300 likes | 543 Views
Air. Chapter 12. Section 1: What Causes Air Pollution?. Primary and Secondary Pollutants. 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
E N D
Air Chapter 12
Primary and Secondary Pollutants • 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
5 Types of Primary Pollutants and Their Sources Primary and Secondary Pollutants
Primary and Secondary Pollutants • 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)
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)
Industrial Air Pollution • Industrial plants burn fossil fuels • Burning releases – Sulfur Dioxide and Nitrous Oxide • Power Plants emit 2/3 of ALL SO2 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)
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)
That’s all for 12.1 • Time for a reading quiz
Effects of Air Pollution on Health • 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
Effects of Air Pollution on Health • 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
Indoor Air Pollution • 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
Indoor Air Pollution • 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 – 2nd 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
Indoor Air Pollution • 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
Noise Pollution • 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
Light Pollution • 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
That’s all for 12.2 • Time for a reading quiz
What Causes Acid Precipitation? • 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 precipitationstarts at 5.0
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 How Does Acid Precipitation Affect Soils and Plants
Acid Precipitation and Aquatic Ecosystems • 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 melt and flows into rivers and lakes the sharp change in pH kills massive amounts of aquatic creatures
Acid Precipitation and Humans • 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
Controlling Acid Rain • 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
That’s all for 12.3 • Time for a reading quiz