1. BIG DUE DATES! IA “RAC” Due: JANUARY 19th (FRIDAY)
QUIZ: JANUARY 25th (THURSDAY)
Acid Deposition A.S: N – R
Ozone Depletion A.S: S – W
Last Chance to See Due 3rd marking pd
Chapter Summaries & Favorite Quote
Come sign out a book!!

2. Urban Air Pollution & Monitoring
Topic 5: Atmosphere
A.S. : X – CC

3. What is Air Pollution?
Air pollution is the introduction of many kinds of gases, chemicals, particulate matter or biological materials into the atmosphere by humans

5. Causes
The combustion of fossil fuels produces primary pollutants such as:
Carbon monoxide
Carbon dioxide
Black carbon (soot)
Unburned hydrocarbons from the incomplete combustion of engine exhaust or VOCs (Volatile Organic Compounds)
NOx
SOx

6. Photochemical Smog
In the presence of sunlight, secondary pollutants are formed when the primary pollutants undergo reactions with other chemicals already present in the atmosphere.
Photochemical Smog is a mixture of about 100 primary and secondary pollutants formed under the influence of sunlight.
Tropospheric Ozone is the main pollutant!

7. Sources of Tropospheric Ozone
                                                                                                                                                                     
EPA Graphic

8. Formation of Tropospheric Ozone
Tropospheric Ozone = “Bad Ozone”
Burning of fossil fuels emitted by automobiles, gasoline vapors, and power plants creates NO (nitric oxide),
The NO reacts with Oxygen (is oxidized) to form NO2 (nitrogen dioxide) a brown gas that contributes to urban haze.
NO2 gets hit with a UV ray, breaking off a free oxygen atom. This combines with an oxygen molecule (O2) to form Tropospheric Ozone (O3).
- When will ozone levels reach their peak in an urban environment?
- Is T. Ozone a primary or secondary pollutant?
SECONDARY!

9. Thermal Inversions The levels of photochemical smog can vary by:
population density, fossil fuel usage, climate, and topography.
Under normal conditions air rises and disperses pollutants.
A thermal inversion, occurs where a layer of warm air sits over a layer of cooler air, which prevents the dispersal of the pollutants.
The trapped dense, cooler air becomes stagnant and accumulates more and more pollutants.
Occurs in cities located in valleys surrounded by mountains, with light winds and lots of people driving cars!
Ex. Los Angeles, Mexico City, Beijing
What will get rid of the pollutants?

10. Thermal Inversion

11. LOS ANGELES, MEXICO CITY, RIO DE JANEIRO, BEIJING, AND EVEN DENVER, CO & SEATTLE, WA
London’s Great Smog of ’52

12. Los Angeles Overtime
A is from 1940’s
B is from 1960’s
C is from 1990’s

13. Face Masks in Beijing

14. Photo taken by Bobak Ha'Eri
                                                                                                                                                                
Beijing, China air on a day after rain (left) and a sunny but smoggy day (right) August 2005.
Photo taken by Bobak Ha'Eri
Sunday 11/8/15
CNN Report

15. Tropospheric Ozone Effects
Respiratory irritation
bronchial constriction
asthma
coughing/wheezing
Eye irritation
Decreases crop yields
slows plant growth
Damages plastics, rubber and nylon
Has a harsh odor

17. Photochemical Smog

18. Direct method of monitoring air pollution
Schoenbein Paper = ozone
- using a mixture of starch, potassium iodide, and water spread on filter paper
- The paper will vary in color depending on the amount of the oxidation.
- Those that have a lavender appearance were exposed to more ozone, and those that look dark purple had high ozone exposures.
- This is a qualitative test for comparison purposes
- Relative humidity can affect results
Evaluate this method:

19. Management Strategies for Urban Air Pollution
Alter Human Activities –
Regulate –
The U.S. Congress passed Clean Air Acts in 1970, 1977, and Brought on by smog deaths in PA
National Ambient Air Quality Standards (NAAQS) were established for six outdoor “criteria” (main) pollutants.
Two limits were established: a primary standard is set to protect human health and a secondary standard is set to prevent environmental, property and crop damage.
Restore –
Alter: alternative energies, energy-efficient technologies, use public transportation, walking, biking………….Use of Catalytic converters
Regulations: government taxation, emissions tests on cars, government fuel efficiency standards/regulations
Restore: Waiting for rain, reforestation/regreening to sequester carbon dioxide.