Term | Definition |
pollutant | Anything that contaminates the soil, water or the air |
Air pollution | any unwanted pollutant (chemical, particulate matter, or biological material) in the air which causes harm to humans and the environment |
primary pollutants | pollutants that are emitted directly into the atmosphere |
secondary pollutant | form when a primary pollutant comes in contact with other primary pollutants or naturally occurring substances |
Sulfur oxides (SOx) | produced by volcanoes and in various industrial processes |
Nitrogen oxides (NOx) | emitted from high temperature combustion; reddish-brown toxic gas has a characteristic sharp, biting odor |
Carbon monoxide | a colorless, odorless, non-irritating but very poisonous gas. It is a product of incomplete combustion of fuel such as natural gas, coal or wood |
Carbon dioxide (CO2) | a greenhouse gas emitted from combustion; a natural gas in the atmosphere |
Volatile organic compounds | a major indoor air pollutant, often divided into the separate categories of methane (CH4) and non-methane (NMVOCs); significant greenhouse gases |
Particulate matter | tiny particles of solid or liquid suspended in a gas;originating from volcanoes, dust storms, forest and grassland fires, living vegetation, and sea spray; burning of fossil fuels in vehicles, power plants and various industrial processes |
Chlorofluorocarbons (CFCs) | harmful to the ozone layer; emitted from products currently banned from use such as aerosols, refrigerants, etc. |
Ammonia (NH3) | emitted from agricultural processes; a gas with a characteristic pungent odor |
Odors | from garbage, sewage, and industrial processes |
Radioactive pollutants | produced by nuclear explosions, war explosives, and natural processes such as the radioactive decay of radon |
Smog | smoke/fog which results from large amounts of coal burning in an area or auto and industrial emissions; caused by a mixture of smoke and sulfur dioxide |
Ground level ozone | formed from NOx and VOCs; At abnormally high concentrations brought about by human activities (largely the combustion of fossil fuel), it is a pollutant, and a constituent of smog when close to earth's surface |
combustion | also called burning |
Ozone | a poisonous form of oxygen, harmful at Earth's surface, but helpful by blocking radiation from the sun when it is in the atmosphere |
acid rain | occurs when pollution in the air is carried to the Earth with rain or snow, mostly caused by air pollution from factories that burn fossil fuels and by vehicles |
pH scale | measures the amount of acid in a substance |
EPA | Environmental Protection Agency: protects human health and the environment through the regulatory process and voluntary programs such as Energy Star and Commuter Choice |
Clean Air Act | the law that allows the EPA to set limits on how much of a pollutant is allowed in the air anywhere in the United States |
Air Quality Index (AQI) | a "public-friendly" way of using actual monitoring data to help assess how clean our air is;The color codes, which range from green to purple, correspond to specific pollution levels |
greenhouse effect | warming of earth's atmosphere caused by atmospheric gases that trap the heat from the sun's rays |
Greenhouse gas | molecules of gas that allow the passage of visible and UV radiation from incoming sunlight, but they absorb the longer wavelength infrared (heat) radiated from the warm earth |
Heat | the total kinetic energy of all atoms or molecules in a substance |
Temperature | the measure of the average kinetic energy within a body |
heat budget | The measurement of energy absorbed and the amount of energy lost by the Earth to space |
climatology | the study of our climate |