| Term | Definition |
|---|---|
| acid rain | Precipitation with elevated acidity caused by atmospheric conversion of pollutants like nitrogen oxides and sulfur dioxide. |
| air pollutants | Harmful substances released into the atmosphere that can negatively affect air quality and human health. |
| carbon dioxide | A greenhouse gas produced by combustion of fossil fuels and respiration; a principal contributor to global climate change. |
| carbon monoxide | A colorless, odorless gas produced by incomplete combustion that is toxic and classified as an indoor air pollutant. |
| Clean Air Act | U.S. legislation that authorized the Environmental Protection Agency to regulate air pollutants and protect air quality. |
| hydrocarbons | Organic compounds containing hydrogen and carbon released during fossil fuel combustion that contribute to air pollution. |
| lead | A toxic metal whose use in fuels was regulated by the EPA under the Clean Air Act, resulting in decreased atmospheric levels. |
| nitric acid | An acid formed in the atmosphere when nitrogen oxides convert, contributing to acid rain. |
| nitrogen oxides | Gaseous compounds of nitrogen and oxygen produced primarily from motor vehicle emissions and combustion processes that contribute to photochemical smog formation. |
| ozone | A secondary pollutant produced through chemical reactions between oxygen and nitrogen oxides in the presence of sunlight, a major component of photochemical smog. |
| particulate matter | Small solid particles or liquid droplets suspended in the air that contribute to air pollution. |
| photochemical smog | Air pollution formed when nitrogen oxides and volatile organic compounds react with heat and sunlight to produce various pollutants. |
| primary pollutants | Air pollutants released directly into the atmosphere from pollution sources. |
| secondary pollutants | Air pollutants formed in the atmosphere through chemical reactions between primary pollutants and other atmospheric components. |
| sulfur dioxide | An air pollutant released during the burning of fossil fuels, particularly coal and diesel, that contributes to acid rain. |
| toxic metals | Harmful metallic elements released during coal combustion that can accumulate in the environment and organisms. |
| Term | Definition |
|---|---|
| eye irritation | A health effect caused by exposure to photochemical smog that causes discomfort and inflammation of the eyes. |
| nitrogen oxides | Gaseous compounds of nitrogen and oxygen produced primarily from motor vehicle emissions and combustion processes that contribute to photochemical smog formation. |
| ozone | A secondary pollutant produced through chemical reactions between oxygen and nitrogen oxides in the presence of sunlight, a major component of photochemical smog. |
| photochemical smog | Air pollution formed when nitrogen oxides and volatile organic compounds react with heat and sunlight to produce various pollutants. |
| respiratory problems | Health issues affecting the lungs and breathing system that can be caused by air pollutants such as tropospheric ozone. |
| volatile organic compounds | Organic chemicals that have a high vapor pressure at room temperature and can be released into the environment during fossil fuel extraction and use. |
| Term | Definition |
|---|---|
| particulate matter | Small solid particles or liquid droplets suspended in the air that contribute to air pollution. |
| smog | A type of air pollution formed when pollutants are trapped near the ground, typically consisting of a mixture of smoke and fog. |
| temperature gradient | The rate of change in air temperature with altitude in the atmosphere. |
| thermal inversion | An atmospheric condition where air temperature increases with altitude instead of the normal decrease, trapping cooler air near Earth's surface. |
| Term | Definition |
|---|---|
| decomposition | The process by which dead organic matter is broken down by microorganisms, releasing CO2 and other nutrients back into the environment. |
| particulate matter | Small solid particles or liquid droplets suspended in the air that contribute to air pollution. |
| respiration | The metabolic process by which organisms break down organic molecules to release energy, producing CO2 as a byproduct. |
| volcanic eruptions | Explosive or effusive events where magma and gases, including CO2, are released from the Earth's interior into the atmosphere. |
| Term | Definition |
|---|---|
| asbestos | A mineral substance that causes mesothelioma and other health problems when inhaled. |
| asphyxiant | A substance that causes asphyxiation by displacing oxygen or preventing oxygen uptake, such as carbon monoxide. |
| carbon monoxide | A colorless, odorless gas produced by incomplete combustion that is toxic and classified as an indoor air pollutant. |
| formaldehyde | A human-made chemical found in building materials, furniture, and carpeting that functions as an indoor air pollutant. |
| indoor air pollutants | Harmful substances or contaminants found in the air inside buildings that can negatively affect human health. |
| lead | A toxic metal whose use in fuels was regulated by the EPA under the Clean Air Act, resulting in decreased atmospheric levels. |
| mold | A fungal growth that occurs naturally indoors and serves as an indoor air pollutant. |
| nitrogen oxides | Gaseous compounds of nitrogen and oxygen produced primarily from motor vehicle emissions and combustion processes that contribute to photochemical smog formation. |
| particulate matter | Small solid particles or liquid droplets suspended in the air that contribute to air pollution. |
| radon | A naturally occurring radioactive gas produced by uranium decay in rocks and soils that accumulates indoors as an air pollutant. |
| radon gas | A naturally occurring radioactive gas that can infiltrate homes through soil, basements, cracks in foundations, and groundwater. |
| Radon-222 | A specific radioactive isotope of radon produced by uranium decay that accumulates as a naturally occurring indoor air pollutant. |
| radon-induced lung cancer | A type of lung cancer caused by prolonged exposure to radon gas, the second leading cause of lung cancer in America. |
| sulfur dioxide | An air pollutant released during the burning of fossil fuels, particularly coal and diesel, that contributes to acid rain. |
| tobacco smoke | Smoke produced by burning tobacco that serves as a combustion-related indoor air pollutant. |
| volatile organic compounds | Organic chemicals that have a high vapor pressure at room temperature and can be released into the environment during fossil fuel extraction and use. |
| Term | Definition |
|---|---|
| air pollutants | Harmful substances released into the atmosphere that can negatively affect air quality and human health. |
| alternative fuels | Energy sources other than fossil fuels, such as renewable or cleaner-burning fuels, used to reduce air pollution. |
| catalytic converter | An air pollution control device in internal combustion engines that converts harmful pollutants (CO, NOx, and hydrocarbons) into less harmful substances (CO2, N2, O2, and H2O). |
| conservation practices | Actions taken to reduce resource consumption and minimize pollution through efficient use of energy and materials. |
| dry scrubber | An air pollution control device that removes particulates and/or gases from industrial exhaust streams without using liquid. |
| electrostatic precipitator | An air pollution control device that removes particulates from industrial exhaust streams using electrical charges. |
| regulatory practices | Government-enforced rules and standards designed to control and reduce air pollution emissions. |
| vapor recovery nozzle | An air pollution control device on gasoline pumps that prevents fuel vapors from escaping into the atmosphere during vehicle refueling. |
| wet scrubber | An air pollution control device that removes particulates and/or gases from industrial exhaust streams using liquid. |
| Term | Definition |
|---|---|
| acid deposition | The process by which acidic compounds from the atmosphere are deposited on Earth's surface through precipitation or dry deposition. |
| acid rain | Precipitation with elevated acidity caused by atmospheric conversion of pollutants like nitrogen oxides and sulfur dioxide. |
| acidification | The process by which soils and bodies of water become more acidic due to the addition of acidic compounds. |
| anthropogenic sources | Acid deposition precursors that originate from human activities, such as vehicle emissions and industrial processes. |
| coal-burning power plants | Industrial facilities that burn coal for electricity generation and emit both nitrogen oxides and sulfur dioxide contributing to acid deposition. |
| corrosion | The gradual wearing away or deterioration of materials, such as human-made structures, due to chemical reactions with acids. |
| limestone bedrock | A calcium carbonate-based rock formation that can neutralize acidic compounds and buffer the effects of acid rain on aquatic systems. |
| motor vehicles | Transportation sources that emit nitric oxides contributing to acid deposition. |
| neutralize | To counteract or reduce the acidity of a substance by adding a base or alkaline material. |
| nitric oxides | Nitrogen oxide compounds that cause acid deposition, primarily emitted from motor vehicles and coal-burning power plants. |
| nitrogen oxides | Gaseous compounds of nitrogen and oxygen produced primarily from motor vehicle emissions and combustion processes that contribute to photochemical smog formation. |
| sulfur dioxide | An air pollutant released during the burning of fossil fuels, particularly coal and diesel, that contributes to acid rain. |
| sulfur oxides | Gaseous compounds containing sulfur and oxygen that contribute to acid deposition, primarily from coal-burning power plants. |
| Term | Definition |
|---|---|
| construction | Building and development activities that generate significant noise pollution in urban environments. |
| domestic activity | Household-related activities that contribute to noise pollution in residential areas. |
| hearing loss | Partial or complete reduction in the ability to perceive sound, often caused by exposure to loud noise. |
| industrial activity | Manufacturing and factory operations that produce noise pollution in urban and surrounding areas. |
| migratory routes | Established pathways that animals follow during seasonal migration, which can be disrupted by noise pollution. |
| noise pollution | Sound at levels high enough to cause physiological stress and hearing loss in organisms. |
| physiological stress | Physical strain on an organism's body systems that can result from environmental conditions outside its tolerance range. |
| sound masking | The obscuring of sounds used by animals for communication or hunting due to background noise. |
| transportation | Movement of people and goods by vehicles, a major source of noise pollution in urban areas. |