powerpoint ® lecture prepared by gary a. beluzo air pollution costs and benefits of clean air 19

PowerPoint® Lecture prepared by Gary A. Beluzo

AIR POLLUTION Costs and Benefits of Clean Air

19

Copyright © 2007 McGraw-Hill Publishing Company

STUDENT LEARNING OUTCOMES

• Describe the factors that determine the atmospheric concentration of air pollutants.

• Compare and contrast the advantages and disadvantages of reducing air pollution via command and control versus market based mechanisms.

• Explain why zero emissions may not be economically efficient and may not be necessary to protect sensitive groups from its effects.

• Explain the benefits and costs of reducing air pollution and describe their relative size.

After reading this chapter, students will be able to


A Trip to Guangzhou, China

• Trip to validate results of satellite image analysis

• How quickly is agricultural land being converted to urban uses?

• Increase of 300% in 9 years

• Guangzhou is so polluted that it blocks out the sun

• People wear surgical masks outdoors

• While in the city the author did not see the sun


Urban Air Pollution

• Air pollutant

• Primary Pollutants

• Secondary Pollutants


Carbon Monoxide• Colorless, odorless

• Incomplete combustion

• Mobile sources

• Stationary sources

• Binds strongly with hemoglobin

• Headaches, dizziness, and death

• 35 ppb per hour

• May also contribute to global climate change


Particulate Matter• Mixture of solid particles and

liquid droplets

• Aerosol• Dust

• Fumes

• Mist

• Smoke or soot

• PM 10

• PM 2.5


Size of Particulates


Effects of Particulates• Respiratory ailments

• Bronchitis, pneumonia, emphysema, asthma

• Implicated in genetic mutations

• Also alter local climate

• The “Weekend Effect”


Sulfur Dioxide• Volcanic eruptions and

sea spray

• Fossil Fuel Combustion

• Smelting Ores

• Emitted as SO2

• Health Effects• Constrict airways

• Change respiratory and pulse rates

• Respiratory diseases

• 50,000 deaths/year U.S.


Acid Deposition

SO3 + H2O H2SO4


Acid Deposition and Buffering• Buffering of acid rain takes place when limestone

(CaCO3) supplies bicarbonate ions (HCO3-)

• The bicarbonate ion (HCO3-) combines with hydrogen

ions from the acid deposition

CaCO3 + CO2 Ca++ + 2HCO3-

2HCO3- + H+ CO2 + H2O

• In areas that have large amounts of calcium carbonate such as western U.S., little effect will occur.

• In other areas, such as New England or upstate NY, acid precipitation quickly lowers pH.


Effects of Acid Deposition

• Lowering pH reduces reproductive success of aquatic organisms

• Lower pH also reduces the nutrient holding capacity of soils

• Metallic ions, such as aluminum, can be released from soil to kill freshwater fish


Nitrogen Oxides

• NO, NO2, NO3, N2O, N2O3, N2O4, and N2O5

• Nitric Oxide (NO) and Nitrogen Dioxide (NO2) known as NOx

• Thermal NOx

• Fuel NOx

• NO precursor to many other pollutants


Tropospheric O3 Formation

2NO + O2 2 NO2

N2 + O2 2NO

NO2 + hv NO + O

O + O2 O3


Nitrogen Oxides and Ozone


Hydrocarbons• Carbon and hydrogen

• Incomplete fuel combustion

• Evaporation of fuel

• VOCs

• Natural and anthropogenic sources

• Carcinogens

• React with many other pollutants to form photochemical smog


Natural vs. Human Emissions


Concentrations

• Exposure

• Quantity/volume of air

• Weight/volume

• Volume/volume

• Standard temperature

• Standard pressure


Atmospheric Convection


Atmospheric Stability


Plume Dispersion


Declining U.S. Pollutants


Dose Response Function


Optimal Level of Air Pollution?• The 1970 Clean Air Act

• Reduction from mobile sources

• 1990 amendments

• New stationary source performance standards

• State Implementation Plan (SIP)

• Costs of Clean Air Act

• Benefits of Cleaner Air

powerpoint ® lecture prepared by gary a. beluzo air pollution costs and benefits of clean air 19

Documents

weekend effect slide

freshwater fish slide

global climate change

acid deposition caco

beluzo air pollution

acid precipitation

benefits of clean air

2hco3 h co2 h