—American Conference of Governmental Industrial Hygienists.
—Association of Flight Attendants.
—FAA’s Accident/Incident Data System.
—Exposure to airborne infectious agents in droplet nuclei is considered airborne transmission. Droplet nuclei and particles of dust <5 μm can remain; suspended in still air longer than larger particles. These particles also.can be carried further on air currents and travel deeper into the lungs.
—A cooling device that accepts high temperature and high-pressure bleed air and that expands, cools, and dehumidifies this air to appropriate pressure, temperature, and humidity conditions to be supplied to the aircraft cabin.
—The portion of a passenger aircraft intended to be occupied by passengers.
Air exchange rate
—The rate that an equivalent volume of air in the cabin is replaced with outside air.
—see Auxiliary Power Unit.
—American Society of Heating, Refrigerating, and Air-Conditioning Engineers.
—Aerospace Medical Association.
—Aviation Safety Reporting System.
—American Transport Association of America.
—The proportion of persons exposed to an infectious agent who become infected.
Auxiliary Power Unit (APU)
—A turbine engine that is used to power electric generators and provide bleed air for pneumatic and environmental control system use. The APU is normally used during ground operations when the main engines are not operating or are not operating at conditions which allow them to fulfill these needs.
—FAA’s Airworthiness Directive.
—Gases, such as CO2 in exhaled breath, human body odors, and volatile compounds produced by fungal and bacterial growth, released by humans, animals, microorganisms, or plants.
—Compressed air extracted from the compressor section of a turbine engine.
—Building Research Establishment.
—Building Related Symptoms.
—The section of an aircraft occupied by passengers.
—The flight attendants who are responsible for the safety and comfort of the passengers. Because the majority of exposure and health-effects data has been collected in the cabin and might not be applicable to the cockpit, this report focuses on the cabin crew except where data are explicitly applicable to the cockpit crew. However, many issues that are pertinent to the cabin crew are relevant to the cockpit crew.
Cabin pressure altitude
—The distance above sea level at which the atmosphere exerts the same pressure as the actual pressure in the aircraft cabin. Cabin pressure altitude is the static pressure measured within the pressurized fuselage (i.e., cockpit and cabin) that represents the equivalent absolute ambient static pressure at a given altitude for a specific standard day or reference day conditions. The cabin pressure altitude is governed by the pressure schedule as set by the airplane manufacturer. Typical commercial transport airplane pressure schedules top out at a pressure of 10.92 pounds per square inch, which is equivalent to an altitude of 8,000 feet at U.S. standard atmospheric conditions.
—A person who harbors a specific infectious agent without visible symptoms of the disease; a carrier acts as a potential source of infection to others.
—Centers for Disease Control and Prevention.
—Code of Federal Regulations.
—Air movement within the aircraft cabin.
—Pilots and flight engineers.
—An illness due to a specific infectious agent or its toxic products that arises through transmission of that agent or its products from an infected person, animal, or inanimate reservoir to a susceptible host (synonym: infectious disease).
—The time during which an infected person or a carrier can transmit an infectious agent.
—A person or animal that has been in an association with an infected person, animal, or contaminated environment that might provide an opportunity to acquire the infective agent.
— Direct contact involves the touching of wounds or mucous membranes of one person with contaminated body fluids from another person.
Indirect contact involves the sharing by an infected person and another person of an item that is contaminated with an infectious agent (e.g., soiled tissues, toys, eating utensils, and other items that are touched by hand, nose, or mouth).
Droplet contact involves large particles (>5 μm) that an infected person or a carrier releases during sneezing, coughing, spitting, singing, or talking. Contact occurs when droplets containing infectious agents from an infected person are projected onto the eyes, nose, or mouth of another person, usually within a distance of no more than a few meters.
—Any unwanted substance in aircraft cabin air.
—Chronic Obstructive Pulmonary Disease.
—A device used to distribute inlet air into the aircraft cabin in the desired manner.
—Use of insecticides to exterminate insect pests.
—U.S. Department of Transportation.
Droplets and droplet nuclei
—The dried residue of a droplet that remains after liquid evaporates is called a droplet nucleus. A droplet nucleus would include any microorganisms contained in the original droplet. The important differences between droplets and droplet nuclei are: (1) their size (respectively, greater or less than ~5 μm); (2) the distance that they can travel (respectively, less or more than a few meters); and (3) the site in the respiratory tract at which they deposit (respectively, the
airways of the head and the upper respiratory system or the lower lungs). Transfer of an infectious agent in a droplet is considered a form of contact, whereas transfer by droplet nuclei is considered an airborne transmission.
—see Environmental Control System.
—A class of lipopolysaccharide-protein complexes that are an integral part of the outer membrane of Gram-negative bacteria.
Environmental Control System (ECS)
—The combination of equipment and controls used to maintain the environmental conditions in the aircraft cabin.
—U.S. Environmental Protection Agency.
—Environmental Tobacco Smoke.
—U.S. Federal Aviation Administration.
—Federal Aviation Regulation.
—Forced expiratory flow.
—Forced expiratory volume in the first second.
—Any means of removing contaminants from an air stream, including mechanisms such as mechanical filtration, chemical adsorption, and catalytic reduction.
—Pilots and flight engineers employed only on the flight-deck.
—Cockpit area of an aircraft.
—Synonymous with outside air. The term fresh air does not imply that it is uncontaminated air.
—Forced vital capacity.
—An individually controlled air inlet device that a passenger may use to direct a flow of air onto herself or himself.
—High Efficiency Particulate Filter.
—International Association of Machinists and Aerospace Workers.
—The development or multiplication of a microorganism in the body. (Infection does not always result in a recognizable disease, and individuals sometimes carry pathogens without becoming infected. A person may be infectious (i.e., able to transmit an agent to others) without experiencing symptoms.)
—Clinically apparent or manifest infection with outward signs.
Infectious disease outbreak
—Occurrence of two or more cases of infection in a limited time period and geographic region. The first cases that are
identified are called primary cases; persons subsequently infected by the primary cases are called secondary cases.
—Joint Aviation Authority
—Joint Aviation Regulation.
—Material Safety Data Sheets.
—Microbial volatile organic compound.
—National Ambient Air Quality Standard.
—Aircraft with fuselages whose diameter is about 12 feet. These aircraft typically have one aisle, with 5 or 6 seats across in the coach section and 4 seats across in the first-class section.
—National Aeronautics and Space Administration.
—National Institute for Occupational Safety and Health.
—Nitrogen oxides, species unspecified.
—Those diseases for which regular, frequent, and timely information on individual cases is considered necessary for prevention and control; examples include mumps, pertussis, measles, tuberculosis and varicella (chickenpox).
—National Transportation Safety Board.
—Occupational Safety and Health Adminstration.
—Air brought into the aircraft cabin from a source outside of the aircraft.
—Polycyclic aromatic hydrocarbon.
—Pressure exerted by a single gas in a mixture of gases; commonly expressed in millimeters of mercury.
Partial pressure of oxygen (PO2)
—The pressure that would be exerted by the oxygen in the air if all other chemical components of air were removed and only the oxygen remained.
—OSHA’s permissible exposure limit.
—Particulate matter less than 2.5 microns in diameter.
—see Partial pressure of oxygen.
—The increase in pressure of the aircraft cabin air above the ambient outside atmospheric air pressure.
—Use of recirculated air in the cabin ventilation system.
—Air that is extracted from the aircraft cabin and then reintroduced to the cabin through the cabin ventilation system.
Reference Concentration (RfC)
—RfC is an estimate of a daily exposure to the human population (including sensitive subgroups) that is likely to be without an appreciable risk of deleterious effects during a lifetime.
—The amount of moisture in air compared to the maximal amount the could contain at the same temperature; expressed as a percentage.
Respirable suspended particles (RSP)
—Airborne material, including dusts, mists, smoke, and fumes, that is small enough to penetrate the lungs on inhalation (approximately 2.5 μm or less).
—see Relative humidity.
—see Respirable suspended particles.
—FAA’s Surveillance Difficulty Reporting System.
—Spacecraft Maximum Allowable Concentrations.
—Short-term exposure level.
—Threshold limit value.
Tuberculin skin test
—An immunological test for tuberculosis in which a purified protein derivative from Mycobacterium tuberculosis (called tuberculin) is injected subcutaneously on the lower part of the arm, resulting in a temporary induration (lump) in two to three days if the tested person was previously exposed to the bacterium.
—The process of supplying outside air to the aircraft, distributing this air to the cabin, and providing adequate air motion within the cabin to prevent the air within the cabin from having excessive levels of contamination; may include outside air and recirculated air.
—The flow rate of outside air supplied to the cabin for ventilation; does not normally include recirculated air even though recirculated air may be used for cabin ventilation.
—Volatile organic compound.
—World Health Organization.
—Aircraft with fuselages whose diameter is about 20 feet. These aircraft typically have two aisles, with 7–10 seats across in the coach section and 6 seats across in the first-class section.