UV Radiation

Liam, don’t you know that you’re still Sophie, come sit with me in the shade. The UV

exposed to UV radiation even in the

radiation is dangerous.

shade?

Read the dialogue between Liam and Sophie. Who do you think is right? Liam? Sophie?

Are we still exposed to ultraviolet (UV) radiation in the shade? Explain why you think so.

Take your einstein™ device outside and measure the UV light intensity both in the sun and in the shade.

Were you surprised by what you observed?

What did you learn from the results of your measurements?

In this investigation we will explore UV radiation. You will observe how well different materials block UV radiation from the sun. You will work in groups. Each group will choose one material and investigate how well it blocks UV radiation. You will create a chart which will bring together the observations from all the groups. Based on your results, you will create a set of guidelines to help students protect themselves from UV radiation.

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einstein™Tablet+ or einstein™Labmate+™ paired with a tablet sunglasses white T-shirt or a square of white T-shirt material hat sunscreen clear plastic bag which does not block UV rays

1. Turn on the einstein™Tablet+ or einstein™Labmate+™ (paired with a tablet).

2. Tap the MiLAB (

Tap the Setup cog (

) icon to open the application.

) and use the table below to set up the measurement parameters:

Predict what will happen when UV light shines on the protective items you are investigating.

Will the materials block the UV rays? Will the intensity of the UV rays measured by the sensor increase, decrease, or remain unchanged?

Make a prediction for each of the items:  Sunglasses  T-shirt  Hat  Sunscreen

1.

2.

In order to get accurate results, you should conduct this investigation on a sunny day in the afternoon.

Each group should choose to study one of the protective materials:

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6.

 Sunglasses  T-shirt  Hat  Sunscreen Make sure that all the groups are measuring under the same conditions. Be careful to always have the UV sensor facing in the same direction and at the same angle towards the sun. Make all the measurements in the same location.

Hold the materials directly in front of the UV sensor on your einstein™ device.

You will need to make two separate measurements:  Measure the UV radiation intensity when exposed to sunlight.  Measure the UV radiation intensity through the protective material you have chosen.

Choose a second location to repeat your investigation.

1.

Position the einstein™ device so that the UV sensor is facing the sun.

2.

Tap Run (

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5.

Tap Stop ( ) when the measurement is completed.

Repeat the measurements three times.

Choose a second location to repeat your investigation.

6.

After making the measurements, give the file a name and save it (

1.

Choose one of the materials for investigation and follow the instructions below for your material.

Sunglasses  You need to measure the UV light intensity through the sunglasses.  Stand in the same spot that you measured the UV intensity without the sunglasses.  Hold the lens of the sunglasses directly in front of the UV sensor, without touching it.  Make sure the UV sensor is facing towards the sun with the same orientation as it was for the original UV measurement.

T-shirt  You need to measure the UV light intensity through the T-shirt material.  Stand in the same spot that you measured the UV intensity without the T-shirt material.  Hold a single layer of T-shirt material directly in front of the UV sensor, without touching it.  Make sure the UV sensor is facing towards the sun with the same orientation as it was for the original UV measurement.

Hat  You need to measure the UV light intensity through the hat.  Stand in the same spot that you measured the UV light intensity without the hat.  Hold the hat directly in front of the UV sensor, without touching it.  Make sure the UV sensor is facing towards the sun with the same orientation as it was for the original UV measurement.

Sunscreen  You need to measure the UV light intensity through sunscreen.  First, hold the plastic bag directly in front of the UV sensor and measure the UV radiation to make sure that the plastic bag does not block the UV radiation.

) to begin collecting data.

) in the archive.

   

Next, rub some sunscreen on the clear plastic bag.

Stand in the same spot that you measured the UV intensity without the sunscreen.

Hold the plastic bag with the sunscreen directly in front of the UV sensor, without touching it.

Make sure the UV sensor is facing towards the sun with the same orientation as it was for the original UV measurement.

2.

Tap Run (

) to begin collecting data.

3.

4.

5.

Tap Stop ( ) when the measurement is completed.

Repeat the measurements three times.

Move to the second location to repeat your investigation.

6.

7.

After making the measurements, give the file a name and save it ( ) in the archive.

Share your data with all the groups and create a data table together like the one below.

Examine the results in your table and discuss the following: 1. Compare the UV light intensity with and without the protective materials. What are your conclusions about how well each material protects you from UV radiation?

2. Consider how well each material blocked the UV rays. What can you recommend in terms of protection from UV radiation? Make sure to think about:  Different areas of the body which need to be protected.  How long the protection needs to last.

3. Some of the materials which you investigated provide protection for a short period of time and some for a long period of time. Would you recommend choosing just one material for protection or using multiple materials together?

Come up with a set of recommendations for protecting yourself from harmful UV exposure. Record a short video commercial in which you need to persuade your classmates to follow your recommendations.

In this investigation we used a sensor to measure the intensity of UV radiation and to observe how the intensity can be reduced by using protective materials. However, we do not know what kind of damage UV radiation can do to the human body.

When we understand how exposure to UV radiation is damaging to our bodies we can decide how best to protect ourselves.

The UV Index is an international standard for measuring the intensity of UV radiation at a particular place and time. The larger the number, the more intense the radiation and the more danger to your health.

The Sun’s radiation is essential for the existence of life on Earth, for plants, animals and human beings. The Sun’s rays provide light and warmth which provide the conditions that allow life on Earth. Plants use the Sun’s light to make nutrients. People and animals eat plants and so they too use the nutrients to grow and develop.

UV radiation, which is part of the radiation which comes from the Sun can be harmful to humans with prolonged exposure. UV radiation is damaging to the skin and to the eyes. It can cause skin cancer and cataracts and other eye damage.

Our bodies produce a pigment called melanin which protects us from UV radiation by absorbing the UV rays. When we are exposed to the Sun’s radiation, the body manufactures melanin. But it takes a while to make enough melanin to protect us. Before enough melanin is manufactured, the body may be damaged

by UV rays. That’s why it is important for us to find other ways to protect ourselves from too much Sun.