Abstract:

In the last decades, the increasing consumption of plastic and the consequent deposition in nature has caused enormous damage to the environment. In order to mitigate this problem, with direct consequences on society, several measures have been adopted in promoting the reduction of plastic consumption. The present investigation, was developed among students of the 2nd cycle of basic education (an intervention class - class A, and a control class - class B), in order to raise not only the students’ awareness but also of their relatives to reducing plastic waste. A didactic sequence was made in a Science, Technology and Society (STS) teaching approach that included six intervention sessions, in which awareness-activities were developed to solve the problem of plastic spreading in nature. Data was collected in the students' interventions, through audio records, the filling in of a form / script when they surfed internet and on the posters created by them. In the intervention class, consumption at the school bar was also recorded and photos of their lunch boxes were taken, before and after the intervention sessions, so that information was collected about the amount of plastic was used to carry their food on a daily basis. Students in the intervention group were also interviewed (pre and post-test), before and after the intervention sessions. Class B (CB) was not intervened, performing the same pre-test and post-test as class A (CA).

The data collected during the intervention sessions shows that, for example, the students diversified their discourse regarding marine pollution, addressed the waste of plastic and their entry into the food chain, the contamination of humans through ingested animals, distinguished different marine environments. The pre and post-test responses were analyzed according to three criteria: Knowledge, Behavior and Citizenship, Critical Thinking and Scientific Literacy. The data obtained in the pre-test shows that the two classes had identical knowledge about plastics, with slightly more positive results in the case study. In the post-test, in CB, there was a slight reduction in the number of students who attributed their learning to the school, unlike CA, whose importance increased, surpassing the sum of the options “Friend / family” and “Means of communication”, revealing that intervention activities were important in expanding knowledge, unlike CB, where the element“ school ”lost preponderance.

The responses in CA reveal a more positive evolution in the perception of this problem. In this class, the concern about environmental problems increased (decreased in CB) as well as the desire to reduce plastic waste and the importance attached to the recycling of bags. The most accentuated evolution in A reveals that the intervention sessions contributed to improve students' awareness of the need to modify behaviours and carry on more active citizenship.

By comparing the results obtained between the intervention class and the control class allows us to conclude that the school context and the strategies used in classes are important, contributing to the acquisition of knowledge and, in the case of this problem, developing greater sensitivity and predisposition to change behaviours. Thus, it appears that the CTS approach was a good teaching strategy for the evolution of students' knowledge regarding the consumption of plastics, while allowing them to develop their critical thinking and scientific literacy.

Keywords:

Natural Sciences, STS Approach, Scientific Literacy, Critical Thinking, Plastics.