Air

Chapter 12

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Section 1: What Causes Air Pollution?

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

3Primary and Secondary Pollutants

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5 Types of Primary Pollutants and Their Sources

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)

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Primary and Secondary Pollutants

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)

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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)

7Industrial Air Pollution

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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)

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Time for a reading quiz

That’s all for 12.1

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Section 2: Air, Noise, and Light Pollution

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

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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

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Effects of Air Pollution on Health

◦ 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

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Indoor Air Pollution

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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

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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

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Indoor Air Pollution

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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

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

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Light Pollution

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Time for a reading quiz

That’s all for 12.2

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Section 3: 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 precipitation starts at 5.0

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What Causes Acid Precipitation?

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What Causes Acid Precipitation

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

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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

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Acid Precipitation and Aquatic Ecosystems

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

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Acid Precipitation and Humans

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

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Controlling Acid Rain

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Time for a reading quiz

That’s all for 12.3