Clean enough? Acceptance of urine-derived dry fertilizer and water shaped by religious and social norms in a water-scarce Islamic context

Although wastewater irrigation is broadly accepted in many water-scarce regions, proposals to recycle human urine often face greater social resistance. We hypothesized that this resistance stems because "urine" is perceived as a symbolic substance that triggers stronger cultural and psychological responses than "wastewater." We further predicted that framing urine recycling as nutrient recovery versus water recycling would elicit distinct patterns of acceptance. To test this, we conducted a structured survey in Jordan, evaluating support for four urine recycling scenarios: dry fertilizer, and reclaimed water for handwashing, toilet flushing, or irrigation-each presented in both general and proximal contexts. Support was consistently high for dry fertilizer, particularly when applied to non-food crops, while recycled water for intimate uses such as handwashing received the lowest support. Perception of Islamic jurisprudence regarding cleanliness emerged as central to how respondents evaluated urine-derived water: those who classified it as taher (clean but not purifying) or tahoor (ritually clean and purifying) were generally more supportive, while those who viewed it as najis (impure) tended to oppose all forms of recycling. Perceived approval from family and close social circles was a stronger predictor of support than perceived views within the wider religious community, affirming that acceptance is negotiated largely through interpersonal norms in this context. Cluster analysis identified two respondent profiles: a more open group who supported most forms of urine recycling, saw environmental value in the practice, and viewed recycled water as taher; and a more skeptical group who were less supportive, particularly in personal or proximate contexts, often viewed the water as najis, and anticipated strong social disapproval. Our findings suggest that a starting point for broadening public acceptance of urine recycling could involve engaging agrarian communities, where familiarity with existing wastewater irrigation practices may contribute to greater openness toward resource recovery from human urine. Among the scenarios tested, dry fertilizer derived from urine appears especially promising, as it bypasses many of the cultural and symbolic barriers associated with recycling.