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Clean Air Glossary

Acid: A sour solution with a pH of less than 7

 

Acid rain: A term referring to acid falling to earth in rain, snow, frost, fog, mist, gases, or dry particles.  Acid rain is caused when sulfur dioxide and nitrogen oxides emitted into the atmosphere become acid through chemical reactions and then fall to earth.

 

Air monitoring:  The measuring of the types and quantities of pollutants in the atmosphere

 

Air pollution: The presence of contaminants in the air in high enough concentrations to harm humans, wildlife, plants, or man-made things

 

Air Quality Index (AQI):   A scale developed by the government to measure how much pollution is in the air.  the AQI is often used in weather reports

 

Alkaline: A substance is alkaline when it has a pH higher than 7 (base) and is capable of neutralizing an acid

 

Atmosphere: The layer of air that surrounds the earth

 

Benzenes: Compounds found in motor fuels, dry cleaning processes, antifreeze, resins, perfumes, medicines, varnishes, lacquers, and solvents.  When evaporated, applied, spilled, or combusted, they emit hydrocarbons into the atmosphere which cases the creation of a harmful ozone

 

Buffer:  The ability to neutralize acidic or alkaline solutions in soil and water

 

Carbon dioxide: A colorless, odorless gas breathed out by humans and animals and emitted from burning fossil fuel

 

Carbon monoxide (CO): A colorless, odorless, deadly gas created mainly by the incomplete combustion of fuel in gasoline engines

 

Combustion: Burning; a chemical reaction that produces heath, light, and other by-products.  For example, in gasoline engines, when oxygen and gas mix and are ignited by a spark, heat, light, carbon monoxide, and water are produced

 

Criteria air pollutants: Common air pollutants that can be found throughout the United States

 

Emissions: Gases, vapors, and particles that go into the air, usually by human activities such as burning fossil fuels in vehicles, factories, power plants, and homes

 

Environment: Everything, living and non-living, on the earth

 

Fossil fuel: Buried deposits of decayed plants and animals that, over millions of years, have been converted to oil, coal, or natural gas by heat and pressure in the earth’s crust.  Fossil fuel provides most of our energy

 

Global warming: The possibility of earth’s temperature rising from excess carbon dioxide and other gases emitted from burning fossil fuels and other man-made sources

 

Groundwater: Water from rain and snow that seeps into the ground and is stored

 

Hazardous products: Products containing chemicals that can be poisonous or otherwise harmful to the environment

 

Hazardous waste: Solid and liquid waste that contains substances that can be harmful or dangerous to the environment

 

Hydrocarbons: Compounds produced by the incomplete burning of gasoline and the evaporation of such things as industrial solvents and oil paints. hydrocarbons contribute to smog and ozone

 

Lead (Pb): A metal added to some gasoline to improve engine performance.  As the engine runs, lead particles escape through the exhaust pipe.  Sources of lead include paint, metal refineries, and manufacturing of lead storage batteries

 

Natural resources: Things in nature that we use to make products and to live (for example: trees, oil, and water)

 

Nitrogen Oxides (NO and NO2): Gases produced during high temperature combustion in motor vehicles, power plants, and industrial furnaces

 

Nonattainment areas: A geographical area in which the level of air pollution is higher than the level allowed by state or federal standards

 

Ozone (O3): A harmful form of oxygen which is produced when sunlight stimulates a reaction between nitrogen oxides and hydrocarbons. Near the earth’s surface, ozone is a major component of smog. Also known as tropospheric ozone which extends from the earth’s surface up to 8 miles above the surface

 

Ozone layer: A layer of atmospheric gases, located in the stratosphere (9-30 miles above the earth’s surface). The ozone layer protects life on earth by filtering out harmful, cancer-causing ultraviolet radiation from the sun

 

Particulate: A tiny bit of solid or liquid matter (soot, dust, fumes, aerosols, mist, etc.) suspended or carried in the air.  Fine particulate matter smaller than 10 microns in diameter is called PM10.  One hair on your head is approximately 70 microns in diameter, so you see PM10 is really, really small

 

Pesticides:  A chemical used on food crops or other plants to kill bugs or other pests that damage them

 

pH: A scale numbered from 0 (acidic) to 14 (alkaline) and used to measure the degree of acidity or alkalinity in a substance

 

Pollutant: A harmful chemical emitted into the air, water, or soil.  Pollutants can be solid, liquid, or gas

 

Scrubber: An antipollution device that uses a spray to remove pollutants from a stream of air passing through a smokestack

 

Smelter: A plant where metals are melted to remove impurities

 

Smog: A mixture of emissions from fossil fuel, chemical vapors, and particles combined (hydrocarbons and nitrogen oxides) with sunlight and oxygen in the air.  Smog is mostly made up of ozone

 

Solvents: Industrial solvents are chemicals used in production processes. Examples include painting and coating automobiles, cleaning machined metal parts, printing and dry cleaning processes. Solvents create hydrocarbons which cause ozone

 

Stratospheric Ozone: Naturally occurring ozone (three oxygen molecules -O3) layer 9to 10 miles above the earth’s surface.  It protects us from the ultraviolet rays that can cause skin cancer, eye problems (cataracts), and can weaken our immune system

 

Sulfur dioxide (SO2): A gas, released mainly from power plants that burn coal and oil to make electricity

 

Ultraviolet radiation: Invisible waves of energy emitted from the sun

 

Volatile Organic Compounds (VOC’s): Are released from burning fuel (gasoline, oil, wood, coal, natural gas) solvents, paints, and glues. Cars are an important source of VOC’s