To explore the link between exposure to the sun’s ultraviolet radiation and the chance of getting a sunburn.
This lesson is part of the Skin Deep Project, which examines the science behind skin. Skin Deep is developed by AAAS and funded by Neutrogena. For more lessons, activities, and interactives that take a closer look at the science behind skin, be sure to check out the Skin Deep Project.
This lesson will increase student awareness of the effects of unprotected sun exposure, both long term in the case of skin cancer and premature aging of the skin, and short term in the case of first- and second-degree burns. Students will make the connection between exposure to the sun’s ultraviolet (UV) radiation and the mutation of skin cells into cancer.
By calculating the different amounts of time each student can safely expose their skin to the sun’s radiation without getting burned, students begin to put together a picture of how damaging it can be to spend too much time in the sun without the benefit of sunscreen and other kinds of protection (i.e., hats, sunglasses, etc.). Students learn how early exposure to the sun can cause premature aging of the skin and skin cancer in later years. By using a sunscreen that is matched to their skin type, students can easily calculate how much more time they can spend outside if properly protected.
By the time they reach high school, students should understand that all living organisms are made up of cells and cells can divide to make more cells for growth and repair. They also should understand that organs and organ systems are composed of cells and help to provide all cells with basic needs. (Benchmarks for Science Literacy, p. 112.) In addition, students should understand that the environment may contain dangerous levels of substances that are harmful to human beings.
One misconception in particular that could have a big impact on how students view the risks involved with sun exposure is that they tend to believe that many factors they consider important to their health and life span are also beyond their personal control. (Benchmarks for Science Literacy, p. 346.) This lesson strives to debunk this misconception by helping students explore how sunscreen can help protect their skin from the harmful rays of the sun.
Present several photos of people with severe sunburns to the class and ask students to write a brief one to two paragraphs detailing their thoughts about the pictures. They should address how this might have happened, how long it took for this to happen, how this might have been prevented, if this has ever happened to them, etc. A variety of pictures of sunburns can be found online by doing a search for images of sunburns or students can bring in their own photos of sunburns.
Share stories and discuss possibilities.
In this part of the lesson, students should look more closely at the link between sun exposure and sunburn. They will study how the amount of ultraviolet (UV) radiation we are exposed to is a major risk factor for not only cancer, but early skin aging and other skin problems. UV radiation alters the chemical composition of skin cells, making them more susceptible to cancer.
In section one, they will do research to answer discussion questions and build background knowledge about skin cancer. In section two, students will make the connection between sun exposure and their own lives. They will see the effects of the use of sunscreens in various locations on the earth. The Assessment finishes off with students taking their new knowledge and presenting it to others in the form of a presentation.
Section One: What is skin cancer?
First, have students use their Sunburn, Sunscreen, and Cancer student esheet to go to and read Skin Cancer and Sunlight, from the Canadian Centre for Occupational Health & Safety. After students have read this resource, hold a class discussion using these questions:
- How does sunlight affect the skin?
- What is sunburn?
- How does the sun affect the aging process of the skin?
- How does the sun affect skin cancer?
- What types of skin cancer are linked to sunlight exposure?
- What factors affect a person's risk?
- Does skin pigment affect the ability to tan?
- (Some ultraviolet radiation is scattered into the tissues just beneath the skin's surface. A fraction of this radiation is absorbed by the skin's living cells. Ultraviolet radiation absorbed by living cells damages sensitive substances that influence the skin's normal growth and appearance. Damage can include: suntan, sunburn, wrinkling, aging of the skin, and skin cancer.)
- (It is an inflammation caused by an increased blood-flow beneath the skin. The skin can turn a bright red color within 15-20 hours after exposure.)
- (Repeated exposure to the sun's ultraviolet radiation eventually causes skin damage similar to the aging process. Patches of skin become thin and less elastic, and develop blemishes, sun freckles, and wrinkles.)
- (Skin damage caused by exposure to sunlight can increase chances of developing one or more forms of skin cancer. Exposure to ultraviolet radiation increases the risk of developing these cancers.)
- (There are three different types of cancer linked to sunlight exposure: basal cell cancer, squamous cell cancer, and malignant melanoma.)
- (There are four main factors that affect a person's risk: skin pigment and ability to tan, heredity, exposure to certain chemicals, amount of exposure to sunlight.)
- (Darker skinned people have lower risk of sun-induced skin cancer. The person most prone to skin cancer caused by sunlight tans poorly and suffers sunburn easily.)
Section Two: Sunscreen and protective factors
Now, explore the link between exposure to the sun and sunburn with your students. Be sure to address the use of tanning products and sunscreens as well as any misconceptions students may have about sun exposure.
Provide students with the Sun Exposure student sheet. Direct students to use their student esheet to go to and read these resources so that they can complete the student sheet:
Once students have completed their student sheets, hold a class discussion with these questions:
- Compare your summary to the other students in the class. Do they differ? Why or why not?
- What factors made each person different?
- Using the information gained from this activity, write a brief summary of the steps you personally should take before going out into the sun in each location and why.
Divide students into groups. Have each group create a public service announcement that will aid people in learning more about the dangerous effects of the sun. Each group will create a poster, design a billboard, write and perform a song, produce a video, or write and perform a radio public service announcement that will educate people. Student presentations can include information from all or just one of these areas:
Students should create at least five questions that their presentation should address. They should choose a media which their group will use to present their information. Then they should create a rough draft of the content and check with you before proceeding. Have students present their final projects to the class and be prepared to answer class questions.
You can use the Teacher Evaluation Rubric to help you evaluate student understanding. You also can go to Rubistar to create an evaluation rubric for these presentations. Go to the homepage and click on products. There are a variety of choices, including oral presentations, video presentations, music, and more.
You can extend the ideas in this lesson by leading students through another Science NetLinks lesson: Sun & Skin.
Use the Global Solar UV Index: A Practical Guide to delve deeper into the environmental factors that affect the UV radiation on skin. These include cloud cover, reflection from the ground and snow, elevation, and latitude. This is an excellent resource to print and use as required reading.