AP Environmental Science --> Unit 7

Acid Rain

acid rain any precipitation—rain, snow, fog, hail—with elevated acidity (low pH)

Air Pollution

The contamination of the atmosphere by harmful chemical, physical, or biological agents

Asbestos

Group of six naturally occurring, fibrous silicate minerals that are resistant to heat and corrosion. Deadly, bad, must wear suit when removing asbestos tiles.

Baghouse Filter

Pollution control device that uses large fabric bags to capture dust and particulates from industrial exhaust, preventing them from entering the atmosphere.

CAFE Vehicle Standards

CAFE (Corporate Average Fuel Economy) standards are U.S. government regulations forcing automakers to meet fleet-wide average fuel efficiency targets

Carbon Dioxide

Natural greenhouse gas crucial for life, absorbed by plants (photosynthesis) and oceans, but released by respiration, decomposition, and burning fossil fuels.

Carbon Monoxide

Colorless, odorless, toxic gas from incomplete combustion of carbon-based fuels, primarily from vehicle exhaust, industrial processes, and faulty indoor appliances.

Catalytic Converter

Exhaust system device in vehicles that uses precious metal catalysts (platinum, palladium, rhodium) to convert harmful pollutants & engine exhaust into less toxic substances.

Clean Air Act

US law empowering the EPA to set science-based National Ambient Air Quality Standards (NAAQS) for pollutants like ozone, lead, and particulate matter.

What are the 6 criteria air pollutants?

Carbon Monoxide (CO)

Ground-Level Ozone (O3)

Lead (Pb)

Nitrogen Dioxide (NO2)

Particulate Matter (PM)

Sulfur Dioxide (SO2)

Crushed Limestone

Used to neutralize acidic soils/waters (Aglime), filter pollutants in water treatment, scrub sulfur dioxide from power plant emissions, and stabilize stream banks

Dry & wet scrubbers

Wet scrubbers use a liquid (like water or a chemical solution) to wash pollutants from exhaust gases

Dry scrubbers use dry absorbent materials (like lime) to react with and neutralize acid gases, forming dry solids.

Dust

Fine, solid particles suspended in the air, originating from natural sources or human activities

Electrostatic Precipitator

pollution control device that uses electric fields to remove particulate matter from industrial exhaust

Externalities

Costs of recourse degradation.

Fluidized Bed Combustion

A clean coal and waste-to-energy technology that burns fuel in a bed of agitated, inert particles (like sand or limestone) suspended by an upward flow of air.

Lead

Lead is a naturally occurring element found in small amounts in the earth's crust. While it has some beneficial uses, it can be toxic to humans and animals.

Mold

A type of fungus that plays a crucial role in nature by decomposing organic matter.

Noise Pollution

Unwanted or excessive sound from human activities (that harms human health and wildlife.

NOx

Group of highly reactive gases, primarily nitric oxide (NO) and nitrogen dioxide (NO₂), formed from fuel combustion in vehicles, power plants, and industry.

Ozone (tropospheric vs stratospheric)

Stratospheric Ozone (the "ozone layer") is vital, naturally absorbing harmful UV radiation to protect life

Tropospheric Ozone (ground-level ozone) is a harmful pollutant, formed from vehicle/industrial emissions reacting in sunlight, causing respiratory problems and smog.

PANs

A group of harmful, secondary air pollutants, primarily Peroxyacetyl Nitrate (PAN)

Particulate Matter

Complex mixture of tiny solid particles and liquid droplets (like dust, soot, smoke, and chemicals) suspended in the air, classified by size (e.g., PM10, PM2.5)

Photochemical Smog

Urban air pollution formed by sunlight (photo) triggering reactions between nitrogen oxides (NOx) and volatile organic compounds (VOCs) from vehicle exhaust and industry.

Pollution Credits

Tradable permits allowing a company to emit a specific amount of a pollutant

Primary Pollutant

Harmful substance emitted directly into the environment from a specific source, like vehicle exhaust or volcanic ash

Radon Gas

A naturally occurring, colorless, odorless, radioactive gas formed from the decay of uranium and thorium in rocks and soil.

Secondary Pollutant

Harmful substance that forms in the atmosphere or environment through chemical reactions between primary pollutants.

SOx

In environmental science, (sulfur oxides) refers to a group of gaseous air pollutants, primarily sulfur dioxide, formed from burning sulfur-containing fossil fuels (Coal)

Thermal Inversion

When a layer of warm air sits above cooler air near the Earth's surface, reversing the usual pattern where air gets colder with altitude, trapping pollutants like smog and particulate matter.

Vapor Recovery Nozzle

Specialized gas pump nozzle with a secondary hose that captures harmful gasoline fumes (Volatile Organic Compounds or VOCs) displaced from a vehicle's fuel tank during refueling,

Volatile Organic Compounds

Carbon-containing chemicals that easily evaporate (vaporize) at room temperature, forming gases that pollute indoor and outdoor air. (Paints, cleaners, etc)