In recent times influenza and other infective disease have continued to dwell and scare the universe. The CDC have deployed many efforts o aid forestall these disease from distributing periodically across the universe. This is where I asked the inquiry if facemasks, a signifier of protection against sources, would maintain the sources inside of the mask. To get down to reply this inquiry, I researched different types of facemasks and their belongingss. I besides researched coughing and sneezing, in general, since these are the two major ways that people infect other people. I conducted an experiment from the usage of bacterial civilizations and tested different ways of bar, facemasks, custodies covering a oral cavity, and nil covering the cough. The bacterial civilization would supply an thought of which ways prevent sources efficaciously. After the experiment was conducted the settlements that grew in the agar medium, of the civilization, would be identified and supply a decision towards the experiment. The consequences concluded that there was a error in sterilising the agar medium ; nevertheless, from the informations collected the facemask seemed to hold less bacterial growing from the beginning of the experiment. Since the agar medium was contaminated the experiment merely proved that the method, used to obtain a bacterial civilization, needs to be improved and modified.
Table of Contentss
Title Page 1
Table of Contentss 3
-Includes the research inquiry, and how I came across the experiment
Background Information 5
-Includes research on certain types of facemasks and coughing/sneezing
Methods and Development 7
Raw Data 14
Data Analysis 21
Decision and Evaluation 29
To get down, I would wish to proudly thank my devoting adviser and Biology teacher, Mr. Earl Hockin, who has helped me every measure of the manner in finishing this Drawn-out Essay. The support I received in completing this piece of work came from a figure of people that are of import in my life.
My parents have been with me through all the late darks and the work that I have put away into this essay, they gave me the encouragement and strength to transport on throughout the difficult times.
I would besides wish to give thanks to the Biology section at the Anglo-American School of Moscow, for leting me to carry on my experiment with the proper equipment.
To what extent does covering our oral cavities when coughing maintain sources inside the confines of a surgical facemask?
Doctors all over the universe are required to have on facemasks when handling patients, particularly with an unfastened lesion or surgery. Why would sophisticate wear these masks, over giving sources to people when in fact sources are everyplace? Doctors wear these masks to maintain as many sources off from their patient as possible, if the incorrect sources were to be present when a surgical process is happening that patient may endure from an infection.
Facemasks are besides presented in the populace, builders use it to maintain little harmful atoms out of their oral cavity and mundane people have began to have on facemasks from the recent H1N1, swine grippe, epidemic of 2009-2010. The thought of this experiment arose from this recent eruption of swine grippe, I continually noticed more and more people have oning facemasks when in crowded public countries. Facemasks are exhibited in every portion of the universe, wherever there are infirmaries and physicians there are facemask, which posed the inquiry, do facemasks maintain harmful sources off from people who where the mask?
There are two chief types of facemasks, surgical facemasks and inhalators. Surgical are a loose piece of filtered fabric that slackly covers the oral cavity, they are use to largely maintain little droplets and sources from 1s mouth off from other people. Respirators are a tightly fitted mask, used to maintain really little atoms from come ining or go outing the individual have oning the mask. Surgical masks and inhalators are said non to maintain a full protection from sources that cause unwellnesss, like the grippe, which poses the inquiry, how much protection do facemasks supply for us?
When have oning a facemask or inhalator people believe that they are immune from the possible menaces of unwellnesss, such as the grippe, this is non true. Scientists are still ill-defined on if facemasks or inhalators are good or useless, this being said presently facemasks and inhalators have non been to the full proven to protect a individual from certain sources.[ 1 ]Because facemask and inhalators do non to the full protect from sources, harmonizing to the CDC, this creates another inquiry, how much make facemasks or inhalators protect us from sources.
Most people do non have on facemasks every clip they get a cold or unwellness, but use other ways to restrict sources to themselves this includes covering their oral cavity, coughing in their cubitus, or turning off from people to cough or sneeze. A cough, nevertheless, can go up to 100 miles per hour, which could potentially breakthrough the facemask.[ 2 ]
When people go to the physician, to happen out if they have an infection of some kind, the physician will take a sample that they can prove from a civilization. A civilization determines whether non a individual has a certain infection, the physicians determine this from what bacteria they see in the civilization. Most civilizations are taken from either a Petri dish or a trial tubing ; the bacteria grows in a type of “ sludge ” called a civilization medium, in this experiment the civilization will utilize agar medium.[ 3 ]Agar medium is used in this experiment due to its stamina against bacteriums ; agar is like gelatin but will non degrade when applied with bacteriums.[ 4 ]
When choosing my drawn-out essay subject for biological science I continually tried to come up with an experiment that involved some type of disease, my biological science instructor ran an thought across me of the recent eruption of swine grippe, how people were afraid of catching this disease, so they wore facemasks.
For this experiment, the surgical facemask will travel against normal defenses a human uses to halt a cough, like covering the oral cavity utilizing custodies. If sources from a cough are transferred from a human into a Petri dish filled with bacteria-encouraging agar medium, so a human have oning a surgical facemask will halt most of the bacteriums from polluting the dish therefore doing less bacterial growing and coughing straight in to the dish will show the most bacterial growing.
Methods and Development
When proving the hypothesis, I will carry on bacterial civilizations of my cough utilizing different methods to seek and efficaciously forestall the cough from distributing sources. To execute this, I must keep a Petri dish near to my oral cavity when I cough, approximately 5 inches. To maintain foreign bacteria from polluting the Petri dish, the procedure should travel rapidly as possible ; the agar in the Petri dishes need to hold the least sum of clip exposed to air. The agar medium must besides be proved to be sterilized in a pre-experiment.
After the civilizations have grown bacteriums for 7 yearss, ciphering the sum of bacteria will include numbering each bacteria that grows in the Petri dishes by the bare oculus. The control of the experiment will be the dish that I cough straight into, without anything to cover my oral cavity. The control will assist compare the differences between my consequences and what is truly happens when I cough into a facemask or into my custodies.
When carry oning my experiment, I will be roll uping civilizations in a clean research lab, which provides the right equipment to carry on the experiment. I will be utilizing a method of culturing that uses the agar medium and a warm environment, this method is widely used in the biological science universe. The civilization will be placed in a controlled environment for a sum of 7 yearss, at a temperature 25A°C. A force per unit area cooker and a heat home base will sterilise the Petri dishes. This will assist sterilise the agar medium and the Petri dishes. Sterilizing my supplies will assist to guarantee that no foreign sources will impact the consequences of my experience.
In my experiment, I will hold three different ways to cover my cough, and five tests. The three ways of bar include non covering oral cavity at all, covering oral cavity with my custodies, and covering my oral cavity with a surgical facemask.
For this experiment, I expected to see a assortment of different consequences in the bacterial growing ; I chiefly predict that custodies will barricade a less important sum of sources than the masks. I predict this because the masks were engineered to barricade sources from get awaying and the organic structure can non maintain all the sources from get awaying.
When roll uping my informations there are three things, which I will be entering as, I conduct my experiment. First, I will number, by the bare oculus, how many bacteria settlements grew, so I shall enter how much infinite each settlement takes up, and eventually I will enter any qualitative informations that I observe. Calculating how much infinite each settlement takes up will be performed by utilizing a crystalline graph paper to number the per centum each settlement takes up.
The independent variable for this experiment would be the methods for covering a cough
The dependant variable for this experiment would be the bacteria that grows in the civilizations, since the independent variable will find the sum of growing from the ways of bar
The control of my experiment is straight coughing into the Petri dishes, since there is no bar used to halt the sources.
Period clip of bacteriums growing:
I will let the agar medium sit for 7 yearss or 1week after I have conducted my experiment, to see maximal bacterial growing
Type of Agar medium:
The agar medium used is from the merchandises of Philip Harris
Room temperature around the Petri dishes:
25A°C Room temperature
The Petri dishes will be kept in a dark closed closet for the clip period of growing
Type of Petri dish:
The glasswork merchandise used was Pyrex with a A± 0.02 uncertainness
Person coughing into the Petri dishes:
I will be the lone individual coughing into the dishes so the consequences merely come from my sources
Temperature of the force per unit area cooker:
The temperature cooker will make to 100A°C to sterilise the agar and the Petri dishes
Temperature of the heat home base:
the temperature of the hot plate would be 100A°C
when coughing into a facemask, that facemask will be replaced to see no construct up of surplus sources
Agar pulverization: Philip HarrisA© 1200mL of H20 and 23g of pulverization
Glass Mixing stick
TefalA© Kettle 1 litre
45 Petri dishes
Pressure Cooker: Land LifeA© 950mL of H20
Axial rotation of Cotton
PyrexA® Glassware 1 litre Uncertainty A± 0.02mL
15 Surgical Facemasks
To guarantee that the agar medium and the Petri dishes are unfertile and have no sources already present, a pre-experiment demands to be conducted.
Sterilize the Petri dishes and the Agar medium ( instructions below )
Pour the agar medium carefully into 15 Petri dishes
Let the dishes sit and dry for 7 yearss
After 7 yearss if any bacterial growing is present so the supplies are non unfertile and the procedure needs to be completed before the experiment is conducted.
Sterilizing the Petri Dishes
Collect supplies: Petri dishes, force per unit area cooker, H2O for the agar medium, agar medium pulverization ( Phillip Harris A© )
Fill the force per unit area cooker with about a milliliter of H20
Pull together dishes so they are sealed together ( one on top and on underside ) and carefully put them in the preset force per unit area cooker, without raising the dishes off each other.
Let the dishes cook for 15 proceedingss.
While waiting for the Petri dishes to cook, fix the agar medium.
Once Petri dishes are done cookery, carefully take each one out at a individual clip without raising them off each other.
Roll up the agar pulverization, H20, a digital graduated table, Pyrex 100mL glass, TefalA© kettle, heat home base, flask, and cotton
Weigh the right sum of agar pulverization on the digital graduated table
Heat up desired sum of H20 in the TefalA© H2O boiler, pour in a Pyrex 100mL glass
Slowly pour agar pulverization in the hot H2O, blending while pouring.
After the agar is to the full dissolved in the H2O, pour the solution into a flask.
Seal the flask with cotton doing certain that air can non flux through.
Let the solution sit until the medium becomes wholly solid, about 1hour.
Heat the solid medium on the heat home base at 100A°C until the medium is liquid ( keep cotton in at this point )
Pouring Medium into the Dishes
After heating the agar medium align the sets of Petri dishes in 3 rows of 5.
Carefully raise the top of a Petri dish, seek to maintain the Petri dish every bit closed as possible, and rapidly make full half of the dish with the liquid medium.
Continue for each of Petri dishes.
Let each serve dry until medium is solid once more, about 20 proceedingss.
When the dishes are wholly dried, get down the experiment with the first row of five dishes. Open the top palpebra, place the dish 5 inches off from your face, and cough barely twice into the dish.
Continue with the remainder of the dishes in the first row.
In the 2nd row, open the top of the first dish and topographic point your manus over your oral cavity, cough twice into the dish and continue for the staying dishes.
For the last row, topographic point a surgical mask over your oral cavity, open the top palpebra of the first dish, and cough twice into the dish. Repeat for the concluding dishes, taking off and replacing the mask for each dish.
After finishing these stairss, repetition another three times. The terminal will ensue in 45 Petri dishes.
Allow dishes to sit in a warm country for 7 yearss.
Count the bacterial settlements, normally can be counted by oculus, and record the informations.
Calculate the per centum of bacteriums growing coverage by puting a sheet of grid paper over the dish and cipher how many settlements take up the boxes of the grid.
The information demonstrated is from the counted bacterial settlements presented from each Petri dish, ensuing in 45 Petri dishes. I tested each set of civilizations in a 3-trial formation, the first test with 15 dishes: three conditions tested five times. The 2nd test, same as the first test, 15 dishes, three conditions tested 5 times, and the last test, once more the same. After these three tests, the bacterial settlements were counted by oculus and recorded.
Directly Coughing into a Petri Dish Observations
Serve A ( Coughing with No Prevention )
Table: Noticeable growing in the agar medium with the control group
Coughing into Hands Observations
Dish B ( Coughing into Hands )
Table: Noticeable bacteria growing from an experimental group, hands covering the oral cavity
Cough into Surgical Facemask Observations
Dish C ( Facemasks )
Table: Noticeable bacteria growing from an experimental group, surgical facemask covering oral cavity
Number of Colonies Counted from Direct Coughs into a Petri Dish
Serve A ( No Prevention )
Number of Bacteria Colonies
Table: the sum of settlements counted in the control group ; bacteria was counted by oculus
Number of Colonies Counted from Covering Mouth With Hands
Dish B ( Coughing into Hands )
Number of Bacteria Colonies
Table: the sum of settlements counted in an experimental group, hands covering oral cavity ; counted by oculus
Number of Colonies Counted from Coughing into a Surgical Facemask
Dish C ( Facemask )
Number of Bacteria Colonies
Table: the sum of settlements counted in an experimental group, coughing into a surgical facemask ; counted by oculus
Calculating the Range for Each Test
The graph above demonstrates the scope between the highest count bacterial settlements and lowest. The graph gives an penetration on the fluctuation of the informations, the higher the figure the higher the fluctuation. In test 1 the fluctuation seems lower than the remainder ; test 2 and 3, nevertheless seem to hold instead higher degrees, the most seeable in the control and the ‘hands ‘ experimental group.
Scopes of Experiment Tests
Serve A ( No Prevention )
Dish B ( Covering Hands )
Calculating the Averages for Each Test
The norms can be calculated with a simple Excel expression:
=AVERAGE ( Cell # : Cell # )
The norm can besides be calculated from the expression:
Data A+ Data B/ figure of elements used
Averages of Experiment Tests
Serve A ( No Prevention )
Dish B ( Covering Hands )
The norms of the informations, presented above, supports the research inquiry since the Surgical Facemasks appear to hold less bacterial growing norms.
The graph above demonstrates how the norms in each test can be compared and nowadayss dependable information. After each test, the bacterial growing norms increased, but the informations concludes that the surgical facemasks had a lower norm of bacteria when compared to the experimental groups ; Dish B presents the highest addition in mean.
The graph above presents the norms of the bacterial growing in a graph that demonstrates the a clear differentiation between the control group and experimental group. As one will detect the control, for the most portion had more bacterial growing than the experimental groups, which supports the hypothesis. However, the experimental group or covering the oral cavity with custodies in the experiment rose above the control in test 3, showing that more bacterial growing was present after coughing into custodies.
The above graph presents the norm of the bacterial growing coverage of the Petri dishes. The coverage was calculated by puting a grid over top of the dish and the per centum was taken from how many boxes contained settlements. The significance of the graph is demonstrated from the degree form that the graph shows, the experiment may hold had an issue with sterilisation or the consequences had more per centum growing after each test.
To get down the treatment the chief factor in this experiment is the cogency of the consequences, the first look the consequences help proves informations that support the hypothesis. The processed information nowadayss different factors that affect the consequences and some parts of the informations may bespeak an mistake in the experiment.
From the information, the hypothesis is plausible from the informations presented in the analysis. Get downing with Chart A, the fluctuation between the experimental group and the control group, gives an thought on the dependability of the information. The control group seems to hold an upward tendency in the first two tests ; nevertheless, the group dips down after the 3rd test. The experimental group, hands covering a oral cavity, provides a positive upward tendency from the first test to the 3rd test. These upward tendencies show that the informations in the analysis is consistent. Finally, the facemask group does non look to hold a tendency, but stay comparatively lower than the remainder since it appears to hold less bacterial growing than the remainder.
Chart B, besides gives some grounds that the hypothesis is supported, since the norms of the bacterial settlements present lower sums of bacteria in the experimental groups. The chart foremost demonstrates the upward tendency of each group, which could besides be a portion of grounds that the sterilisation of the agar medium was flawed. However, Dish C ( facemasks ) proves to hold the lowest count of settlements in the group, which does back up the hypothesis. This is besides presented in Chart C, the facemasks have a lower norm, and the control and other experimental group both have similar high norms, I would state that the control group has a high norm since it was ever higher than the custodies over mouth status, until the 3rd test came.
Chart D, eventually presents the sum of coverage that the bacterial settlements created, and merely like the remainder of the graphs, there is an upward tendency. The sum of coverage provides an thought on how much the settlements grew, non merely figure, nevertheless, the size of the settlements that took up the Petri dish. To a surprising consequence the more bacteria coverage, was from the facemasks ( merely presented in tests 1 and 2 ) and the control had the least sum of coverage. I feel that there are other factors that have affect this experiment from these consequences, such as the environment around the experiment.
The environment around the experiment may impact the consequences since other sources could hold contaminated the agar medium, or the Petri dishes. When a Petri dish, with the agar medium interior, is opened so all the sources environing the room would expose the unfertile stuffs with new sources and bacteriums. This can be proven since in my experiment there was an case where cast was grown, since a spore had travelled its manner into the dish. Now the experiment calls for complete asepsis since the bacterial civilization needs to show the bacterium from the individual coughing, but non the bacteria or other lending factors should be present in the civilization. I proved that the agar medium was sterilized in the pre-experiment, and the consequences returned with no settlements presented. However, I merely conducted this pre-experiment one time, before I started the experiment, during the experiment when I created a new batch of agar medium, I did non prove to look into if the medium was sterilized.
From this factor, the experiment illustrates that there was a sterilisation issue with some, if non most of the information. In the Dish B experimental group, this was covering custodies over the oral cavity, was proved to hold this issue, since it had the piece of mold turning in the agar medium. This issue could hold affected non merely the experimental group, but besides the whole test with the experimental group and control group. The agar medium that was prepared could hold had a breach of air when being processed, or another individual could hold tampered with the beaker that contained the medium. If the outside air contaminated the agar medium, so the full test that I used the medium for would hold been affected. I merely created a new batch of agar medium when the old batch would run out, therefore I did non carefully look into each batch to see if it was unfertile.
If this event occurred so the bacteria count would be higher than usual during that test. The Dish B test does show some grounds that the test could hold been flawed. Charts B, C, and D ( the label in the upper left manus corner ) give support that does propose there was an mistake in my experiment. From Chart B, the norms of the settlements in each test, the first test had comparatively low mean counts, so as the tests went on the norms kept increasing at a rapid rate. Trial 1, in Chart B about showed small to no norms. In Chart C, the upward tendency of the graph proves that from the start, test 1, the norms were low, so as the tests went on the positive addition hints the thought that there was more and more bacteria presented.
From my first “ pre-experiment ” I conducted, I made an inordinate sum of agar medium, so that the leftovers, after this beginning experiment, could be used towards my existent experiment. The consequences of my “ pre-experiment ” concluded that none of the Petri dishes had any hint of bacteria ; I so conducted my first test for my experiment, with the sterilised medium. Since the Numberss from the norms of the first test were enormously lower, when compared to the others, this could be grounds that the first test worked, while the other tests did non, or the medium was contaminated from bacteriums before coughing. In add-on, the agar medium could hold non encouraged growing for bacteriums. Bacteria normally live in topographic points above freeze and some bacteria are known to populate in utmost topographic points with an acidic environment.[ 5 ]If the agar medium did non supply an environment for bacteria to turn so the consequences would be altered. However, from the grounds in the charts above, the more realistic thought would be that bacteria, and in some instances mold, had contaminated the agar medium, which was suppose to be to the full unfertile.
Decision and Evaluation
The experiment I conducted has shown some issues with the sterilisation, therefore the forms that were illustrated through my informations were non forms but errors from the contaminated agar medium. The hypothesis does hold some supported stuff to reason that it has some plausibleness ; nevertheless, since most of the experiment had a error, the hypothesis can non be confirmed or rejected.
The experiment should be refined so the same errors will non be made in another experiment. If the pre-experiment was conducted more than one time, so the agar medium will ever be sterilized decently and the consequences will non be affected by taints. The experiment could hold more tests to show whether all the information is affected by a error, and more informations would supply more grounds towards the hypothesis.
When puting up this experiment at that place needs to be careful safeguards and unfertile trials. I feel like the cotton seal in the beaker of agar medium may supply excessively much air acquiring into the beaker. The warming home base, could besides be turned up to a higher temperature to do certain that the agar medium is wholly germ and bacteriums free. If more unfertile trials and careful manoeuvres were used in the experiment, so their might hold non been an issue, or I would hold noticed the error before it was excessively late. I did take safeguards when pouring and managing the agar medium, nevertheless, I merely conducted one “ pre-experiment ” unfertile trial of the agar medium.
The design of the experiment could really good be changed, if person were to desire to prove some other type of mask. Different trade names of masks could be the focal point of this experiment, or different types of bodily fluids could be tested, such as sneezing. The design could be about sneezing and coughing, does one green goods more sources than the other? If a individual wanted to prove the sources on the interior of the mask, a sample can be taken from inside of the mask and placed in a civilization.