New Perspectives in Science Education

In September 13th, 1987, took place in Goiânia, capital of Brazilian state of Goiás, an accident with Caesium-137. In this context, it was the largest radiological incident, except considering the ones at nuclear power plants, according CNEN, the National Nuclear Energy Commission. Negligence in the storage of equipment in the ruins of the Instituto Goiano de Radioterapia (IGR), a private radiotherapy institute, was responsible for contamination of hundreds of people.  With the opening of teletherapy radiation capsule, the environment was exposed to 93 g of highly radioactive caesium chloride, producing about six thousand Tons of radioactive waste,   which were packaged in concrete containers and taken to the definitive repository located in the town of Abadia de Goiás, 23 km away from Goiânia, where CNEN installed the Regional Center of Nuclear Sciences to monitor radioactive waste and to perform environment control. Even almost three decades past the tragedy, the accident still leaves remnants of fear, mainly because there is a lack of knowledge of what really happened. The purpose of this work was to elaborate, apply and analyze a Teaching-Learning Sequence on Nuclear Physics, especially addressing radioactivity, totaling eight classroom meetings, aimed at undergraduate students in Chemistry and Brazilian public high school teachers from Itumbiara, a town located only 200 km away from the scene of this tragic accident. Our approach privileged the use of the History of Science, articulated to the conception of science as something that is not immutable, namely, that has continuous development. Initially, a test is applied to check participants' misconceptions. The students watched documentaries related to the Goiânia accident, and about concepts and phenomena in Nuclear Physics, followed by a discussion mediated by the teacher. Reading of texts and studies on radioactive decay and half-life, discussions on natural and artificial radioactivity were also implemented. Several test in punctual moments allowed to verify and feedback topics understanding. The results from the activities carried out highlighted that students’ knowledge about modern physics is very limited, restricting considerably their world interpretation, revealing the need to insert such themes in basic education curricula.

Keywords: Modern Physics, Radioactivity, Teaching Learning Sequences, Goiânia Accident;

References