1. The “Big Five” Air Pollutants

2. Carbon Monoxide When fossil fuels and other organic fuels (e.g. wood) burn, they release water vapor and carbon dioxide by a process called “complete combustion” This reaction is never truly perfect, however, and as a result, we get a fair amount of “incomplete combustion” Incomplete combustion is the source of several waste products that come from burning fossil fuels One product of incomplete combustion is carbon monoxide, a very deadly poison

3. Carbon Monoxide Carbon monoxide binds to hemoglobin which would normally carry oxygen to the body’s organs, but instead carry carbon monoxide

4. Carbon Monoxide Oxygen

5. Carbon Monoxide Sources of carbon monoxide include: – Automobile exhaust – Furnaces – Cigarettes – Fires Indoor carbon monoxide detectors can be installed to protect residents of the house from over-exposure

6. Carbon Monoxide We can minimize (but not eliminate) the amount of carbon monoxide released by a car using a catalytic converter Catalytic converters cause carbon monoxide (and other waste products) to react and form less harmful substances

7. Unburned Hydrocarbons Also called volatile organic compounds (VOC’s) Sources – Incomplete combustion of gasoline – Evaporation of gasoline or other solvents (paints, cleaning fluids, etc) Are partly dealt with by catalytic converters

8. Nitrogen Oxides Referred to as No x as it can be several compounds of nitrogen and oxygen (NO 2, N 2 O 4, for example) Sources – Incomplete combustion in car engines – Incomplete combustion in furnaces

9. VOC and NO x When VOC’s and NO x ’s are combined together in the atmosphere, and exposed to sunlight, the combination produces photochemical smog Smog contains three components – VOC’s – NO x ’s – Ozone

10. VOC and NO x Ozone is found in two places: – Stratosphere – protects sun from ultraviolet radiation – Troposphere – acts as key component of smog

11. VOC and NO x VOC’s & No x undergo a chemical reaction in the sun to produce ozone Ozone in the troposphere – Lung irritant – Eye irritant – Been shown to cause emphysema NO x – Brown color of smog – Shown to cause numerous breathing disorders, including lung cancer

12. VOC and NO x

13. Sulfur Oxides (SO x ) Coal contains sulfur (though the higher quality coals, anthracite, have a very low sulfur content). When coal burns, this sulfur becomes a sulfur oxide (SO x ) released into the air. So x react with water in the air to become very acidic, forming acid rain Can be controlled by scrubbing, a process used to remove sulfur from emissions where coal is burned

14. Sulfur Oxides (SO x )

15. Particulates Particulates – small solid particles or liquid droplets suspended in air currents Most are natural (pollen, fog for example) Many arise from industrial and combustion processes Particulates reduce visibility, cause stains, and may play a role in climate change