1. Introduction to Environmental Engineering Dr. Kagan ERYURUK

2. Air Pollution

3. Composition of Standard Dry Air

4. Prefixes used in naming compounds
Example: CO2 = carbon dioxide
CO = carbon monoxide

5. Converting between ppm and %
1 % = 1 particle per 100 particles
= 10 particles per 100 particles
= 100 particles per particles
= 1000 particles per particles
= particles per particles
1% = ppm
1 million!
Example:
What is % in ppm?
0.007 % x 10,000 ppm = 70 ppm
1 %
0.007 % = 70 ppm

6. What is air pollution?
Air pollution consists of gases, liquids, or solids present in the atmosphere in high enough levels to harm humans, other organisms, or materials

7. Sources of Outside Air Pollution
Combustion of gasoline and other hydrocarbon fuels in cars, trucks, and airplanes
Burning of fossil fuels (oil, coal, and dinosaur bones)
Insecticides
Herbicides
Everyday radioactive fallouts
Dust from fertilizers
Mining operations
Livestock feedlots

8. Classification of Air Pollutants
Classic Air Pollutants:
Gaseous: SO2, CO, O3, HC, NO, NO2
Particulate: Dust, Fume Mist, Smoke, Spray
Other Types of Air Pollutants:
Fog
Radioactivity
Excess Radiation (U.V., Visible, etc.)

9. Primary vs. Secondary Air Pollutants
Primary air pollutants:
Harmful chemicals that enter directly into the atmosphere
Carbon oxides
Nitrogen oxides
Sulfur dioxide
Particulate matter
Hydrocarbons
Secondary air pollutants: (produced by chemical reactions in atmosphere)
Harmful chemicals that are produced from chemical reactions involving primary air pollutants
Ozone
Sulfur trioxide

10. Sources of Primary Air Pollutants

11. Particles
Particles are typically classified by their size (mass median aerodynamic diameter).
In air pollution terminology, fine particles are 2.5 μm in diameter or smaller (≤2.5 μm) (PM2.5).
Coarse particles are between μm (PM10) in diameter.
Ultrafine particles, generally considered <0.1 μm, is a subset of fine particles.

12. Metallurgical dust and fumes
Ultrafine
Particles
Fine
Large
Sea salt nuclei
Carbon black
Pollens
Cement dust
Oil smoke
Combustion nuclei
Metallurgical dust and fumes
Photochemical smog
Insecticide dusts
Coal dust
Average particle diameter (micrometers or microns)
0.001
0.01
2.5
10.0
100.0
Tobacco smoke
Paint pigments
Fly ash
Milled flour

13. VOCs (Volatile Organic Compounds)
In rural areas, natural sources dominate.
In urban areas, transportation dominates.
The major anthropogenic sources of VOCs include;
Solvent Use (including paints, adhesives, aerosols, metal cleaning and printing)
Road transport (emissions from fuel / petroleum use)
Production processes
Extraction and distribution of fossil fuels
Natural Sources of Volatile Organic Compounds;
Plants synthesize many organic molecules and release some VOCs (including a range of terpenes) into the atmosphere

14. Sulfur dioxide (SO2)
Sulfur is contained within all fossil fuels, and is released in the form of sulfur dioxide (SO2) during fossil fuel combustion. Fossil fuel combustion accounts for almost all anthropogenic (human-caused) sulfur emissions. 
Natural occurances like volcanoes also emit sulfur dioxide.
A colorless gas with a pungent, suffocating odor.
A dangerous air pollutant because it is corrosive to organic materials and it irritates the eyes, nose and lungs.

15. Nitrogen oxides (NOx)
Two main nitrogen oxides (NOx): Nitric oxide (NO) and nitrogen dioxide (NO2).
Nitric oxide (NO) and nitrogen dioxide (NO2) are gaseous products of combustion from both stationary sources (e.g., power plants) and from motor vehicles.
When inhaled, nitrogen dioxide becomes a serious air pollutant which may:
Cause pulmonary edema (accumulation of excessive fluid in the lungs)
Be part of acid rain (destroying fish and plant life in lakes, damaging surfaces of buildings etc)
Contribute to photochemical smog.

16. Ozone (O3)
Ozone (O3) is a colorless, poisonous gas with a sharp, cold, irritating odor.
The natural stratospheric ozone is considered to be of beneficial nature – it keeps harmful excessive ultraviolet sunlight from reaching the surface of the Earth.
As a result of anthropogenic emissions of primary pollutants, has negative effects on humans and the natural environment.
Effects of Ozone as an Air Pollutant;
Irritation of the respiratory system
Inflammation and damage to the lining of the lungs
Aggravation of asthma
Reduction in agricultural yields

17. Altitude (kilometers) Ozone concentration (ppm)
Altitude (miles)
Stratospheric ozone
Stratosphere
Troposphere 40 35 30 25 20 15 10 5
Photochemical ozone
Air

18. Ozone Depletion
Several pollutants attack the ozone layer. Chief among them is the class of chemicals, chloro-fluoro-carbons (CFCs).
CFCs are used as refrigerants (notably in air conditioners), as agents in some manufacturing processes, and formerly as propellants in spray cans.

19. Ozone Depletion
In the stratosphere, intense UV radiation breaks the CFC molecules apart, releasing the chlorine atoms.
These chlorine atoms then react with ozone (O3), breaking O3 down into ordinary oxygen molecules (O2).

20. 5.2 Layers of the Atmosphere
The atmosphere has four layers:
Thermosphere
Mesosphere
Stratosphere
Troposphere

21. Layers of the Atmosphere
The four layers of the atmosphere include:
the troposphere, where we live;
the stratosphere, which contains the ozone layer;
the mesosphere, where meteors burn; and
the thermosphere, where satellites orbit Earth.

23. Indoor Air Pollution Indoor Air pollution
May have higher levels of air pollutants than outdoor air.
Include;
radon, cigarette smoke, carbon monoxide, nitrogen dioxide, formaldehyde, pesticides, cleaning products, ozone, asbestos, allergens, and pathogens

24. Radon
Radon is a colorless, tasteless radioactive gas produced naturally by uranium decay in the Earth’s crust.
Breathing low levels of radon can lead to lung cancer
Radon is the most serious indoor air pollutant

25. Asbestos
A mineral fiber that has been used in construction materials for insulation and as a fire-retardant
Most commonly found in older homes
Exposure to asbestos can lead to long-term risk of chest and abdominal cancers and lung diseases

26. Air pollution affects human lungs, like these of this non-smoker

27. Temperature Inversion
If the there is a temperature inversion (a warm layer above the cool surface layer), the air will not rise.
This may lead to a severe pollution episode.
Temperature inversions are frequently caused by radiative cooling of the ground at night.

28. Thermal Inversions Cities near mountain ranges
When a warm front follows a cold front
Result: intense local smog