1. Air Pollution Dr. R. B. Schultz

2. Introduction Air pollution Types Air pollution Types Sources of pollutants Sources of pollutants Pollution and weather Pollution and weather Acid Rain Acid Rain Solutions Solutions

3. What is an air pollution? A substance present in sufficient concentration in the air to produce a harmful effect on humans or animals, vegetation, or materials. A substance present in sufficient concentration in the air to produce a harmful effect on humans or animals, vegetation, or materials.

4. Air pollution A) Natural A) Natural B) Man-made B) Man-made

5. “Natural” Pollution Air is never perfectly clean. Air is never perfectly clean. Examples of “natural” air pollution include: Examples of “natural” air pollution include: Ash, Ash, salt particles, salt particles, pollen and spores, pollen and spores, smoke and smoke and windblown dust windblown dust  These are produced naturally, such as, by volcanic activities and bacterial actions.

6. “Man-made” Pollution Examples of “man-made” air pollution include: Examples of “man-made” air pollution include: CO, CO, CO 2, CO 2, Oxides of nitrogen (NO x ), Oxides of nitrogen (NO x ), Oxides of sulfur (SO x ), Oxides of sulfur (SO x ), Particulates, and Particulates, and Volatile Organic Compounds (VOCs) Volatile Organic Compounds (VOCs)  These are produced by human activity due to increased urbanization, industrialization (such as electrical power plants), transportation, forest fires, incineration of solid wastes.

7. Air Pollutant Types Although some types of air pollution are recent creations, others, such as London's infamous smoke pollution, have been around for centuries. Although some types of air pollution are recent creations, others, such as London's infamous smoke pollution, have been around for centuries. One of the most tragic air pollution episodes ever occurred in London in December 1952 when more than four- thousand people died. One of the most tragic air pollution episodes ever occurred in London in December 1952 when more than four- thousand people died.

8. Pollutants can be grouped into two categories: Pollutants can be grouped into two categories: (1) primary pollutants, which are emitted directly to the air from identifiable sources. (1) primary pollutants, which are emitted directly to the air from identifiable sources. (2) secondary pollutants, which are produced in the atmosphere when certain chemical reactions take place (for example, formation of ozone). (2) secondary pollutants, which are produced in the atmosphere when certain chemical reactions take place (for example, formation of ozone). Air Pollutant Types

9. Primary Pollutants The major primary pollutants include: carbon monoxide, and CO 2 carbon monoxide, and CO 2 nitrogen oxides (NO x ), nitrogen oxides (NO x ), sulfur dioxide, sulfur dioxide, particulate matter (PM), particulate matter (PM), volatile organic compounds (VOCs), volatile organic compounds (VOCs), lead. lead.

10. CO, Carbon monoxide Natural source– atmospheric oxidation of methane Natural source– atmospheric oxidation of methane 2CH 4(g) + 3O 2(g)  2CO(g) + 4H 2 O (l) Man-made source—incomplete combustion of fossil fuels (e.g., petrol used in the internal combustion engine for transportation), forest fires. Man-made source—incomplete combustion of fossil fuels (e.g., petrol used in the internal combustion engine for transportation), forest fires.

11. CO, Carbon monoxide Effect on health – Metabolic poison. Prevents haemoglobin from carrying O 2. Effect on health – Metabolic poison. Prevents haemoglobin from carrying O 2.

12. Oxides of Nitrogen (NO x ) N 2 O, NO, NO 2 are important air pollutants. N 2 O, NO, NO 2 are important air pollutants. Natural source for NO and N 2 O – Decomposition of N containing compounds by bacterial action Natural source for NO and N 2 O – Decomposition of N containing compounds by bacterial action N 2 and O 2 in the air will not normally react (because N 2 is very stable and ~ 1500°C is required for them to react). This temperature is reached in the engines of cars, airplanes, and trains, and make N 2 and O 2 react to produce NO x. N 2 and O 2 in the air will not normally react (because N 2 is very stable and ~ 1500°C is required for them to react). This temperature is reached in the engines of cars, airplanes, and trains, and make N 2 and O 2 react to produce NO x.

13. Oxides of Nitrogen (NO x ) Other sources: Stationary sources (furnaces fuelled by natural gas), industrial processes (e.g. nitric acid production), agricultural burning, forest fires. Other sources: Stationary sources (furnaces fuelled by natural gas), industrial processes (e.g. nitric acid production), agricultural burning, forest fires.

14. Oxides of Nitrogen (NO x ) NO 2 is a secondary pollutant because NO is converted to NO 2 in the atmosphere. NO 2 is a secondary pollutant because NO is converted to NO 2 in the atmosphere. 2NO (g) + O 2 (g)  2NO 2 (g) 2NO (g) + O 2 (g)  2NO 2 (g)

15. Oxides of Nitrogen (NO x ) Effect on health -- breathing problems, irritation of the respiratory tract, pulmonary edema. Effect on health -- breathing problems, irritation of the respiratory tract, pulmonary edema.

16. Oxides of Sulfur (SO x ) SO 2, and SO 3. SO 2, and SO 3. Secondary : SO 3 Secondary : SO 3 2SO 2 (g) + O 2 (g)  2SO 3 (g) Natural source for SO 2 – volcanic and bacterial activites Natural source for SO 2 – volcanic and bacterial activites

17. Oxides of Sulfur (SO x ) SO 2, and SO 3. SO 2, and SO 3. Secondary : SO 3 Secondary : SO 3 2SO 2 (g) + O 2 (g)  2SO 3 (g) Sources: Combustion of sulfur containing fossil fuels (e.g., coal), some fuels used by ships and power stations, Sulfuric acid factories, smelting plants. Sources: Combustion of sulfur containing fossil fuels (e.g., coal), some fuels used by ships and power stations, Sulfuric acid factories, smelting plants.

18. Oxides of Sulfur (SO x ) Effect on Health : Acid rain formed, irritation of the respiratory tract, affecting the asthma sufferers. Effect on Health : Acid rain formed, irritation of the respiratory tract, affecting the asthma sufferers.

19. Particulate Matter Solid particles suspended or carried in the air. Solid particles suspended or carried in the air. Natural sources -- sandstorms, volcanoes, forest fires started with lightning. Natural sources -- sandstorms, volcanoes, forest fires started with lightning.

20. Particulate Matter Man-made sources-- smoke produced by combustion of coal petroleum, wood, etc., dust from mechanical break-up of solid matter, asbestos from industrial plants, metallic particles (e.g., Hg, As, Pb, compounds of Pb) from industrial plants, fly ash (unburnt carbon and oxides of many metals) from coal burning power plants. Man-made sources-- smoke produced by combustion of coal petroleum, wood, etc., dust from mechanical break-up of solid matter, asbestos from industrial plants, metallic particles (e.g., Hg, As, Pb, compounds of Pb) from industrial plants, fly ash (unburnt carbon and oxides of many metals) from coal burning power plants.

21. Particulate Matter Effect on health -- irritation of the lungs, asbestosis (scarring of the lungs), some metal poisonings (e.g., Be poisoning). Effect on health -- irritation of the lungs, asbestosis (scarring of the lungs), some metal poisonings (e.g., Be poisoning).

22. Volatile Organic Compounds (VOCs) Hydrocarbon gases (e.g., CH 4 ), petroleum (mixture of organic compounds), solvents used in paints. Hydrocarbon gases (e.g., CH 4 ), petroleum (mixture of organic compounds), solvents used in paints. Natural Sources – Natural Sources – - CH 4 : biological anaerobic bacterial decomposition of organic matter swamps, rice fields, rivers, and lakes (this also produces terpenes); as a digestive gas by the cows.

23. Volatile Organic Compounds (VOCs) Man-made Sources – Petroleum extracting, refining, transporting, and use; paint production; incomplete combustion of gasoline, coal, wood. Man-made Sources – Petroleum extracting, refining, transporting, and use; paint production; incomplete combustion of gasoline, coal, wood.

24. Volatile Organic Compounds (VOCs) Effect on Health – some are carcinogenic, irritation of mucous membrane. Effect on Health – some are carcinogenic, irritation of mucous membrane.

27. Secondary Pollutants Atmospheric sulfuric acid is one example of a secondary pollutant. Atmospheric sulfuric acid is one example of a secondary pollutant. Air pollution in urban and industrial areas is often called smog. Air pollution in urban and industrial areas is often called smog. Photochemical smog, a noxious mixture of gases and particles, is produced when strong sunlight triggers photochemical reactions in the atmosphere. Photochemical smog, a noxious mixture of gases and particles, is produced when strong sunlight triggers photochemical reactions in the atmosphere. The major component of photochemical smog is ozone. The major component of photochemical smog is ozone. Although considerable progress has been made in controlling air pollution, the quality of the air we breathe remains a serious public health problem. Although considerable progress has been made in controlling air pollution, the quality of the air we breathe remains a serious public health problem.

29. Strategies to deal with air pollution Laws Laws Catalytic converters, Catalytic converters, Burn “ban” days Burn “ban” days Cleaner burning fuels and gas “scrubbing” Cleaner burning fuels and gas “scrubbing” More public transport More public transport Cut emissions Cut emissions

30. Conclusion Air pollution Types Air pollution Types Sources of pollutants Sources of pollutants Pollution and weather Pollution and weather Solutions Solutions