ABSTRACT This paper provides a re-signification of industrial risk as a slow-burning issue (Mah [2017] “Environmental justice in the age of big data: challenging toxic blind spots of voice, speed, and expertise.” Environmental Sociology 3 (2): 122–133.), invisibly and violently diffusing across time and space and affecting relational entanglements between human and non-human components of risk landscapes. As an alternative to a planning approach based on quantitative and objective data, the authors propose to build strategic planning of riskscapes upon what they call small data, that is, the ensemble of qualitative and embodied data that can be gathered through street science (Corburn [2005]. Street Science: Community Knowledge and Environmental Health Justice. Cambridge: MIT Press.) and toxic autobiographies (Armiero et al. [2019]. “Toxic Bios: Toxic Autobiographies – A Public Environmental Humanities Project.” Environmental Justice, 1–5. ). In order to discuss the potential role of both small data and toxic autobiographies in the planning field, the authors present the results of an ongoing empirical case study in Gela, a Sicilian town converted into one of the main Italian petrochemical poles in the 1960s by a multinational oil company. The authors analyse Gela’s risk landscapes through the perceptions of citizens and their initiatives to tackle environmental injustices. Finally, the authors argue that small data can provide a better understanding of the landscape of risk through four lenses that allow seeing the slow and diffused change brought by industrial risk: memories of injustice, memories of smell, trans-corporeal stories, and relational stories.