Comparison of Vital Lung Capacity of between Smokers and Non-Smokers
Kasra Sadjadi and Cassra Minai
Department of Biological Science
Saddleback College
Mission Viejo, CA 92629
Cigarette smoking decreases the amount of oxygen intake per breath. In order to
compensate for this lack of oxygen, the subject’s respiratory rate increases (citation). This
experiment examines the respiratory rate of cigarette smokers and non-smokers prior to
(resting) and after cardiovascular exercise on a stationary bicycle. During the resting and
the exercising protocol, the subject will inhale and exhale as much as physically possible
while their vital lung capacities are measured. The mean vital lung capacity of the smokers
was 3.285 L, and the mean vital lung capacity of the non-smokers was 1.844 L (WAS THIS
DURING RESTING OR DURING EXERCISE???). A significant difference was observed
between the vital lung capacities of the smokers compared to the non-smokers (unpaired,
one-tailed t-test, p=0.003). thus increasing the respiratory rate in order to compensate for
lack of Oxygen. In this experiment respiratory rate was measured, while the volunteers
(smokers and non-smokers) were resting and after cardiovascular exercise on a stationary
bike, by having them exhale and inhale as much as physically possible and measuring their
vital capacities with the Oxycon Mobile. Results showed a Mean significant difference
between their vital capacities thus rejecting the null hypothesis.
Introduction
Oxygen intake is extremely important to the survival of vital organs. The amount of
oxygen intake is extremely important for amount of oxygen transfer to vital organs. An
unhealthy individual (smoker?) will increase the amount of respirations they take per minute
because they are unable to transfer the needed (adequate?) amount of oxygen compared to a
person with healthy lungs and adequate respirations. The more respirations one takes is because
they are not able to transfer the needed amount of oxygen in the same amount of respirations as a
person with healthy lungs and therefore increases their respiration rate in order to increase their
oxygen intake so that it is equivalent to a healthy person’s. Studies show that occasional smokers
were found to have a greater lung capacity, also known as a forced vital capacity (FVC), than
nonsmokers (Holmen et al., 2002). Cigarette smoking produces an inflammatory response in the
airways of smokers or those exposed to cigarette smoking everyone, but only 15-20% of smokers
will develop airways obstruction (Hogg et al., 1994). The inflammatory response of smoking
makes it more difficult for the individual to intake adequate (what is normal??) amount of
oxygen; therefore, their respiration rate will increase in response to the inflammation of their
airway to compensate for their decreased oxygen levels (somehow change this…. it’s very wordy
and does not make sense). Because smoking inflames the airways, it makes it harder for the
individual to inhale normal amount of oxygen, thus their respiration rate increases in response to
the inflammation to compensate for the decrease in oxygen inhalation.
Materials and Methods
The experiment was executed at the Department of Biological Sciences, Saddleback
College. Two groups (smokers and non-smokers) of volunteers, consisting of five subjects each
participated in the investigation. The subjects (n=10) ranged from 18 to 25 years of age, and
each participant signed a waiver form and answered a questionnaire to determine (estimate?)
how much tobacco they have smoked throughout their life. Experiment was held at the Biology
lab with two groups of random volunteers, five in each group from age range of eighteen to
twenty-five years old, who have filled out waiver forms and questionnaires asking how much
tobacco they have smoked in their life.
Then the The Oxycon Mobile (which…does what? Measures what? Why was this chosen
for this experiment? Serial number? Make? Year?) was calibrated at to 21.01% oxygen and
0.02% carbon dioxide. and hooked up to one of the volunteers. The Oxycon Mobile was attached
to each subject, and they were instructed to inhale and exhale as much as possible while at rest.
The subjects (smokers and non-smokers) vital lung capacities (VC) were measured for a total of
one minute. The volunteer then inhales and exhales as much as possible, thus measuring the
vital capacity of the participant. For about one minute the volunteers inhale and exhale as much
as possible to measure to vital capacity in smokers and non-smokers, and by doing that we were
able to determine the forced vital capacity (FVC), amount of air that can be exhaled after taking
the deepest breath possible. After a minute of measurement taking for their respiration rate at
rest, then the volunteer rides the stationary bike for five minutes, intermittently increasing their
pace to full speed to max their respiratory rate to its greatest capabilities in order to get minute
errors in the readings. For the cardiovascular exercise protocol, the subjects were to ride the
stationary bicycle for five minutes. During the five minutes, the subjects were instructed to
gradually increase their pace to full speed, in order to fully maximize their respiratory rate.
Similar to the resting protocol, the subjects were asked to inhale and exhale as many time as
possible to determine their vital lung capacity.
To determine the vital lung capacity of each participant, the following equation was used,
VC = IRV + TV + ERV
where IRV is inspiratory reserve volume, TV is tidal volume, and ERV is exspiratory reserve
volume.
By determining the participant’s vital lung capacities, the forced vital capacity, which is
the amount of air that can be exhaled after taking the deepest breath possible, was calculated.
The data was compared between the smoking and non-smoking groups prior to and after the
exercise protocol. The results were analyzed using an unpaired, one-tailed t-test to determine
whether there was significance between the two groups (p<0.05).
Then after the volunteer has exercised for five straight minutes they inhale and exhale as
much as possible for a minute or so, measuring the difference from the data at rest.
Results among both groups were analyzed with an unpaired one-tailed T-test to determine
the p-value, which happens to be P<0.05 (0.003) and the mean of each group.
Results
The results, analyzed by an unpaired, one-tailed t-test (p<0.05), rejected the null
hypothesis (STATE THE HYPOTHESIS CLEARLY IN THE INTRODUCTION). The mean
average VC of the smokers (3.285 L) was significantly greater than the non-smokers (1.844L), as
shown by Figure 1. (WAS THIS FOR RESTING OR THE EXERCISE GROUP??).
From the unpaired one-tailed T-test, the P<0.05, thus rejecting the null hypothesis. Also
their mean average of the smokers vital capacity is actually significantly more greater than the
non-smoker group (3.285L v. 1.844L) (Fig.1).
The smoker group appeared to be breathing heavier and more frequently than the nonsmokers, whom appeared to be breathing at a steadier pace and taking deeper breaths. The
equation for the vital lung capacity (VC) =inspiratory reserve volume (IRV)+tidal volume
(TV)+exspiratory reserve volume (ERV).
Now if the investigators were given the ERV(expiratory reserve volume) and IRV
(inspiration reserve volume), they would be able to solve the TV (tidal volume), or in
lamens terms amount of air moved in and out of lungs during normal breaths, which would
give a deeper insight as to why smokers have a higher VC. (DOES THIS RELATE OR
JUST CONFUSE WHAT YOU ARE TRYING TO CONVEY TO THE READER ABOUT
YOUR FINDINGS??? MAYBE RE-WORD THIS PARAGRAPH AND ADD TO FUTURE
RESEARCH OR POSSIBLE FACTORS BUT PUT IN THE DISCUSSION??)
4
3.5
Air Intake (L)
3
2.5
2
1.5
1
0.5
0
Average VC Non-Smokers
Average VC Smokers
Figure 1. Average Vital Capacity between Smokers and Non-Smokers, with the average mean of
VC for non-smokers at 1.844L and for smokers at 3.21L; P-value=0.003; thus showing
significant difference in VC between the two groups (unpaired, one-tailed t-test, p<0.05). (AT
REST OR AFTER EXERCISE??)
Discussion
Though the results were unexpected, the higher VC for the smoker group could be due to
their bodies trying to compensate for the lack of a steady respiratory rate causing an increase in
their respirations.?? The results were unpredicted by the investigators, but when thought about
conceptually, the higher VC for smokers could relate to their bodies compensating for lack of
steady respiratory rate, by increasing the rate. Chronic cigarette smoking may be can be partially
explained by loss of lung elastic recoil pressure which reduces the force that drives air out of the
lungs. This loss of elastic recoil pressure is attributed to microscopic enlargement of the air
spaces rather than to grossly visible emphysema (Hogg et al., 1994). The color of a healthy
lung is pinkish-white, which also looks like that at a young age. As humans become adults,
their lungs form dark patches on the lungs, similar to how the chemicals from cigarette
smoke change the lungs color to black. The coloring matter (from aging) consists of
granules of carbon-like substances in the areolar tissue close to the surface of the organ
(Gray 975). (DOES THIS RELATE TO YOUR EXPERIMENT? IF SO, HOW??)
Literature Cited
Dosman, James, Bode, Frederick, Urbanetti, John, Martin, Richard, Macklem, Peter T. (1975).
The Use of a Helium-Oxygen Mixture during Maximum Expiratory Flow to Demonstrate
Obstruction in Small Airways in Smokers. The Journal of Clinical Investigation. 55(5):
1090-1099.
Gold, Diane R., Wang, Xiaoban, Wypij, David, Speizer, Frank E.,Ware James H., Dockery,
Douglass W. (1996). Effects of Cigarette Smoking on Lung Function in Adolescent Boys
and Girls. The New England Journal of Medicine. (335): 931-937.
Gray, Henry. Gray’s Anatomy: The Classic Collectors Edition. Edited by: Pick, T. Pickering,
Howden, Robert. Crown Publishers, Inc. Bounty Books, New York. ISBN: 0-517223651.
Hogg, J.C., Wright, J.L., Wiggs, B.R., Coxson, H.O., Saez, A. Opazo, Paré, P.D. (1994). Lung
Structure and Function in cigarette smoking. Thorax. (49):473-478.
Holmen, T.L., Barret-Connor, E., Clausen, J., Holmen, J., Bjemer, L. (2002). Physical exercise,
sports, and lung function in smoking versus nonsmoking adolescents. European
Respiratory Journal. (19):8-15.
Review Form
Department of Biological Sciences
Saddleback College, Mission Viejo, CA 92692
Author (s):__Sadjadi and Minai___________________________________
Title: Comparison of Vital Lung Capacity between Smokers and Non-Smokers
Summary
Summarize the paper succinctly and dispassionately. Do not criticize here, just show that you understood the paper.
This paper compares the vital lung capacities between smokers and non-smokers prior to and after
cardiovascular exercise. An unpaired, one-tailed t-test compared the results of the smokers and nonsmokers and rejected the null hypothesis of the investigators. The average VC of the smokers was
greater than the VC of the non-smokers (p=0.003). I don’t understand if these results were the ones
recorded at rest or during exercise on the stationary bike.
General Comments
Generally explain the paper’s strengths and weaknesses and whether they are serious, or important to our current
state of knowledge.
I added ONE TOO MANY comments on the paper, mainly grammatical and wording problems. The study
was very interesting to see the significant difference between the smokers and non-smokers, and I think
that if the paper was slightly more organized and addressed all the points they said they were going to
measure that it would be a very good paper. It is very pertinent to our current health issues.
I also think that the paper needs more background information, and more of an explanation on why
they did this study, what they wanted to find, what they initially wanted to find, etc.
Technical Criticism
Review technical issues, organization and clarity. Provide a table of typographical errors, grammatical errors, and
minor textual problems. It's not the reviewer's job to copy Edit the paper, mark the manuscript. OOPS!!!
(couldn’t help it)
This paper was a final version
 This paper was a rough draft
Recommendation
 This paper should be published as is
 This paper should be published with revision
 This paper should not be published
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