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Environmental Issues Associated with the Atmosphere

Quality of the air Climate

Chemicals that we breathe

Toxic, potentially fatal

Harmful to lungs

Causing cancer

Chemicals harmful to non-humans

Harmful to breathing animals

Harmful to vegetation & habitats

Impacting water quality

Harmful to aquatic life

Affecting buildings & monuments

Excessive greenhouse gases

Global warming

Other climatic changes

Melting of sea ice

Melting of land ice (glaciers)

Rising sea level (added water)

Change in precipitation patterns

Change in vegetation

Rising sea level (thermal expansion)

More extreme weather

Affecting visibility

Overview of Issues in Air Quality(Nazaroff & Alvarez-Cohen, Section 7.A)

Both indoor and outdoor problems.

Chernobyl-type accidentsStratospheric ozone depletionClimate change

decadesto centuries

20,000 kmPlanetary atmosphere

Acid depositionseveral daysto a week

1000 kmRegional / continental

Ground-level ozoneCarbon monoxideParticulate matter

day-night cycle10 to 100 kmUrban airshed

Toxic organicsMercury and other metals

10 minutes1 kmIndustrial plumes

Radon in basementTobacco smokeAirplane cabin air

1 hour10 mIndoor environment

ExamplesTime scaleLength scaleSystem

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In some U.S. cities

Newark, NJ

Los Angeles, CA

It used to be worse a century ago

Sign of prosperity in Pittsburgh in 1906(Carnegie Library of Pittsburgh)

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and still 50 years later

Riders of a local message delivery company in Los Angeles being outfitted with protective gas masks in the fall of 1955.

At the 1958 Air Pollution Conference, Dr. James P. Dixon, Health Commissioner of Philadelphia said :

If gas masks are not to become as common in a hundred years as shoes are today in the civilized world, we should do well to heed our somewhat submerged instincts of self-preservation and remember that - whatever other uses man may devise for it - air is essentially for breathing.

Brief historical review in the United States:

Almost no concern until problems became highly visible.Initially also, air pollution problems were viewed as local and not a federal matter.

1955: First federal action Air Pollution Control Act (funding for research, not control!)

1970: Establishment of the U.S. Environmental Protection Agency (EPA)

1970: Clean Air Act

1973-1993: Gradual elimination of lead emission

Mid-1980s: Concern over acid rain; regulation of sulfur dioxide

1990: Clean Air Act Amendments

1990s: Concern over climate change

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(Taken from Masters, 1998)

Two-prong strategy:

1. Control emissions, with goal of reduction- Command & Control (requiring use of Best-Available ControlTechnology (BACT)- Incentives (cap-n-trade of emissions)

2. Control of ambient concentrations: Six criteria pollutants- National Ambient Air Quality Standards (NAAQS)

Distinction:

Primary pollutant: emitted directly from a source

Secondary pollutant: formed in the air by chemical reactions from precursor species

Air-Quality Management

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Framework for understanding air pollution problems(Nazaroff & Alvarez-Cohen, Figure 7.A.1, page 390, slightly modified)

Level of regulationsBACT, Cap-n-Trade

Level of regulationsNAAQS

Level of concernhealth studies, other impacts

Emissionstandards

Components of an Air-Pollution Management System

Emissionallocation

Social andpolitical

considerations

Air-qualitystandards

Costeffectiveness

Damagefunctions

Air pollutioneffects

Atmosphericchemistry

Airquality

Transport& dispersion

EmissionsSources Controlmethods

Pollutionforecasts

Social andpolitical

considerations

Episode-controltactics

CostAlternateproducts

orprocesses

Air-qualitycriteria

Social andpolitical

considerations

Start Here

RegulateHere

RegulateHere

TARGET

ACTION

MODELS

TARGET

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Blood poisoningKidney damageMental retardation

Industrial processesLead pipes, solder

PPbLead

Visibility impairmentRespiratory impairment

Industrial combustionOther industrial activities

both P and SPM10 and PM2.5Particulate Matter

Lung irritantAcid deposition

Sulfur in fuels, esp. coalPSO2Sulfur Dioxide

Coughing, Chest painLung damage

From NO and NO2mostly SO3Ozone

Respiratory irritantVisibility impairmentAcid deposition

From NO in combustionSNO2Nitrogen Dioxide

Impairs oxygen-carryingcapacity of blood

Incomplete combustionPCOCarbon Monoxide

Effect(s)Source(s)Primary /Secondary

Criteria Pollutant

The six so-called Criteria Pollutants

National Ambient Air Quality Standards (NAAQS)(Nazaroff & Alvarez-Cohen, Table F.3, page 657)

Primary & Secondary1.5 g/m3Lead (Pb)

Secondary500 ppb (1.3 mg/m3)3-hour average

Primary140 ppb (365 g/m3)24-hour average

Primary30 ppb (80 g/m3)Annual average

Sulfur dioxide (SO2)

Primary & Secondary65 g/m324-hour average

Primary & Secondary15 g/m3Annual average

Particulate Matter 2.5 m (PM-2.5)

Primary & Secondary150 g/m324-hour average

Primary & Secondary50 g/m3Annual average

Particulate Matter 10 m (PM-10)

Primary & Secondary120 ppb (235 g/m3)1-hour average

Primary & Secondary80 ppb (157 g/m3)8-hour average

Ozone (O3)

Primary & Secondary53 ppb (100 g/m3)Annual average

Nitrogen dioxide (NO2)

Primary35 ppm (40 mg/m3)1-hour average

Primary9 ppm (10 mg/m3)8-hour average

Carbon monoxide (CO)

TypeStandardPollutant

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(http://en.wikipedia.org/wiki/Image:US-overall-nonattainment-2007-06.png)

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(Taken from Masters, 1998)

Air Pollutants in the United States by source type

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Problems caused by nitrogen oxides

NO

NO2

O3Visibility HNO3

223

32

2

ONOONO :RelaxationOOO :formation Ozone

ONOsunlightNO :Excitation

+++

++120 ppb

Problems caused by sulfur dioxide

Sulfurin fuel

SO2 infumes

Respirationirritant H2SO4

Acid rain

Tree damage Acid lakes

Dead fish(http://www.robl.w1.com/Pix/I-900991.htm)

Damaged buildings &monuments

(http://ww

w.m

erritton.ca/acid55.jpg)

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Best Available Control Technology (BACT)

Most common types of end-of-pipe treatment

Particulates: CycloneElectrostatic precipitator

Stationary combustion fumes (incl. SO2): Wet scrubber

Mobile exhaust: Catalytic converter

(http://www.epa.gov/eogapti1/module6/matter/control/control.htm)(http://www.aa1car.com/library/p0420_dtc.htm)