If someone wears various face masks for a various amount of time, then their blood oxygen level will stay within the normal range (95%-100%), because healthy lungs can continue working properly with small changes in air flow.

(3 types of face masks, 4 different times)

Surgical: Before: 96%, 94%, 98%, 96% Average: 96% 15 min: 93%, 96%, 96%, 100% Average: 96.25% 30min: 92%, 97%, 96%, 97% Average: 95.5% 1 hr: 98%, 95%, 96%, 95% Average: 96%

Cloth: Before: 95%, 97%, 95%, 96% Average: 95.75% 15 min: 95%, 98%, 95%, 96% Average: 96% 30min: 94%, 96%, 98%, 96% Average: 96% 1 hr: 93%, 97%, 95%, 97% Average: 95.5%

KN95: Before: 96%, 97%, 97%, 96% Average: 96.5% 15 min: 95%, 98%, 97%, 98% Average: 97% 30min: 94%, 97%, 97%, 96% Average: 96% 1 hr: 94%, 98%, 97%, 98% Average: 96.75%

Constant (Controlled) Variables: People being experimented on, health conditions, activity doing, environment, same Pulse oximeter

Manipulated (Independent) Variables: amount on time wearing mask, mask type

Responding (Dependant) Variable: Blood oxygen level

1. measure participant's blood oxygen level before wearing mask
2. set timer for 15 minutes
3. measure blood oxygen level again when timer is up and record data
4. set timer for another 15 minutes (total 30 min)
5. measure blood oxygen level again when timer is up and record data
6. set timer for 30 minutes (total 1 hr)
7. measure blood oxygen level again when timer is up and record data
8. repeat with all participants
9. repeat with all 3 mask types. Write Observations:

Before wearing a surgical mask, the average blood oxygen level of each participant is 96%. After wearing a surgical mask for 15 minutes, the average blood oxygen level of each participant rose 0.25% to 96.25%. After wearing a surgical mask for 30 minutes, the average blood oxygen level of each participant lowered by 0.75% to 95.5%. After wearing a surgical mask for 1 hour, the average blood oxygen level of each participant rose 0.5% to 96%.

Before wearing a cloth mask, the average blood oxygen level of each participant is 95.75%. After wearing a cloth mask for 15 minutes, the average blood oxygen level of each participant rose by 0.25% to 96%. After wearing a cloth mask for 30 minutes, the average blood oxygen level of each participant stayed the same at 96%. After wearing a cloth mask for 1 hour, the average blood oxygen level of each participant lowered by 0.5% to 95.5%.

Before wearing a KN95 mask, the average blood oxygen level of each participant is 96.5% After wearing a KN95 mask for 15 minutes, the average blood oxygen level of each participant rose by 0.5% to 97%. After wearing a KN95 mask for 30 minutes, the average blood oxygen level of each participant lowered 1% to 96%. After wearing a KN95 mask for 1 hour, the average blood oxygen level of each participant rose 0.75% to 96.75%.

The recorded data suggests that human lungs are able to adapt to slight air shifts and after wearing a surgical, cloth, and KN95 mask, there was only a small change in the average blood oxygen level (0-1%) and in all cases, it was all within the normal range (95%-100%).

For the surgical mask, before wearing it, the average blood oxygen level was 96%, and after wearing it for 15 minutes, it increased slightly to 96.25%. After wearing it for another 15 minutes (total 30 minutes), it shifted down a bit to 95.5. Later on, at 1 hour, the average blood oxygen level rose by 0.5% back to the original average blood oxygen level, 96%. This suggests minor shifts rather than a consistent upwards or downwards trend.

For the cloth mask, before wearing it, the average blood oxygen of the participants was 95.75%, and after wearing it for 15 minutes, the average rose by 0.25% to 96%. When the participants wore a cloth mask for a total of 30 minutes, their average blood oxygen level stayed the same at 96%. Afterwards, when the timer reached 1 hour, their average blood oxygen level fell to 95.5. Again, due to the inconsistent up and down shifts, it's also not a continuous pattern.

Lastly, for the KN95 mask, the average blood oxygen level of the participants was 96.5%, and after 15 minutes, it rose slightly to 97%. Later, when the timer reached 30 minutes, the average lowered by 1% to 96%. When the participants wore the KN95 for a total of 1 hour, the average blood oxygen level rose to 96.75%.

Overall, none of the masks caused a significant increase or reduction in the participants' blood oxygen level. The variations noticed (0-1%) are very minor and are all within the typical range of human blood oxygen level. The results show wearing a surgical, cloth, or KN95 mask doesn't noticeably affect human blood oxygen level.

The results proves my hypothesis that if someone wears different types of face masks for various amounts of time their blood oxygen will stay within the normal range ( 95%-100% ) was correct, because there was no significant trend of blood oxygen level rising or falling in any of the trials i did, rather, they all just shifted sightly and randomly by 0-1%.

In real life, this could impact what face mask people choose to wear knowing how long they're going to wear it and how it'll impact their blood oxygen level.

One source of error might be that my pulse oximeter might not be very accurate, which might've impacted my results. Another is that the experiment was performed at different times of the day.

https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/lung-function? https://www.ncbi.nlm.nih.gov/books/NBK554401/? https://www.ncbi.nlm.nih.gov/books/NBK542183/? https://my.clevelandclinic.org/health/diagnostics/22447-blood-oxygen-level

I would like to thank my teacher and family for all their support. I would also like to thank all the participants who helped perform this experiment and everyone who made this project possible.