adolescence: A transitional stage of physical and psychological development that begins at the onset of puberty, typically between the ages of 11 and 13, and ends with adulthood.
atom: The basic unit of a chemical element. Atoms are made up of a dense nucleus that contains positively charged protons and uncharged neutrons. The nucleus is orbited by a cloud of negatively charged electrons.
bond: (in chemistry) A semi-permanent attachment between atoms — or groups of atoms — in a molecule. It’s formed by an attractive force between the participating atoms. Once bonded, the atoms will work as a unit. To separate the component atoms, energy must be supplied to the molecule as heat or some other type of radiation.
cancer: Any of more than 100 different diseases, each characterized by the rapid, uncontrolled growth of abnormal cells. The development and growth of cancers, also known as malignancies, can lead to tumors, pain and death.
carbon: A chemical element that is the physical basis of all life on Earth. Carbon exists freely as graphite and diamond. It is an important part of coal, limestone and petroleum, and is capable of self-bonding, chemically, to form an enormous number of chemically, biologically and commercially important molecules. (in climate studies) The term carbon sometimes will be used almost interchangeably with carbon dioxide to connote the potential impacts that some action, product, policy or process may have on long-term atmospheric warming.
chemical: A substance formed from two or more atoms that unite (bond) in a fixed proportion and structure. For example, water is a chemical made when two hydrogen atoms bond to one oxygen atom. Its chemical formula is H2O. Chemical also can be an adjective to describe properties of materials that are the result of various reactions between different compounds.
colleague: Someone who works with another; a co-worker or team member.
compound: (often used as a synonym for chemical) A compound is a substance formed when two or more chemical elements unite (bond) in fixed proportions. For example, water is a compound made of two hydrogen atoms bonded to one oxygen atom. Its chemical symbol is H2O.
concentration: (in chemistry) A measurement of how much of one substance has been dissolved into another.
degrade: To break down into smaller, simpler materials — as when wood rots or as a flag that’s left outdoors in the weather will fray, fade and fall apart. (in chemistry) To break down a compound into smaller components.
density: The measure of how condensed some object is, found by dividing its mass by its volume.
electron: A negatively charged particle, usually found orbiting the outer regions of an atom; also, the carrier of electricity within solids.
environment: The sum of all of the things that exist around some organism or the process and the condition those things create. Environment may refer to the weather and ecosystem in which some animal lives, or, perhaps, the temperature and humidity (or even the placement of things in the vicinity of an item of interest).
Environmental Protection Agency: (or EPA) A national government agency charged with helping create a cleaner, safer and healthier environment in the United States. Created on Dec. 2, 1970, it reviews data on the possible toxicity of new chemicals (other than foods or drugs, which are regulated by other agencies) before they are approved for sale and use. Where such chemicals may be toxic, it sets limits or guidelines on how much of them may be released into (or allowed to build up in) the air, water or soil.
environmental science: The study of ecosystems to help identify environmental problems and possible solutions. Environmental science can bring together many fields including physics, chemistry, biology and oceanography to understand how ecosystems function and how humans can coexist with them in harmony. People who work in this field are known as environmental scientists.
fabric: Any flexible material that is woven, knitted or can be fused into a sheet by heat.
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.
fluorine: An element first discovered in 1886 by Henri Moissan. It takes its name from the Latin word meaning “to flow.” Very reactive, chemically, this element had little commercial use until World War II, when it was used to help make a nuclear-reactor fuel. Later, it was used as ingredients (fluorocarbons) in refrigerants and aerosol propellants. Most recently, it has found widespread use to make nonstick coatings for frying pans, plumbers’ tape, and waterproof clothing.
immunity: The ability of an organism to resist a particular infection or poison by providing cells to remove, kill or disarm the dangerous substance or infectious germ. Or, when used colloquially, it means the ability to avoid some other type of adverse impact (such as firing from a job or being bullied).
millennia: (singular: millennium) Thousands of years.
mineral: Crystal-forming substances that make up rock, such as quartz, apatite or various carbonates. Most rocks contain several different minerals mish-mashed together. A mineral usually is solid and stable at room temperatures and has a specific formula, or recipe (with atoms occurring in certain proportions) and a specific crystalline structure (meaning that its atoms are organized in regular three-dimensional patterns). (in physiology) The same chemicals that are needed by the body to make and feed tissues to maintain health.
molecule: An electrically neutral group of atoms that represents the smallest possible amount of a chemical compound. Molecules can be made of single types of atoms or of different types. For example, the oxygen in the air is made of two oxygen atoms (O2), but water is made of two hydrogen atoms and one oxygen atom (H2O).
PFAS: Short for polyfluoroalkyl substances. Also known as perfluorocarbons and perfluorinated chemicals. These synthetic (human-made) chemicals contain a long chain of linked carbon atoms that act like a backbone from which fluorine atoms dangle (like little legs). They are long-lived chemicals and have the ability to build up in organisms (including people). They have gained widespread industrial use for being stain- and water-repellent and having general non-stick properties. Among the best-known examples is Teflon.
PFOA: Short for perfluorooctanoic acid. It’s one of a host of synthetic, fluorine-rich molecules designed to keep water, oils and other materials from sticking to something. It is one of the most heavily studied members of a large family of very persistent, fluorine-rich compounds used as a nonstick coating and fabric treatment (to repel water and stains). Data in animals suggest that ingestion or inhalation of this compound could cause harm. Sometimes known as C8, this abbreviation denotes the number of carbon atoms making up the molecule’s backbone (and to which fluorine atoms are bound).
PFOS: Short for perfluorooctane sulfonate. It’s one of a series of chemicals used in “nonstick” cookware, stain-resistant carpeting, food packaging and waterproof clothes. Some are even used in fire-fighting chemicals (such as foams). All are based on molecules with a carbon backbone to which fluorine atoms are bound. These potentially toxic compounds are remarkably stable and therefore persistent in the environment.
pollutant: A substance that taints something — such as the air, water, our bodies or products. Some pollutants are chemicals, such as pesticides. Others may be radiation, including excess heat or light. Even weeds and other invasive species can be considered a type of biological pollution.
polyfluoroalkyl substances: Also known as perfluorocarbons and perfluorinated chemicals. These synthetic (human-made) chemicals contain a long chain of linked carbon atoms that act like a backbone from which fluorine atoms dangle (like little legs). They are long lived chemicals and have the ability to build up in organisms (including people). They have gained widespread industrial use for being stain- and water-repellent and having general non-stick properties. Among the best-known examples is Teflon.
potassium: A chemical element that occurs as a soft, silver-colored metal. Highly reactive, it burns on contact with air or water with a violet flame. It is found not only in ocean water (including as part of sea salt) but also in many minerals.
radiation: (in physics) One of the three major ways that energy is transferred. (The other two are conduction and convection.) In radiation, electromagnetic waves carry energy from one place to another. Unlike conduction and convection, which need material to help transfer the energy, radiation can transfer energy across empty space.
reactive: (in chemistry) The tendency of a substance to take part in a chemical process, known as a reaction, that leads to new chemicals or changes in existing chemicals.
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.)
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.
synthetic: An adjective that describes something that did not arise naturally, but was instead created by people. Many synthetic materials have been developed to stand in for natural materials, such as synthetic rubber, synthetic diamond or a synthetic hormone. Some may even have a chemical makeup and structure identical to the original.
technology: The application of scientific knowledge for practical purposes, especially in industry — or the devices, processes and systems that result from those efforts.
Texas: The second largest state in the United States, located along the southern border with Mexico. It is about 1,270 kilometers (790 miles) long and covers an area of 696,000 square kilometers (268,581 square miles).
toxic: Poisonous or able to harm or kill cells, tissues or whole organisms. The measure of risk posed by such a poison is its toxicity.
ultraviolet: A portion of the light spectrum that is close to violet but invisible to the human eye.
waste: Any materials that are left over from biological or other systems that have no value, so they can be disposed of as trash or recycled for some new use.
wastewater: Any water that has been used for some purpose (such as cleaning) and no longer is clean or safe enough for use without some type of treatment. Examples include the water that goes down the kitchen sink or bathtub or water that has been used in manufacturing some product, such as a dyed fabric.
