I Scream, You Scream, We All Scream Without Sunscreen

Challenge
The sun emits harmful UV rays year-round. Even on cloudy days, up to 80 percent of the sun’s harmful UV rays can penetrate your skin. Sunlight consists of two types of harmful rays that reach the earth — UVA rays and UVB rays. Overexposure to either can lead to skin damage. In addition, here are other effects of what each of these rays can do:

• UVA rays (or aging rays) can prematurely age your skin, causing wrinkles and age spots, and can pass through window glass.
• UVB rays (or burning rays) are the primary cause of sunburn and are blocked by window glass.

So how do you prevent damage from the sun? Hopefully, you answered with something along the lines of using sunscreen or SPF (sun protection factor). There are so many different versions! Which is the best? How long does sunscreen work in the sun? Does the brand matter? These are all questions that you can try out for this month’s STEM Challenge. But just remember, no sunscreen is able to block 100 percent of the sun’s rays.
For criteria and constraints, it’s up to you to figure them out! It’s suggested that you put the same number of beads in the same kind of bag. The testing protocols are yours to choose, but just make sure everything you conduct is a fair test.

Materials

• plastic UV beads (similar to these https://www.amazon.com/dp/B01LZFI7AF/ref=sspa_dk_detail_1?psc=1&pd_rd_i=B01LZFI7AF&pf_rd_m=ATVPDKIKX0DER&pf_rd_p=1713835751726239774&pf_rd_r=5ZBP9BH4RE8NTT7QE165&pd_rd_wg=Ag2T5&pf_rd_s=desktop-dp-sims&pf_rd_t=40701&pd_rd_w=mByta&pf_rd_i=desktop-dp-sims&pd_rd_r=ac5f2b23-807f-11e8-94ad-0d6a86c107a2)
• marker
• plastic sandwich bags
• other materials as needed
• various sunscreens with various SPF if needed

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Hints and Tips for Success

1. Allow students planning and discussion time for creating fair tests of how they will answer the question of their choice. Evaluate trials to ensure there is fairness and equity. Questions to consider but are not limited to: Are all brands of a certain SPF the same protection? Can you be in the sun longer with a different SPF? What’s the best sunscreen? How often should you reapply sunscreen? Does there come a time limit when SPF doesn’t matter?
2. After discussing and creating fair tests, allow student groups to plan their trial with the materials provided. Include as many ways to improve their trials as needed.
3. For differentiation, provide the question students need to answer, provide the fair test steps, have all groups working on the same question, limit the amount of questions in the class. Adjustments could be made to make it more challenging or simpler.
4. Make sure groups are measuring the same amount of sunscreen for each trial as close as possible, using the same number of beads for every trial, laying the beads out the same number of minutes/hours in the same location, and labeling each bag with the brand and SPF of the sunscreen. Students should be trying to answer the question stated for their challenge.
5. Determine a process for adhering sunscreen to the beads for a fair test. One way is to put the beads in a sandwich bag, flatten the bag, and apply an even amount of sunscreen over the bag.
6. Connect to science by discussing the effects of sunlight or UV rays.
7. Connect to ELA by reading Sammy Learns About Sunscreen by Manisha Shelley Kaura, Sunscreen Irene by Larry and Jen Cheifetz, or Hey! Don’t Forget the Sunscreen by Kimberly Kennedy. Each book provides examples of the importance of wearing sunscreen when going outside with helpful hints.