Ch. 12 Air Pollution

8/2/2019 Ch. 12 Air Pollution

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Air and Noise Pollution

Ch. 12


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Food forthought

I thought I saw a blue jaythis morning. But the

smog was so bad, it turnedout to be a cardinal holdingits breath.

Michael J. Cohen

Humor is often used to getpeoples attention. With

your neighbor, use humor

to complete the followingsentence to draw attentionthe air pollution problem.

You know the air ispolluted when.


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What is in air?

Mixture of gases

78% nitrogen

21% oxygen 1% argon, carbon dioxide,

water vapor

Pollutants harmfulmaterials that enter theenvironment picked up byair currents


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Air pollution

Air pollution collection of harmfulsubstances released into the atmosphere

Some from natural sources (sand, duststorms, volcanic eruptions, forest fires)

Human activity = major source of pollutantsthat continues to grow


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History of air pollution

Industrial revolution 1700s dependent onburning of wood and coal for fuel

Elevated air pollution to a widespread status Illness and death due to air pollution sky

rocketed


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Primary and secondary

Primary pollutants putdirectly into the air byhumans, i.e. smoke

Secondary pollutants

primary pollutants reactwith other substances inthe air, i.e ground-levelozone


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Outdoor pollutants

Particulates tiny solids suspended in the air ash, dust, soot, plant pollen

Can be inhaled and become trapped in the lungs

Gases usually oxides compounds ofoxygen and another element

Released when fossil fuels are burned


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Photochemical smog yellow brown hazeformed when sunlight reacts with pollutantsfrom cars

I. e. Ozone (O3) very corrosive, nitrogen dioxidebrown gas, methane from livestock and decayingmatter

Chlorofluorocarbons(CFCs) compoundsof chlorine, fluorine, and carbon once used inrefrigerators, acs, aerosol cans, and theproduction of foams


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Indoor Pollutants

Indoor Pollutant effects are multipliedby poor air circulation and the longamounts of time people spend inside

Cigarette smoke deadliest of all IP

Microorganisms bacteria and fungifrom air ducts and vents

Radon colorless, odorless, radioactivegas comes from soil when radium

breaks down Asbestos minerals that form in long

thin fibers banned in US
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Air pollution and living things

Pollution linked to many healthproblems and can worsen existingmedical conditions

Carbon monoxide binds tohemoglobin in oxygens place

Ozone and oxides irritate eyesand respiratory tract

Emphysema disease in which tinyair sacs in the lungs break down

Lung Cancer 150,000 deaths /year in US


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How does air pollution effect anecosystem?

Ozone and sulfur oxides hazardous to plants, causestems to be brittle and leaves spotted

US loses $10 million of crops / year due to AP Loss of plants disrupts the food web and deprive

animals of food

Same health problems for animals as for humans(cancer, lung irritation, etc.)

Temperature Inversions usually warm air rises andtakes pollutants up into atmosphere Sometimes the air near the ground is colder than the air

above Pollutants become trapped near the surface of theground

i.e. Los Angeles cities in vallies


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Global effects of air pollution

Acid rain

precipitation that is moreacidic than normal

Normal precip = 5.6 pH

Water in the atmosphere reacts withsulfur and nitrous oxide to form nitricacid and sulfuric acid

Strong and corrosive

Falls on forests and accumulates inmtn. lakes making them uninhabitable

by fish Absence of aquatic life disrupts

ecosystems

Damages trees and destroys forests


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Controlling Air Pollution

Natural controls precipitation is most

effective particles in air stick to precip and fall to the

ground

many aerosols dissolve in rain CO2 removed biologically by plants and

microorganisms, also removed by ocean waters(cooler temps hold more)


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Human controls Emission control standards for automobiles

catalytic converters remove pollutants fromexhaust

Use unleaded gas, cars get better gas mileagethan in past (reduce lead pollution by 90%)

Will always put out some pollution when gas isburned

Electric cars, hybrid cars Zero Emissions Vehicles no tailpipe emissions

Legistlation (EPA) Clean Air Act 1970 Require pollution control devices in factories

Regulates vehicle emissions

Power plants Burn fossil fuels to produceelectricity use techniques to remove pollutants from exhaust Scrubbers machine that moves gases through a

spray of water that removes many pollutants

Electrostatic precipitators remove dust particlesfrom smoke stacks


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Noise Pollution

Comes from airplanes,machinery, loud concerts, etc. Causes annoyance, stress,

hearing loss

Living things harmed by loud orhigh-pitched sounds Sound measured in decibels

70-80 dB = annoyance, hearingloss

120 130 dB = physical pain andhearing damage

Noise Control Act 1972 setsstandards for maximum noise

levels in workplace


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Ch. 12 Air Pollution

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