Learn about the importance of washing your hands while also learning about mold! Mold spores are all around us: in the air, on our hands, even in foods we eat. Some mold, like the one in blue cheese, is harmless and delicious. But some molds can make us sick. Washing our hands can help remove harmful microbes from our skin. In this experiment you will see how much mold can be passed onto the bread in different scenarios.
Before you begin, make a prediction of what will happen. Which bread do you think will have the most mold? Which will have the least?
EQUIPMENT:
- Loaf of bread
- Hand sanitiser or hand soap
- 5 zip lock bags and a pen to label them with
- Clean rubber gloves
Step 1:
Label the zip lock bags “Air,” “Dirty hands,” “Washed hands,” “Door handle,” and “Control.”
Step 2:
Now that the bags are ready, it’s time to begin the experiment. First, we must set up the control. In a science experiment, the control group is the one that is not altered with the experimental treatment (in this case, not exposed to mold). It is used as a comparison to see what effect your treatment had. To make sure the “control” is not contaminated, use rubber gloves to put 1 slice of bread into the bag labeled “control.” Make sure it is sealed tight.
Step 3:
Now we will make the rest of the treatment groups. As we said, mold is everywhere. We will use the bread as a food source for the mold, to help it grow. We will explore where the most mold is and whether washing hands can help get rid of mold from our skin.
Step 3.1: door handle
Wearing rubber gloves, take a piece of bread and wipe it on the door handle. Put this piece in the bag labeled “door handle.”
Step 3.2: dirty hands
Have a partner wear rubber gloves, take a piece of bread, and place it on your hands. Put it in the bag labeled “dirty hands.”
Step 3.3: clean hands
Now, go clean your hands with hand sanitizer. Wait until they are super dry! Using gloves, take out a slice of bread and put it in your now clean hands. Place it in the bag labeled “clean hands.”
Step 3.4: air
For our last treatment group, we will try to see the mold in the air. To do this, use rubber gloves to take out another piece of bread. Place this slice on top of the bag labeled “Air.” Leave this here until the end of class. This will give the bread time to collect mold that might be floating in the air. Then using gloves, move the slice of bread into the bag and zip it closed.
Step 4:
Now it’s time to wait and see! In 5-7 days or so you will see some mold start to grow. Which one has the most? Write down what you see when you see it. Take pictures of the mold growth so we can see the results of your experiment.
- Level: Moderate
- Theme: Indoor air quality
- Entry evidence: To get credit for this activity, take a picture of your moldy bread and have a grown-up submit the challenge form. Complete 3 challenges and we will plant a tree.
Mold in the air changes throughout the year. Mold grows best in damp conditions so is more common in humid areas. Under the right conditions, mold can grow anywhere and can destroy the material on which it grows. Mold will grow more rapidly on some material types than others, in particular materials like wood, certain textiles, and cardboard/paper. Try repeating this experiment at different times during the year to see how humidity changes with the seasons and affect mold risk.
