1. Major Air Pollutants Clean Air Act – EPA
Air Pollution
Major Air Pollutants
Clean Air Act – EPA

2. Air Pollution
During the 1950’s and 1960’s, most factories looked like this

3. Air Pollution
The term “Smog” (smoke and fog) was first used in 1905 to describe sulfur dioxide emission
In 1952, severe pollution took the lives of 5000 people in London
“It isn’t pollution that’s harming the environment. It’s the impurities in our air and water that are doing it.” Former U.S. Vice President Dan Quayle

4. Air Pollution
Natural sources of air pollution are often made worse by human activity.
Land use policies
‘Slash and burn’ agriculture
Build up of fuel wood from fire suppression in U.S. national forests

5. Air Pollution Anthropogenic (human caused) air pollution Point sources
Coal-fired power plant’s smokestack
Non-Point sources
Automobiles

6. Air Pollution Primary air pollutants Secondary air pollutants
Come directly out of a smokestack or exhaust pipe
Carbon monoxide
Carbon dioxide
Sulfur dioxide
Nitrous oxides
Most suspended particulate matter
Secondary air pollutants
Have undergone chemical change or transformation in the presence of sunlight with water or with oxygen in the atmosphere
Sulfuric acid
Ozone

7. Where do the air pollutants come from?

8. Major Sources of Primary Pollutants
Stationary Sources
Combustion of fuels for power and heat – Power Plants
Other burning such as Wood & crop burning or forest fires
Industrial/ commercial processes
Solvents and aerosols
Mobile Sources
Highway: cars, trucks, buses and motorcycles
Off-highway: aircraft, boats, locomotives, farm equipment, RVs, construction machinery, and lawn mowers

10. Human Impact on Atmosphere
Refining petroleum and burning fossil fuels and manufacturing
Adds CO2 and O3 to troposphere
Climate Change
Produces Acid Rain
Releases SO2 into troposphere
Releases toxic heavy metals (Pb, Cd, and As) into troposphere
Using Nitrogen fertilizers and burning fossil fuels
Releases NO, NO2, N2O, and NH3 into troposphere
Produces acid rain

11. Where are we at today?
There are six criteria air pollutants established by the EPA
Carbon Oxides
Nitrogen Oxides
Particulate matter
Lead
Sulfur Oxides
Tropospheric Ozone (ground)

12. Major Air Pollutants Carbon oxides Properties
colorless, odorless, heavier than air, % of atmosphere
highly toxic gas that forms during the incomplete combustion of carbon-containing materials.
Sources
incomplete combustion of fossil fuels % from auto exhaust
Carbon monoxide (CO) is a 93% of carbon dioxide (CO2) in the troposphere occurs as a result of the carbon cycle.
7% of CO2 in the troposphere occurs as a result of human activities (mostly burning fossil fuels).
Effects
binds tighter to Hgb than O2
Impairs mental functions and visual acuity, even at low levels
EPA Standard: 9 ppm
5.5 billion tons enter atmosphere/year

13. Mobile Source Emissions - CO

14. Major Air Pollutants Suspended particulate matter (SPM) Properties
Consists of a variety of solid particles and liquid droplets small and light enough to remain suspended in the air.
The most harmful forms of SPM are fine particles (PM-10, with an average diameter < 10 micrometers) and ultrafine particles (PM-2.5).
Sources
Burning coal or diesel
Volcanoes
Asbestos
PCBs, dioxins, pesticides
unpaved roads, plowing, burning fields
lint, pollen, spores
Effects
lung damage,
mutagenic, carcinogenic, teratogenic
EPA Standard: 50 ug/m3 (annual mean)
SPM is responsible for about 60,000 premature deaths a year in the U.S.

15. Mobile Source Emissions: Fine Particulate Matter (PM2.5)

16. Major Air Pollutants Nitrogen oxides EPA Standard: 0.053 ppm
Properties
Reddish brown gas
NO reacts with air to form NO2.
NO2 reacts with water vapor in the air to form nitric acid (HNO3) and nitrate salts (NO3-) which are components of acid deposition.
Sources
lightening and certain soil bacteria.
fossil fuels combustion at high temperatures
power plants, forest fires, volcanoes, bacteria in soil
Effects
acid rain
lung and heart problems
decreased visibility (yellow haze)
suppresses plant growth
EPA Standard: ppm

17. Mobile Source Emissions: Nitrogen Oxides

18. Major Air Pollutants Lead Properties Heavy metal Effects
Is a powerful neurotoxin.
accumulates in tissue
affects kidneys, liver and nervous system (children most susceptible)
mental retardation
possible carcinogen;
20% of inner city kids have high levels
Sources
particulates, smelters, batteries
Was removed from gasoline over three decades ago
Concentrations in the air have declined precipitously
Mercury from coal fired power plants is now of greater concern than lead
EPA Standard
1.5 ug/m3
2 million tons enter atmosphere/year

19. Major Air Pollutants Volatile organic compounds (VOCs) Properties
Most are hydrocarbons emitted by the leaves of many plants and methane
Organic compounds that evaporate easily, usually aromatic
Benzene
Chlorofluorocarbons (CFCs
Sources
Vehicles (largest source), evaporation of solvents or fossil fuels, aerosols, paint thinners, dry cleaning
About two thirds of global methane emissions comes from human sources.
Other VOCs include industrial solvents such as trichlorethylene (TCE), benzene, gasoline, paint thinner, and vinyl chloride.
Effects
Long-term exposure to benzene can cause cancer, blood disorders, and immune system damage.
eye and respiratory irritants
Carcinogenic
Liver, CNS, or kidney damage
Damages plants
Lowered visibility due to brown haze
Global warming

20. Major Air Pollutants Sulfur dioxide (SO2) Properties
colorless gas with irritating odor
Sources
About one-third of SO2 in the troposphere occurs naturally through the sulfur cycle.
Two-thirds come from human sources, mostly combustion (S+ O2  SO2) of sulfur-containing coal and from oil refining and smelting of sulfide ores, paper manufacture
Effects
produces acid rain (H2SO4),
breathing difficulties,
eutrophication due to sulfate formation (lichen and moss are indicators)
EPA Standard: 0.3 ppm (annual mean)

21. Major Air Pollutants Ozone (O3) Properties colorless, unpleasant odor
highly reactive gas
major component of photochemical smog
Sources
Created by sunlight acting on NOx and VOC
Photocopiers, chemical solvents
Cars
Industry
Incomplete fuel combustion products
Effects
Lung irritant
Cause and aggravate respiratory illness
Can aggravate heart disease
Eyes
Damage plants, rubber in tires, fabrics, and paints
0.1 ppm can lower PSN by 50%
10,000 to 15,000 people in US admitted to hospitals each year due to ozone-related illness
Children more susceptible
Airways narrower
More time spent outdoors
Major Air Pollutants

22. Mobile Source Emissions: Hydrocarbons – Precursors to Ozone

23. Sunlight plus Cars Equals Photochemical Smog
Mexico City is one of the many cities in sunny, warm, dry climates with many motor vehicles that suffer from photochemical smog.

24. Sunlight plus Cars Equals Photochemical Smog
Photochemical smog is a mixture of air pollutants formed by the reaction of nitrogen oxides and volatile organic hydrocarbons under the influence of sunlight.

25. Clean Air Act of 1963 Congress found:
Most people now live in urban areas
Growth results in air pollution
Air pollution endangers living things
It decided:
Prevention and control at the source was appropriate
Such efforts are the responsibility of states and local authorities
Federal funds and leadership are essential for the development of effective programs

26. Clean Air Act Originally signed 1963
States controlled standards
1970 – Uniform Standards by Federal Govt.
Standards were stricter
Limits on emissions
New funding
Pollution control research
Citizens could sue
Criteria Pollutants
Primary – Human health risk
Secondary – Protect materials, crops, climate, visibility, personal comfort

27. Clean Air Act
1990 version
Strengthened regulations pertaining to air quality standards
Set nation wide standards for emissions of the six “criteria pollutants”
Left it up to the States to regulate and monitor
Emissions trading program introduced (Cap and Trade)
Total emissions have declined by 60% despite substantial increases in energy consumption, miles traveled by vehicles and gross domestic product

28. Clean Air Act 1990 Policy changes and developments
Catalytic converters - Required on all new U.S. autos since 1975
Scrubbers – use a combination of air and water that separates and removes particulates and SO2 before they are emitted from smokestacks
Leaded gasoline – phase out caused U.S. lead emissions to plummet by 93% in the 1980’s alone
Electrostatic precipitators – installed in smokestacks use an electrical charge to make particulates coalesce to that they can be physically removed

29. Clean Air Act 1997 version Reduced ambient ozone levels
Cost $15 billion/year -> save 15,000 lives
Reduce bronchitis cases by 60,000 per year
Reduce hospital respiratory admission 9000/year

30. Clean Air Act
2007
U.S. Supreme Court ruled that carbon dioxide should be considered an air pollutant under the Clean Air Act
2009
EPA proposed that it should be considered an air pollutant at some point in the future

31. General Status of Global Air Quality
Some pollutants are not declining, some new air pollutants are emerging and green house gas emissions continue to rise
CO2 rose 44% from 1970 to 2008
Industrializing nations such a China and India are suffering increasing air pollution problems
China has fueled its rapid industrial development with its abundant reserves of coal.
Brown Cloud
Rural issue – great deal of air pollution emanates from feedlots (dust, methane, hydrogen sulfide, ammonia

32. South Asia’s Massive Brown Cloud
A huge dark brown cloud of industrial smog, caused by coal-burning in countries such as China and India, stretches over much of southeastern Asia.
In areas beneath the cloud, photosynthesis is reduced interfering with crop development.
Fine particles and droplets in the cloud appear to be changing regional climates (including rainfall).
May have contributed to floods in 2002 and 2005 which killed thousands of people.

34. Hopefully Not The End