Ground-level Ozone: Your Vehicle
Introduction
This exercise examines ground-level ozone, the air pollution commonly referred to as "smog"
("smoke" + "fog" = "smog"). Smog is formed by a combination of air pollutants and sunlight, and
can have adverse effects on humans and other organisms. You have likely heard of ozone in a
different capacity. Ozone also occurs high above Earth's surface in the stratosphere, where it
serves a protective function by blocking harmful ultraviolet radiation from the Sun. The ozone in
each case is the same molecule, but in one location (high in the atmosphere) it is beneficial to
living things, while at another location (ground-level), it is harmful. The major differences
between stratospheric and ground-level ozone is reviewed in the brochure below from the U.S.
Environmental Protection Agency
Ozone: Good Up High, Bad Nearby
Online database of vehicle fuel efficiencies
U.S. Department of Energy
http://esa21.kennesaw.edu/activities/smog-car/ epa-good-up-high.pdf
Ground-level Ozone: Vehicles
The goal of this exercise is to quantify and analyze your
personal contributions of smog-forming compounds due
to driving. As detailed in the brochure, vehicles can be a
significant contributor of the compounds that cause
ground-level ozone. In this exercise, you will estimate the
amount of smog-forming compounds from driving and
investigate how you might reduce this. To begin your
analysis, let's review information on vehicles and ozone
with an online brochure from the Federal Highway
Administration of the U.S. Department of Transportation
on Transportation Air Quality. Fig. 1: Los Angeles smog (EPA)
Vehicle Emissions (PDF) (448 KB)
United States Federal Highway Administration (Department of Transportation)
http://www.fhwa.dot.gov/environment/
To estimate the amount of ozone-forming compounds generated by your car, we will use data
from the Department of Energy’s FuelEconomy web site. This site allows you to see how your
car rates on air pollution emitted, as well as estimating the tonnage of greenhouse gases
emitted driving an average number of miles. As you learned in the Transportation Air Quality
brochure, a number of factors influence NOx and VOC emissions from vehicles. While this data
does not take all of these factors into account, it does provide a good estimation of your
emissions.
Ground-level Ozone: Your Vehicle 1
