1. Faculty of allied medical science
Environmental health
(NREH-101)

2. Supervision Prof.dr/Mervat Salah
Air pollution
Supervision
Prof.dr/Mervat Salah

3. Outcomes 1-To know the meaning of air pollution
2-To differentiate between outdoor and indoor pollution
3-To know types of air pollution
4-To understand the ways to control air pollution

4. AIR POLLUTION Type of Air pollution:- Sources of out door pollution
outdoor pollution – indoor pollution
Sources of out door pollution
Combustion of fuel (natural gas, petroleum, coal and
wood)
Industrial process
Natural process (Volcanic)

5. Types of Major Air Pollutants
Carbon oxides (CO)
Nitrogen oxides and nitric acid (NO, HNO3)
Sulfur dioxide and sulfuric acid (SO2, H2SO4)
Particulates (SPM)
Ozone (O3)
Volatile organic compounds (VOCs) )
Types of Major Air Pollutants

6. Pollutants - Secondary pollutants - Primary pollutants
Pollutants can be classified as either
primary or secondary
- Primary pollutants
are substances directly emitted from a process, such as the carbon monoxide gas from a motor vehicle exhaust or sulfur dioxide released from factories.
- Secondary pollutants
are not emitted directly. Rather, they form in the air when primary pollutants react or interact. An important example of a secondary pollutant is ground level ozone

7. Sources and Types of Air Pollutants

8. Environmental challenges
Green house effect: Increasing global temperature. Scientists predicting that earth's temperature will increase by 3-40C by year 2030 if the pollution continues to increase at the same pace.
Ozone depletion: As ozone layer in the upper atmosphere absorbs incoming harmful ultraviolet radiation but it is now getting thinner & more UVs are reaching in to earth creating different disease like cancer& eye problems.
Photochemical smog: In 1952 London was covered by smog for 10 days .This smog was caused by fog, smoke, ash,& SO2 plus NO2.Sunlight played a great role in the formation of this smog .
Acid rain: is caused by oxides of nitrogen & sulphur.
It increases acidity of soil & effects the growth of trees & plants.

9. Acid Deposition Sulfur dioxides and nitrogen oxides
Wet and dry deposition
Acid rain
Regional air pollution
Midwest coal-burning power plants
Prevailing winds

10. Acid Deposition Wind Transformation
to sulfuric acid (H2SO4) and nitric acid (HNO3)
Windborne ammonia gas
and some soil particles partially
neutralize acids and form dry
sulfate and nitrate salts
Wet acid deposition
(droplets of H2SO4 and
HNO3 dissolved in rain
and snow)
Nitric oxide (NO)
Sulfur dioxide
(SO2) and NO
Dry acid deposition
(sulfur dioxide gas
and particles of
sulfate and nitrate salts)
Acid fog
Lakes in shallow soil
low in limestone
become acidic
Figure 15.4: Acid deposition, which consists of rain, snow, dust, or gas with a pH lower than 5.6, is commonly called acid rain. Soils and lakes vary in their ability to buffer or remove excess acidity.
Question: What are three ways in which your daily activities contribute to acid deposition?
See an animation based on this figure at ThomsonNOW.
Lakes in deep
soil high in limestone
are buffered
Fig. 15-4, p. 351

11. Effects Of Pollution Respiratory diseases in human
Toxic metal leaching
Structural damage
Kills fish and other aquatic organisms
Leaches plant nutrients from soil
Acid clouds and fog at mountaintops

12. Acid Rain + water H2SO4 (Sulphuric Acid) HNO3 (Nitric Acid) Lake Sea
Solar Radiation
H2SO4 (Sulphuric Acid)
HNO3 (Nitric Acid) +
water
Acid Rain
SO2 & NOX
Factories, Transportation
Lake
Sea
SEA

13. The Greenhouse Effect Earth’s natural greenhouse effect
Natural greenhouse gases
Water vapor (H2O)
Carbon dioxide (CO2)
Methane (CH4)
Nitrous Oxide (N2O)
Enhanced greenhouse effect
Global warming

14. Effect of Global warming
Rise in average global surface temperature
Changes in glaciers, rainfall patterns, hurricanes
Droughts and floods. Threat to biodiversity
Decreased food production
Diseases (Threats to human health)
Economic and social disruption
Rising sea levels
Extreme weather

15. Government Roles in Reducing the Threat of Climate Change (1)
Regulate carbon dioxide as a pollutant
Carbon taxes
Cap total CO2 emissions
Subsidize energy-efficient technologies
Technology transfers

16. Photochemical Smog Sources Photochemical reactions Photochemical smog
Brown-air smog
Sources
Climate effects
Urban areas
Photochemical Smog

17. Unbalanced Green House Effect Naturally Moderated Green House Effect
Methane
Carbon Dioxide
Nitrous oxide
Ozone
Carbon Dioxide
50%
Methane
18%
Chlorofluorocarbons
14%
Ozone
12%
Nitrous oxide
06%
Earth
Earth
This natural balance may be distorted by Green House Effect as gases such as carbon dioxide have built up in the atmosphere trapping more heat
Green house gases in natural condition insulates the earth against extreme of temperature by limiting both incoming solar radiation & escape of reradiated heat in to space.
Contribution of different gases to cause green house effect
Less reradiated heat escapes in to space
Some reradiated heat escapes in to space
sun
sun
sun
More reradiated heat reflected back to earth
Infra-red radiation
Some reradiated heat reflected back to earth
Surface Temperature increases
Surface Temperature normal
Atmosphere
Atmosphere
Unbalanced Green House Effect
Naturally Moderated Green House Effect

18. Formation of Photochemical Smog
Ultraviolet Radiation
NO Nitric Oxide
O2 Molecular Oxygen
H2O Water
NO2 Nitrogen dioxide
O Atomic Oxygen
Hydrocarbons
HNO3 Nitric Acid
O Ozone
PANs Peroxyacyl nitrates
Aldyhydes (e.g. Formaldehyde)
Photochemical Smog
Formation of Photochemical Smog

19. Ozone Layer thinning Affect on seasonal changes
Causes – chlorofluorocarbons (CFCs) that uses in:
Coolants in air conditioners and refrigerators
Propellants in aerosol cans
Cleaning solutions for electronic parts
Fumigants
Bubbles in plastic packing foam

20. Ozone layer depletion Ultraviolet rays from Sun
Chlorofluorocarbons are entering in to atmosphere releasing chlorine. The chlorine than break down the ozone
The Ozone layer in stratosphere blocks these harmful UV rays
Oxygen
ozone
Whole in Ozone layer
chlorine
The chlorine released from CFCs break down the ozone molecule.
More ultraviolet radiations are reaching in to earths surface as there is a whole in ozone layer.

21. Reversing Ozone Depletion
Stop producing ozone-depleting chemicals
Slow recovery
Montreal Protocol
Copenhagen Protocol
International cooperation

22. Indoor air quality
Indoor air quality (IAQ) is a term referring to the air quality within and around buildings and structures.
IAQ can be affected by microbial contaminants (mold, bacteria), gases (including carbon monoxide, radon, volatile organic compound and particulates) .

24. Major Indoor Air Pollutants
Tobacco smoke
Formaldehyde
Radioactive radon-222 gas
Very small particles
Sick-building syndrome (SBS)
Developing countries
Indoor cooking and heating

25. Air Pollution and the Human Respiratory System
Natural protective system
Lung cancer, chronic bronchitis, emphysema, asthma
Premature deaths

26. Air Pollutants and its impact on human health
Particulate Matter
Dust and smoke particles cause irritation of the respiratory tract and produce bronchitis, asthma and lung diseases.
Dust and smoke function as nuclei for condensation of water vapors and produce smog which attract chemicals like SO2, H2S, NO2,etc. Smog not only reduce visibility but is also harmful due to its contained chemicals.

27. NOISE POLLUTION Sources
The term noise is applied to the sound that cause irritation on hearing of healthy human being.
Sources
Transport noise--- Originates from road traffic (vehicular), air craft and rail traffic.
Industrial noise--- It produced by presses; punch and stamp machine, pneumatic drills, milling machines, cutter and routers, dust extractors. etc.
Domestic noise--- It is generated from domestic appliance like washing machines, spin dryers, food mixer, sink waste grinder and vacuum cleaner.

28. Effects Of Noise Pollution
Hearing damage from noise exposure
Pathological and Physiological disorders
The impact of noise may cause permanent
hearing loss due to the exposure to noise
levels exceeding 90 dB

29. What is sick building syndrome ?
The feeling of illness among majority of occupants of a conditioned space is called “Sick Building Syndrome”.
A variety of illness symptoms reported by occupants in sick buildings are – Headache, fatigue, irritation in eyes, nose and throat, shortness of breathe etc.

30. What is sick building syndrome ?
Causes:
Inadequate ventilation , insufficient
supply of outside air; poor mixing;
fluctuations in temperature & humidity;

31. Health Effects of Indoor Air Pollutants
Health effects due to indoor air pollutants may be short- as well as long-term.
Short-term problems
include a stuffy, odorous environment and symptoms such as burning eyes, skin irritation, and headaches.
Long-term health problems
have a longer latency period or are chronic in nature.
Health conditions involving some allergic reactions, including hypersensitivity pneumonitis, allergic rhinitis, and some types of asthma, are triggered by bioaerosols

32. Control of Indoor Air Pollution
Examples include banning smoking in public buildings.
Source-isolation strategy is used in situations where a source cannot be completely eliminated. For instance, copy machine areas, food service stations, and bathrooms are often separately vented outside buildings to avoid the recirculation of return air.

33. Questions 1-Sources of out door pollution are……………….
2-Effects Of Noise Pollution are……………
3-Two of Effects Of Noise Pollution are…………and………
4- Source-isolation strategy is used in situations where a source…………..
5- primary pollutants are substances directly emitted from a process, such as the ……………from a or ……..released from ……………..

34. 6-What is sick building syndrome
6-What is sick building syndrome ? And it is effect on the health status of human being ?
7- What are the environmental challenges?
8-What are the classification of pollutants ?

35. Recommended text book
Basic Environmental Health