The Environmental Protection Agency (EPA) website dealing with education resources reported the results of an inspection, by an environmental engineer, that revealed radioactive materials in a Massachusetts high school. All sources were found within open storage in science classrooms. Given this scenario and similar ones, this month’s column addresses the following questions: How dangerous is ionizing radiation and what are the sources? Should high schools abandon the use of ionizing radiation sources in their students’ science programs? If these sources are used, what prudent safety practices should be in place?