Perceptions of waste valorization and hazardousness: A methodological approach based on ordinal proximity measures

Citizens play a crucial role in achieving circular economy and sustainable waste management. This study introduces a novel methodological framework to assess public perceptions of potential waste valorization and hazardousness. Utilizing ordinal proximity measures, the framework also explores how individuals perceive qualitative scales used in these assessments. A case study involving 175 participants, including waste management experts and engineering students, was conducted to elucidate perceptual differences between these groups across 14 types of waste. It was found that 45% and 62% of respondents did not perceive the scales of waste valorization and hazardousness as uniform. Both groups identified glass as the most valuable and pharmaceutical waste as the least valuable. However, perceptions varied considerably for other wastes depending on the respondents’ expertise. Cereal straw and batteries were perceived as the least and most hazardous wastes, respectively, by both students and experts, with paint exhibiting the greatest variance in perceived hazardousness between the two groups.