APES Ch. 19 - Air Pollution

Density

• number of gas molecules per unit of air volume

Atmospheric pressure

force (mass per unit area) of a column of air

Troposphere

• lowest layer of Earth's atmosphere

• where weather occurs

  • where most air pollution is concentrated

Most common gases in air

Nitrogen (78%)

Oxygen (21%)

Trace elements

Examples of greenhouse gases

• H2O, CO2, CH4, N2O

Stratosphere

• layer of Earth's atmosphere above the troposphere,

• containing the ozone layer

• temperature increases with altitude

Ozone layer equation

3 O2 + UV light → 2 O3

Air pollution

presence of chemicals in the atmosphere in concentrations high enough to harm organisms, ecosystems, or human-made materials, or to alter climate

Primary pollutants

Chemicals or substances emitted directly into the air from natural processes and human activities

Secondary pollutants

Primary pollutants react with each other/natural components of air to form a new harmful chemical

Major pollutants

• Carbon monoxide - CO

• Carbon dioxide - CO2

• Nitric oxide - NO

• Sulfur dioxide - SO2

• NO_x

• SO_x

• O₃

• PMs

• VOCs

PM- particulate matter rankings

PM-10

PM-2.5

Industrial smog

• results from the burning of fossil fuels

• produces a mixture of smoke and sulfur dioxide

• aka grey air smog

Solutions to Lead Poisoning

Prevention:

• replace lead pipes and plumbing

• remove lead paint and dust

• phase out leaded gasoline

• ban use of lead solder

• wash fresh fruits and vegetables

Control

• reduce lead emissions from incinerators

• remove lead from TV sets and computer monitors before incineration or land disposal

• test blood for lead by age 1

• test for lead in existing dishware

Photochemical smog

• formed when sunlight reacts with pollutants like volatile organic compounds (VOCs) and nitrogen oxides

• leading to the production of harmful ozone and other chemicals

• aka brown-air smog

Acid deposition types

• wet deposition

• dry deposition

Ways to reduce acid deposition

Prevention

• reduce coal use and burn only low-sulfur coal

• use natural gas and renewable energy sources in place of coal

• remove SO₂ and NO_x from motor vehicle exhausts

Cleanup

• add lime to neutralize acidified lakes

• add phosphate fertilizer to neutralize acidified lakes

• add lime to neutralize acidified soils

Radon-222

• dangerous gas produced by radioactive decay of uranim-238

• second most prevalent cause of lung cancer

  • kills 20,000 people in the US yearly

Effects of air pollution on humans

• cancer

• respiratory diseases

• ENT irritation

• asthma

• heart attacks

• strokes

Law to reduce air pollution

Clean Air Acts

Technology to reduce outdoor air pollution

• electrostatic precipitator

• wet scrubber

• catalytic converters

• improve fuel efficiency

• reduce use of private vehicles

• require emission control devices

• inspect car exhaust systems

• set emission standards

Solutions for indoor air pollution

• ban indoor smoking

• prevent radon infiltration

• use naturally based cleaning agents/paints

• use adjustable fresh air vents for work spaces

• circulate air more frequently

• use solar cookers and efficient, vented woodburning stoves

Montreal Protocol

An international treaty designed to protect the ozone layer by phasing out the production of CFCs

Explain how CFCs impact ozone formation

CFCs (chlorofluorocarbons) are released into the atmosphere, where they eventually reach the stratosphere. There, UV radiation breaks them down, releasing chlorine atoms that catalyze the destruction of ozone molecules, leading to ozone depletion.