Chapter 12 1

2

 Air Pollution – Harmful substances built up in the air to an unhealthy level ◦ Pollutants can be from human activity – industry soot ◦ Pollutants can be natural – volcanic ash  Primary Pollutant – put into air directly by human activity ◦ Soot from smoke and fires 3

4

 Secondary Pollutant – form when primary pollutants react with each other or natural substances ◦ Ground Level Ozone – is formed when car emissions (primary) interact with oxygen and UV rays (both natural) 5

 Is air pollution new? ◦ In 1273 King Edward I declared burning coal illegal  “Be it known that whosoever shall be found burning coal shall suffer the loss of his head”  Clean Air Act 1970 – ◦ Overseen by Environmental Protection Agency (EPA)  Regulates the emissions (what comes out the tailpipe) of automobiles  The EPA required the gradual elimination of lead in gasoline. To date lead pollution has been reduced by more than 90 % in US.  California – Zero Emission Law – Is that possible? Battery operated vehicles are the only “true” ZEVs (zero emission vehicles ) 6

 Industrial plants burn fossil fuels ◦ Burning releases – Sulfur Dioxide and Nitrous Oxide  Power Plants emit 2/3 of ALL SO 2 and 1/3 of ALL NO  VOCs (Volatile Organic Compounds) - chemical compounds that form toxic fumes ◦ Given off by – Oil refineries, Dry Cleaners, Chemical plants  Clean Air Act Requires Industries to use: ◦ Scrubber: cleans emissions of plants by washing it and filtering it ◦ Electrostatic Precipitator: uses static charges to get particulates to clump together and collect, clean gas continues on. (used in cement factories/coal burning plants) 7

8 Smog: Air pollution that hangs over urban areas and reduces visibility

 Temperature Inversion: ◦ Air circulation usually stops pollution from accumulating to dangerous levels. ◦ Inversions trap pollution near the Earth’s Surface  Temperature usually decreases with altitude  But a warm layer above a cold layer will trap pollution (Hot air rises, right? Hot smoke rises, but if atmosphere is just as warm, the smoke stays put) 9

10

 Time for a reading quiz 11

12

 Many air pollution effects are short term ◦ Can be reversed when exposure is decreased  Short term effects:  Nausea  Headaches  Eye Irritations  Coughing  Upper respiratory infections (bronchitis, pneumonia)  Will make asthma worse 13

 Many air pollution effects are long term ◦ Cannot be reversed when exposure is decreased  Long term effects:  Emphysema  Lung Cancer  Heart Disease  May damage lungs of young children 14

◦ Air inside a building is sometimes WORSE than air outside  Chemicals used in making carpets, furniture, paints can pollute indoor air ◦ Sick Building Syndrome – buildings with very poor air quality  Found in hot climates where buildings are sealed to keep out heat.  Fungi can grow and there is no release of the toxic chemicals released from carpet, paint etc.  All builds up to drastically reduce indoor air quality 15

16

 Preventing bad indoor air pollution ◦ Remove the source of the pollution  Remove carpet, new paint ◦ Good ventilation to mix the indoor air with outdoor air  Decreases the amount of pollution per unit of air  Radon Gas ◦ Colorless, odorless gas – 2 nd leading cause of lung cancer ◦ Occurs after uranium decays, found naturally in the earth, can seep into houses.  Have a radon detector in the house 17

 Asbestos ◦ A fire resistant substance used in building materials before the 1970s. ◦ When inhaled the fibers can cut and scar the lungs leading to breathing difficulties and heart failure. ◦ Billions of dollars have been spent in asbestos removal 18

19 Defined as unwanted sound Noise kills nerve cells in the ear 12% of teens have permanent hearing loss Intensity of sound is measured in decibels 120 dB is at the threshold of pain. Noise levels greater than this can cause permanent damage. Protection from noise pollution: Mufflers on autos and yard equipment MP3 players in Europe can only go up to 100 dB Ear protection

 Not a direct hazard to human health ◦ Does impact environment and enjoyment of night sky.  Bigger threat is wasted energy ◦ Upward directed light is wasted, only goes to space 20

 Time for a reading quiz 21

22

 Acid precipitation is rain with a high concentration of acids  pH measures acid concentration ◦ Low numbers are more acidic. Below 7 is acidic. The closer to zero – the more acidic. ◦ Each change in pH (1 to 2) indicates a ten times difference in acidity  Normal rain has a pH of 5.6, acid precipitation starts at

24

 Acidification – Increase of acid in soils or lakes  Acid chemically reacts with soil minerals ◦ Some nutrients are dissolved and washed away from where plants can use them ◦ Metals like aluminum are released into the soil and possibly absorbed  High enough levels of these metals can be toxic 25 How Does Acid Precipitation Affect Soils and Plants

 Aquatic animals live within a very narrow pH range ◦ Acid rain changes pH level of lake and kills fish  Acid precipitation leaches metals like aluminum from soil near lake/river ◦ Metals accumulate in fish bodies until reach toxic levels  Acid Shock In the spring when acid snow melts and flows into rivers and lakes the sharp change in pH kills massive amounts of aquatic creatures 26

 Humans depend on plants, animals, and seafood items for food ◦ If plants, animals, fish die off we lose food sources.  Toxic metals taken in by plants, animals, fish also accumulate in us and can reach toxic levels  Aesthetics – Statues and buildings are deteriorating due to acid rain 27

 Acid rain is hard to regulate because the pollution that causes it blows with the wind.  One country’s pollution could float into another country causing acid rain there.  Countries are signing Air Quality agreements with each other to help reduce polluting emissions 28

 Time for a reading quiz 29