I. The atmosphere
A. layers (fig.19-2)
- significance of troposphere and stratosphere
- note temperature and pressure changes
B. composition – see text p. 440
II. outdoor air pollution
A. primary vs. secondary pollutants
B. natural and human sources (fig. 19-3)
C. major classes of primary pollutants – tables 20-1 and 20-2
1. Carbon monoxide (CO)
2. NOx
3. SO2
4. ozone
5. particulates (see also fig. 20-6)
6. lead
7. CFC’s and CO2 - next chapter
EPA Air Quality trends
- real-time air pollution data and forecasts
- real-time air quality data for DC Metro area
- Look up local air pollution data
- Real-time air quality data (and a webcam) for downtown DC | other sites around the country
National Park Service and FWS air monitoring- air quality reports
- air quality data - latest statistics
- Office of Air Quality standards (background info on pollutants)
- Overview of the 6 primary pollutants addressed by the clean air act
- transportation and air quality
- the Appalachian Mountain Club using volunteers to track air quality in natural areas
- flash animations of US air pollution trends from 1985-2003
D. thermal inversions (fig. 19-5) can trap pollutants near cites
- note atmospheric and geographical conditions that lead to the two types
- overview - thermal inversions and the formation of smog
E. Secondary pollutants
1. photochemical smog (fig.19-4)
- satellite image - haze over the Eastern US
- see other components p. 445
2. ground level ozone (usually a part of smog)
3. acid deposition (see below)
III. Acid deposition
A. pH scale
- pH of normal rainwater = 5.0 - 5.6 because of natural acids in the air
- EPA Acid rain page:
- Acid rain data from USGS
- effects on public buildings in Washington DC
- acid rain research at Hubbard Brook in New Hampshire
B. causes (fig. 19-6)
1. NOx from power plants and gasoline engines
2. SO2 from power plants (70%) and other sources
- both react with water in the air to form acids; rain often falls with pH below 5.0 or even 4.0
3. note pH data from around the US – 19-7. Do any patterns emerge? Any surprises?
C. effects – see text p. 448-450
1. trees – damage to leaves on contact (especially trees at higher elevations – see fig. 19-9)
2. bird’s egg shells
3. lakes and soils – lost nutrients and general food web disruption (fig. 19-9)
4. stone – monuments, buildings
D. prevention/cleanup (summary fig. 20-12)
1. areas with low limestone/calcium carbonate content in soil are in most danger (fig. 19-8)
2. add lime to lakes and soil
3. reduction of SO2 and NOx emissions (how can this be achieved? See below)
4. prevention/cleanup overview - fig. 19-10
IV. indoor air pollution
A. household sources and effects (fig. 19-11)
B. radon – a naturally occuring pollutant (fig. 19-13)
C. asbestos
D. ventilation is the key indoors! (sick building syndrome)
IV. Human health and other effects from pollution
A. estimation of human deaths from pollution – and text p. 456
B. plants are harmed, especially by acid rain
C. stone, building materials, etc
D. visibility is an issue, especially in parks and wilderness areas
V. Regulation of air pollution
A. Clean Air Act and pollution trends since its inception
- recent controversies include changes to the mercury and particulate standards, and whether to regulate CO2 as a pollutant
- overview of the pollutants
B. reducing emissions – power plants and industry (fig. 19-17)
1. pollution trading rights for SO2 have been a successful market-based solution and will probably be attempted for other pollutants
2. burning low-sulfur coal
3. scrubbers remove pollutants from the stack (fig. 19-18)
C. reducing emissions – automobiles
1. emission controls and auto inspections (19-19)
2. hybrid vehicles and other efficiency improvements
3. carpooling/bikes/mass transit
4. the EPA has an "anti-idling campaign" aimed at reducing emissions from school busses
D. indoor - fig. 19-20 and 19-21