| 6147270561 | Air pollutants | Gases and particulate material added to the atmosphere that can affect climate or harm people or other organisms | | 0 |
| 6147270562 | hydroxyl radical (OH) | The hydroxyl group (OH), missing the electron. The hydroxly radical is a natural cleansing agent of the atmosphere. It is highly reactive, readily oxidizes many pollutants upon contact, and thus contributes to their removal from the air. | | 1 |
| 6147270563 | industrial smog | Type of air pollution consisting mostly of a mixture of sulfur dioxide, suspended droplets of sulfuric acid formed from some of the sulfur dioxide, and suspended solid particles.
Smog resulting from emissions from industry and other sources of gases produced by the burning of fossil fuels. | | 2 |
| 6147270564 | photochemical smog | A brownish haze that is a mixture of ozone and other chemicals (mainly from auto exhaust), formed when pollutants react with each other in the presence of sunlight, | | 3 |
| 6147270565 | temperature inversion | A deviation from the normal temperature distribution in the atmosphere, resulting in a layer of cold air temporarily trapped near the ground by a warmer, upper layer, resulting in the prevention of dispersion of air pollutants | | 4 |
| 6147270566 | atmospheric brown cloud (ABC) | A 1-to-3 km-thick blanket of pollution that frequently sits over south and central Asia, made up of black carbon and soot from biomass and fossil fuel burning. | | 5 |
| 6147270567 | particulates | small particles of dust (including soot and asbestos fibers) released into the atmosphere by many natural processes and human activities | | 6 |
| 6147270568 | Volatile Organic Compounds (VOCs) | A category of major air pollutants present in the air in the vapor state. The category includes fragments of hydrocarbon fuels from incomplete combustion and evaporated organic compounds such as paint solvents, gasoline, acetone, and cleaning solutions. A major factors in the formation of
photochemical smog. | | 7 |
| 6147270569 | Carbon Monoxide (CO) | Undetectable primary pollutant from incomplete combustion of fossil fuels that is highly toxic. Binds to hemoglobin reducing blood's ability to carry O2. Reduction accomplished by catalytic converters, oxygenated fuel, and mass transit. | | 8 |
| 6147270570 | Nitrogen Oxides (NOx) | A group of nitrogen-oxygen compounds formed when some of the nitrogen gas in the air combines with oxygen during high-temperature combustion. A major category of air pollutants and, along with hydrocarbons, are a primary factor in the production of ozone and other photochemical oxidants that are the most harmful components of photochemical smog. Also contribute to acid precipitaion. | | 9 |
| 6147270571 | Sulfur Dioxide (SO2) | A major air pollutant and toxic gas formed as a result of burning sulfur. The major sources are burning coal (in power plants) that contains some sulfur and refining metal ores (in smelters) that contain sulfur. | | 10 |
| 6147270572 | lead additive | Heavy metal added to gasoline to improve octane rating prior to the EPA-directed phaseout in the '80s and '90's. Emitted with the exhaust, it remained airborne and traveled great distances before settling. | | 11 |
| 6147270573 | air toxins | air pollutants known to cause cancer or other serious health problems. Smoke, soot | | 12 |
| 6147270574 | secondary pollutants | air pollutants formed when primary air pollutants react with sunlight and other atmospheric components to form new harmful compounds | | 13 |
| 6147270575 | ozone | A gas that absorbs ultraviolet solar radiation, found in the stratosphere, a zone between 15 and 50 kilometers (9 to 30 miles) above Earth's surface. A harmful secondary pollutant in the troposphere. | | 14 |
| 6147270576 | Peroxyacetyl Nitrates (PANs) | A pollutant formed from photochemical reactions invlving nitric oxide (NO) and volatile organic compounds (VOCs). Irritating to eye, nose, and throat membranes and is particularly damaging to plants. | | 15 |
| 6147270581 | national emissions | primary air pollutants tracked by EPA | | 16 |
| 6147270582 | ambient concentrations | EPA measurement of primary air pollutants that gives certain levels of pollutants that should not be exceeded for health reasons | | 17 |
| 6147270583 | photochemical oxidants | class of air pollutants formed as a result of sunlight acting on compounds such as nitrogen oxides and hydrocarbons that are damaging to forests and plants | | 18 |
| 6147270584 | sulfuric acid | products of sulfur dioxide and nitrogen oxides reacting with water vapor, the acids in acid rain | | 19 |
| 6147270585 | nitric acid | A secondary air pollutant and a major component of acid deposition, nitric acid is produced when NOx in the air reacts with the hydroxyl radical and water. | | 20 |
| 6147270586 | acid deposition | acid precipitation plus dry-particle fallout | | 21 |
| 6147270587 | acid | Any compound that increases the number of hydrogen ions when dissolved in water | | 22 |
| 6147270588 | base | Any compound that increases the number of hydroxide ions when dissolved in water | | 23 |
| 6147270589 | p.H. | The scale used to designate the acidity or basicity of solutions or soil, expressed as the logarithm of the concentration of hydrogen ions (H+). 7 is neutral; values decreasing from 7 indicate increasing acidity, and values increasing from 7 indicate basicity. Each unit from 7 indicates a 10-fold increase over the preceding unit. | | 24 |
| 6147270590 | Acid precipitation | Includes acid rain, acid fog, acid snow, and any other forms of precipitation that is more acidic than normal (lower than pH 5.6). Excess acidity is derived from certain air pollutants- namely, sulfur dioxide and oxides of nitrogen. | | 25 |
| 6147270591 | Sulfuric acid (H2SO4) | The major constituent of acid precipitation. formed when sulfur dioxide emissions react with water vapor in the atmosphere. | | 26 |
| 6147270592 | benzene | An organic chemical present in crude and refined oil products and tobacco smoke, a known human carcinogen. | | 27 |
| 6147270593 | Buffer | A substance that prevents appreciable changes in pH in solutions to which small quantities of acids or bases are added | | 28 |
| 6147270596 | Ambient standards | Air-quality standards (set by the EPA) determining certain levels of pollutants that should not be exceeded in order to maintain environmental and human health. | | 29 |
| 6147270597 | Criteria pollutants | Pollutants judged to pose especially great threats to human health (carbon monoxide, sulfur dioxide, nitrogen dioxide, tropospheric ozone, particulate matter and lead) | | 30 |
| 6147270598 | National Ambient Air Quality Standards (NAAQS) | The allowable levels of ambient criteria air pollutants set by EPA regulation | | 31 |
| 6147270599 | Primary standard | A limit set by the EPA in accordance with national ambient air quality standards (NAAQS) to protect human health. | | 32 |
| 6147270601 | National Emission Inventory | Database of criteria and hazardous air pollutants the EPA uses to regulate pollutants | | 33 |
| 6147270603 | Catalytic converter | A platinum-coated device that oxidizes most of the VOCs and some of the CO that would otherwise be emitted in automobile exhaust, converting them to CO2 and water. | | 34 |
| 6147270605 | Energy Independence and Security Act | Enacted in 2007, Aims to improve vehicle fuel economy and reduce US dependence on petroleum, increase the supply of renewable alternative fuel sources by setting a mandatory Renewable Fuel Standard (requires transportation fuel sold in US to contain minimum of 36 billion gallons of renewable fuels annually by 2020) Sets the Corporate Average Fuel Economy standard at 35 miles per gallon per passenger cars and light trucks by the year 2020 | | 35 |
| 6147270606 | Point source pollution | Pollutants discharged from a single identifiable location (e.g., pipes, ditches, channels, sewers, tunnels, containers of various types). | | 36 |
| 6147270607 | Area sources | Diffuse sources of pollution such as urban runoff or automobile exhaust. | | 37 |
| 6147270610 | Clean Air Interstate Rule (CAIR) | A U.S. Environmental Protection Agency (EPA) regulation issued on March 10, 2005, designed to permanently cap emissions of sulfur dioxide, nitrogen oxides, an | | 38 |
| 6147270611 | Clean Air Mercury Rule (CAMR) | A U.S. Environmental Protection Agency (EPA) regulation issued on March 15, 2005, that required coal-fired power plants to reduce mercury emissions 47 percent by 2010, and 79 percent by 2018, through a cap-and-trade plan. | | 39 |
| 6147270612 | Ozone shield | The layer of ozone gas in the upper atmosphere that protects Earth from some of the sun's radiation | | 40 |
| 6147270613 | Chlorofluorocarbons (CFCs) | Chemicals in refrigerators aerosols and air conditioners that destroy the ozone layer | | 41 |
| 6147270614 | Chlorine catalytic cycle | In the stratosphere, a cyclical chemical process in which chlorine monoxide breaks down ozone. | | 42 |
| 6147270615 | Catalyst | A substance that initiates or accelerates a chemical reaction without itself being affected | | 43 |
| 6147270617 | Montreal Protocol | An international agreement signed in 1987 by 105 countries and the European Union. The protocol called for a reduction in the production and consumption of chloroflourocarbons (CFCs) of 50 percent by 2000 to protect the ozone layer. | | 44 |
| 6147270618 | Clean Air Act | (CAA, 1970) United States federal law designed to control air pollution on national level. It requires the Environment Protection Agency (EPA) to develop and enforce regulations to protect the public from airborne contaminants determined to be hazardous to human health. Sets emission standards for automobiles and factories. | | 45 |
| 6299064057 | Non Point Source Pollution | Pollution that comes from many sources rather than from a single, specific site | | 46 |
| 6299408007 | PM2.5 and PM10 | Standard criterion air pollutants for suspended particulate matter. PM10 refers to particles smaller than 10 micrometers in diameter; PM2.5 refers to particles smaller than 2.5 micrometers in diameter. The smaller particles are readily inhaled directly into the lungs. | | 47 |
| 6299453170 | Radon | Radioactive gas from decay of uranium in rocks, can lead to lung cancer. Escapes naturally to the surface and seeps into buildings through cracks in foundations and basement floors. | | 48 |
| 6299484366 | Aerosols | Microscopic liquid and solid particles originating from land and water surfaces and carried up into the atmosphere. Examples include: dust, salt, pollen, water droplets, microorganisms. | | 49 |
| 6299510901 | COPD | Chronic Obstructive Pulmonary Disease, lung disease commonly seen in smokers, but often seen in developing countries as a result of burning wood and dung for cooking and heating. Involves 3 processes: emphysema, bronchitis, and asthma. | | 50 |
| 6299543403 | Carcinogen | Cancer causing substance | | 51 |
| 6299545462 | Mutagen | A chemical or physical agent that interacts with DNA and causes a mutation. | | 52 |
| 6299549720 | Teratogen | Substance that can produce developmental malformations (birth defects) during the prenatal period | | 53 |
| 6299564995 | CAFE Standards | Corporate Average Fuel Economy standards enacted into law in 1975, established fuel efficiency standards for passenger cars and light trucks. The fuel economy ratings for a manufacturer's entire line of passenger cars must currently average at least 27.5 mpg for the manufacturer to comply with the standard and at least 54.5 mpg by 2025. | | 54 |
