eb82e2758c074719be14c53bd131595c
Posts: 6
Joined: Mon Nov 23, 2020 4:54 pm
Occupation: Student

Seeking advice for my science fair

Postby eb82e2758c074719be14c53bd131595c » Mon Nov 23, 2020 5:17 pm

Hi,

I am a bit confused about the project I am doing. Basically, I am comparing the efficiency of different masks (n95, surgical, cloth, and a metamask-a mask made of nanofibers). I am kind of confused on how I should do this. I'm not sure about how to test the difference in filtering efficiency between them, and couldn't find a valid method that is within budget. I would appreciate it if you would help :)

Thank you!

koneill18
Expert
Posts: 84
Joined: Thu Aug 06, 2020 8:22 am
Occupation: Other Adult

Re: Seeking advice for my science fair

Postby koneill18 » Tue Nov 24, 2020 10:53 am

Hello!

This seems like a really interesting project! You can try using a spray bottle filled with water to simulate the aerosols that people release when they talk, sneeze, or cough. Here's a link to a Science Buddies video that talks through a procedure that you may be able to modify to use for your experiment.

https://www.youtube.com/watch?v=ZoBslwE ... e=youtu.be

Here are some links to two other message threads from the Ask an Expert forum that discuss project ideas relating to mask efficiency. These might help give you some inspiration for your own project.

viewtopic.php?t=21749

viewtopic.php?t=21654#p70730

I hope this helps!

eb82e2758c074719be14c53bd131595c
Posts: 6
Joined: Mon Nov 23, 2020 4:54 pm
Occupation: Student

Re: Seeking advice for my science fair

Postby eb82e2758c074719be14c53bd131595c » Tue Nov 24, 2020 11:11 am

Hi, thank you for your help!

I just wanted to clarify-I'm actually testing mask efficiency against wildfire smoke pollutants, not Covid-19. I don't think I specified that before, so I apologize! Are there ways to test how much smoke particles masks can filter?

Thank you again!

koneill18
Expert
Posts: 84
Joined: Thu Aug 06, 2020 8:22 am
Occupation: Other Adult

Re: Seeking advice for my science fair

Postby koneill18 » Tue Nov 24, 2020 5:45 pm

Oh gotcha! Testing mask efficiency against smoke is a little trickier than testing efficiency against aerosols. The methods for testing particulate matter filtration seem to require equipment that you wouldn't have access to outside of the lab. I did some searching for alternative techniques, and I found this one that might work for you if you have access to a microscope. It's on page 4 of the document in the Materials and Methods section.

https://www.ncbi.nlm.nih.gov/pmc/articl ... 7-7142.pdf

The researchers used what they called the "particle counting method." They placed a microscope coverslip in a petri dish, covered the the dish with the mask, and secured it with a rubber band. They left the dish outside in the area where they wanted to test the mask's air filtration abilities and they let the particulate matter in the air pass through the mask. Then they took out the coverslip and used a microscope to count the number of particles that were deposited onto the coverslip. The number of particles that were able to pass through each mask were compared to see which masks were the best at filtering particulate matter out of the air.

This was the simplest procedure that I could find, but some of the other experts may chime in if they think of other methods. I hope this helps!

eb82e2758c074719be14c53bd131595c
Posts: 6
Joined: Mon Nov 23, 2020 4:54 pm
Occupation: Student

Re: Seeking advice for my science fair

Postby eb82e2758c074719be14c53bd131595c » Tue Nov 24, 2020 6:19 pm

Thank you! This article is really useful, and I will try to implement the method in my project.

Thanks again!!

eb82e2758c074719be14c53bd131595c
Posts: 6
Joined: Mon Nov 23, 2020 4:54 pm
Occupation: Student

Re: Seeking advice for my science fair

Postby eb82e2758c074719be14c53bd131595c » Thu Dec 03, 2020 9:59 pm

Hi again,

Thank you for your advice. I have a few more questions. What is a way to expose the mask to particulate matter and let it pass through the mask? Like can I place the mask around a running car to see if the exhaust coming from the car passes through the mask? Also, in the article it says a bright field microscope was used to count the particles. Is this a method I can do at home? Or do I need to perform it in a lab? Your help is greatly appreciated!

Thank you!

koneill18
Expert
Posts: 84
Joined: Thu Aug 06, 2020 8:22 am
Occupation: Other Adult

Re: Seeking advice for my science fair

Postby koneill18 » Fri Dec 04, 2020 9:16 am

Hello!

If you place the masks about 6 feet or so behind a running car, you should be able to collect particulate matter from the exhaust coming from the tail pipe. Just make sure that you do it outside so you're not breathing in the exhaust. Keep in mind that this experiment would be testing the efficacy of masks against air pollutants coming from vehicle exhaust. If you still wanted to test the efficacy against wildfire smoke pollutants, you would probably have to put the masks near something like a campfire, which may not be feasible or safe depending on where you live. But understanding how to protect people against air pollution caused by vehicle exhaust is also very important, so it's still a good topic for a science project!

For the microscope part of the experiment, you can do it at home if you have a bright field microscope. They sell them online, but they're usually a few hundred dollars. If you have access to a school or lab that already has microscopes, that would be a much cheaper option.

I hope this answers your questions! Feel free to ask any other questions that you have.

eb82e2758c074719be14c53bd131595c
Posts: 6
Joined: Mon Nov 23, 2020 4:54 pm
Occupation: Student

Re: Seeking advice for my science fair

Postby eb82e2758c074719be14c53bd131595c » Sun Jan 03, 2021 3:53 pm

Thank you again for your help. My experiment is testing how much each mask (N95 mask, surgical mask, cloth mask, and a metamask) is able to filter out smoke pollutants.

Just to make sure, can an optical microscope in bright field mode actually count the amount of particles filtered from each mask?

Based on the article, https://www.ncbi.nlm.nih.gov/pmc/articl ... 7-7142.pdf, the experimenters left the assembly (petri dishes with the coverslip inside and the mask covered on top, like you said) 20 ft above the ground and allowed pollutants from exhausts, factories, and poorly maintained roads to gather. However, in the area where I live, there isn't much pollution, so placing the assembly outside wouldn't do much good. I don't think campfires are safe to test with, so what is an alternative that is equally efficient to test with, so that pollutants are still deposited onto the coverslip, and I can measure them?

Thank you!

koneill18
Expert
Posts: 84
Joined: Thu Aug 06, 2020 8:22 am
Occupation: Other Adult

Re: Seeking advice for my science fair

Postby koneill18 » Tue Jan 05, 2021 7:28 pm

Hello!

Scientists who simulate air pollution in a lab setting usually use a lot of complex equipment to do it. I don't know of any methods to simulate air pollution outside of a lab setting. But even if you don't have a lot of pollution where you live, I think you'll still be able to pick up some air particulates if you leave your petri dishes outside. Air pollution can refer to many different types of particulates including dust, dirt, plant particle debris, pollen, vehicle exhaust, or smoke. If you set up the dishes near a well traveled road or somewhere that has dirt/dust, you should be able to pick up something.

Being able to see the particles under the microscope is the part I'm more concerned about. If you collected air particles without a mask, there would be big particles in the dish that you could easily see with a microscope, or even just a magnifying glass. But I'm guessing that the mask will catch a lot of those bigger particles and only the small particles will get through. The article says that the researchers were able to see the particles at 100X magnification. If you have access to a microscope that can go up to 100X, I'm guessing you'll be able to see something. If you don't, we can work on trying to modify your project to be more compatible with the resources that you have. You can always do a test run by setting up one petri dish without a mask and another dish with a mask and then comparing the two under the microscope. If you can see particles from the dish that didn't have a mask over it but you can't see anything on the coverslip that was covered by the mask, then that microscope probably won't work for the project.

I also just realized Science Buddies has an air pollution project that's kind of similar to the one in the article, except without the masks. I linked it here in case you want to use it as another reference.
https://www.sciencebuddies.org/science-fair-projects/project-ideas/EnvSci_p009/environmental-science/air-particles-and-air-quality#summary

I hope this helps!

eb82e2758c074719be14c53bd131595c
Posts: 6
Joined: Mon Nov 23, 2020 4:54 pm
Occupation: Student

Re: Seeking advice for my science fair

Postby eb82e2758c074719be14c53bd131595c » Fri Jan 08, 2021 1:46 pm

Thank you! This helps


Return to “Grades 6-8: Life, Earth, and Social Sciences”