Developing a lesson plan on conventional and green pesticides in chemistry education – a project of participatory action research
The debate on the use of pesticides is very current in the public media when it comes to topics such as organic farming, bee mortality, and the use of glyphosate. The broad range of pesticide applications and their potential environmental impact makes pesticides an interesting topic for science education in general and for chemistry teaching in particular. This is particularly true when conventional pesticide use is contrasted with current chemistry research efforts to develop alternatives based on the ideas of green chemistry. This paper discusses the potential relevance of pesticides for chemistry education in connection with education for sustainable development. It gives a brief outlook on pesticides in science teaching and connects the topic to socio-scientific issue-based chemistry education. A case study which developed a lesson plan for secondary school students is presented here. It defines pesticides, before focusing on the development of green pesticides as potential alternatives to current products. The lesson is focusing learning about chemistry rather than learning of chemistry in the means that the lesson introduces quite young chemistry learners (age range 15–17) to ideas of green and sustainable chemistry and how green alternatives in chemistry can be assessed and compared to traditional alternatives. Video vignettes of a scientist are used to introduce the topic to students. Finally, both glyphosate as a conventional, industrial pesticide and orange oil as an example of a green pesticide are compared using spider chart diagrams. The lesson plan was cyclically designed by a group of ten chemistry teachers using participatory action research. It was piloted with the help of secondary school chemistry student teachers and then tested in five German secondary school classes (grades 10/11). The use of the spider charts was regarded as especially helpful by the learners, most of whom felt that they had been able to understand the controversy surrounding pesticides.