Air Pollution

Miller & Spoolman Chapter 18

Core Case Study: South

Asia’s Massive Brown Cloud Asian Brown Cloud

Causes: burning of forests for crops, drought, burning

coal, diesel, and other fossil fuels

Chemical composition: Hg, Pb, Carbon compounds

Areas impacted: India and China the worst

Air pollution connects the world!

~2 weeks for long-live pollutants to circle the globe

Steps taken in China and India to reduce air

pollution

The Asian Brown Cloud

Air Pollution in Shanghai, China, in 2004

18-1 What Is the Nature of

the Atmosphere?

Concept 18-1 The atmosphere is structured in layers, including the

troposphere = supports life, and the stratosphere = contains the

protective ozone layer.

Natural Capital:

The Earth’s

Atmosphere Is a

Dynamic System

with Four Layers

18-2 What Are the Major

Outdoor Pollution Problems?

Concept 18-2 Pollutants mix in the air

to form industrial smog, mostly the

result of burning coal, and

photochemical smog, caused by

motor vehicle, industrial, and

power plant emissions.

Air Pollution Comes from

Natural and Human Sources

Air pollution

Presence of chemicals in air that cause harm

Natural sources

Dust blown by wind

Pollutants from wildfires and volcanoes

Volatile organics released by plants

Air Pollution Comes from

Natural and Human Sources

Human sources - mostly in

industrialized and/or urban areas

Stationary sources: power and

industrial plants

Mobile sources: motor vehicles

Case Study: Air Pollution in

the Past: The Bad Old Days

Discovery of fire (poorly ventilated caves)

Middle Ages (wood smoke in urbanizing areas)

Industrial Revolution (burning coal)

London, England

1850s: term “smog”

1952: yellow fog

Clean Air Act of 1956

Case Study: Air Pollution in

the Past: The Bad Old Days United States

1948: Donora, PA; first U.S. air pollution

disaster

• Mixture of coal, steel mills, zinc smelter, and

sulfuric acid plants

1963: New York City

• 300 died

Global problem

It takes about 2 weeks for long-lived air

pollutants to circle the world

Some Pollutants in the Atmosphere

Combine to Form Other Pollutants

Primary pollutants

Harmful chemicals emitted directly into the air

Secondary pollutants

New chemicals formed from reaction of air with

primary pollutants

Air quality improving in developed countries

More needs to be done in developing countries

Indoor pollution: big threat to the poor

***Important***

Sources and Types of Air Pollutants

Indoor Air Pollution

What Are the Major Outdoor

Air Pollutants? Carbon oxides

Carbon monoxide (CO)

• Reduces ability of blood to transport oxygen

(hemoglobin)

• Trigger heart attacks, aggravate lung diseases

Carbon dioxide (CO2)

• 93% natural and 7% human activities

• Climate change contributor (“accelerator”)

Sources: CO -car exhaust, burning forests/grasslands

CO2 – burning fossil fuels, clearing forests

What Are the Major Outdoor

Air Pollutants? Nitrogen oxides (NO) and nitric acid (HNO3)

Sources: engines, coal plants

Acid deposition

Photochemical smog

Irritate eyes/nose/throat, aggravate lung ailments –

Suppress plant growth when in acid form

Sulfur dioxide (SO2) and sulfuric acid

(H2SO4)

Sources: Sulfur-coal, oil refining and smelting, sulfur

cycle

Acid deposition, feeds Asian brown cloud

What Are the Major Outdoor

Air Pollutants?

Particulates

Suspended particulate matter (SPM)

• Fine (PM-10) Ultrafine (PM-2.5)

Sources: 62% natural 38% human activities

Damage lungs, aggravate asthma/bronchitis

Toxic particulates: cancer, reproductive

problems

What Are the Major Outdoor

Air Pollutants? Ozone (O3)

Troposphere ozone = Bad

Stratosphere ozone = Good

Volatile organic compounds (VOCs)

Hydrocarbons and terpenes

Benzene: long-exposure causes leukemia,

blood disorders

Statue Corroded

by Acid

Deposition and

Other Forms of Air

Pollution, RI, U.S.

Science Focus: Detecting

Air Pollutants

Chemical instruments

Satellites

Nanotechnology

Biological indicators

Lichens

Lidar ceilometer: Using scattered

laser lights to detect particles in

atmosphere

Natural Capital: Lichen Species,

Vulnerability to Air Pollutants

Case Study: Lead (Pb) is a

Highly Toxic Pollutant

Does not break down in the environment

Sources: paint, long lasting lipstick, leach

from water pipes and faucets

Human health and environmental impact

Harm nervous system

Decrease mental functions (esp verbal and

visual in older people)

Case Study: Lead Is a

Highly Toxic Pollutant

Reduction of lead (Pb)

Unleaded gasoline

Unleaded paint

Still problems

2007: toys made in China with Pb paint recalled

Global ban on lead in gasoline and paint (began in

1976 total phase out by 1986)

Burning Coal Produces

Industrial Smog

Chemical composition of industrial smog

Mostly sulfur dioxide

Also carbon monoxide and dioxide

Reduction of this smog in urban cities of the

United States

Use of scrubbers on coal boilers

China and smog

Human deaths: ~750,000/year according to World Bank

62% China’s cities with industrial smog

How Pollutants

Are Formed from

Burning Coal and

Oil, Leading to

Industrial Smog

Sunlight Plus Cars Equals

Photochemical Smog Photochemical Smog

Primary/Secondary pollutants + UV radiation

Sources: mainly motor vehicles, also trees, business

like dry cleaners

VOCs + NO2 + Heat + Sunlight yields

Ground level O3 and other photochemical oxidants

Aldehydes

Other secondary pollutants

Human health and environmental impact

Irritates eyes and respiratory tracts

A Model of How

Pollutants That

Make Up

Photochemicals

Are Formed

Global Outlook:

Photochemical

Smog in

Santiago, Chile

Several Factors Can Decrease or

Increase Outdoor Air Pollution Outdoor air pollution may be

decreased by…

Settling of particles due to gravity

Rain and snow

Salty sea spray from the ocean

Winds

Chemical reactions

Several Factors Can Decrease or

Increase Outdoor Air Pollution

Outdoor air pollution may be

increased by…

Urban buildings

Hills and mountains

High temperatures

Emissions of VOCs from certain trees

and plants

Grasshopper effect

Temperature inversions

A Temperature Inversion

18-3 What Is Acid Deposition

and Why Is It a Problem?

Concept 18-3 Acid deposition is caused

mainly by coal-burning power plant and motor vehicle emissions, and

in some regions, threatens human health,

aquatic life and ecosystems, forests, and

human-built structures.

Acid Disposition Is a Serious

Regional Air Pollution Problem

Acid deposition (acid rain)

Formation: Sulfur dioxide and nitrogen oxides combine with elements in the air making the acids

Local versus regional problems: tall smokestacks reduce local but increase regional air

pollution

Effects of prevailing winds: transport

Buffers: basic compounds neutralizing the acids

Where is the worst acid deposition?

Natural Capital Degradation:

Acid Deposition, Acid Rain

Current and Possible Future

Acid Rain Problem Areas

Acid Deposition Has a

Number of Harmful Effects

Human respiratory disorders

Aquatic ecosystems affected

Fish can’t survive in a pH less than 4.5

Asphyxiation occurs from excess aluminum ions

Release of toxic metals

Hg and Pb release from soils and rocks

Bioaccumulation in fish of toxic metals

Acid Deposition Has a

Number of Harmful Effects

Leaching of soil nutrients

Can hinder tree/plant growth

Loss of crops and trees

Soil pH drops below 5.1 reduces plant

productivity

30% of China’s crops have excess acid

Damage to buildings, statues, and

monuments

Natural Capital Degradation: Air Pollution

Damage to Trees in North Carolina, U.S.

Science Focus: Revisiting Hubbard

Brook to Study Effects of Acid Rain

White Mountains, NH, U.S.

Damaged trees were not recovering after CAA

Experimentation supports:

Trees do not suffer from direct contact with

acid rain

Nutrients are leached out of the soil

Effect of Ca2+ on regrowth of the forest

18-4 What Are the Major Indoor

Air Pollution Problems? Concept 18-4 The most threatening

indoor air pollutants are smoke and

soot from wood and coal cooking

fires (a hazard found mostly in

developing countries) and chemicals

used in building materials and products.

Indoor Air Pollution Is a

Serious Problem Developing countries

Indoor burning

Poor suffer the greatest risk

Developed countries

Indoor air pollution is greater

than outdoor air pollution

Indoor Air Pollution Is a

Serious Problem Why?

11 of the common air pollutants higher

inside than outside

Greater in vehicles than outside

Health risks magnified: people spend

70–98% of their time is indoors

Black mold and Rat

feces in an attic

Indoor Air Pollution Is a

Serious Problem

Who are at greatest risk from indoor air

pollution?

Children under 5 and the elderly

Sick

Pregnant women

People with respiratory disorders or heart

problems

Smokers

Factory workers

Indoor Air Pollution Is a

Serious Problem Four most dangerous indoor air pollutants:

Tobacco smoke

Formaldehyde (big problem in developed countries)

– If exposed 34% chance of getting Lou Gehrig’s (ALS)

Radioactive radon-222 gas

Very small particles

Indoor Air Pollution Is a

Serious Problem

Other possible indoor air pollutants

Pesticide residue

Pb particles

Living organisms and their excrements

• E.g., Dust mites and cockroach droppings

Airborne spores of molds and mildews

Sick-building syndrome

Science: Magnified View of a

Household Dust Mite in a Dust Ball

Science:

Sources and

Paths of Entry

for Indoor

Radon-222

Gas

18-5 What Are the Health

Effects of Air Pollution?

Concept 18-5 Air pollution can

contribute to asthma, chronic

bronchitis, emphysema, lung cancer,

heart attack, and stroke.

Your Body’s Natural Defenses against Air

Pollution Can Be Overwhelmed

Respiratory system protection from air

pollutants

Role of cilia, mucus, sneezing, and coughing

Effect of smoking and prolonged air

pollution exposure

Asthma: 6% of US population

Chronic bronchitis

Emphysema: damage to alveoli, loss of lung

elasticity, acute shortness of breath

Major Components of the

Human Respiratory System

Normal Human Lungs and the

Lungs of a Person Who Died of

Emphysema

Air Pollution Is a Big Killer

3 Million deaths per year world-wide

Mostly in Asia

Main causes: 73% from indoor air pollution

EPA: proposed stricter emission standards for

diesel-powered vehicles

Link between international trade and air

pollution

Cargo ships and pollution

Premature Deaths from Air

Pollution in the U.S.

18-6 How Should We Deal

with Air Pollution?

Concept 18-6 Legal, economic, and

technological tools can help to clean

up air pollution, but much greater

emphasis should be focused on

preventing air pollution.

Laws and Regulations Can

Reduce Outdoor Air Pollution

United States

Clean Air Acts: 1970, 1977, and 1990

EPA

National ambient air quality standards (NAAQs) for 6 outdoor criteria pollutants: CO, NOx, SO2, PM, O3, Pb

National emission standards for 188 hazardous air pollutants (HAPs)

• Toxic Release Inventory (TRI): 1st report 1988

Laws and Regulations Can

Reduce Outdoor Air Pollution

Good news in U.S.

Decrease in emissions

49% between 1980-2006

Use of low-sulfur diesel fuel

• Cuts pollution

• Also addition of $0.05/gallon of diesel gas

Developing countries

More air pollution

Case Study: U.S. Air

Pollution Can Be Improved

Rely on cleanup more than prevention of pollution

Raise fuel-efficiency for cars, SUVs, and light trucks

Better regulation of emissions of motorcycles and two-cycle gasoline engines

Regulate air pollution for oceangoing ships in American ports

Case Study: U.S. Air

Pollution Can Be Improved

Why are airports exempt from many

regulations?

Regulate greenhouse gas emissions

Ultrafine particles are not regulated

Urban O3 levels too high

Case Study: U.S. Air

Pollution Can Be Improved

What about indoor air pollution?

Better enforcement of the Clean Air

Acts

Is intense pressure needed from

citizens to make improvements?

We Can Use the Marketplace to

Reduce Outdoor Air Pollution

Emission trading or cap-and-trade

program

Mixed reactions to program

SO2 emissions down significantly

NO2 will be tried in the future

There Are Many Ways to

Reduce Outdoor Air Pollution

1980 –2006

SO2 emissions from U.S. electric power

plants decreased by 66%

NOx emissions by 41%

Particulate emissions by 28%

Older plants not governed by the same

regulations

New cars have better emissions

Reducing Indoor Air Pollution

Should Be a Priority

Greater threat to human health than

outdoor pollution

What can be done?

Prevention

Cleanup

What Can You Do? Indoor Pollution:

Ways to Reduce Your Exposure

We Need to Put More Emphasis

on Pollution Prevention

Output approaches

New shift to preventing outdoor and

indoor pollution

Pressure from citizens