Receptor-centric modeling of phosphate dust deposition and resuspension health risks near Kpémé plant, Southern Togo

Industrial phosphate processing in fragile coastal ecosystems emits toxic stack particles, threatening environmental and human health across boundaries, yet critical knowledge gaps impede mitigation in vulnerable regions like Southern Togo. Current approaches lack high-resolution atmospheric deposition quantification, receptor-specific exposure linkages, secondary resuspension pathway integration, and context-adapted regulatory standards. This study pioneers a receptor-centric modelling framework to establish the first mechanistic chain connecting primary deposition to resuspended dust health risks. We integrate high-resolution (100 m/hourly) AERMOD View deposition modelling using validated hybrid meteorology, derive contextually adapted standards (annual: 31.5 g/m2; daily: 0.26 g/m2; hourly: 0.0036 g/m2) via modular EU benchmark localisation, and quantify resuspension-exposure pathways with calibrated flux modelling (Kres=1.2 × 10− 5 m− 1) and EPA risk protocols. Results demonstrate severe exceedances including hotspot (e.g. Zen Nath Nath) deposition at 53.05 g/m2/year (68% above standard) and extreme 1-hour peaks at 15.06 g/m2 (4,183-fold exceedance). Resuspended dust dominates health risks, particularly for children at schools and clinics, with hazard quotients reaching 111.55 (Goumou Kopé Dispensary) and carcinogenic risks for Cr(VI) at 2.67 × 10− 3 (2,670-fold above thresholds). This work redefines particulate risk paradigms by confirming resuspension as a critical exposure vector and provides an adaptable framework for receptor-specific mitigation, advancing science-backed policymaking under SDGs 3 and 11.