Term
Air Quality Control Regions (AQRs)
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Definition
| An area designed by the federal government, where communities share a common air pollution problem |
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(Associated with human activies)
Include motor vehicles, fossil fuel burning for electricity and heat, industrial processes, solid waste disposal, and miscellaneous burning of things such as leaves and brush |
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| The air quality in the area equals or is better than the primary standard |
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| The air quality in the area does not meet the primary standard |
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| Device that converts toxic exhaust emissions from an internal combustion engine into non-toxic substances |
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| Compounds made of chlorine atoms, flourine atoms, and a carbon atom that react with the ozone, converting ozone to oxygen, which continuously depletes the ozone layer. |
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A list of pollutants developed by the EPA that are considered to be hazardous to health.
(CO, Pb, NO2, O3, SO2, PM10, and PM2.5) |
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| The plume height alone, with the physical stack height |
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| Particulate matter carried in the effluent gases from furnaces burning fossil fuels |
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| Radioactively active gases that absorb at wavelengths greater than 4 micrometers |
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| Hazardous Air Pollutants (HAPs) |
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Definition
| Regulated through risk-based approach through EPA, called National Emission Standards for Hazardous Air Pollutants (NESHAP) |
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| Cities, which are largely covered in concrete and asphalt, heat the air at ground level more than the countryside. This heat creates vertical convection currents that help to remove ground level pollutants from the city. |
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Normally, temperatures decrease with height, but when at some point above the ground the temperature increases with height, that area is known as an inversion layer. An inversion layer acts as a ceiling on the air below it, which is bad from a pollution standpoint, because it limits "dilution."
Inversion- a "ceiling" of warm air that prevents cold air from rising; an increase of temperature with elevation. |
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| A relationship between wind speed and the change in air temperature with height |
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| Diffusion process wherein the pollutant gas moves from points of higher concentration to points of lower concentratoin |
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| Maximum Achievable Control Technology |
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Definition
The National Emissions Standards for Hazardous Air Pollutants (NESHAPs) are emission tandards set by the US EPA for an air pollutant not covered by NAAQS that may cause an increase in fatalities or in serious, irreversible, or incapacitating illness.
The standards for a particular source category require the maximum degree of emission reduction that the EPA determines to be achievable, which is known as the Maximum Achievable Control Technology (MACT).
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| Chemical fragmentation, or rearrangement of a chemical, upon the absorption of radiation of the appropriate wavelength |
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| Particular matter having a diameter of 2.5 micrometers or less, and which is easily inhaled deep into the lungs |
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| Particulate matter having a diameter of 10 micrometers or less. |
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Term
| Point Source Gaussian Model |
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| An air dispersion model in which it is assumed to flow from a point source to a distance downwind based on the flow rate, wind speed, and plume standard deviations. |
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| Air quality standards established to protect human health with an "adequate margin of safety" |
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| A type of system in flue gas desulfurization (FGD) where the reagent that removes the sulfur oxides is recovered and reused. |
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| Photochemical oxidants resulting entirely from atmospheric reactions and not emitted from people or nature |
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| Air quality standards intended to prevent environmental and property damage |
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| The tendency of the atmosphere to resist or enhance vertical motion and is related to the wind speed and temperature change with respect to height. |
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Definition
| Combinations of pollutants that alone cause no damage are known to create acute effects when combined |
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| Volatile Organic Compounds (VOCs) |
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Definition
| Found in paints and plastics and other places, VOCs are compounds that tend to "leak out" of products over time. These products can reach dangerous levels in a new home. |
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