1. Chapter 19: Air Pollution and Noise
Living and Working in a Healthy Environment

2. Sources of air pollution
Image from

3. Sources of air pollution
Emissions
Anthropogenic (manmade): Fossil fuel combustion, biomass burning, industrial processes, etc.
Biogenic: Emissions from vegetation, soil, wildlife, forest fires, etc.
Other natural: Volcanos, lightning, sea salt, meteors, windblown dust, etc.
Photochemical production from other compounds in atmosphere (“secondary source”)
Transport: If considering only troposphere, then transport from stratosphere is a source

4. Primary & secondary pollutants
CO2, etc.
CO, VOC
HO2 OH NO
NO2 O3
Secondary
VOC
NOx O3
Primary
(e.g., lead)
Primary: Emitted directly to the atmosphere
Secondary: Forms in the atmosphere

5. Sources of the 5 major pollutants in the U
Sources of the 5 major pollutants in the U.S Note: Historically, the 6th Major Pollutant was lead.

6. Source and Composition of Particulates
meteoritic material
soot
sulfates, ash
Soot, sulfates, VOCs
soot
sea salt
Soot, organic
Soot, NOx, VOCs
methane,
ammonia
Minerals, clays

7. Emission events (Nov. 18, 2008) Textruve Plant on 2001 Sheldon Road (Channelview, TX)
Picture taken at 6:00 pm on site
Picture taken at 4:00 pm from 20 miles away

8. Impacts: Ozone and PM2.5 Non-Attainment
U.S. EPA, 2006
Source: U.S. EPA

9. Fine PM levels in Clinton Drive (Houston, TX)
Very close to non-attainment

10. Primary standard: Necessary to protect the public health
Texas Air Quality
Let’s consider those compounds that the Federal Government regulates  National Ambient Air Quality Standards (NAAQS)
Secondary standard: Necessary to protect the public welfare and the environment
The Clean Air Act requires these standards to be set at levels that protect public health with an adequate margin of safety and without consideration of cost.
Primary standard: Necessary to protect the public health 10
The light gray standards have been recently added.

11. Lecture 32 Texas Air Quality

12. U.S. Federal Regulation of Air Pollution
Air pollution Control Act of 1955
Clean Air Act of 1963
Amendment to CAA - Motor Vehicle Air pollution Control Act of 1965
1970 Clean Air Amendments and formation of the EPA.
1975 catalytic converter developed.

13. Signs that regulation works!
U.S. pollution
trends since 1977

14. Stratospheric ozone—The good ozone

15. Types of SMOG
1.Industrial London Smog – combination of smoke and fog
At the end of the 1800’s, 40% less sunlight in London than surrounding towns
Health effects
Vitamin D deficiency, Rickets, Tubercolosis

16. 2. Photochemical Smog
Consists mainly of secondary pollutants: Ozone (O3), NO2, VOCs
Forms when sunlight induces chemical changes in gases and aerosols
Causes poor visibility, burning eyes, sore lungs, worsen conditions of the heart and lungs,
possible mortality.

17. Photochemical and Industrial Smog
“London Smog or Industrial Smog”
Gray-air in New York City
“LA Smog”:
Brown-air smog in Los Angeles
© Dean D. Fetterolf/ShutterStock, Inc.
© Chad Littlejohn/ShutterStock, Inc.

18. Houston Case Which kind of smog do you think Houston has?
Why is Houston different from London or LA case?
How much do you think pollution from Houston will influence College Station?

19. Ozone (O3) in the Troposphere
Photochemical Smog
Ozone (O3) in the Troposphere
Most problematic air pollutant in many areas of the U.S.
Ozone is not directly emitted into the atmosphere, but instead forms through a complex series of reactions.
It is largely because of this complexity that ozone is so difficult to control.
I usually apologize for the excessive chemistry here, but explain that it’s impossible to discuss tropospheric ozone without it.
Explain that hn simply indicates that a photon is absorbed by the molecule, which leads to decomposition (i.e., photolysis). The n is just frequency.

20. Ozone chemistry (gas-phase only) NO3 N2O5 hn O3 NO2 NO HNO3 HONO HO2
RO2
H2O hn
H2O2
VOC
This represents a simplistic overview of the gas phase reactions involved in ozone production. I highlight NOx and VOCs since these are the precursors that we can control.

21. The next two slides are meant to accompany a discussion of how emissions rates are measured. Measuring what comes out of a stack is pretty straightforward. Measuring the thousands of small leaks in a massive refinery such as those in Houston is more challenging. During TexAQS2000 aircraft measurements indicated that VOC emissions from many of the refineries in Houston far exceeded the reported values.

22. What’s a dynamometer?
Measuring auto and truck emissions is usually accomplished by either putting the vehicle on a dynamometer and sampling the exhaust, or by sampling pollutant levels in tunnels. The Caldicott tunnel shown above (near San Francisco) has been used extensively for the latter type of study since it has two bores, one of which is used only by cars. This permits separation of the auto emissions from those from diesel trucks
Measuring auto and truck emissions is usually accomplished by either putting the vehicle on a dynamometer and sampling the exhaust, or by sampling pollutant levels in tunnels. The Caldicott tunnel shown above (near San Francisco) has been used extensively for the latter type of study since it has two bores, one of which is used only by cars. This permits separation of the auto emissions from those from diesel trucks.

23. NOx and VOC sources in the Greater Houston Area
The take-home message from these figures is that NOx is emitted almost entirely as a result of combustion,
whereas VOC emissions are often dominated by other sources such as trees, especially in the HOUSTON AREA….
The refineries and chemical plants in Houston are important sources of a range of VOCs.
The take-home message from these figures is that NOx is emitted almost entirely as a result of combustion, whereas VOC emissions are often dominated by other sources such as trees. The refineries and chemical plants in Houston are important sources of a range of VOCs.

24. This is called an ozone isopleth diagram, and shows the ozone concentration that will result from different NOx / VOC mixtures. The plot on the previous slide essentially represents a vertical line here.

25. What is a unique hour.(just one hour at a time?)
What is AQMD ??
I think H-G-B is Houston Galveston Beaumont
Explain how sunlight drives photochemistry and causes high OZONE
This shows the number of exceedances in Houston over the past 9 years. Most high ozone days occur in the summer when there is plenty of sunlight to drive the photochemistry, warm temperatures accelerate some of the reactions, and temperature inversions often limit vertical mixing.
After taking the lead in 1999 and 2000, Houston has dropped back below Los Angeles in the number of annual exceedences. The annual variability is caused primarily by meteorology.
This shows the number of exceedances in Houston over the past 9 years. Most high ozone days occur in the summer when there is plenty of sunlight to drive the photochemistry, warm temperatures accelerate some of the reactions, and temperature inversions often limit vertical mixing.
After taking the lead in 1999 and 2000, Houston has dropped back below Los Angeles in the number of annual exceedences. The annual variability is caused primarily by meteorology.

26. Ozone Non-attainment: Old standard

27. Ozone Non-attainment: New standard

28. 19.2 The Effects of Climate and Topography on Air Pollution
Air pollution levels in a region are affected by a number of factors, among them:
Temperature
Sunlight
Wind
Other climate factors
They are also affected by the topography.

29. FIGURE 05a: Temperature profiles: normal pattern

30. FIGURE 05b: Temperature profiles: temperature inversion

31. The Health Effects of Air Pollution
FIGURE 6: Urban air pollution and incidence of emphysema in Winnipeg and St. Louis
Air pollution:
adversely affects human health
damages the environment and the organisms that live in it
damages buildings and a wide assortment of materials, costing billions of dollars a year
Air pollution causes many immediate effects, such as:
shortness of breath
eye irritation
upper respiratory tract irritation
Few people are aware of the source of these problems.
In extreme cases, pollutants can become lethal
Long-term exposure to air pollution may result in a number of diseases, including:
Bronchitis
Emphysema
Asthma
Lung cancer
Three groups are generally the most susceptible to air pollution:
The young
The old
The infirm (sick)

32. Effects on Plants and Nonhuman Animals
FIGURE 7:
Trees killed by acid deposition in Pisgah Nation Forest, North Carolina
© Jerry Whaley/age fotostock

33. Power Plant NOx Control: Staged Combustion
Low-NOx Burners: Precisely control combustion to reduce NOx
Natural gas reburn: Creates fuel-rich zone and radicals which destroy NOx
Over-fire air: Completes the combustion
Together, can reduce NOx by ~50-75%
US DOE NETL

34. Power Plant Sulfur Dioxide Control
Initially dispersed by tall chimneys
“Solution to pollution is dilution”
Low sulfur coal
Some coals (e.g., Western U.S.) contain less sulfur
Flue Gas Desulfurization
Sorbent such as limestone or lime is injected to remove 80-98% of SO2
Cobenefit of reducing mercury emissions
Byproduct can be used in wallboard, cement
3-7% energy penalty
Parish Power Plant
Unit 8 FGD System

35. Power Plant NOx Control: Selective Catalytic Reduction (SCR)
Ammonia is injected after boiler to convert NOx to N2 and water
Requires catalyst
Specific temperature range
~85% NOx reduction

36. Automobile Emission Controls
3-way catalytic converter
Reduces NOx, oxidizes CO and hydrocarbons
Oxygen sensor: Controls air-fuel ratio
Diesel particulate filters and oxidation catalysts
Cleaner burning fuels
Unleaded gasoline: No lead emissions; preserves catalyst
Low sulfur fuels: Preserves catalyst
Added oxygenates: Reduce CO

37. Catalytic Converters A. Reduction Catalyst: B. Oxidation Catalyst:
2NO  N2 + O2
B. Oxidation Catalyst:
2CO + O2  2CO2
CxHy + (x+y/4)O2  xCO2 + (y/2)H2O
CO2 is dominant component of exhaust, not significantly affected by controls
19.4 lb CO2/gal gasoline; 22.2 lb/gal diesel 37

38. Diesel Particulate Filter
Volkswagen

39. Electrostatic Precipitator (ESP)
Suspended particles are charged by electron field
Particles travel to collection plate
Plates are rapped to make PM fall to hoppers
~99% efficiency
ceenve3.civeng.calpoly.edu/cota/ENVE411-ESP.html

40. 19.5 Noise: The Forgotten Pollutant
Sound is characterized by loudness (measured in decibels) and pitch (how high or low it is).

41. How Loud is Too Loud? www.warrencenter.org/howloud.html
Prolonged exposure to any noise above 85 decibels (dB) can cause gradual hearing loss.
At higher decibel levels, hearing protection is strongly recommended.
100 decibels - no more than 15 minutes prolonged exposure recommended
110 decibels - regular exposure of more than one minute risks permanent hearing loss without hearing protection.

42. FIGURE 14: Radon protection
Indoor Air Pollution
FIGURE 14: Radon protection