of particles of biological origin/activity or is itself a living organism, which may affect living things causing infection, allergies, toxicity, or other. Particle sizes may range from aerodynamic diameters of ca. 0.5 to 100 microns. Examples of bioaerosols are fungi, bacteria, viruses, protozoa, pollen, animal dander, insect emanations, microbial endotoxins, and human skin scales. |
| Biohazard | A combination of the words, biological and hazard meaning organisms or products of organisms that present a risk to humans. |
| Bronchitis | Inflammation of the mucous membranes of the large (bronchia) airways, characterized by cough. |
| Building Related Illness | An identifiable illness or disease caused by conditions in or nearby to a facility. |
| CARPETCHEK | A .8 micron MCE filter cassette uses to collect dust from carpeting for the analyses of microbial contaminants. |
| Chain of Custody | Written form that contains fields for reporting, billing (optional), sample identification and analysis request. This form must be accompanying samples to be analyzed by a laboratory. This form is particularly important if litigation becomes involved. |
| Colony | A number of individual cells or organisms of a given species growing on the surface of a solid medium that usually can be seen with the naked eye. |
| Conditioned Space | The portion of a facility being heated, cooled, humidified, dehumidified, or otherwise controlled to maintain desired conditions. |
| Conidia | Asexual spores of fungi that form at the tips and the sides of hyphae. Conidia are not unusually resistant to adverse environmental conditions and serve to promote aerial dissemination. |
| Conjunctivitis | Inflammation of the surface of the eye, characterized by redness, itching, soreness, and tearing. |
| Contaminant | An undesirable substance that pollutes the quality of the air. |
| Cubic Centimeters (cc) | A volumetric measurement that is also equal to one milliliter (ml). |
| Cubic Meter (m³) | A measure of volume in the metric system. |
| Dander | Tiny scales of animal skin. |
| Dermatitis | Inflammation of the skin characterized by redness, itching, and/or formation of a rash. |
| Dimorphic Fungus | Fungus that can grow either as mold (mycelial form) or as yeast depending on the environment. |
| Disinfectant | Chemical agents used for disinfection. Disinfectants for general use should be active against a range of common microorganisms and should be biocidal rather than biostatic. |
| Dust | An air suspension (aerosol) of particles of any solid material, usually with particle size less than 100 micrometers (um). |
| Dust Mites | Tiny insects that live in dust, and that are a common asthma trigger. |
| DUSTCHEK | A filter collection bag used in conjunction with a standard vacuum cleaner to collect dust samples to be analyzed for microbial contamination or allergens. |