Have you ever stood in front of the shelves at the store searching for the "best" sunscreen but were overwhelmed by the number of choices? I know I have! Sprays, creams, tinted, mineral, chemical, different SPFs, the number of choices is endless. We all know that sunscreen is important in protecting against skin cancer, but where to begin with making a selection?
These questions are how the UV Radiation Investigation was born. Over the last 2 years, my physics students have sought to answer the question: What is the most effective sunscreen?
This is my favorite project/experiment I do with my students all year and it is actually the final project of the year. This project concludes my unit on waves and was significantly modified from a project I found through the Savvas Realize platform. The majority of my physics students have seemed to really enjoy this project because of the direct real life applications and the amount of creativity they are afforded.
The Process
In groups of 3-4, my students begin their investigation with research. Where does UV radiation come from? what are the wavelengths? how does each band of UV impact the different layers of the skin? What are the types of sunscreen? What does SPF and broad spectrum mean? What are the common ingredients in sunscreens? What does current research say the pros and cons are of each sunscreen?
After finishing their research, they design an experiment to test 2-3 different sunscreens using UV beads. All student groups had access to the same materials.
Each group is required to have 10 steps in their procedure and have a control group which shows how the UV beads reacted to sunlight with no protection. All groups conducted their investigation at the same time so that the amount of UV radiation was the same for each project.
Throughout the investigation, they record data and take pictures for evidence.
Once the investigation is complete, they synthesize their data, communicate their results, and evaluate their overall project.
The Results
In 2022, the research questions my students investigated were:
Effectiveness of 30 SPF vs. 50 SPF spray
Effectiveness of 30 SPF vs. 50 SPF cream
Effectiveness of 30 SPF spray vs. 30 SPF cream
Effectiveness of 50 SPF spray vs. 50 SPF cream
Effectiveness of 50 SPF mineral or 50 SPF chemical cream
For all projects, students had access to Banana Boat, Coppertone, and Up&Up (Target) brand sunscreens. Groups were asked to use a nickel size amount of sunscreen to keep amounts consistent from group to group.
Based on all the results, students determined that the mineral sunscreen was more effective than the chemical sunscreens and that no matter the SPF or brand, the creams were more effective than the sprays.
In 2023, I was more specific with the requirements for the research questions as my students had access to more types of sunscreen and I had more students than in 2022. I also cut out the sprays as an option. The research questions my students investigated were:
Effectiveness of mineral (blue lizard) vs. Banana Boat 30 SPF chemical
Effectiveness of Banana Boat 30 SPF chemical vs. generic (Up&Up) 30 SPF chemical
Effectiveness of Neutrogena 30 SPF with oxybenzone vs. Neutrogena 30 SPF no oxybenzone **In 2021 the FDA required sunscreen companies to provide evidence that oxybenzone is a safe ingredient. Companies did not provide the required information and is now not found in sunscreens. It is also a banned ingredient in Hawaii, Key West, and many other island nations for coral reef destruction.**
Effectiveness of Banana Boat expired chemical vs. Banana Boat new chemical
Effectiveness of Banana boat 30 spf chemical vs. Neutrogena 30 spf chemical with no oxybenzone
Effectiveness of combo mineral (Blue Lizard) vs. zinc oxide (thinkbaby)
Effectiveness of Neutrogena tinted mineral vs. mineral (blue lizard)
Again all groups were asked to only use a nickel size amount of sunscreen to keep amounts consistent from group to group. Students then reviewed all the research gathered by all groups and determined that the mineral sunscreens (Blue Lizard and thinkbaby) far out performed the chemical sunscreens and the overall most effective sunscreen of the ones tested was the Neutrogena tinted mineral sunscreen.
Sources of Error
Overall, I think the data gathered by my students is credible but there are many sources of error to keep in mind in regards to the results. The number of beads was not the same from group to group, amount of time spent outside was not constant, the way data was collected was not constant, and in general, some students were just less motivated than others throughout the project.
**As an Amazon Associate I earn from qualifying purchases**
Comments