APES NIT PICKY INFO

What are the 6 criteria air pollutants tracked by the AQI?

Particulate matter (PM), sulfur dioxide (SO₂), carbon monoxide (CO), nitrogen dioxide (NO₂), ozone (O₃), and lead (Pb)

SOx — what is it, where does it come from?

Sulfur oxides (mainly SO₂). Source: burning coal & diesel fuels. Effect: acid rain, respiratory issues

NOx — what is it, where does it come from?

Nitrogen oxides (NO, NO₂). Sources: motor vehicles & coal-burning power plants. Effects: acid rain, photochemical smog, tropospheric ozone

What pollutants does coal combustion release?

CO₂, sulfur dioxide (SO₂), toxic metals, and particulates

What pollutants does fossil fuel combustion release?

NOx, CO, hydrocarbons, particulate matter, SO₂ (especially diesel)

What are primary vs. secondary air pollutants?

Primary: emitted directly (e.g., SO₂, CO). Secondary: formed in atmosphere from reactions (e.g., tropospheric ozone, nitric acid, photochemical smog)

How does photochemical smog form?

NOx + VOCs react with heat & sunlight → ozone + smog. Peak ozone is in the afternoon; higher in summer

What are VOCs? Examples?

Volatile Organic Compounds — evaporate/sublimate at room temp. Examples: formaldehyde, gasoline. Trees are a natural VOC source

What causes acid rain?

NOx (from cars & coal plants) + SOx (from coal plants) react in atmosphere → nitric acid & sulfuric acid → acid rain/deposition

What is a thermal inversion?

Normal temperature gradient flips — warm air traps cold air near ground, preventing pollutant dispersal. Traps smog and particulates

How does a catalytic converter reduce pollution?

Converts CO, NOx, and hydrocarbons in exhaust → CO₂, N₂, O₂, and H₂O

What do wet/dry scrubbers do?

Remove particulates and/or gases from industrial exhaust streams (coal-burning plants). Electrostatic precipitators also remove particulates

What is an electrostatic precipitator?

Device that uses electric charge to remove particulates from coal plant exhaust

What is a vapor recovery nozzle?

Device on gas pump nozzles that prevents fuel vapors (VOCs) from escaping into the atmosphere when refueling

How does the Clean Air Act relate to lead?

The EPA (under the Clean Air Act) regulated lead in fuels, dramatically reducing atmospheric lead levels

What indoor pollutants are classified as particulates?

Asbestos, dust, and smoke

What are common natural indoor air pollutants?

Radon, mold, and dust

What are common human-made (non-combustion) indoor air pollutants?

Insulation; VOCs from furniture/carpets/paneling; formaldehyde from building materials/upholstery; lead from old paints

What are combustion-source indoor air pollutants?

Carbon monoxide (CO), nitrogen oxides, sulfur dioxide, particulates, and tobacco smoke

What is carbon monoxide classified as?

An asphyxiant (indoor air pollutant)

What is radon-222 and what causes it?

Naturally occurring radioactive gas produced by uranium decay in rocks/soils. Enters homes via basement, wall cracks, or well water

What health risk does radon cause?

Radon-induced lung cancer — the #2 leading cause of lung cancer in the US

What disease is caused mainly by asbestos exposure?

Mesothelioma (cancer of the lung lining)

What is eutrophication?

Excess nutrients (N, P) enter water → algal bloom → algae dies → decomposers consume O₂ → hypoxia/dead zone

What are anthropogenic causes of eutrophication?

Agricultural runoff (fertilizers with N & P), sewage/wastewater discharge, urban stormwater

What is an oxygen sag curve?

Plot of dissolved oxygen vs. distance from a pollution source — oxygen drops near the source, recovers downstream

What are oceanic dead zones?

Areas of low oxygen (hypoxia) in oceans caused by increased nutrient pollution (eutrophication)

What happens when elemental mercury enters water?

Bacteria convert it to methylmercury — a highly toxic bioaccumulative form

What is thermal pollution?

Warm water discharged into water bodies (often from power plants) — reduces dissolved oxygen, stresses aquatic life

How does increased sediment harm aquatic ecosystems?

Reduces light infiltration (hurts primary producers & visual predators); settles and disrupts habitats

How do heavy metals enter groundwater?

Mining and fossil fuel burning — metals leach from industrial sites into groundwater, affecting drinking water

What factors affect marine natural resource distribution?

Salinity, depth, turbidity, nutrient availability, and temperature

What are POPs?

Persistent Organic Pollutants — synthetic carbon-based molecules (e.g., DDT, PCBs) that don't easily break down in the environment

Why do POPs bioaccumulate?

They are fat-soluble → accumulate in organisms' fatty tissues and are not excreted

How far can POPs travel?

Long distances via wind and water before being redeposited — global distribution even in remote areas

What is bioaccumulation?

Selective absorption and concentration of fat-soluble compounds by cells in a single organism over time

What is biomagnification?

Increase in concentration of a substance in successively higher trophic levels of a food chain/web

Name 3 substances that bioaccumulate with major environmental impacts

DDT, mercury (methylmercury), and PCBs

What are ecological effects of biomagnification?

Eggshell thinning and developmental deformities in top carnivores; reproductive, nervous, and circulatory damage in humans

What are endocrine disruptors?

Chemicals that interfere with the endocrine (hormone) system of animals

What are effects of endocrine disruptors?

Birth defects, developmental disorders, and gender imbalances in fish and other species

What causes stratospheric ozone depletion?

Anthropogenic: CFCs (chlorofluorocarbons). Natural: melting of polar ice crystals at start of Antarctic spring

What are the health effects of ozone depletion?

Increased UV reaching Earth's surface → skin cancer and cataracts in humans

What replaced CFCs and what is the concern?

Hydrofluorocarbons (HFCs) — but some HFCs are strong greenhouse gases

What are the 5 principal greenhouse gases?

Carbon dioxide (CO₂), methane (CH₄), water vapor (H₂O), nitrous oxide (N₂O), and CFCs

Why doesn't water vapor drive climate change despite being a GHG?

It has a short residence time in the atmosphere

GWP ranking: which greenhouse gas is most potent?

CFCs (highest GWP), then nitrous oxide (N₂O), then methane (CH₄). CO₂ = 1 (reference point)

What is the GWP of CO₂?

1 — used as the reference baseline for comparing all other greenhouse gases

What natural sources produce CO₂?

Respiration, decomposition, and volcanic eruptions

How does increased CO₂ cause ocean acidification?

CO₂ dissolves in seawater → carbonic acid → lowers pH. Harms shell-forming organisms (corals, mollusks)

What does the greenhouse effect do for Earth?

Maintains surface temperatures necessary for life — without it, Earth would be too cold

What layer of the atmosphere contains the ozone layer?

The stratosphere (above the troposphere)

List all 9 major terrestrial biomes (from CED)

Taiga, temperate rainforest, temperate seasonal forest, tropical rainforest, shrubland (chaparral), temperate grassland, savanna, desert, tundra

Taiga — key characteristics

Coniferous forest (boreal); cold, long winters; low precipitation; dominant trees = spruce, fir, pine; nutrient-poor soils

Tundra — key characteristics

Coldest biome; permafrost layer; very low precipitation; treeless; mosses, lichens, sedges; short growing season

Tropical rainforest — key characteristics

Highest biodiversity; year-round warm temps; high precipitation (200+ cm/yr); dense canopy; nutrient-poor soils (nutrients in biomass)

Temperate seasonal forest — key characteristics

Deciduous trees; distinct seasons; moderate precipitation; fertile soils; e.g., Eastern US, Europe

Temperate rainforest — key characteristics

Coastal; very high rainfall; mild temps; coniferous or mixed trees; e.g., Pacific Northwest

Savanna — key characteristics

Tropical grassland with scattered trees; distinct wet/dry seasons; frequent fires; Africa, South America

Temperate grassland — key characteristics

No trees; moderate precipitation; rich, deep soils (great for agriculture); e.g., Great Plains (US prairies)

Shrubland / Chaparral — key characteristics

Mediterranean climate; hot dry summers, mild wet winters; fire-adapted shrubs; California coast, Mediterranean Basin

Desert — key characteristics

What determines the global distribution of biomes?

Climate, geography, latitude, altitude, nutrient availability, and soil type

Which biome has the most nutrient-rich soils?

Temperate grassland — deep, fertile soils. (Note: tropical rainforest has nutrient-poor soil — nutrients are in living biomass)

What are the freshwater biomes?

Streams, rivers, ponds, and lakes

What are the marine biomes?

Oceans, coral reefs, marshland (salt marshes), and estuaries

What is the ecological role of marine algae?

Supply a large portion of Earth's oxygen AND absorb CO₂ from the atmosphere

What factors determine marine resource distribution?

Salinity, depth, turbidity, nutrient availability, and temperature

What is an estuary?

Where freshwater meets saltwater (river meets ocean); highly productive; nursery habitat for many species

What are threats to wetlands and mangroves?

Draining, development, pollution, and sea-level rise (from climate change)

What ecosystem services do wetlands provide?

Water filtration, flood control, carbon storage, habitat for biodiversity, shoreline protection

What does the Clean Air Act do?

Authorizes the EPA to regulate air pollutants that affect human health; led to removal of lead from fuels; sets National Ambient Air Quality Standards

What does the Clean Water Act do?

Regulates discharge of pollutants into US waters; sets water quality standards; requires permits for point-source discharges (NPDES)

What is CERCLA (Superfund)?

Comprehensive Environmental Response, Compensation, and Liability Act — funds cleanup of contaminated hazardous waste sites; holds polluters liable

What does the Endangered Species Act (ESA) do?

Protects threatened and endangered species and their habitats from harm; prohibits 'taking' of listed species

What does CITES do?

Convention on International Trade in Endangered Species — international treaty that regulates/bans trade in endangered plants and animals

What did the Montreal Protocol do?

International treaty (1987) to phase out production of ozone-depleting substances (CFCs and other halogenated chemicals)

What did the Kyoto Protocol do?

International treaty that committed industrialized nations to reduce greenhouse gas emissions (binding targets); US did not ratify

What does the Safe Drinking Water Act (SDWA) do?

Sets standards for drinking water quality in the US; EPA regulates contaminants in public water systems

What is the Delaney Clause?

Part of the Food, Drug, and Cosmetic Act — prohibits approval of any food additive found to cause cancer in humans or animals (zero-tolerance for carcinogens in food)

What does RCRA do?

Resource Conservation and Recovery Act — regulates generation, transport, treatment, storage, and disposal of solid and hazardous waste (cradle to grave)