Bio 2106: Environmental Biology
Lab 8: Air Pollution
Lab Requires: 1 week to compete (must have
agar plates to complete)
You need to make arrangements to come by
my office to pick up you plates if you did not get them already. Please give me
1-2 days notice so I can have them made for you. I can meet you either at RVS
(T-H) or RVS (M-W) or leave them for you at either place. Or you can buy them
at science stuff (see syllabus)
(Note: This lab has been
modified from the ENVIRONMENTAL AIR POLLUTION MONITORING MODULE, provided by
Texas Southern University, June 1996.)
Lab Objectives:
1. Apply
the scientific method to various environmental problems:
a. observation
b. hypothesis formation
c. experimentation
d. collection of data
e. data calculations
f. presentation of data
g. analysis of data
2. Examine
issues in indoor air quality.
Safety: Wash you hands after you have handled the petri dishes.
Background:
This lab will demonstrate the presence of
fungi (molds) and other microorganisms that are present indoors. Most of us are
not conscious of these organisms because they are invisible. The invisible
organisms are universally present in air. More attention is focused on their
presence in our air due to environmental health concerns about "indoor
air". Many people are concerned that inside air can contain unusually high
numbers of molds and microorganisms, which may have a harmful effect upon
people who are sensitive to them. Air particulates can cause or contribute to
respiratory diseases and other illnesses. There has been a
increased awareness of indoor air quality as more and more homes in the
There are 2 major types of air pollution: solid
particles and gases. This lab focuses on the solid particles in the
air that come from natural sources, such as pollen from flowers or
microorganisms such as mold spores. Other solid particles arise from human
activities such as burning coal, burning garbage in combustors or incinerators,
or burning oil in furnaces.
Yeast, molds, and mushrooms are organisms
that are found in Kingdom Fungi. They live on other plants and animals,
absorbing nutrients by decomposition. A fungus reproduces by forming
reproductive cells called spores. The spores are released into the air
and settle on an acceptable surface (a proper medium), begin to grow, and
utilize the host’s nutrients.
Humid areas, such as Austin and Houston, encourage
the growth of molds. As a result, our air is full of such particles even though
we cannot see them. We can take precautionary measures to reduce their
accumulation only when we are environmentally aware of their presence.
Materials:
5 petri dishes
with nutrient agar
Procedure, Part 1:
1. Individuals
will select locations for sampling. Choose 4 indoor and one outdoor as your
control. Try to think of a variety of different places- both public and
private.
A. _______________________________
B. _______________________________
C. _______________________________
D. _______________________________
E. (outside)________________________
2. Label
the bottom of each Petri dish containing nutrient agar with the
following:
date
location where Petri dish will be placed
Location Time Petri dish uncovered
_________________ ________________
_________________ ________________
_________________ ________________
________________ __________________
________________ __________________
I expect plate A to have the highest number
of mold colonies because I placed it in a place with lots of people, and warm,
moist conditions conducive to mold growth. Plate C will have the next highest
number of colonies because…. And so on.
HYPOTHESIS
5. Check the dishes for growth. Count the
number of colonies and observe the physical appearance of the colonies: shape,
color, wet/dry appearance. Record the results in the data chart.
LAB REPORT – Air Quality
Name
________________________
1. Data Table
|
LOCATION |
# OF COLONIES |
COMPARISON TO OUTSIDE PLATE |
A |
|
|
|
B |
|
|
|
C |
|
|
|
D |
|
|
|
E |
(outside) |
|
1.0 |
|
AVERAGE |
|
|
|
|
|
|
Note: use you
outside plate as your control. If the outside plate had 6 colonies, an inside
plate with 6 colonies would have an index number of 1 (6/6 = 1.0)
2. Which indoor location had the most mold
and microorganisms? Why?
3. Which indoor location had the least?
Why?
4. How did the outdoor air compare to the average
indoor air?
5. What do the results of this lab
indicate about indoor air quality?
Part 2. Learning
more about indoor air pollution
Go to the web and
look up indoor air quality. One good site is EPA Indoor Air, but there
are a variety of others you may wish to examine.
2) Pick one of the sources described above,
and investigate it in more detail. Find out a) how this source of pollution
gets into homes and offices, b) what types of buildings are most susceptible c)
what are the warning indicators for that type of pollution and d) how does one
clean up the pollution, once it has been detected.
Make sure to list
your web site.