Unit 7: Atmospheric Pollution

Comprehensive vocabulary flashcards covering atmospheric pollutants, their sources, consequences, and methods of reduction as presented in Unit 7.

Pollution

Any substance that has harmful effects on people, ecosystems, or infrastructure and the economy.

Primary pollutants

A pollutant emitted directly from a source, including natural sources like volcanic ash and anthropogenic sources like products of fossil fuel combustion such as $CO_2$, $NO_x$, and $SO_2$.

Secondary pollutants

Pollutants that are not directly emitted but form when primary pollutants react in the atmosphere, usually with water; examples include Ozone and acid rain.

Nitrogen oxides ($NO_x$)

A family of poisonous, highly reactive gases that form when fuel is burned at high temperatures, often emitted by vehicles and construction equipment.

Volatile organic compounds (VOCs)

Compounds with high vapor pressure and low water solubility that evaporate or sublimate at room temperature; sources include paints, pharmaceuticals, gasoline, and trees.

Sulfur dioxide ($SO_2$)

A gaseous air pollutant formed when sulfur-containing fuel such as coal, oil, or diesel is burned, or from natural sources like volcanoes.

Ozone ($O_3$)

Ground level pollution created by chemical reactions between $NO_x$ and VOCs in the presence of sunlight; often referred to as smog.

Sulfur scrubbers

Air pollution control devices that remove $SO_2$ from the exhaust of coal-fired power plants by spraying a wet slurry of limestone into a chamber.

SPLONC

An acronym for the six pollutants regulated under the National Ambient Air Quality Standards (NAAQS): Sulfur dioxide ($SO_2$), Particulate matter (PM), Lead ($Pb$), Ozone ($O_3$), Nitrogen dioxide ($NO_2$), and Carbon monoxide ($CO$).

Photochemical smog

A variety of pollutants formed when nitrogen oxides and volatile organic hydrocarbons react with heat and sunlight, typically in urban areas with high motor vehicle density.

Thermal inversion

An atmospheric condition where the normal temperature gradient is altered so that air at the Earth's surface is cooler than air at higher altitudes, trapping pollution and smog close to the ground.

Ocean acidification

The process by which elevated $CO_2$ concentrations absorbed by the ocean decrease its pH, lowering the availability of carbonate ions needed by shell-building organisms.

Particulate matter (PM)

Solid and liquid particles in the air small enough to be inhaled, categorized by size such as $PM_{10}$ (upper respiratory concern) and $PM_{2.5}$ (lower respiratory concern).

Radon-222

A naturally occurring, invisible, odorless gas resulting from decaying uranium in rocks; it is the second leading cause of lung cancer in the US.

Asbestos

A mineral fiber found in rocks and soil used in building materials for fiber strength and heat resistance; exposure is linked to lung cancer, mesothelioma, and asbestosis.

Carbon monoxide ($CO$)

An asphyxiant produced by burning carbon-based fuels that reacts with hemoglobin in red blood cells, impairing the body's ability to carry oxygen.

Electrostatic precipitators

Devices that force flue gas through a chamber that adds an electric charge to pollutants, causing soot particles to stick to metal plates or filters with an opposite charge.

Catalytic converter

An exhaust emission control device used in gasoline or diesel engines to convert pollutants like $CO$, $NO_2$, and hydrocarbons into less-toxic pollutants like $H_2O$, $CO_2$, and $N_2$.

Acid rain

Secondary pollutants created when $SO_2$ and $NO_x$ react with water and oxygen in the atmosphere to form sulfuric and nitric acids, which are then deposited as wet or dry deposition.

Aluminum toxicity

An environmental impact of acid rain where acidic conditions promote the leaching of aluminum ions from soils, which is toxic to plants and aquatic life.

Noise pollution

Noise levels or patterns that cause physiological stress and hearing loss in humans or mask sounds used by animals to communicate or hunt.