Effects of Tobacco Use on the Vital Lung Capacity of Healthy Male Students
Laura Powell and Nicole Mills
Department of Biological Science
Saddleback College
Mission Viejo, CA 92692
Abstract
(Abstract needs to be bolded) Smoking tobacco, while a continuing health concern,
remains prevalent in society today. In this study, the exhaled vital capacities of healthy
smoking and nonsmoking male college students were measured using a bell spirometer.
All data was collected and a one-tailed, unpaired t-test assuming unequal variances was
performed using Microsoft Excel. The average vital capacity of nonsmoking males was
found to be 4.46 L + 0.22 (+SE, N=10)(S.E.M.?). Similar to the previous group, the
average vital capacity of smoking males was found to be 4.07 L + 0.18 (+ SE, N=10)
(S.E.M.?). The vital capacities of smoking males were not found to be significantly
lower than the vital capacities of nonsmoking males (If your hypothesis was that vital
capacities would be lower in smoking males than nonsmoking males, you should clearly
state that near the beginning of your abstract. Also, you could rephrase the previous
sentence as “Our results yielded that there was no significant difference in the vital
capacities of smoking and nonsmoking males; thus, the null hypothesis is supported).
Although the results did not show a significant difference in lung capacity, this does not
suggest that smoking males have the equivalent lung function (what kind of function?) of
nonsmoking males. It simply shows that smoking males have the capability to uptake the
same volume of air as nonsmoking males. Maybe make last two sentences more concise
(you want the abstract to be as brief and direct as possible; for example “This does not
infer that smoking and nonsmoking males have the same lung capabilities, but rather
suggests only that they have the ability to uptake the same volume of air.”
.
Introduction
(Body should be in pt. 12 font- not 11) Tobacco use in the population is a continuing
health concern. Chemicals are released by the burning of tobacco. When smoke is inhaled,
airway resistance increases. Carbon monoxide, one of many harmful byproducts of tobacco
smoke, binds to the red blood cells’ hemoglobin faster and stronger than oxygen does. The result
of the competition between the excess carbon monoxide and oxygen is a decrease in the diffusion
capacity for oxygen (Tzani et al. (2008). Tobacco use can also cause asymmetry in lung units
which results in increased alveolar volumes and pulmonary obstruction (Prediletto et al, 2007).
Evidence has also been found of a relationship between tobacco use and the forced expiratory
volume in one second/vital capacity of the lungs (Taylor et al. 2002). Rizzi et al. (2004) found
that smokers had significantly poorer lung function, even in the absence of any clinical
symptoms. Based on the previous research, there is suspicion (or “the researchers take interest in
the possibility”) that some of the adverse tobacco affects may be overlooked in seemingly healthy
adult males.
The purpose of this project is to determine the percent difference in the vital lung
capacity (VC) of healthy smoking and nonsmoking males at rest. Along with vital capacities, the
tidal volumes, expiratory reserve volumes and inspiratory reserve volumes will be collected and
compared. Because of the negative impact of smoking on lung function, our (use third person“the investigators” or “the researchers”?) hypothesis is that smoking males will have a lower
average lung vital capacity than nonsmoking males. It is expected that there will be a direct
relationship between smoking and decreased lung function resulting in lower lung vital
capacities.
Materials and Methods
Ten smoking and ten (10) nonsmoking male students attending Saddleback College in Mission
Viejo, CA participated in this study. All 20 subjects were between the ages of 18 and 25 and in
good health with no history of asthma, lung or heart diseases.
The height and weight of all subjects as well as the daily smoking habits of the smoking male
subjects were recorded prior to conducting the tests Did you only use subjects with average
height and weight?. A bell spirometer, provided by the Biological Department at Saddleback
College, was used to record (in liters) the vital lung capacity (VC), tidal volume (TV), and
expiratory reserve volume (ERV) of both groups. After the necessary measurements were
recorded, the inspiratory reserve volume (IRV) was calculated using the following formula:
IRV = VC - (TV + ERV)
The measurements of the TV (volume of air exhaled when taking a normal and unforced
breath), ERV (additional air that can be forced out after exhaling a normal and unforced breath),
and VC (maximum volume of air completely exhaled after taking a complete and deep breath in)
were recorded by having each subject exhale into the cardboard mouthpiece.
To deflect possible measurement errors, all subjects were asked to firmly place their lips
around the cardboard mouthpiece to minimize the amount of air escaping through gaps between
the subjects’ mouths and cardboard mouthpieces. If a subject’s TV was measured as being
greater than or equal to 1.0 L or the subject appeared to have been forcing his breath, the
measurement was retaken.
Using Microsoft Excel, a one-tailed t-test assuming unequal variances was performed to
compare the average VCs for each group.
These last 3 paragraphs are all 1-2 sentences; you could probably tie them into one!
Results
The average vital capacity for nonsmoking males was 4.46 L + 0.22 (+SE, N=10)
(S.E.M.?). The average vital capacity for smoking males was 4.07 L + 0.18 (+ SE, N=10)
(S.E.M.?). A one-tailed t-test revealed that the average lung vital capacity for nonsmoking
males was not significantly higher (in the rest of your paper, you use the phrase “smoking males
will have a lower average lung vital capacity than nonsmoking males” which is a little confusing.
The idea is stated clearly, but it may be more consistent to use the phrase “the average vital lung
capacity for smoking males was not significantly lower than that of nonsmoking males”) than the
average lung vital capacity for smoking males (p=0.091) (Figure 1). Delete this sentenceThe
supporting data is shown in Figure One.
Table 1. A comparison between the mean TV, ERV, and IRVs of smoking and nonsmoking males.
No significant differences were observed in this comparison. (Caption should be below table)
TV
ERV
IRV
Mean
Standard Error P(T<=t) one-tail
0.50 L
0.044
0.380
2.44 L
0.222
0.261
1.52 L
0.224
0.233
(Can’t read this chart in Word 2004 version… and it’s not necessary)
Figure 1. Compared mean vital capacity values of nonsmoking and smoking males. There was
no significant difference between the two groups.
The mean TV, ERV, and IRV of both groups are shown in Table One. Also shown in
Table One are the results for the one-tailed t-test for each group. Rephrase these sentences to say
what these results mean, then reference (Table 1) instead of saying “shown in Table One”.
You should switch the order of your table and figure so that they’re in the order you reference
them in.
Discussion
The results show that although there is a difference between the vital capacities of
nonsmoking and smoking males, the difference did not reach the level of significance. There was
also no significant difference in TV, ERV, or IRV of smoking males when compared to
nonsmoking males. There were some factors that could have been better addressed (accounted
for) in this experiment. Because of the equipment used in this experiment, the collected data
depended upon each subject fully understanding the action they were being asked to perform. If a
subject misinterpreted the type of exhalation desired, then the results may have been negatively
affected. Also, increased selectivity of subjects in this experiment would have been beneficial.
Having subject groups that were more unified would have cut down the impact of outside factors.
In what way could you have made the subject groups more unified? Specific factors? However,
given the time period in which this experiment was performed, strict selectivity may be an
unrealistic feat. In a previous analysis of 7882 subjects, passive smokers were observed over the
course of a year and found to have lower lung function than those who were not exposed,
although the difference was only marginally significant (Janson et. al. 2001). This suggests that a
larger sample size and longer observation time may increase the likelihood of finding a statistical
difference. (may yield more accurate results)
Although the results did not show a significant difference in lung capacity, this does not
suggest that smoking males have the equivalent lung function of nonsmoking males. It simply
shows that smoking males have the capability to uptake the same volume of air as nonsmoking
males. Smoking can affect oxygen kinetics and uptake at different levels. (Tzani et al., 2008)
Even though the smoking males in this experiment could hold the same amount of air as
nonsmoking males, the project did not continue on to find the efficiency of oxygen uptake. You
could say “, further studies should be conducted to determine efficiency of oxygen intake”.
References
Janson, C., Chinn, S., Harvis, D., Zock, J., and et al. (Year) Effect of passive smoking on
respiratory symptoms, bronchial responsiveness, lung function, and total serum IgE in the
European Community Respiratory Health Survey: A cross-sectional study. The Lancet
358.9299 (2001): 2103-2109. Retrieved November4,2009.
Prediletto, R., Fornai, E., Catapano,G., Carli,C. (2007). Assessment of the alveolar volume when
sampling exhaled gas at different expired volumes in the single breath diffusion test. BMC
Pulmonary Medicine 2007, 7:18. Retrieved September 4, 2009, from BioMedCentral.com.
Rizzi, M., Sergi, M., Andreoli, A., Pecis, M., Bruschi, C., & Fanfulla, F. (2004). Environmental
tobacco smoke may induce early lung damage in healthy male adolescents. CHEST, 125(4),
1387-1393. Retrieved September 5, 2009, from CINAHL Plus with Full Text database.
Taylor, D., Fergusson, D., Milne, B., Horwood, L., Moffitt, T., Sears, M., et al. (2002, August). A
longitudinal study of the effects of tobacco and cannabis exposure on lung function in young
adults. Addiction, 97(8), 1055-1061. Retrieved September 5, 2009, from CINAHL Plus with Full
Text database.
Tzani, P., Aiello, M., Colella, M., Verduri, A., Marangio, E., Olivieri, D., and Chetta, A. (2008).
Lung Diffusion Capacity Can Predict Maximal Exercise in Apparently Healthy Heavy Smokers.
Journal of Sports Science and Medicine (2008) 7, 229 – 234. Retrieved September 4, 2009, from
jssm.org.
Review Form
Department of Biological Sciences
Saddleback College, Mission Viejo, CA 92692
Author (s):Laura Powell and Nicole Mills
Title: Effects of Tobacco Use on the Vital Lung Capacity of Healthy Male Students
Summary
Summarize the paper succinctly and dispassionately. Do not criticize here, just show that you understood the paper.
Because the effect of tobacco on smokers’ health is a prevalent issue in today’s society, the investigators
are interested in whether or not it affects vital lung capacity. They hypothesize that smokers will have a
lower average vital lung capacity than nonsmokers. The hypothesis was tested by measuring test subjects’
exhaled vital capacity for two separate groups: smoking and nonsmoking college males. Variables
accounted for were sex, age, and health history. The investigators used a one-tailed, unpaired t-test on
Microsoft Excel to analyze their data. The results yielded no significant difference in average vital lung
capacities for the two test groups; thus, the null hypothesis was supported. These results do not necessarily
suggest that smokers and nonsmokers have equally healthy lung function, but rather only suggest that
smokers and nonsmokers are capable of the same volume of air intake. Further studies should be conducted
to determine other factors that affect lung function between smokers and nonsmokers.
General Comments
Generally explain the paper’s strengths and weaknesses and whether they are serious, or important to our
current state of knowledge.
Strengths:
The introduction gives sufficient background information that shows why the investigators would be
interested in this project. It is important for the reader to recognize that the topic is relevant. The paper is
concise, short and to the point (with a few exceptions), which is important so that the reader is able to
understand the content without having to search through wordy long paragraphs. Overall, I could clearly
understand the experiment, what variables were accounted for and how it is relevant to today’s society.
Weaknesses:
Some sentences are vague and need a little more detail, which is necessary for better clarification. There are
some sentences that could be combined together rather than having two separate sentences that may
improve clarification as well. The abstract leaves out the hypothesis and has minor structural errors, which
are important to clear up because it is the first thing the reader reads and they should be able to understand
what your entire paper is about from it. The paper contains some grammatical errors. The paragraphs in
“Materials and Methods” could be organized into longer related paragraphs.
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.
This paper was a final version
This paper was a rough draft
There weren’t many technical issues in the paper. However, the paper could have been organized
more clearly- I mentioned previously the “Materials and Methods” section in particular that had 5
short paragraphs that probably could have been tied into 1 or 2 longer related paragraphs.
Otherwise, the paper was well organized. The paper also had good clarity, with the exception of
some sentences that could have been worded a little differently (I marked them with suggestions
in red).
Typographical Errors
Grammatical Errors
Minor Textual Problems
Forgotten periods or commas (which I corrected)
Body paragraphs in pt. 11
Abstract not bolded
Used “our “ in hypothesis
One-tailed, rephrase some sentences for clarification
(suggestions in paper)
Overall the paper contained few grammatical, typographical and textual errors!