• Concept 18-2 Pollutants mix in the air to form industrial smog, primarily as a result of burning coal, and photochemical smog, caused by emissions from motor vehicles, industrial facilities, and power plants.

18-2 Continued…

What Are the Major Outdoor Air Pollutants? (1)

• _______________ _______________

• Carbon monoxide (____)…colorless, odorless, highly toxic gas that forms during incomplete combustion• Binds with hemoglobin in red blood cells…prevents

blood from ________________ oxygen to body cells

• Carbon dioxide (______)…colorless and odorless • Part of the carbon cycle• Until recently has NOT been classified as a pollutant,

but growing evidence indicates that increasing levels of CO2 are contributing to atmospheric ______________

Carbon oxides

CO

transporting

CO2

warming

What Are the Major Outdoor Air Pollutants? (2)

• _______________ _________ (NOx) and __________ ___________ (HNO3)• Nitric oxide (_____) is emitted from engines and power

plants • NO reacts with oxygen in the air to form nitrogen

dioxide _______• NO2 reacts with __________ ___________ in the air to

form nitric acid (HNO3), which is a large component of acid rain or acid ___________________

• NO and NO2 also help to form _____________ ______• N2O, __________________, is a greenhouse gas

nitrogen oxides nitricacid

NO

NO2

water vapor

deposition

photochemical smogNitrous oxide

What Are the Major Outdoor Air Pollutants? (2)

• __________ __________ (SO2) and ____________ ___________ (H2SO4)• SO2 is a colorless gas with an irritating __________• 1/3 comes from natural sources and is a part of the

___________ ___________ • 2/3 comes from…

• combustion of sulfur-containing ____________• Oil ___________________• _______________ of sulfide ores

• SO2 may also be converted to H2SO4, which returns to the earth as acid ___________________

Sufur dioxide sulfuricacid

odor

sulfur cycle

coalrefining

smelting

deposition

Statue Corroded by Acid Deposition and Other Forms of Air Pollution, RI, U.S.

Fig. 18-7, p. 471

What Are the Major Outdoor Air Pollutants? (3)

• Particulates• Suspended particulate matter (______)• Variety of solid particles and liquid droplets that are

small and ____________ enough to remain suspended in the air for ______________ periods of time

• Fine…diameter less than ______ micrometers• Ultrafine…diameter less than _______ micrometers

• 62% of outdoor SPM comes from natural sources, like _________, _____________ or ____________

SPM

lightextended

102.5

dust wildfires Sea salt

What Are the Major Outdoor Air Pollutants? (3)

• 38% comes from human sources such as….• __________ burning power plants• ________________ plants• Motor ___________________• Road ____________________

• Indoor air pollution from particulates include ________________ smoke and from ___________ wood, charcoal, dung, or coal in open fires or leaky stoves

• SPM linked to many human ______________ problems

South Asian Brown Clouds

coal

industrialvehicles

construction

cigarette burning

health

What Are the Major Outdoor Air Pollutants? (4)

• Ozone (O3)

• Stratospheric ozone is __________, but tropospheric ozone is _______.....causes photochemical ________

• Human and environmental impact

• Volatile organic compounds (_________)• Organic compounds that exist as gases in the atmosphere

or that evaporate from sources on earth• Hydrocarbons emitted by the _____________ of many

plants• _________________....greenhouse gas• Industrial solvents like _____________, dry cleaning

fluids, _____________

goodbad smog

VOCs

leaves

methanebenzene

paints

Low and Zero VOC Paint

Chemical Reactions That Form Major Outdoor Air Pollutants

Table 18-1, p. 470

Case Study: Lead Is a Highly Toxic Pollutant (1)

• Lead (___) is a pollutant found in air, water, soil, plants, animals

• Because it is chemical _______________, it does not break down in the environment

• Considered a __________________...harms the nervous system• Children most vulnerable • Can cause death, mental retardation, paralysis

Pb

element

neurotoxin

Case Study: Lead Is a Highly Toxic Pollutant (2)

• Between 1976 and 2006, blood lead levels above the safety limit in U.S. children dropped from 85% down to ______• Government regulations banned __________ gasoline• ______________ paint

• Still problems• Old homes may still have lead paint or ________ with

lead parts• 15-18 million children have brain damage• Need ____________ ban on lead in gasoline and paint

1%leaded

unleaded

pipes

global

Fig. 18-8, p. 472

Solutions

Lead Poisoning

Prevention Control

Phase out leaded gasoline worldwide

Replace lead pipes and plumbing fixtures containing lead solder

Phase out waste incineration

Remove leaded paint and lead dust from older houses and apartments

Ban use of lead solder Sharply reduce lead emissions

from incineratorsBan use of lead in computer and TV monitors

Remove lead from TV sets and computer monitors before incineration or land disposal

Ban lead glazing for ceramicware used to serve food

Test for lead in existing ceramicware used to serve food

Ban candles with lead cores Test existing candles for lead

Test blood for lead by age 1

Wash fresh fruits and vegetables

Science Focus: Detecting Air Pollutants• Chemical _________________ and ______________

– small aircrafts measured the concentrations of the South Asian Brown Clouds

• _______________ and remote sensors

– Used by some European countries

• ___________________ indicators

– Lichens

• symbiotic relationship between a fungus and alga living together…________________ species that continually _________________ air

• May change _______________ or sicken and ________

instruments satellites

Lasers

Biological

pioneerabsorbcolor

die

Natural Capital: Lichen Species, Vulnerability to Air Pollutants

Fig. 18-A, p. 473

Old Man’s Beard Red and Yellow Crustose

Burning ______ Produces Industrial Smog• Industrial smog

– Unhealthy mix of __________________, suspended drops of ______________ acid, and a variety of suspended _____________ particles (Gray Air Smog)

• The U.S. has greatly _______________ the amounts of industrial smog produced in the past 60 years

• Still a major problem in industrialized urban areas of ___________, ________________, and some ____________ European countries – Annual death toll from air pollution in China is about

________________

Coal

Sulfur dioxidesulfuric

solid

reduced

China Indiaeastern

750,000

Burning coal and oil

Oxygen (O2)

Stepped Art

Ammonium sulfate [(NH4)2SO4]

Ammonia (NH3)

Sulfuric acid (H2SO4)

Water vapor (H2O)

Sulfur trioxide (SO 3 )

Oxygen (O2)

Sulfur dioxide (SO2)

Sulfur (S) in coal and oil

Carbon monoxide (CO) and

carbon dioxide (CO2)

Carbon (C) in coal and oil

Fig. 18-9, p. 474

Industrial Smog in India

Fig. 18-10, p. 474

____________ Plus ________ Equals Photochemical Smog

• Photochemical Smog– Mixture of primary and secondary pollutants formed under the

influence of _______ radiation (Brown Air Smog)

• VOCs + NOx + Heat + Sunlight

• Oxidizes chemicals in the ___________________ and inside our ______________

ground level O3

+ other photochemical oxidants

+ Aldehydes

+ Other secondary pollutants

Sunlight Cars

UV

atmospherelungs

Global Outlook: Photochemical Smog in Santiago, Chile

Fig. 18-12, p. 475

More of a problem in cities with sunny, warm, and dry climates

Several Factors Can Decrease or Increase Outdoor Air Pollution (1)

• Outdoor air pollution may be decreased by1. __________________ of particles due to

gravity2. ______________ and snow partially cleanse

the air3. Salty sea _____________ cleans air over the

ocean4. ___________________5. Chemical reactions…may just turn into

something else bad like acid rain

Settling

Rain

spray

Wind

Several Factors Can Decrease or Increase Outdoor Air Pollution (2)

• Outdoor air pollution may be increased by

1. Urban buildings

2. Hills and mountains

3. _____________ temperatures

4. Emissions of VOCs from certain trees and plants..._________________ areas

5. ____________________ effect…occurs when air pollutants are transported at _________ altitudes from tropical and temperate areas to the _________

6. Temperature ____________________...a layer of warm air ______________ cool air prevents mixing

(block wind)

High

urban woodedGrasshopper

highpoles

Inversionon top of

A Temperature Inversion

Fig. 18-13, p. 476

The sun normally heats surfaceair causing it to ________

Sometimes a layer of warmair will lie atop a layer coolerair that is ____________than theair above it

Causes ____________ air where pollution accumulates

rise

denser

stagnant

• Two types of areas are susceptible to temperature inversions– Type 1: City located in a valley where the weather

may turn __________....blocks sun from heating surface air

Donora, Pennsylvania• 1948 Killer Fog• 6,000 became ill and 20 died

cloudy

– Type 2: _________________ city blocked by mountains on 3 sides…blocks ocean winds from dispersing pollution

Los Angeles

Coastal

Review Questions!

• Distinguish between primary and secondary pollutants.

• What are the six major categories of outdoor air pollutants?

Primary – emitted directly into atmosphere

Secondary – result from reactions

Carbon oxides

Nitrogen oxides and nitric acid

Sulfur dioxide and sulfuric acid

particulatesozone

VOCs

Review Questions!

• Distinguish between industrial and photochemical smog.

• What happens during a temperature inversion?

Coal burning(Gray)

Sunlight + Cars(Brown)

A layer of warm air lies on top of denser cool air thatbecomes stagnant