Even first grade students can practice epidemiology, the science of tracking disease transmission. After school, ask your family and friends if they have ever been sick. Good types of sickness for this project include a stomach bug, a cold, a flu, the measles, cold sores (when someone's lip breaks out in spots) or chickenpox. Write down that person's name and the list of diseases they have had. Then ask the person where they think they caught the disease and if they thought the disease was caused by a virus, a fungus or a bacterium. Bring the project into school to show the teacher and the teacher will be able to tell you how many of your family and friends were correct in identifying the cause of the disease and how they caught it.
Germs are present on food as well as on people. Choose three types of food to show how the germs that are on the food, or that land on the food from the air, affect the food over time. Good examples are lemons, bread and a container of milk. Keep the milk container closed, because spoiled milk smells terrible, and to show that the milk already has germs in it, and is not getting any extra germs from the air. Record what the food looks like after three days.
Slice two potatoes into halves. Hold each potato half by the skin side. Put one half into a plastic freezer bag and seal and label it. Rub another half on the floor of the classroom and put it into another bag and seal and label it. Get everyone in the class to handle the third half and then place it in a different labeled bag. Ask the class to breathe on the last half, and put it into a final labeled bag. Leave the closed bags in a cupboard for a week. Take out the potato halves after this time and see which potato has the most germs on it and which has the least. This will demonstrate the amount of germs on each surface and in breath.
Cover a ball in petroleum jelly and then sprinkle lots of glitter on to it. This ball is your source of germs, and each glitter sparkle counts as one germ. Throw the ball to one of your classmates. She throws it to another classmate and they throw it to another. Continue passing the ball until all of the class has touched it. Line up the class in order of who touched the ball. When everybody holds their hands out, you will see that the people who touched the ball first have the most glitter. Then get the class to wash their hands. This project illustrates how germs, which are so small that we cannot see them, get passed from person to person.