AP Environmental Science Lab #8
Name: __________________________________
Period: _____
MONITORING AIR QUALITY LAB
Purpose: To understand and monitor air quality and see how characteristics of air quality are related.
Background: Air pollution comes from many different sources: stationary sources such as factories, power plants, and
smelters and smaller sources such as dry cleaners and degreasing operations; mobile sources such as cars, buses, planes,
trucks, and trains; and naturally occurring sources such as windblown dust, and volcanic eruptions, all contribute to air
pollution. Air Quality can be affected in many ways by the pollution emitted from these sources. These pollution sources
can also emit a wide variety of pollutants. The EPA has these pollutants classified as the six principal pollutants (or
"criteria pollutants" - as they are also known). These pollutants are monitored by the EPA, as well as national, state and
local organizations.
The Clean Air Act provides the principal framework for national, state, and local efforts to protect air quality. Under the
Clean Air Act, EPA's Office of Air Quality Planning and Standards (OAQPS) is responsible for setting standards, also
known as national ambient air quality standards (NAAQS), for pollutants which are considered harmful to people and the
environment. OAQPS is also responsible for ensuring that these air quality standards are met, or attained (in
cooperation with state, Tribal, and local governments) through national standards and strategies to control pollutant
emissions from automobiles, factories, and other sources. EPA is dedicated to monitoring the quality of the air we
breathe.
Particulate matter (PM), also known as particle pollution, is a complex mixture of extremely small dust and soot
particles. PM is divided into two categories, “PM10” and “PM2.5.” PM10 is matter 10 micrometers in diameter or less. That
would be about one-seventh the width of a strand of human hair. PM2.5 is even smaller - measuring 2.5 micrometers or
less.
PM concentration is reported in micrograms per cubic meter or µg/m3. The particulate is collected on a filter and
weighed. This weight is combined with the known amount of air that passed through the filter to determine the
concentration in the air.
Particle pollution is made up of a number of components. Soil and dust particles and certain metals are emitted directly
into the air as PM. The primary human-caused sources of PM include blowing dust from construction sites and
agricultural activities, as well as combustion products from solid fuels. In Utah, elevated levels of PM can also occur
when dust blows off the west desert. Figure 1 shows the sources of direct PM emissions along the Wasatch Front.
AP Environmental Science Lab #8
Figure 1: 2002 Direct PM Emission Summarizes for the Wasatch Front
During winter temperature inversions when we have historically exceeded the national standards, we find the
majority of our PM is composed of particles that have formed from chemical reactions in the air. These
particles include organic chemicals and acids such as nitrates and sulfates. Figure 2 shows the sources of
nitrates and sulfates along the Wasatch Front.
Figure 2: NOx and SOx Emission Summarizes for the Wasatch Front
AP Environmental Science Lab #8
Ozone is formed when hydrocarbons (also known as volatile organic compounds, or VOC) and nitrogen oxides
(NOx) chemically react in the presence of sunlight and heat. Hydrocarbons are emitted from automobiles,
gasoline stations, paint, degreasers, cleaning fluids, and many other sources. Plants also give off some reactive
hydrocarbons, such as terpenes from pine trees. Nitrogen oxides are emitted by automobiles, power plants,
and other combustion processes.
Ozone production is a year-round phenomenon. However, the highest ozone levels occur during the summer
when strong sunlight, high temperatures, and stagnant meteorological conditions combine to drive the
chemical reactions and trap the air in the region for several days. Ozone produced under these conditions can
then be transported many miles outside the urban formation area.
Ground-level ozone should not be confused with the stratospheric ozone layer that is located approximately
15 miles above the Earth’s surface. It is this layer that shields the earth from cancer-causing ultraviolet
radiation. Ozone at ground level, where it can be inhaled, is a pollutant, and is known to have harmful effects
in both humans and plants. Those most susceptible to harm from ozone are the sick and elderly, newborn and
unborn infants, and those with asthma and other chronic lung diseases. Ground level ozone is usually
controlled by regulating sources of VOC and NO2. Control strategies include the vehicle inspection and
maintenance program and implementation of rules for reasonable, achievable control technologies for
industrial sources. Ozone formation can be reduced by voluntary measures such as postponing use of
gasoline-powered engines until evening. (United States Environmental Protection Agency)
Materials:
Internet Source
Methods:
1. Go to the Utah Department of Environmental Quality website—a link can be found at my website
2. Click on the little thermometer that says ‘Current’ Click on Davis (so you are getting our local condtions) Record the
PM2.5, Ozone, Temperature and Wind in the Air Quality Data Table.
Make sure units are in metric.
3. Go the Weather Underground website—a link can be found at my website, same was as above.
4. Find Syracuse, UT data and record the Visibility in the Air Quality Data Table. Make sure units are in metric.
AP Environmental Science Lab #8
Data:
Air Quality Data
DAY
PM2.5 (µg /m3)
Ozone (ppm)
Temperature (*C)
1
2
3
4
5
6
7
8
9
10
Comparing PM2.5, Ozone and Temperature over Time
Wind (km/h)
Visibility (km)
AP Environmental Science Lab #8
Key
Comparing PM2.5, Ozone and Wind over Time
Key
Comparing PM2.5, Ozone and Visibility over Time
AP Environmental Science Lab #8
Key
Key
Analysis:
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AP Environmental Science Lab #8
What did you learn from Monitoring Air Quality Data?
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Literature Cited
United States Environmental Protection Agency. “Air Quality.” EPA. EPA. 4 Nov. 2011. Web. 6 Dec. 2012
Supplemental Labs
You will participate in one of the three following Air Quality Labs—all data from these labs must be completed
and brought to class on ________________________. We will look at the results from ALL of these labs on
this day.
Even though you will only complete one of the three labs, you are required to fill out this ENTIRE sheet.
Lab 1: Let’s Sock Car Exhaust!
Data: Car Particulate Ranking from Greatest to Least
Car Model
Type of Fuel
Follow-up Questions—please write in complete sentences.
1. What is the independent variable in this lab?
2. What is the dependent variable in this lab?
AP Environmental Science Lab #8
3. What was one variable that was hard to control in this lab? (Think of all the students involved)
4. Can you describe a link between type of fuel used, car model size to the data rankings above?
Lab 2: Particulate Lab
Data: Qualitative Observations –compare 3 sites of data
Site 1:
Site 2:
Site 3:
Follow-up Questions—please write in complete sentences.
1. What is the independent variable in this lab?
2. What is the dependent variable in this lab?
3. What are some of the controlled variables in this lab?
4. Compare the qualitative data from the 3 areas. Can you see a make any conclusive statements based on location and
amount of observed particulate?
Lab 3: Tropospheric Ozone Lab
Data: Schoenbein Site Comparison
Short Site Description
Schoenbein Color
Scale Number
Ozone (ppb)
AP Environmental Science Lab #8
Follow-up Questions—please write in complete sentences.
1. What is the independent variable in this lab?
2. What is the dependent variable in this lab?
3. What are some of the controlled variables in this lab?
4. Look at and interpret the data from the table above. Can you see a make any conclusive statements based on
location and ozone (ppb) amount?