To date, the amount of solid waste generated annually continues to increase significantly. According to current statistics, the world generates approximately 0.74 kilograms of solid waste per person daily, with an estimated 2.01 billion tons per year [1]. By 2050, global waste generation is expected to grow to 3.40 billion tons since some countries are not managing their waste in an environmentally safe manner. The East Asia and Pacific region, which includes Thailand, has been recognized as the world’s leading waste generator [1]. According to a recent Thai government report, the daily waste generated per capita has averaged 1.03 kilograms, which is higher than the world’s average rate. Although the amount of municipal solid waste decreased from 27.37 million tons in 2017 to 24.98 million tons in 2021, the amount of hazardous waste in rural communities, in the way of electronic waste, batteries, chemical containers, and aerosol cans, increased from 618,749 tons in 2017 to 669,518 tons in 2021 [2]. Moreover, at least 31% of waste generation was improperly disposed of by open burning, uncontrolled dumping, being burnt in incinerators without proper air pollution treatment systems, and by being discharged into waterways [1, 2]. This mismanagement of waste is a crucial issue affecting public health and the environment. This is evident in the form of water, air, soil, and marine pollution and in how waste mismanagement contributes to global warming, the transmission of diseases, and a rise in respiratory problems [1-4]. In the northern part of Thailand, there have been significant increases in water and air pollution, respiratory diseases, and dengue fever in the last decade [4]. Thus, effective waste management would be an important and necessary measure in the conservation of the environment and the protection of human health.

Promoting public participation by raising awareness, changing attitudes towards waste management, and providing waste management education among citizens, is a meaningful way to achieve sustainable waste management [1, 4, 5]. However, changing citizen behavior can be a difficult and time-consuming task. Therefore, a school can serve as a strategic place to foster the younger generation’s awareness of public health and their understanding of the importance of complying with waste management guidelines and sustainable regulations [5-8]. Many studies conducted in developed and developing countries have found that participatory learning is an important approach to waste management education which could help to lead students to participate in waste management practices at their schools [8-11]. Therefore, promoting waste management education through participatory learning could raise awareness [1, 10], while improving the attitudes [9] and knowledge of the student body with regard to the importance of proper waste management [8-11]. This, in turn, could influence the students’ behavior in their daily lives outside of school [8-10].

In Thailand, the government has been concerned with the impacts of waste mismanagement on both the environment and the public’s health. Thus, the Thai government has engaged in environmental management practices since 2012. Accordingly, the government has recently announced a national agenda for waste management and has proposed policies for pollution control and the effective management of waste. Furthermore, the Thai government has begun to disseminate information to the public pertaining to the three R’s approach (reduce, recycle, and reuse) in order to raise awareness among the citizens and to promote public participation in waste management in every sector of society. This requires the involvement of government agencies, manufacturers, community members, hospitals, and non-governmental organizations [2, 3, 12]. In school settings, many previous studies have helped to introduce the concept of waste management education into the curriculum [7, 13, 14] and have promoted extracurricular activities that involve waste management practices [15-18]. This has influenced students’ attitudes, knowledge, and behavior regarding waste management. However, few studies have emphasized the need to promote student participation regarding these public health concerns [15, 16, 18].

Lamphun is a small province located in the northern part of Thailand. In 2021, waste generated in Lamphun was about 280 tons daily, 92 tons (32.85%) of which were not correctly managed [2]. The three sub-district municipalities with the most solid waste were Pa Sak, Ban Klang, and Sri Bua Ban, accounting for 2.57, 0.78, and 0.47 tons per day, respectively [19]. A pilot survey conducted in four schools in the Sri Bua Ban Sub-district municipality cited open dumping, littering outside bins, non-waste separation, and minimal promotion of waste management awareness and behavior as key contributors to the existing problem. Therefore, this study aimed to develop a waste management intervention program based on student participation in a rural school in Lamphun Province and investigated the appropriateness of the intervention for expanded implementation.

This study employed principles of research and development (R & D) to develop a waste management intervention program in one rural school located in the Sri Bua Ban Sub-district, Lamphun Province, Thailand. Data were collected using qualitative and quantitative methods between the months of May 2019 and December 2020.

These findings indicate how the R & D method was used to design the school-based intervention program to improve waste management knowledge among students in grades 4-9. This waste management intervention program was created based on the problems and needs of all stakeholders in the school, as well as by integrating the participation of peer leaders to design suitable activities that could promote positive attitudes and cultivate good habits for waste management among students. The developed intervention program was found to be appropriate and practical in a Thai rural context, where students wanted information that was concise, iterative, and easy to understand. This confirmed the outcomes of previous studies, which found that a successful intervention would need to be developed to be appropriate for each context [23]. The development of an intervention program that was suitable for each context involved the contribution of the research participants, such as discussions on the apparent problems and needs for waste management in researched settings [7, 8, 14, 17], and participant participation promotion by encouraging them all to identify and suggest waste management solutions [10, 16, 18].

Our school-based intervention program consisted of various action plans to raise awareness and promote positive attitudes and knowledge for waste management amongst participants, including 1) empowering peer leadership; 2) supporting peer-led activities; 3) setting up enough bins, and 4) promoting extracurricular activities in the school. The interventions that simultaneously included the promotion of personal knowledge, the skills of how to manage each waste type, and the improvement of a suitable environment could allow students to adopt sustainable practices for waste management [8, 16]. The action plans were similar to those of many previous studies that developed activities to improve student’s knowledge and skills for waste management by integrating these concepts into the school curriculum [11, 13, 14] by promoting waste management campaigns [10, 16-18], and by providing enough bins appropriate for each setting [14, 16].

Moreover, this intervention program applied participatory learning through group discussions, reflections, games, the viewing of video clips, and the building of peer leader capacity in the development of strategies to raise awareness and to promote positive attitudes, knowledge, and skills among the participants for effective waste management. The results from the implementation of this program indicated that students, who participated in all action plans of the school-based intervention program, exhibited a significant increase in waste management knowledge immediately after implementation of the program and at the one-month follow-up point when compared with the baseline data. Participatory learning is a process that triggers students or learners to share their experiences, think critically, and discuss their ideas, which might promote positive opinions and change the behavior of participants via group discussion [7, 24]. In addition, it could encourage peer leaders to participate in waste management practices in schools. Therefore, using a participatory learning process in a school waste management program that involves cartoon books, videos, group discussions, sharing ideas or experiences, and participating in role plays, could promote students' awareness and help students to better understand and retain the knowledge related to waste management [11, 13, 14].

Furthermore, our findings are supported by the outcomes of many prior studies that have promoted the competency of peer leaders to create and conduct practical activities in schools [10, 15, 25, 26]. Moreover, the goal of enhancing students’ capacity to become competent leaders can be accomplished by teaching elements of leadership, communication, teamwork, and knowledge transfer and by engaging in activities that can improve attitudes, knowledge, self-efficacy, and practice among trained students [10, 25, 26]. Similarly, studies promoting peer education for waste management in schools and communities [10, 15, 27] have shown that competent peer leaders, who exhibit greater degrees of knowledge and confidence and who organize activities that lead to improved attitudes and the dissemination of essential information, can help students take their environmental responsibilities even more seriously and change their behaviors related to waste separation and sustainable waste management.

Although this school-based intervention program promoted positive attitudes, knowledge, and skills for more effective waste management practices, the appropriateness of this intervention program was tested only in terms of the students' waste management knowledge. Thus, this intervention program must be tested in other aspects with a more rigorous research design. In addition, participants were collected from only one school located in Lamphun, Thailand, which may not be representative of the cultural diversity across Thailand and cannot necessarily be generalized as representative of other high school students in other locations.

This developed school-based intervention program was deemed to be appropriate and practical in a Thai rural context. The intervention program was comprised of four action plans: empowering peer leadership, supporting peer-led activities, setting up enough bins, and promoting extracurricular activities by peer leaders, teachers, and community leaders. The results of the implementation of the intervention program showed increased knowledge regarding waste management among students. Participatory learning and peer leader capacity building were key strategies that could ensure the success of the program. Therefore, the development of an effective waste management program that would be suitable in each school context, and the inclusion of associated healthcare providers, would need to be modified for each intervention program in accordance with the existing stakeholders, specifically with regard to the students’ needs.