National Radon Program Services

Radon is a colorless, odorless, tasteless, and chemically inert radioactive gas. Radon gas can also be a wonderful topic for student science fair projects. The National Safety Council (NSC) has provided some topics and ideas to explore further and present in science fair projects. Many of these ideas can be done in a multi-layer or three-dimensional format that is not only more interesting to create and cool to look at, but which can provide a unique perspective to a pervasive problem. In the sidebar on the right is a list of resources for additional information on radon that may be helpful to the students as they formulate ideas or hypothesis to test.

Students who complete a radon science fair project can send a summary to the National Safety Council. Students will receive a Certificate of Participation in appreciation for their efforts in helping to educate the public regarding radon.

1. Health Effects of Radon

Radon is the second leading cause of lung cancer and can also cause damaging effects to the human DNA structure. Radon gas decays into radioactive particles that can get trapped in your lungs when you breathe. As they break down further, these particles release small bursts of energy. This can damage lung tissue and lead to lung cancer over the course of your lifetime

Potential projects:

• Draw a diagram of lungs and using overhead transparencies show the progression of lung cancer as the lungs go from healthy to damaged over a span of years.
• Construct a model of the lungs, providing a breakaway of the lung to show its inner tissue (bronchioles, alveoli, bronchial tubes). A student can also show how radon daughter progeny (RDPs) can stick to lung tissue and cause damage.
• Create a model of the human torso from the waist up showing how the radon enters the body, travels to lungs, and then breaks down further causing damage to the lungs.

2. How Radon Mitigation Systems Work

The recommended action level for a home that is tested for radon is 4 picocuries (4 pCi/L) and above. At that level, it is usually recommended that the house owners have a radon mitigation system installed. A radon mitigation system is any system or steps designed to reduce radon concentrations in the indoor air of a building. The type of system installed depends of the foundation of the building.

Potential projects:

• Build a miniature home or provide a miniature section of a home and construct a model radon mitigation system and with narrative on how the system works. Plastic tubing can be used for construction of the system. A miniature fan can even be attached to the tubing to replicate commonly used mitigation systems in the home.
• Build a model demonstrating the different types of foundations that a building can have: basement, slab, crawl space, and combinations. Show how each foundation would require a different type of mitigation system.
• Visit a house having a mitigation system installed and photograph the different stages of the installation. Create a display board with the photographs and a narrative explanation of what stage is doing.

3. The Geology of Radon

Radon is formed by the natural radioactive decay of uranium in rock, soil, and water. Naturally existing, low levels of uranium occur widely in Earth's crust. It can be found in all 50 states. Once produced, radon moves through the ground to the air above. Some remains below the surface and dissolves in water that collects and flows under the ground's surface. Two houses side by side can have very different radon levels. This is due to the geology below the individual homes, including the types of soil and rock and the cracks and fissures.

Potential projects:

• In a plastic box with small air holes in the bottom, show layers of Earth, identifying each layer and explaining which ones form radon. Create cracks and fissures in the layers and blow air up through the bottom holes to show radon can travel upwards through the path of least resistance.
• Do a study of the geology in the community, displaying different types of soil (sand and silt; clay; sand and gravel). Show which soils are more permeable for radon to move through. Discuss the source of radon (uranium) and which types of rocks have higher than average uranium content.

4. Radon Pathways into the Home

Radon rises through the soil and gets trapped under the building. The trapped gases build up pressure. Air pressure inside homes is usually lower than the pressure in the soil. Therefore, the higher pressure under the building forces gases though floors and walls and into the building. Most of the gas moves through cracks and other openings such as cracks in floors and walls, gaps in suspended floors, openings around sump pumps and drains, cavities in walls, joints in construction materials, gaps around utility penetrations (pipes and wires), and crawl spaces that open directly into the building

Potential projects:

• Draw a cut-away of a home showing the pathways that radon can use to enter a building -- both from the soil and through the water system. Make suggestions on short-term fixes to reduce the intake of radon. Explain the settling of homes and why the short-term fixes are only short-term.
• Build a model home on a platform showing the geology below and pump colored smoke (explaining that real radon is colorless, odorless, and invisible) up through the ground and into the home through cracks in the foundation, through sumps, pipes, and other openings in the house.

5. Radon in Water

When the ground produces radon, it can dissolve and accumulate in water from underground sources (called ground water), such as wells. When water that contains radon is run for showering, washing dishes, cooking, and other uses, radon gas escapes from the water and goes into the air. Some radon also stays in the water. Radon levels in neighborhoods that use well water tend to be higher than neighborhoods that use treated water.

Potential projects:

• Compare water samples in well water, treated water, and rivers or reservoir water and explain why there are different levels.
• Create chart explaining the difference in health effects of inhaled versus ingested radon, showing the comparative risks.
• Create a cut-away model of a home showing how radon in water gets into the home and how it is dispersed once inside.

6. Radon Decay Process

Radon has a half-life of about four days—half of a given quantity of it breaks down every four days. When radon undergoes radioactive decay, it emits ionizing radiation in the form of alpha particles. It also produces short-lived decay products, often called progeny or daughters, some of which are also radioactive. Unlike radon, the progeny are not gases and can easily attach to dust and other particles. Those particles can be transported by air and can also be breathed. The decay of progeny continues until stable, non-radioactive progeny are formed. At each step in the decay process, radiation is released. Radon itself does not harm a person but the alpha particles from its decay products can be the most physical or chemically damaging.

Potential projects:

• Create a display board showing the progression of Radon-222 into its various decay products highlighting the most damaging decay products. Explain the various units of measurement.
• Create a display showing the various types of radon detectors. Explain the components of the detectors and how they work to measure radon. Explain benefits and short-comings of long- and short-term tests

7. Radon in the Community

Radon has been found in homes all over the United States. Any home can have a radon problem. On average, one out of every fifteen U.S. homes has a problem. The only way to know whether or not your home has a radon problem is to test for it. Radon levels within a building often change on a day-to-day basis. Highest indoor levels are often found during the heating season. Weather conditions, operation of furnaces and fireplaces, and opening/closing of windows and doors are among the factors that cause these patterns. Short-term test kits are the quickest way to test. These kits should remain in the building from two to 90 days, depending on the device. Testing must be conducted for at least 48 hours. Some devices must be exposed for a longer time. Because radon levels tend to vary from day to day and season to season, a short-term test is less likely than a long-term test to tell you your year-round average radon level.

Potential projects:

• Use a map of the school and surrounding neighborhoods. Plot a geological breakdown of the area with low, medium and high radon potential. The student should test his/her home using a short term test kit and plot the results on the map. See if the radon test results correlate with the radon potential of area. If it does not match the potential, provide possible explanations.
• As a group project: supply all the students in a class (or grade depending on the size of the school) with short-term radon test kits (contact Kansas State University at Radon@ksu.edu <mailto:Radon@ksu.edu> or call 1-800-557-2366 to discuss orders of over 24). Have each family test the lowest lived in level of the home. Plot the results on a map of the school and surrounding neighborhood and compare with geological map of the same area.