Mapping of Mycotoxin Contamination Hotspots in the Sorghum Value Chain in Katsina State Using Geospatial Analysis

Mycotoxin contamination of sorghum is a significant food safety challenge across northern Nigeria, yet spatial patterns of contamination risk along the value chain have not been systematically mapped. Understanding contamination hotspots is critical for targeting interventions effectively across the large geographic expanse of Katsina State in the North West geopolitical zone. This study mapped mycotoxin contamination hotspots in the sorghum value chain in Katsina State using a geospatial analysis approach. Sorghum samples were collected from 96 sites across the value chain including farms, storage facilities, and markets in twelve Local Government Areas. Samples were analysed for aflatoxins, fumonisins, and zearalenone using enzyme-linked immunosorbent assay. Geographic coordinates of each sampling site were recorded using global positioning system devices. Spatial autocorrelation analysis using Moran's I and kernel density estimation were applied using ArcGIS software, and contamination risk maps were generated. Climate data from the Nigerian Meteorological Agency were overlaid to identify environmental risk correlates. Results revealed significant spatial clustering of aflatoxin contamination in the southern agricultural zone of Katsina State, associated with higher rainfall and humidity gradients. Fumonisin hotspots were concentrated in market storage nodes with documented cross-season carryover stock. The study provides the first contamination risk map for sorghum mycotoxins in Katsina State and recommends geospatially targeted intervention deployment. Keywords: mycotoxins, sorghum, geospatial analysis, value chain, Katsina.