ENVIRONMENTAL RADIOACTIVITY AS TEACHING MATERIAL (6) -THE TRIAL TEACHING IN UPPER SECONDARY SCHOOL AND TEACHERS COLLEGE -

Abstract

A study on a science curriculum including experimental demonstration of environmental radioactivity was carried out for science classes in an upper secondary school and a teachers college. In the classes, radioactivity of K-40 in cigarette ash and air-borne Rn-progeny were first revealed by means of radiochemical measurements using GM and scintillation counters, and then the explanation for radioactivity was followed on the uses of radiation and nuclear energy. The college students majoring in science fully understood the concept of risk-benefit balance in the environmental and/or energy problems through their learning of permissible concentration of radioactivity. The other college students performed the experimental work in a mediocreway, and an additional lecture on the statistical treatment of the data was necessary to help them in estimatingthe reliability of information. The students of secondary school also understood the natural occurence of radioactivity by the experimental demonstration. However, fairly large differences were observed among schools in the degrees of understanding in the subjects such as half-life of radioactivity and control of nuclear fission. Thus, for students of secondary schools, it is suggested that the subjects be chosen corresponding to their abilities.