Apes chapter 18 air pollution
Key Concepts
Structure and composition of the atmosphere
Types and sources of outdoor air pollution
Types, formation, and effects of smog
Sources and effects of acid deposition
Effects of air pollution
Prevention and control of air pollution
Core Case Study: South Asia’s
Massive Brown Cloud
Asian Brown Cloud
Causes
Chemical composition
Areas impacted
Air pollution connects the world
Steps taken in China and India to reduce air pollution
The Asian Brown Cloud
Air Pollution in Shanghai, China, in 2004
Air Pollution in Shanghai, China, in Jan. 2013
18-1 What Is the Nature of the Atmosphere?
Concept 18-1 The atmosphere is structured in layers, including the troposphere, which supports life, and
the stratosphere, which contains the protective ozone layer.
Air Movements in the Troposphere Play a Key Role in Earth’s Weather and Climate
Troposphere
75–80% of the earth’s air mass
Closet to the earth's surface
Chemical composition of air
Rising and falling air currents: weather and climate
Involved in chemical cycling
The Stratosphere Is Our Global Sunscreen
Stratosphere
Similar composition to the troposphere, with 2 exceptions
Much less water
O3, ozone layer, filters UV
Location
18-2 What Are the Major Outdoor Pollution Problems?
Concept 18-2 Pollutants mix in the air to form industrial smog, mostly the result of burning coal, and
photochemical smog, caused by motor vehicle, industrial, and power plant emissions.
Outdoor Air Pollution
Air pollution: The presence of chemicals in the atmosphere in concentrations high enough to affect
climate and harm organisms and materials
Primary pollutants: Chemicals emitted directly into the troposphere in a harmful form
Secondary pollutants: Primary pollutants that react with other chemicals in the atmosphere and change
form into new pollutants
Air Pollution Comes from Natural and Human Sources
Natural sources
Dust blown by wind
Pollutants from wildfires and volcanoes
Volatile organics released by plants
Withdrawing groundwater
Human sources: mostly in industrialized and/or urban areas
Stationary sources
Mobile sources
Case Study: Air Pollution in the Past:
The Bad Old Days
Discovery of fire
Middle Ages
Industrial Revolution
London, England
1850s
1952: yellow fog
Clean Air Act of 1956
Case Study: Air Pollution in the Past:
The Bad Old Days
United States
1948: Donora, PA; first U.S. air pollution disaster
1963: New York City
Global problem
What Are the Major Outdoor Air Pollutants?
Carbon oxides
Carbon monoxide (CO)
Carbon dioxide (CO2)
Sources
Human health and environmental impact
Nitrogen oxides (NO) and nitric acid (HNO3)
Sources
Acid deposition
Photochemical smog
Human health and environmental impact
What Are the Major Outdoor Air Pollutants?
Particulates
Suspended particulate matter (SPM)
Fine
Ultrafine
Sources
Human health and environmental impact
What Are the Major Outdoor Air Pollutants?
Ozone (O3)
Sources
Human and environmental impact
Volatile organic compounds (VOCs)
Hydrocarbons and terpenes
Sources
Human and environmental impact
Case Study: Lead Is a Highly
Toxic Pollutant
Does not break down in the environment
Sources
Human health and environmental impact
Most vulnerable
Reduction of lead (Pb)
Unleaded gasoline
Unleaded paint
Still problems
2007: toys with Pb paint recalled
Global ban on lead in gasoline and paint
Photochemical Smog
Photochemical Smog: Air pollution formed by the reaction of nitrogen oxides & volatile hydrocarbons by
sunlight
Photochemical reaction: Chemical reaction caused by sunlight
Brown-air smog
Photochemical oxidants: Can oxidize certain compounds
Burning Coal Produces Industrial Smog
Chemical composition of industrial smog
Reduction of this smog in urban cities of the United States
China and smog
Human deaths
Industrial Smog
Industrial smog: Mainly a mixture of sulfur dioxide, droplets of sulfuric acid, and suspended solid
particles from burning coal
Particulates
Sulfur dioxide
Sulfuric acid
Gray-air smog
Emission Reduction
Several Factors Can Decrease or Increase Outdoor Air Pollution
Outdoor air pollution may be decreased by
Settling of particles due to gravity
Rain and snow
Salty sea spray from the ocean
Winds
Chemical reactions
Several Factors Can Decrease or Increase Outdoor Air Pollution
Outdoor air pollution may be increased by
Urban buildings
Hills and mountains
High temperatures
Emissions of VOCs from certain trees and plants
Grasshopper effect
Temperature inversions
Temperature Inversions
Subsidence inversion
18-3 What Is Acid Deposition and
Why Is It a Problem?
Concept 18-3 Acid deposition is caused mainly by coal-burning power plant and motor vehicle emissions,
and in some regions, threatens human health, aquatic life and ecosystems, forests, and human-built
structures.
Acid Deposition and Humans
Respiratory diseases
Toxic metal leaching
Damage to structures, especially containing calcium carbonate
Decreased visibility
Decreased productivity and profitability of fisheries, forests, and farms
Regional Outdoor Air Pollution from Acid Deposition
Wet deposition & Dry deposition
Acid Deposition in the US
Acid Deposition
Aquatic Systems
Fish declines
Aluminum toxicity
Acid shock
Plants, and Soil
Nutrient leaching
Heavy metal release
Weakens trees
18-4 What Are the Major Indoor Air Pollution Problems?
Concept 18-4 The most threatening indoor air pollutants are smoke and soot from wood and coal
cooking fires (a hazard found mostly in developing countries) and chemicals used in building materials
and products.
Indoor Air Pollution
Developing countries
Indoor burning
Poor suffer the greatest risk
Developed countries
Indoor air pollution is greater than outdoor air pollution
Why?
11 of the common air pollutants higher inside than outside
Greater in vehicles than outside
Health risks magnified: people spend 70–98% of their time is indoors
Indoor Air Pollution
Who are at greatest risk from indoor air pollution?
Children under 5 and the elderly
Sick
Pregnant women
People with respiratory disorders or heart problems
Smokers
Factory workers
Indoor Air Pollution
Four most dangerous indoor air pollutants
Tobacco smoke
Formaldehyde
Radioactive radon-222 gas
Very small particles
Other possible indoor air pollutants
Pesticide residue
Pb particles
Living organisms and their excrements
E.g., Dust mites and cockroach droppings
Airborne spores of molds and mildews
Sick-building syndrome
Indoor Air Pollution
Case Study: Radioactive Radon Gas
Sources
Human health risks
Testing for radon
Correcting a radon problem
Radon
Radioactive radon-222
Lung cancer threat
Occurs in certain areas based on geology
Associated with uranium and organic material in rock
18-5 What Are the Health Effects of
Air Pollution?
Concept 18-5 Air pollution can contribute to asthma, chronic bronchitis, emphysema, lung cancer, heart
attack, and stroke.
Effects of Air Pollution on People
Respiratory diseases
Asthma
Lung cancer
Chronic bronchitis
Emphysema
Premature death
Air Pollution Is a Big Killer
3 Million deaths per year world-wide
Mostly in Asia
Main causes
EPA: proposed stricter emission standards for diesel-powered vehicles
Link between international trade and air pollution
Cargo ships and pollution
18-6 How Should We Deal with Air Pollution?
Concept 18-6 Legal, economic, and technological tools can help to clean up air pollution, but much
greater emphasis should be focused on preventing air pollution.
Laws and Regulations Can Reduce Outdoor Air Pollution
United States
Clean Air Acts: 1970, 1977, and 1990
EPA
National ambient air quality standards (NAAQs) for 6 outdoor criteria pollutants
National emission standards for 188 hazardous air pollutants (HAPs)
Toxic Release Inventory (TRI)
Case Study: U.S. Air Pollution Can
Be Improved
Rely on cleanup more than prevention of pollution
Raise fuel-efficiency for cars, SUVs, and light trucks
Better regulation of emissions of motorcycles and two-cycle gasoline engines
Regulate air pollution for oceangoing ships in American ports
Case Study: U.S. Air Pollution Can
Be Improved
Why are airports exempt from many regulations?
Regulate greenhouse gas emissions
Ultrafine particles are not regulated
Urban O3 levels too high
Case Study: U.S. Air Pollution Can
Be Improved
What about indoor air pollution?
Better enforcement of the Clean Air Acts
Is intense pressure needed from citizens to make improvements?
We Can Use the Marketplace to Reduce Outdoor Air Pollution
Emission trading or cap-and-trade program
Mixed reactions to program
SO2 emissions down significantly
NO2 will be tried in the future
There Are Many Ways to Reduce
Outdoor Air Pollution
1980 –2006
SO2 emissions from U.S. electric power plants decreased by 66%
NOx emissions by 41%
Particulate emissions by 28%
Older plants not governed by the same regulations
New cars have better emissions
Reducing Indoor Air Pollution Should
Be a Priority
Greater threat to human health than outdoor pollution
What can be done?
Prevention
Cleanup
We Need to Put More Emphasis on Pollution Prevention
Output approaches
New shift to preventing outdoor and indoor pollution
Pressure from citizens