With schools being asked to accomplish more and more, it is increasingly important to, whenever possible, address multiple goals in teaching. The call for high school rigor and relevance demands that students be given opportunities to engage in real-life issues requiring them to use higher-order thinking (Daggett 2005). Educating the whole child dictates that we find ways to ensure our graduates are well-rounded, independent thinkers capable of becoming well-adjusted, contributing adults. Thus community service has become a key component of the high school curriculum. Luckily, these goals are consistent with helping students successfully transition to post-secondary programs (NASSP 2004). In addition, teachers must address the National Science Education Standards, which direct instruction in terms of both content and pedagogy (NRC 1996). To meet these many objectives, learning activities must be carefully scrutinized to ensure that more than just content goals are being addressed.

With this multiplicity of goals in mind, I applied for and received a Toyota Tapestry grant designed to address a local issue of air quality. The city where I teach—Cedar Falls, Iowa—was in the midst of a debate about leaf burning in which it was obvious that many voters were making decisions about air quality in the absence of scientific information on the issue. In addition, the local county public health department was concerned about air quality in another context—radon gas levels in area homes—but had thus far been unable to translate that concern to the public sector. By investigating air quality in the area, it was hoped that students, their families, and the general public would become better informed regarding air-quality issues. After all, an informed citizenry is the first step to responsible action.

The project described here, in which students conducted radon testing in area homes, was comprised of four components—content knowledge; public awareness; data collection, analysis, and interpretation; and presentation of data—each designed to accomplish specific goals (Figure 1). In addition to learning the science of radon, students were engaged in extensive analysis of data using technology (Microsoft Excel) to aid in the interpretation and presentation of that data. Community connections were made not only directly through the testing, but also through informational brochures and newspaper articles prepared and distributed by students.

Content knowledge

This unit began as part of a study of nuclear chemistry that focused on radioactive decay and nuclear reactions. Students actively constructed solid concepts through activities such as “Penny Half-Life,” in which students shake a box containing 100 pennies. After 30 seconds of shaking, all of the tails are removed and the remaining heads are counted, a procedure that is repeated until there are no pennies remaining in the box. This activity is an excellent model for radioactive decay in that approximately half of the pennies are removed with each series of shaking (half-life)—graphing the number of heads after each shake yields a graph very similar to that seen in radioactive decay.

In “Clocking Half Reactions” students compare the decay curve for a short-lived radioactive isotope, radon, to that of a long-life radioactive isotope, uranium. In the process, examples are presented using radon, but students gained most of their specific knowledge of radon and radon poisoning by conducting their own research.

Figure 2. Samples of student-prepared radon brochures.

Public awareness

The public awareness phase of the project combined gaining additional content knowledge with literacy and technology goals. When presented with the task of conducting research so they could inform the public about how radon operates, its dangers, how to measure radon levels, and how to obtain professional help to mitigate high levels of radon, students became much more engaged in learning about radon. Most students did their research online, although several students gained information through interviews with radon mitigators.

Students were asked to present their research in the form of a radon informational brochure designed to educate area residents about radon. Students were provided with a list of the categories of information that should be included in their brochure, but were given leeway to be creative and go beyond these minimum criteria. It was their job to develop a logical, yet engaging and creative, way in which to present the information to readers. Students were required to use the computer to generate their brochure and were given a scoring rubric to guide its development. After being checked for both accuracy and appeal, selected samples of these brochures were then reproduced and circulated throughout the community (Figure 2).

Data collection, analysis, and interpretation

Through their own investigations, students found that the existing research on radon in homes has shown that there is no reliable way to predict high radon levels. Factors such as the year a home was built, its location, the building materials used for basement walls, or even the number of cracks in basement walls and floors are not good predictors of radon levels. Many students were not only surprised by this information, they did not believe it. The class decided to collect data to determine if this lack of a pattern held true in their community, and developed a questionnaire to give homeowners who were participating in the radon testing. The questionnaire was designed to collect data on the year the home was built, the building materials used, and the number of cracks in the basement floors and walls.

Each student was asked to find at least two homeowners willing to have their houses tested for radon. Most students chose to have their own home tested, as well as that of a neighbor or relative. The class developed a letter of request-to-participate as well as the questionnaire. Most homeowners approached by students were willing to participate in the project, since to test their homes independently would require the purchase of a $10 radon test kit. Students delivered and set up test kits for homeowners and collected the completed questionnaires. Test kits were placed in the basement and remained “open” for three to five days. The exposed test kits were collected by students and mailed to a radon test lab for analysis. Homeowners generally received their results within two to three weeks.

It is important to maintain the confidentiality of the homeowners who participate in testing—when selling a home, owners are obligated to disclose any high radon levels that have been discovered there. To maintain this confidentiality and prevent students from knowing which homes correspond to which radon levels, the teacher should mail results to homeowners, along with information about how to interpret results. In addition, all homeowners who agreed to the testing were informed that if their radon levels were high, or if they questioned the validity of the reported radon levels, they should conduct a second test on their own. A number of homeowners did, in fact, request additional radon testing kits and took the initiative to conduct and send in the exposed radon kits on their own. In the case of retests, results were sent directly to the teacher; in the vast majority of cases, the retests yielded results similar to those of the original tests.

Each homeowner was given an identification number, and their names and addresses were removed from the data set. Data were made accessible to students by posting them on the class web page in the form of a summary Excel data table. I compiled the data (the testing company sent me the results one test at a time). Once students had an Excel copy, they could manipulate the data to have the Excel program calculate averages for the different variables in the study, such as the foundation type and the year the home was built. Students could also then use Excel to make graphs of the summary data. Students could retrieve and manipulate that data directly by generating data tables and graphs that could easily be understood by the public.

For students, the most difficult part of this project was analyzing and interpreting the test data. While they were familiar with using Excel to make graphs, students had difficulty deciding what to do with the large amount of data that this project produced. One way I had students manage the large amount of data from this project was to clump the data into meaningful categories; students were then asked to determine averages for the categories. For example, I asked students to use Excel to calculate the average radon level for homes with three different types of foundation (limestone, poured concrete, or blocks).

One approach used to help students was to present data tables and graphs that were somehow misleading, in spite of the fact that they contained valid data and were labeled correctly. For example, when students were asked to interpret the data shown in Figure 3 (p. 30), they immediately concluded that the older a home, the higher its radon levels. Asking students to figure out why this is misleading was a great way to start them thinking about how data can be presented in ways that may lead to incorrect conclusions.

Several students suggested that since most of the homes tested were older homes, these numbers were high for older homes. In truth, there was no pattern among age of home and radon level. When students turned the numbers into percentages, the conclusion was quite different. What better way to teach this important concept to students than with real data that they had a part in collecting? In the final analysis, student findings did indeed match the research; there was no way to predict high radon levels based on the year a home was built, building materials, or number of cracks in the foundation.

Presentation of data to the community

The final component of this project was sharing students’ findings with the community. Using the radon data from their study, each student wrote a newspaper article explaining what the class did, what they found, and how this information could help residents of the community. As part of the article, students were asked to find a relationship between the items listed on the questionnaires and the radon levels. Articles were evaluated using a rubric that students were given in advance (Figure 4, p. 31).

Some of the general findings most students included in their newspaper articles are shown in Figure 5. One article was published in the school newspaper and another was published in the city newspaper. We also sent an article to the university newspaper, which did not get published. The articles to submit were chosen based on the top scores received for the assignment.

Using this project as a model

This project, which illustrates how one idea can address multiple teaching goals while raising the level of rigor and relevance in the science classroom, serves as a model that can be adapted for a variety of community-based science projects. While the cost of the radon kits used for this project was significant, expenses are totally dependent on the nature of the project that is adopted. It is important to keep cost factors in mind when developing a project, and to remember that there are many sources of funding for community outreach projects. It is a good idea to select a topic that is of interest to the community which addresses a community need.

Teachers should also consider incorporating more student choice and increased community collaboration into the selection of a project. For example, is there a way to have students select their own community project, rather than having the teacher select it for them? Is there a way to encourage more collaboration between community members and students?

Many projects, such as this radon study, center on students performing a service for the community. However, new approaches to encouraging two-way involvement place community members in a more central role. As teachers continue to evaluate where they are in terms of community engagement, they will be able to tailor community-engagement projects that move students along a continuum toward increased student choice, increased student involvement, and increased community collaboration. The rewards for such a project are great for students, the school, and the community.

Jody Stone (stone@uni.edu) is a science teacher at Price Laboratory School, University of Northern Iowa, in Cedar Falls, Iowa.

Editor’s note

Further information about radon levels in homes can be found at the national safety council website (www.nsc.org/library/facts/radon.htm). For example, 1 in 15 homes in the United States have radon levels above the “low” level of 4 pCi/L.

References

Daggett, W. 2005. Reforming American high schools—Why, what, and how. New York: International Center for Leadership in Education.
National Association of Secondary School Principals (NASSP). 2004. Breaking ranks II: Strategies for leading high school reform. NASSP: Reston, VA.
National Research Council (NRC). 1996. National science education standards. Washington, DC: National Academy Press.