Mapping aflatoxin risk from milk consumption using biophysical and socio-economic data: a case study of Kenya

Abstract

This research reports a mapping of aflatoxin risk in the milk value chain in Kenya using a geographic information systems (GIS) approach. The objective was to spatially locate regions at risk by taking into account biophysical and socio-economic factors such as humidity and rainfall, dairy cattle density, maize production and travel time to urban centres. This was combined with historical data of aflatoxin outbreaks obtained from literature search and geo-referenced. Median values for the datasets were then used to define the thresholds. Criteria-based mapping using Boolean overlays without weighting was implemented in the ArcGIS v10.3 platform. Areas of convergence were overlaid with regions of historical outbreaks to come up with likely locations of aflatoxin risk and target sample surveys to these areas. Higher resolution maize production and consumption data would be desirable to ensure more accurate results. The process followed in this project ensures an evidence-based and replicable methodology that can be used in other regions and with different crops. Feed and milk samples collected in the different categories identified support that this approach can be used to guide sampling and regional studies. The research also discusses the strengths and limitations of the approach.

Keywords: mycotoxins, Kenya, GIS, risk maps, aflatoxins, East Africa, dairy consumption, dairy products