air quality

1. What is OBE ?
 OBE (Outcome Based Education) is education
based on producing particular educational
outcomes that focuses on what students can
actually do after they are taught and expect
all learners/students to successfully achieve
particular (sometimes minimum) level of
knowledge and abilities.
 In a nutshell, OBE can also be thought as “It’s
not what we want to teach, BUT more
importantly, it’s what the students should
learn”.

2. Programm
e Learning
Outcome -
PLO

3. C6
C5
C4
C3
C2
C1

4. Chap 1.1 Global Warming and Climate Change
Course Learning Outcome
(CLO 1)
BT
Level
or
Domai
n
PL
O
W
K
Discuss global warming and
climate change, the effect of
carbon dioxide on the
environment, sustainable
development, as well as define
sustainable development goals
(SDG) and national policy on
sustainability
C2 PLO
7
WK7
Blooms Taxonomy
6 Cognitive Domains
C1 - Knowledge
C2 - Understand
C3 - Analyse
C4 - Apply
C5 - Evaluate
C6 - Create

5. Fundamentals of air pollution
Introduction to air pollution
Historical perspectives
Global air pollution issues
Air pollution legislation and policies
Chapter 1
Introduction to air
pollution

6. Air Pollution ?
1. What is air pollution
 What is it that is not poison? All things are poison and
nothing is without poison. It is the dose only that
makes a thing a poison. (Paracelsus, 1493-1541)
 Air pollution may be defined as the presence in the
atmosphere of substance(s) added directly or indirectly
in such amounts as to affect living and non-living things
adversely.
 What is classified as a pollutant therefore depends
upon recognition of which substances cause adverse
effects. It is an ever-changing definition.
 Centuries ago only soot or odoured gases may have
been considered air pollutant.
 Now we recognise that pollutants can cause more
subtle effects than producing unpleasant smells. Even
CO2 (a natural respiration product) is now considered a
pollutant.

7.  The key points of air pollution: i) substance; ii) man-made
or naturally produced; iii) with adverse effects to living and
non-living things; and iv) high concentrations or large
amount.
 Questions arise: How do we define the above vague
points? How is adversity defined? At what concentration
should a pollutant be considered high? What are the
substance that should be considered as pollutants?

8. atmosphere
response on man,
animals, plants, materials
detection
systems
pollution
generation
control
systems
air pollutants
process control
legislations and policies
2. Flowchart of air pollution issues

9. 3. Little history of air pollution
 As soon as I had gotten out of the heavy air of Rome and
from the stink of the smokey chimneys thereof… poured
forth whatever pestilential vapours and soots they had
enclosed in them, I felt an alteration of my disposition.
(Seneca, 61)
 Open coal burning was prohibited in London in 1317.
 A baker erected a chimney “so high as to convey the
smoake clear of the topps of the houses” (first abatement
technology)
 Elizabeth I barred the burning of coal in London during
parliament session.

10.  Fumifugium was submitted to King
Charles II by John Evelyn in 1661:
means to tackle air pollution in
London.
 “Her (London) inhabitants breathe
nothing but an impure and thick
mist, accompanied with a
fuliginous and filthy vapour, which
renders them obnoxious to a
thousand inconveniences,
corrupting the lungs and dis-
ordering the entire habits of their
bodies, so that catarrhs, phthisicks,
coughs and consumptions rage
more in this city than in the whole
earth besides.”
 Evelyn suggested moving the sources
of pollution to remote areas. It was
ignored

11.  Smoke and ash abatement handled by Public Health Act
in 1848, 1866 and 1875.
 Meuse Valley episode, Belgium (1930)
 Smog episode in Los Angeles (1940s)
 Donora Pennsylvania episode (1948)
 First National Air Pollution Symposium, Pasadena (1949)
 London smog (1952)  Clean Air Act (1956)
 Clean Air Act (1977, 1990)
 Montréal Protocol (1987), London (Amendment 1990),
København (1992), Wien (1995), Beijing (1999), Kyoto
Protocol (2000)
 Stern Report (2007)

12. 3.1 Meuse Valley Episode 1930
 In December 1930, all Belgium
was blanketed in dense fog
 Above the Meuse Valley there
was temperature inversion which
prevented upward movement of
air
 On a 15 mile stretch of the Valley
with hills of 100 m either side…
 6000 people became ill
 60 died on the 3rd and 4th
days
 many cattle also died

13.  On the 15 mile stretch there were 27 factories (steel
works, iron works and glass works)
 mostly emitting sulphur dioxide and sulphuric acid
 only one plant emitted fluorine
 The symptoms were of fluorine poisoning but the
committee insisted the deaths were due to sulphuric acid
dissolved in the fog droplets
 Traces of fluorine were found in vegetation twenty years
after the event
 The debate still continues as to the exact identity of the
fatal chemical but either way it was a serious air pollution
episode

14. 3.2 Denora episode 1948
 Donora and Webster lie in a deep,
narrow valley of the Monongahela
River, Pennsylvania
 In the valley were
 a zinc works
 a steel plant
 a wire mill
 two nail galvanising plants
 People had long complained of
sulphur fumes from the zinc works
 October 27-31 saw a temperature
inversion trapping the pollutant
 6,000 of the 13,000
inhabitants were ill
 20 died

16. 3.3 London Smog Disaster 1952
 River valley - much larger than the
Meuse
 Polluting emissions - mainly domestic
(open hearth fires, stoves), with some
industrial
 Very stable meteorological conditions
 Anticyclone approached from the
NW and stopped
 Air was stationary
 Temperature remained near
freezing
 Visibility < 20m over an area of 20
by 40 km

17. Daily air pollution (SO2 and particulates)
and deaths during the London Smog
1 2 3 4 5 6 7 8 9 10 11 12 13 14
Sulphur Dioxide
Deaths
Smoke
3830 mgm-3
4460 mgm-3
919
December 1952

18. Death in the London Smog
 Tonnes of particles of tar and gaseous sulphur dioxide
were emitted into the foggy air
 mostly came from hearths in people’s houses
 The water from the fog condensed around the soot
particles
 The sulphur dioxide reacted inside the droplets to form
dilute sulphuric acid
 pH of about 1.6 (battery acid)
 Inhaling the acidic aerosol produced mucus in the lungs
 people choked to death on mucus
 died of heart attacks fighting for breath

19. The London Smog: the aftermath
 1954 - government sets up an inquiry
into the incident
 1956 - Clean Air Act passed making it
illegal to burn coal in certain urban
areas
 Deaths occurred in 1957
 Smogs are now a thing of the past in
the United Kingdom
 cheap gas from the North Sea
 The smogs of Los Angeles are
photochemical smogs

20. London smog today: photochemical smog

21.  Bhopal chemical plant accident (1984)
 3300 people died and more than 200000 suffered
from respiratory and eye diseases when 40 tonnes
of methyl-isocyanate (MIC) were accidentally
released
 Chernobyl radiation accident (1986)
 More than 250 curies of radioactive isotopes were
released in a nuclear power plant explosion. Entire
Northern and Eastern Europe were affected. 30
casualties, countless radiation sickness
 Antarctica ozone hole (since 1983)
 Ozone depletion at Antarctica due to CFC
 Forest fire in Indonesia (1997)
 More than 30000 people suffered from respiratory
problems in SE Asia, visibility often less than 30 m, it
was reported that breathing the air was the same as
smoking 100 cigarettes per day.

22. 4. The atmosphere
78.084%
20.946%
0.934%
0.036%
0.002%
0.001%
Average composition of
dry clean air by volume
 N2
 O2
 Ar
 CO2
 Ne
 He
 ...
0 ~ 70000
360
1.5
0.1
0.02
0.01
0.001
0.0002
0.0002
Typical concentrations of
various gases in clean air (ppm)
 H2O
 CO2
 CH4
 CO
 O3
 NH3
 NO2
 SO2
 H2S

23. Relationship between GDP and
pollutant emissions for OECD countries
0
20
40
60
80
100
120
140
160
180
200
1970 1975 1980 1985 1990
Relative
economic
activity
GDP
NOx
CO2
SOx

24. Number of items of EC environmental
legislation adopted each year
0
5
10
15
20
25
30
67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90
Year
Number
of
Legislative
Orders

25.  Particulate matter:
 total suspended particulate (TSP) (typical size <
100 mm)
 respirable suspended particulate (RSP) (typical size
< 2.5 or 10 mm) (PM2.5, PM10, particulate matter of
size < 2.5 or 10 mm)
 Gaseous pollutants:
 Primary gaseous pollutants: SOx, NOx, CO, volatile
organic compound (VOC), Pb;
 Secondary gaseous pollutants: peroxyacetylnitrate
(PAN), ozone (O3)
 Photochemical pollutants:
 VOC, O3, PAN, CFC, greenhouse gases (CO2,
H2O)
5. Common air pollutants

26. 5.1 Air pollutants sources
 Natural pollutant sources
 Volcano eruption: emitting smoke, particulate
matter, SO2, H2S, CH4…
 Fires: emitting smoke, unburnt hydrocarbons,
CO, CO2, NOx...
 Dust or sand storms dispersing dust
 Oceans are emitting corrosive salt aerosols
 Lightning produces NOx and O3
 Normal human respiration produces CO2
 Artificial or anthropogenic sources
 Stationary sources: combustion, fuel usage,
waste incineration, industrial processes…
 Mobile sources: all emissions and exhausts from
transportation

27. 6. Sources of air pollutants
in a typical metropolis
Particulate matter
Aircraft
0.5%
Marine
4.3%
Fuel combustion
3.7%
Pow er generation
36.7%
Vehicle
54.8%
Sulphur dioxide
Vehicle
1.7%
Marine
5.0%
Pow er generation
86.4%
Fuel combustion
6.6%
Aircraft
0.3%

28. Nitrogen oxides
Marine
13.1%
Aircraft
3.6%
Pow er generation
42.9%
Vehicle
35.8%
Fuel combustion
4.6%
Carbon monoxide
Aircraft
2.5%
Vehicle
89.3%
Fuel combustion
3.2%
Marine
2.1%
Pow er generation
2.9%

29. 7.1 Particulate matter
 typical size varies: gravel
2000µ, sand 20 ~ 1000µ,
hair, 50µ, RSP with
health effects 0.1 ~ 10µ
 Sizes that cause
significant air pollution
problems are 0.01 ~ 50µ,
as larger particles tend to
settle
 Sources of PM: Natural:
wind, sandstorm, forest
fires, volcano eruption;
Anthropogenic: industry,
automobiles

30.  Size of particles
 Large particles (2.5 ~ 250µ): produced in mechanical, crushing,
crashing, milling or grinding processes. Most mechanical
processes cannot produce particles of size smaller than 10µ
 Fine particles (0.1 ~ 10µ): produced in combustion, evaporation,
condensation, settling, e.g. tobacco smoke contains particles of
condensed hydrocarbons at 0.01 ~ 1µ. As usual the finer the size,
the more volatile the material.
 Agglomeration of fine particles: Fine particles tend to stick
together when they get close together due to electrostatic and Van
Der Waal’s forces.
 Aerosols: Particles small enough to remain suspended in the
atmosphere for a long time are referred to as aerosols

31. Heinsohn 239

32.  Effects of particulate matter pollutions
 Visibility: Particles are able to scatter lights with wavelengths
close to the particle size. Because of this particulate matter
pollutions usually yield hazy days and visible smog. Since
visible lights have wavelength between 0.4 ~ 0.8µ, hazy
days are caused by secondary particles.
 Health: Inhalable lung-damaging dust ranges from 0.5 ~ 5µ;
asthma, respiratory syndromes, bronchitis, decreased lung
functions.
 Climate: Fine particles can be called condensation nuclei in
meteorology. When wet air reaches saturation condition, the
existence of fine particles makes it easier for water vapour to
condense and form tiny droplets, forming fog and mist. It
also leads to formation of clouds.

33. 7.2 Gaseous pollutants: NOx and SOx
 Both N and S are essential to our bodies.
However N and S oxides are strong irritants that
cause health damage at high concentrations.
They also undergo atmospheric reactions to form
PM10 in urban areas.
 N and S oxides react with water and O2 to form
nitric and sulphuric acid, which are principal
contributors to acid rain.
 Both N and S have many sources, the main of
them being combustion or chemical plants.
 S oxides are formed from the sulphur
contaminants in fuels or incomplete combustion in
sulphur ores. N oxides come mainly from
atmospheric nitrogen due to lightning.

35. Anthropgenic sources of NOx and SOx
 Effects of NOx pollutions
 smog problems: respiratory
problems, visibility issues
 acid rain
 nutrient overload in water:
decreasing water quality
 toxic atmosphere
 global warming
 Since 1970, all air pollutants
have shown a decreasing
trend except NOx, which has
increased around 10%.
 Effects of SOx pollutions
 PM formation
 acid rain
 respiratory problems

36. 7.3 VOC
 VOCs are those organic compounds whose room
temperature vapour pressures are greater than about
0.0007 atm. It usually contains carbon bonded with H, N
or S and can vaporise at significant rates
 VOCs are contributors to the problem of photochemical
oxidants (smogs, ozone): NOx + O2 + VOC O3 + smog
 Some VOCs are infrared absorbers and thus contribute to
greenhouse effects. Other are known to be toxic or
carcinogenic.
 Most VOCs are emitted from smaller sources like
automobiles, paints, solvent usage, nail polish and vanish,
correcting fluids. Plants, due to stringent laws, produce
comparatively less VOC as emissions
sunlight

37. 7.4 Ozone
 O3 layer absorbs ~3% of UV radiation. It controls the
amount of incoming and outgoing solar radiation to and
from the Earth surface, thus maintaining a normal evolution
of global climate.

38. • Ozone occurs in two layers of the atmosphere.
• The layer surrounding the earth's surface is the
troposphere.
• Here, ground-level or "bad" ozone is an air pollutant
• that damages human health, vegetation, and many
common materials. It is a key ingredient of urban smog.
• The stratospheric or "good" ozone layer extends upward
from about 15 to 45 km and protects life on earth from the
sun's harmful ultraviolet rays (UV-b)

39. Any chlorofluorocarbon (CFC) molecule in the upper
atmosphere tends to become stripped of a chlorine atom
photochemically, by bombardment with radiation. That
loose atom combines readily with any nearby ozone
molecule, to form normal oxygen and chloro-monoxide:
Cl + O3  ClO + O2
The monoxide then combines with any available atom of
oxygen in the atmosphere to form normal oxygen and
chlorine: ClO + O  Cl + O2

40. So the outcome is a chlorine atom, as at the beginning,
once again available to destroy more ozone. The
chlorine thus acts as a catalyst. This catalytic process
occurs most effectively on a foreign surface, for
instance on an ice crystal. Since the lower
stratosphere is cold over Antarctica in winter, the little
water vapour there is forced to condense in polar
stratospheric clouds. There is good evidence that
every winter the catalytic process of CFCs virtually
totally consumes the ozone between 15~25 km over
Antarctica. Any CFC has a lifetime in the troposphere
of ~100 years, so it can remain available to destroy
ozone for a long time. Even if CFC production were
stopped today, what is in the atmosphere already
would damage the ozone layer for decades.

41. Nitric oxide, NO, is a catalyst in the same way. First it
reacts with ozone to form oxygen and nitrogen oxide
NO2, and then that reacts with loose atoms of oxygen to
create O2 and NO once more:
NO + O3  NO2 + O2
NO2 + O  NO + O2
The reactions occur most readily on the surface of ice
particles found in the winter stratosphere above
Antarctica, where temperatures are ~ -80 °C.
One common misconception:
O3 is poisonous. Its only function is to block radiation.
O3 is also a pollutant itself, it is the chief reason for smog

44.  In 1985, a team led by British
scientists J. Farman (1985) shocked
the scientific community by
reporting massive annual
decreases of stratospheric ozone
over Antarctica in the polar spring.
 In fact such phenomenon has been
detected as early as 1977 aboard
Nimbus-7 satellite, only that the
observations were being discarded
as wrong data.

45.  Same thing actually happen in Arctic.
However, since temperature is slightly
higher in Arctic, ozone depletion is less.
 The effect of a compound on
stratospheric ozone depletion is
assessed by the unit ozone depletion
potential (ODP). ODP is usually defined
as the total steady-state ozone
destruction, vertically integrated over the
stratosphere, that results per unit mass
of species i emitted per year relative to
that of CFC-11.
11
CFC
,
3
,
3
O
O
ODP



 i
i

46.  In September 1987, Montréal Protocol on Substances
that Deplete the Ozone Layer, each signer agreed to
reduce the production of CFC-11 ~ CFC-114 and
halons. Consumption of these CFCs was frozen at
1986 level from 1989 and is to be reduced to 80% and
then 50% of these values at 1994 and 1999.
 For undeveloped countries, production must not exceed
110% of the 1986 levels.
compound ODP
CFC-11 (CFCl3) 1.00
CFC-12 (CF2Cl2) 0.82
CFC-113 (CFCl2CF2Cl) 0.92
CFC-115 (CF2ClCF3) 0.40
HCFC-22 (CF2HCl) 0.04
HFC-225ca (CF3CF2CHCL2) 0.02

48. 7.5 CO
 CO is a major pollutant in industrial or urban areas.
 Incomplete combustion from hydrocarbons.
 Major source: vehicular emission (~95%)
 Reduces oxygen delivery to body’s organs and tissues
Road Mobile Sources Non-Road Mobile Sources

49. 8. Greenhouse effect
 The atmosphere absorbs a high fraction of long-
wave radiation of the earth. Greenhouse effect
 Water in vapour form is the principal agent for this
effect. CO2 is the next in importance only. CO2 is
not as important because its concentration is much
lower and its main infrared absorption is localized in
a narrow band near 1.5 x 104 nm.
 However the amount of water in the atmosphere is
fairly constant, whereas the amount of CO2 is
increasing quickly due to rapid growth in industrial
activities for the past century.

50. 9. Man-made emissions of
common pollutants
0 50 100 150 200
1990
1980
1970
1990
1980
1970
1990
1980
1970
1990
1980
1970
Emissions (millions of tonnes/year)
OECD
Rest of World
CO
SPM
NOx
SOx

51. 10. Scales of air pollution
 Local or proximal scale:
 Vehicular emissions
 Ground-level emissions
 Accidental releases
 Urban scale:
 Multiple major sources
 Regional scale:
 Carryover of urban oxidant problems to the regional
scale
 Slow-reacting primary air pollutants that undergo
reactions and transformation during long-range
transport
 Visibility

52.  Continental / Global scale:
 Ozone layer problems
 Radioactivity release
 Greenhouse effects
 Volcano eruptions: blocking of incoming solar
irradiation, a ‘mini-ice-age’ occurred in mid 1800s
when a huge volcano erupted in the Pacific. Snow
occurred in New England in July