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Air Pollution HistoryAir Pollution History
Air Pollution in the newsAir Pollution in the news
The historical origins of bad airThe historical origins of bad
air
ModernModern air pollution: Industrial smogair pollution:
Industrial smog
Los Angeles: Bad to worse to betterLos Angeles: Bad to worse to
better
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You Can Run, But You Can!t Hide
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What Industry Wants You to Think
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Need Energy: Put Up With Pollution
A Hobbesian choice clean air or electricity without
brownouts.
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Lots of Health Impacts
Studies consistently show significant negative health effects
from living inpolluted environments.
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Lessons Not Learned
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Proposition 65 NotificationProposition 65 requires most
companies that handle toxic materials to provide apublic warning
and information concerning their activities and pollution.
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Toxic Emissions in the "hood
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Ooops: UCLA Comes Clean
The UCLA campus has come clean, and now it is trying to get
green. The UCLAInstitute of the Environment is a focal point for
these efforts.
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The Dawn of Human TechnologyThe Dawn of Human Technology
The story of pollution begins with the developmentof human
technology. The first controlled fires builtin caves or huts would
have created a chokingatmosphere. Later, the invention and growth
ofsettlements would concentrate such pollution insmall, confined
areas. The increasing consumptionof energy resources would
accelerate andexacerbate the effects of air pollution.
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Some Historical Comments
James Branch Cabell, 1926: The optimist proclaims that we live
in the best of allpossible worlds; and the pessimist fears this is
true.
Moses Maimondies, c. 1200: In the city, becauseof all that pours
forth from itsinhabitants and their superfluitiesthe air becomes
stagnant, turbid, thick, misty,foggy.
Percy Bysshe Shelley, 1819: Hell is a city much like London a
populous andsmoky city. From Peter Bell the Third, 1819.
William Henry Davies, c.1900 : What glorious sunsets have their
birth in citiesfouled by smoke! This tree whose roots are in a
drain becomes the greatestoak! From Loves Rivals.
Buckminster Fuller, c. 1950: Pollution is nothing but resources
were notharvesting.
John Evelyn 1661: the constant and unremitting poison is
communicated bythe foul air, which, as the town still grows larger,
has made regular and steadyadvances in its fatal influence. From
The Inconvenience of the Air and Smoke ofLondon Dissipated.
King Edward I, circa 1300: Be it known to all within the sound
of my voice whosoever shall be found guilty of burning coal shall
suffer the loss of his head.[In response to the complaints of Queen
Eleanor about the noxious smoke.]
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Civilization Generates Pollution
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The Fate of a Polluted World?Forecasts of pollution since
historical times to the present and into the future haveusually
predicted a worsening situation that eventually crashes. However,
we havenot yet hit the wall, and that leaves some people confident
we will avoid a disaster.
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Early Signs of Modern TroubleIn the 1800s, thousands of deaths
are attributed to heavy airpollution in London air pollution
events. Dr. Harold Des Voeux, atthe beginning of the twentieth
century, coins the word smog fromthe combination of smoke and fog,
which are responsible forthese episodes.
In the first half of the twentieth century,similar smog events
occur throughoutthe industrialized nations, including theU.S, and
European countries.Thousands die.
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London, 1952
Early Smog Episodes: London 1952Early smog events involved fog
tainted by smoke and sulfur dioxide inducedsulfuric acid. This is
the origin of the term, smog = smoke + fog.
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London Smog
London smog is characterized by the combination of highly
acidicwater (fog) droplets and fine particles.
This smog is primarily the result of high emissions of sulfur
dioxideand soot associated with the burning of coal.
The high acidity is caused by theoxidation of SO2 in water
droplets toform sulfuric acid (H2SO4).
An important factor in London smog isthe weather; typically
cool, stagnant,foggy conditions contribute to Londonsmog
formation.
The solution to London smog is relatively simple; stop burning
coalfor heating and cooking in home furnaces use cleaner natural
gas,or electricity generated outside of the city.
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Photochemical (Los Angeles) Smog
Photochemical smog is characterized by the presence of
noxiousoxidants such as ozone and nitrogen dioxide in high
concentrations.
This smog is primarily the result of emissions of primary
pollutantssuch as nitrogen oxides (NOX) and reactive hydrocarbons
frominternal combustion engines.
The secondary pollutants such as ozone and a variety of
toxicorganic compounds is the result of photochemical reactions
that aredriven by sunlight and heat.
An important factor in photochemical smog is the weather;
typicallywarm, clear conditions under stationary high pressure
contribute tophotochemical smog formation.
The solution to photochemical smog is relatively simple; limit
theamount of gasoline consumed in vehicles, and control the
emissionsof hydrocarbons and NOX from all sources.
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Comparison of Smogs
Low visibility,
respiratory stress,
eye irritation
Low visibility,
breathing difficultyEffects
Afternoon hoursMorning hoursPeak pollution
period
Subsidence or
marineMarine or radiationInversion type
Warm, sunny, clearCool, stagnant,
foggy
Weather
conditions
Ozone, organic
toxinsSulfuric acid
Secondary
pollutants
Nitrogen oxides,
reactive organicsSulfur dioxide, sootPrimary pollutants
LA SmogLondon Smog
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Air Pollution Awareness: U.S.1 9 4 8 Air pollution inversion in
Donora, Pennsylvania, kills 20 people
1 9 6 3 Air pollution episode in New York leads to 405
deaths
1 9 6 7 Air Quality Control Act passed by Congress, setting
timetables for establishing air
quality standard s
1 9 7 0 Congress passes the Clean Air Act: the new Environmental
Protection Agency is
allowed to set national air quality standards. States are
allowed to establish stricter
standards (e.g., Californ i a )
1 9 7 5 Catalytic converter developed and used on auto emissions
systems, cutting
hydrocarbon and carbon monoxide emissions by 96 percent and
nitrogen oxides by
75 percent .
1 9 7 7 Revised Clean Air Act Amendments passed by Congress
extend time for compliance
with standard s .
1 9 8 8 EPA establishes Indoor Air Division to address indoor
air quality issues.
1 9 8 8 Congress approves Indoor Radon Abatement Act to address
indoor radon problems
1 9 9 0 National ban on smoking aboard domestic flights
enacted
1 9 9 0 Further revisions to Clean Air Act Amendments further
delays compliance
1 9 9 1 American Lung Association sues EPA to force review of
ozone air quality standard,
and wins
1 9 9 3 EPA classifies secondhand smoke as a group A
carcinogen
1 9 9 7 EPA strengthens the standard for particulate matter air
pollution
2 0 0 0 EPA passes new rule for diesel fuel, capping sulfur
levels by 2 0 0 7
2 0 0 2 Landmark legislation (AB 1493) passed in California
requiring automakers to
reduce greenhouse gases from motor vehicle s
2 0 0 2 California adopts more stringent particulate matter
standards for PM10 and PM2 . 5
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History of Los Angeles Smog
Los Angeles, 1943: Much of the early pollution in Los Angeles
isdue to smoke from fires. People are allowed to burn rubbish
inbackyard incinerators. The automobile is becoming
increasinglypopular in the sprawling city, and everybody wants one.
Theexhaust is now contributing to the degradation of air
quality.
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1943: First recognized smog episode in LA isreferred to as the
gas-attack. Visibility isreduced to about 3 blocks, people suffer
fromdiscomfort, nausea, and vomiting.
History of Los Angeles Smog (cont.)
1945: LA initiates its first air pollution controlprogram.
However, by 1950, clean efficientpublic electric transit systems
are being replacedwith smoke belching buses.
1952: Dr. Arie Haagen-Smit, a Cal Tech chemist, discovers
thenature of photochemical smog while studying the degradation
ofrubber exposed to Los Angeles air. He finds high concentrationsof
the strong oxidant, ozone, in Los Angeles. Laboratory studiesreveal
the photochemical smog formation process involvinghydrocarbons and
nitrogen oxides.
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1956: Federal Highway Act accelerates roadway construction
inCalifornia. Cars are becoming king.
History of Los Angeles Smog (cont.)
1963: First Federal Clean Air Actdefines air quality
standards.
1965: The first reliable ozonemeasurements are started in LA.
Themaximum recorded 1-hour-averageozone concentration is an
extremelyhazardous 580 ppbv!
1966: Auto tailpipe emission standardsare adopted for CO and
reactivehydrocarbons in California. The statetakes leadership in
setting air qualitycontrol standards.
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1975: Catalytic converters for NOx and carbon monoxide come
intowide use; in that year, LA exceeded the Stage-1 smog alert
level(that is, O3 above 200 ppbv) on 118 days!
History of Los Angeles Smog (cont.)
1970: The US EnvironmentalProtection Agency (EPA) is funded
byCongress as the national policy-makerand environmental
watchdog.
1971: Air quality standards are definedfor the first time; the
O3 standard is setat 120 ppbv for 1 hour, whereas LAhas experienced
580 ppbv of ozone!
1968: The California Air Resources Board (CARB) is launched,with
the statewide mandate to reduce air pollution.
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2004: Finally! There were fewerthan 30 days on which thefederal
ozone standard wasexceeded.
History of Los Angeles Smog (cont.)
1985: The maximum ozone in LA reaches a dangerous level of
390ppbv, and LA exceeds the Stage 1 alert threshold of 118 days
thatyear.
1995: The ozone maximum inLA is still 260 ppbv, and LA has14
Stage 1 smog alerts.
1984: California Smog Check program is introduced. All
vehiclesare periodically checked for emission levels as part of
registration;the program is fine-tuned in later years.
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Source: AQMD
Ozone 1-Hour Concentrations: 1976-2004The number of days each
year since 1976 on which ozone exceededthe state standard show weve
come a long way since the old days.
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What Is It About Cars?Why are cars the culprit in Los Angeles
air pollution? Obviously,there are millions of vehicles in LA, and
there has been a tendencytoward larger, gas guzzling SUVs. Still,
why is it that cars pollute?We already know that the temperatures
in internal combustionengines are high enough to generate nitrogen
oxides from thenitrogen and oxygen in air. Catalytic converters are
used to reducethis inevitable NOX emission. But engines also emit
unburned orpartially burned hydrocarbons (UHC), which constitute a
majorsource of that other key ingredient of photochemical smog.
If automobile engines burned fuel perfectly referred to
asstoichiometric combustion, in which every fuel molecule
reactedwith just enough oxygen to produce only water and carbon
dioxide we would have much cleaner air. The stoichiometric process
is:
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HC + O2Combustion" # " " " H2O + CO2 (+NO + SO2 )
The sulfur dioxide is due to the sulfur residue in most fossil
fuels.Unfortunately, the real burning of fuel is not
stoichiometric:
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HC + O2Combustion" # " " " H2O + CO2 +UHC + CO (+NO + SO2 )
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Experiment on CombustionThis demonstration should not to be
attempted at home!!!
The distribution of aflame can be controlledusing a porous
metalmesh.
The principal at work isheat conduction, whichcontrols the
removal ofheat from the flame byconduction through themetal mesh to
bedissipated in theatmosphere.
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Combustion in an Engine
In an engine block,which is manufacturedout of heavy metal,
theheat generated by thefuel detonation in thecylinder is absorbed
bythe metal in the housingas the flame frontapproaches the
cylinderwall. This quenches thecombustion reactions,which require
hightemperatures, leavingsome of thehydrocarbon fuelunburned near
the wall,and ready to be forcedout the tailpipe.
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The story of air pollution is a long one, extending back to the
firstintroduction into ordinary life of technology by humans.
Increasingpopulation, and the tendency for societies to congregate
in cities, hasaccelerated and intensified the levels and impacts of
air pollution inmodern times. Smog comes in two forms: London-type
air pollution,which is dominated by smoke from combustion
especially coal and involves chemical processing in fog droplets;
and Los Angeles-type photochemical smog, which is dominated by the
nitrogen oxidesand reactive hydrocarbons as well as soot associated
with cars andtrucks. The London-type smog is no longer an issue in
developedcountries, which have developed cleaner energy sources
over the last50 years. However, in developing nations, this kind of
basic industrialair pollution still persists, as the energy source
that produces it isrelatively cheap and simple. Photochemical smog
has been a greaterchallenge to control. In Southern California, it
has taken a long andconcerted effort of federal, state and local
agencies to design andimplement the regulations that have, until
recently, steadily improvedthe quality of the air we breathe in Los
Angeles..
Concluding RemarksConcluding Remarks