Air Pollution History

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

You Can Run, But You Can!t Hide

What Industry Wants You to Think

Need Energy: Put Up With Pollution

A Hobbesian choice clean air or electricity without brownouts.

Lots of Health Impacts

Studies consistently show significant negative health effects from living inpolluted environments.

Lessons Not Learned

Proposition 65 NotificationProposition 65 requires most companies that handle toxic materials to provide apublic warning and information concerning their activities and pollution.

Toxic Emissions in the "hood

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.

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.

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.]

Civilization Generates Pollution

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.

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.

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.

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.

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.

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

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

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.

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.

1956: Federal Highway Act accelerates roadway construction inCalifornia. Cars are becoming king.


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.

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!


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.

2004: Finally! There were fewerthan 30 days on which thefederal ozone standard wasexceeded.


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.

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.

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:

!

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:

!

HC + O2Combustion" # " " " H2O + CO2 +UHC + CO (+NO + SO2 )

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.

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.

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

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Air Pollution History