aerosol: (adj. aerosolized) A tiny solid or liquid particle suspended in air or as a gas. Aerosols can be natural, such as fog or gas from volcanic eruptions, or artificial, such as smoke from burning fossil fuels.
allergy: The inappropriate reaction by the body’s immune system to a normally harmless substance. Untreated, a particularly severe reaction can lead to death.
buoyant: (n. buoyancy) An adjective for something that can float on or rise above some liquid or gas.
cell: (in biology) The smallest structural and functional unit of an organism. Typically too small to see with the unaided eye, it consists of a watery fluid surrounded by a membrane or wall. Depending on their size, animals are made of anywhere from thousands to trillions of cells. Most organisms, such as yeasts, molds, bacteria and some algae, are composed of only one cell.
clinical: (in medicine) A term that refers to diagnoses, treatments or experiments involving people.
colleague: Someone who works with another; a co-worker or team member.
component: Something that is part of something else (such as pieces that go on an electronic circuit board or ingredients that go into a cookie recipe).
condensation: The process of moisture in the air turning into a liquid as it comes into contact with a very cold surface. Or the term can refer to the liquid water that condenses out of the air.
condense: To become thicker, denser or to distill out the essence of something. This can occur, for instance, when moisture evaporates out of a liquid. Condense also can mean to change from a gas or a vapor into a liquid. (This can occur when water molecules in the air join together to become droplets of water.) It can also mean to identify the central meaning of something through analysis of data or through discussions.
contagious: An adjective for some disease that can be spread by direct contact with an infected individual or the germs that they shed into the air, their clothes or their environment. Such diseases are referred to as contagious. Or it can be an idea or behavior that spreads from person to person.
coronavirus: A family of viruses named for the crown-like spikes on their surface (corona means “crown” in Latin). Coronaviruses cause the common cold. The family also includes viruses that cause far more serious infections, including SARS and COVID-19.
Corsi-Rosenthal box: A low-cost, do-it-yourself air filter that’s quick to build and easy to make. It can effectively remove small aerosols from a room-size indoor space. It’s made from a box fan sealed inside four furnace filters — preferably HEPA filters — that have been taped in a shape of a box (one on each side). A fifth filter is taped to form a top (above the fan). The fan is faced to blow air out the top filter. In the process, it draws air in from below and to the sides. All of these filters collect indoor aerosols, which can be germs, wildfire smoke or pollen. These filters became especially popular during the COVID-19 pandemic.
COVID-19: A name given to the disease that erupted into a massive global pandemic in 2020. It first emerged in 2019 and is caused by a new coronavirus known as SARS-CoV-2. Symptoms can include pneumonia, trouble breathing, feeling too tired to walk more than a few steps, fever, headaches, low blood-oxygen levels, blood clots and brain “fog.”
defense: (in biology) A natural protective action taken or chemical response that occurs when a species confronts predators or agents that might harm it. (adj. defensive)
disorder: (in medicine) A condition where the body does not work appropriately, leading to what might be viewed as an illness. This term can sometimes be used interchangeably with disease.
engineer: A person who uses science and math to solve problems. As a verb, to engineer means to design a device, material or process that will solve some problem or unmet need.
environmental engineer: A person who uses science to study and solve problems in ecosystems — from forests to the human body.
epidemiologist: Like health detectives, these researchers look to link a particular illness to what might have caused it and/or allowed it to spread.
evaporate: To turn from liquid into vapor.
exhaust: (in engineering) The gases and fine particles emitted — often at high speed and/or pressure — by combustion (burning) or by the heating of air. Exhaust gases are usually a form of waste.
filter: (n.) Something that allows some materials to pass through but not others, based on their size or some other feature. (v.) The process of screening some things out on the basis of traits such as size, density, electric charge. (in physics) A screen, plate or layer of a substance that absorbs light or other radiation or selectively prevents the transmission of some of its components.
flu: Short for influenza. It is a highly contagious viral infection of the respiratory passages causing fever and severe aching. It often occurs as an epidemic.
genetic: Having to do with chromosomes, DNA and the genes contained within DNA. The field of science dealing with these biological instructions is known as genetics. People who work in this field are geneticists.
germ: Any one-celled microorganism, such as a bacterium or fungal species, or a virus particle. Some germs cause disease. Others can promote the health of more complex organisms, including birds and mammals. The health effects of most germs, however, remain unknown.
HEPA: An acronym for high-efficiency particulate air. It’s a term for a type of pleated air filter (usually made of cloth). It can theoretically remove at least 99.97 percent of airborne particles that are at least 0.3 microns in diameter. That includes most bacteria, dust, mold and pollen. Any particles that are larger or smaller may be trapped even more efficiently. Such filters are often used on vacuums, ventilation systems and as covers to protect the nose and mouth.
humidity: A measure of the amount of water vapor in the atmosphere. (Air with a lot of water vapor in it is known as humid.)
immune: (adj.) Having to do with immunity. (v.) Able to ward off a particular infection. Alternatively, this term can be used to mean an organism shows no impacts from exposure to a particular poison or process. More generally, the term may signal that something cannot be hurt by a particular drug, disease or chemical.
immune system: The collection of cells and their responses that help the body fight off infections and deal with foreign substances that may provoke allergies.
immunology: The field of biomedicine that deals with the immune system. A doctor or scientist who works in that field is known as an immunologist.
infection: A disease that can spread from one organism to another. It’s usually caused by some type of microbe.
infectious: An adjective that describes a type of microbe or virus that can be transmitted to people, animals or other living things.
journal: (in science) A publication in which scientists share their research findings with experts (and sometimes even the public). Some journals publish papers from all fields of science, technology, engineering and math, while others are specific to a single subject. Peer-reviewed journals are the gold standard: They send all submitted articles to outside experts to be read and critiqued. The goal, here, is to prevent the publication of mistakes, fraud or work that is not novel or convincingly demonstrated.
microRNA: Short pieces of RNA that do not code for the production of proteins. Instead, they influence whether and how proteins are produced by interfering with normal production processes.
moisture: Small amounts of water present in the air, as vapor. It can also be present as a liquid, such as water droplets condensed on the inside of a window, or dampness present in clothing or soil.
mucus: A slimy substance produced in the lungs, nose, digestive system and other parts of the body to protect against infection. Mucus is made mainly of water but also includes salt and proteins such as mucins. Some animals use mucus for other purposes, such as to move across the ground or to defend themselves against predators.
nasal: Having to do with the nose.
phlegm: A thick, sticky mucus produced by the lungs. The body uses it to help carry germs and other unwanted materials out of the lungs.
protein: A compound made from one or more long chains of amino acids. Proteins are an essential part of all living organisms. They form the basis of living cells, muscle and tissues; they also do the work inside of cells. Antibodies, hemoglobin and enzymes are all examples of proteins. Medicines frequently work by latching onto proteins.
respiratory: Of or referring to parts of the body involved in breathing (called the respiratory system). It includes the lungs, nose, sinuses, throat and other large airways.
risk: The chance or mathematical likelihood that some bad thing might happen. For instance, exposure to radiation poses a risk of cancer. Or the hazard — or peril — itself. (For instance: Among cancer risks that the people faced were radiation and drinking water tainted with arsenic.)
RSV: See respiratory syncytial virus
salt: A compound made by combining an acid with a base (in a reaction that also creates water). The ocean contains many different salts — collectively called “sea salt.” Common table salt is a made of sodium and chlorine.
SARS-CoV-2: A coronavirus that emerged in Wuhan, China, in late December 2019. It would go on to cause widespread — and sometimes lethal — disease throughout China and many other nations. Its name reflects its close similarity to the original coronavirus known as SARS (for severe acute respiratory syndrome). That SARS virus sparked a global outbreak of disease in 2003.
sensor: (in biology) The structure that an organism uses to sense attributes of its environment, such as heat, winds, chemicals, moisture, trauma or an attack by predators.
sinus: Air-filled cavities (known as sinus cavities) around the nose and eyes. The tissue lining the sinuses makes mucus. It collects foreign materials and helps it drain into the nose. A painful inflammation of these tissues is known as sinusitis, which can create intense facial pressure and headaches around the cheeks and eyes.
society: An integrated group of people or animals that generally cooperate and support one another for the greater good of them all.
stress: (in biology) A factor — such as unusual temperatures, movements, moisture or pollution — that affects the health of a species or ecosystem.
system: A network of parts that together work to achieve some function. For instance, the blood, vessels and heart are primary components of the human body’s circulatory system. Similarly, trains, platforms, tracks, roadway signals and overpasses are among the potential components of a nation’s railway system. System can even be applied to the processes or ideas that are part of some method or ordered set of procedures for getting a task done.
thermostat: A temperature sensor that allows a system to know when a change — either heating or cooling — is called for.
ventilation: A system that supplies a room with fresh air or processes that move air around and between different rooms.
vesicle: A small fluid-filled sac inside cells. These sacs can hold chemicals that can be released either within the cell or outside of it.
virus: Tiny infectious particles consisting of genetic material (RNA or DNA) surrounded by protein. Viruses can reproduce only by injecting their genetic material into the cells of living creatures. Although scientists frequently refer to viruses as live or dead, in fact many scientists argue that no virus is truly alive. It doesn’t eat like animals do, or make its own food the way plants do. It must hijack the cellular machinery of a living cell in order to survive.
vitamin: Any of a group of chemicals that are essential for normal growth and nutrition and are required in small quantities in the diet because either they cannot be made by the body or the body cannot easily make them in sufficient amounts to support health.
