Spatial Assessment of Asbestos Fiber Release Potential in a Post-Ban Urban Environment: Cartagena, Colombia

Urban environments in developing countries remain affected by legacy asbestos-containing materials, yet integrated assessments of multi-pathway asbestos release and environmental mobilization integrated with demographic distribution remain limited. This study aimed to develop a spatially explicit framework to assess environmental deterioration and asbestos-related environmental hazard where multiple asbestos release pathways converge in a post-ban urban setting, using Cartagena, Colombia, as a case study. A multi-pathway approach was implemented, combining source characterization of asbestos-cement (AC) roofs through microvacuum sampling, analysis of roof runoff and drinking water, spatial distribution of AC pipelines, and demographic data at the neighborhood scale. A total of 72 roof surface samples were collected, of which 92% showed detectable asbestos fibers, with concentrations reaching up to 326 × 106 structures/cm2. Runoff water analysis indicated 85% detection, with average concentrations of 3.5 ± 3.14 million fibers per liter (MFL). Drinking water samples showed 11% positivity, with lower concentrations (mean 1.01 ± 1.59 MFL). Spatial analysis revealed that approximately 9.5% of the urban area exhibited high airborne release potential and 3.1% exhibited high runoff-related hazard, while integrated spatial prioritization identified 5.59% of the city as high priority for intervention. Results indicated that less deteriorated roofs exhibited higher surface fiber availability, suggesting that emission potential is not directly proportional to visible degradation. The integration of environmental and demographic data supported the identification of critical hotspots where multiple asbestos release pathways converge. The proposed methodology provides a novel framework for multi-pathway asbestos spatial prioritization in urban environments and highlights the need for source-based monitoring approaches. These findings support the development of targeted mitigation strategies in cities with widespread legacy asbestos infrastructure.