Environmental Science and Policy Review

Comprehensive vocabulary flashcards covering population phases, air and water pollution, toxicology, energy sources, and climate change agreements.

Pre-industrial Stage (Phase 1)

The demographic stage characterized by high CBR (crude birth rate) and high CDR (crude death rate), resulting in a stable population.

Transitional Stage (Phase 2)

The demographic stage involving high CBR but a decreasing CDR, leading to a rapid rise in human population and the most rapid rate of increase.

Industrial Stage (Phase 3)

The stage characterized by low CDR and decreasing CBR; the population is still growing but growth is slower and heading toward stabilization.

Post-industrial stage (Phase 4)

The stage with low CBR and low CDR, where the population has stabilized or is in a decline.

Primary pollutant

Pollutants being discharged directly into the troposphere, such as $CO_2$, $NO$, and $SO_2$.

Secondary pollutant

Pollutants formed from a reaction between a primary pollutant and other chemicals, such as $SO_3$, $H_2SO_4$, and $O_3$.

Thermal inversion

A lack of mixing or convection due to density difference where warm, lower density air is positioned on top of cooler air.

$Ozone (O_3)$ Comparison

Stratospheric ozone is beneficial as it blocks harmful UVA and UVB radiation; tropospheric ozone is a harmful irritant and a component of smog.

Nitrogen dioxide ($NO_2$)

A brown fume and primary outdoor air pollutant from fossil fuel combustion; also a criteria pollutant under NAAQS.

Carbon monoxide ($CO$)

A highly toxic, colorless, and odorless gas formed when burning without sufficient oxygen.

Sulfur dioxide ($SO_2$)

A precursor of sulfuric acid ($H_2SO_4$) and acid rain; the subject of a cap and trade program established in 1990.

Particulate matter ($PM$)

Fine particles divided into two major classes, $PM2.5$ and $PM10$, representing significant outdoor and indoor air pollutants.

Mercury ($Hg$)

A neurotoxin and teratogen discharged from coal burning, often existing in the form of $CH_2Hg$, capable of bioaccumulation.

Radon-222

A primary indoor air pollutant that is a decay product from Uranium-238.

Asbestos

Fine and abrasive particles formerly used for insulation and fire prevention; a known carcinogen.

Volatile organic compounds (VOCs)

A category of indoor and outdoor pollutants including methane, benzene, and formaldehyde.

NAAQS

National Ambient Air Quality Standards set in 1973 for six criteria air pollutants: CO, $NO_2$, $SO_2$, particulates, Ozone, and Lead.

HAP

Hazardous Air Pollutant; the EPA enlists 187 total chemicals in this category.

Cultural eutrophication

Excessive supply of nutrients by humans, usually from inorganic fertilizers, leading to toxic algal blooms.

Bioaccumulation

The accumulation of fat-soluble toxins in an individual's body over time.

Biomagnification

The amplification of toxic concentrations as they move from one trophic level to a higher trophic level.

Dissolved oxygen (DO)

An important criterion for aquatic species survival that decreases drastically due to pollution or toxic blooms.

Phytoplankton

Microscopic plant species and producers dwelling at the water surface that are major contributors of DO.

Ogallala Aquifer

The largest aquifer in the world, used as a significant source of groundwater storage.

Dioxins

Highly toxic chemical results of combustion processes that can cause cancer and immune system diseases.

Primary Water Treatment

A physical treatment involving sedimentation where solids are allowed to settle to form sludge.

Secondary Water Treatment

A biological treatment using an aeration tank to provide oxygen for bacteria to remove harmful agents.

Tertiary Water Treatment

A chemical treatment process specifically for the removal of nitrates and phosphates.

Clean Water Act (1972)

Legislation regulating discharges from traditional point sources like municipal sewage plants but not covering groundwater.

Safe Drinking Water Act (1974)

Requires the EPA to regulate pollutants with negative health effects and protect drinking water sources including groundwater wells.

$LD_{50}$ (Lethal dose-50)

The dosage of a toxin required to kill $50\%$ of a test population.

Threshold toxin

A toxin that shows a negative effect only after reaching a specific dosage level; examples include oxygen and water.

Non-threshold toxin

A toxin that shows a linear direct response with dosage exposure, such as Lead ($Pb$) or benzene.

Teratogens

Chemicals that cause birth defects, such as Mercury ($Hg$).

Persistent Organic Pollutants (POPs)

Powerful toxins that bioaccumulate and biomagnify, such as DDT, DDE, PCBs, dioxins, and furans.

Toxicological synergy

A combination of toxins that greatly amplifies or reduces harmful effects, such as the lethal combination of cadmium and copper.

Toxic Substances Control Act (1976)

Grants the EPA authority to ban chemicals from being manufactured or imported if they are deemed a human-health hazard.

Stockholm Convention (2001)

An international agreement where countries pledged to reduce or eliminate the production and release of 12 key POPS.

Grades of Coal

The progression of coal from Lignite (brown coal), to Bituminous (soft coal), to Anthracite (hard coal), with increasing heat and carbon content.

Fractional distillation

The method used to refine crude oil into various products like fuel, plastic, and vaseline based on boiling points.

Hydropower Environmental Impact

While it has no $CO_2$ emission during generation, decomposition in upstream reservoirs is a major source of $CO_2$ and $CH_4$.

Fuel Cell

An experimental energy stage involving hydrogen with a net energy ratio less than 1; its only byproduct is water vapor.

Geothermal Power

Energy derived from magma in seismic zones; the U.S. is the leading country in this type of electricity generation.

Albedo

The reflectivity of an object; significant in climate change as melting ice reduces reflectivity and increases heat absorption.

Keeling Curve

A graph showing the atmospheric $CO_2$ concentration measured at Mauna Loa, Hawaii, which reached 413 ppm in April 2019.

Montreal Protocol (1987)

An international agreement that successfully phased out the production of CFCs and HCFCs to protect the ozone layer.

Kyoto Protocol (1997)

An agreement aiming to cut greenhouse gas emissions including $CO_2$, $CH_4$, and $N_2O$; notably not signed by the U.S.A.

Paris Climate Accord (2016)

Aims to keep global temperature rise this century well below $2^\circ C$ above pre-industrial levels.

Ocean Acidification

The process where excess atmospheric $CO_2$ dissolves in the ocean to form carbonic acid ($H_2CO_3$), lowering the water's pH.