Mycotoxin profile of staple grains in northern Uganda: Understanding the level of human exposure and potential risks

Abstract

Mycotoxins are toxic metabolites of fungi that contaminate food and feed. These toxins can cause acute and chronic health threats to both humans and animals. In sub-Saharan Africa, exposure to mycotoxins is chronic and under-reported. The study explores contamination of grains (sorghum, maize, groundnut, millet) with four mycotoxins (aflatoxins, fumonisins, ochratoxins, and deoxynivalenol) and dietary exposure to quantify associated health risks in northern Uganda. The results underscored the high prevalence of mycotoxins, only 7% of the samples were free from toxins. Sorghum grains seemed to be the most susceptible to toxin contamination, whereas in millet the toxin levels were, in general, the lowest. Besides, the results showed that the majority of grains were contaminated with more than one mycotoxin and that the toxin pattern was dependent on the grain type. Co-contamination with all four mycotoxins mainly occurred in sorghum grains. Besides the differences between grain types, there were also significant differences in toxins levels depending on the district where the grains came from. The estimated daily intakes for the mycotoxins were far above the recommended tolerable daily intake (TDI), especially for sorghum. So, it can be concluded that the majority of the people whose diet is mainly based on sorghum are exposed to multiple mycotoxins in a single diet and at a dose above the TDI. Such exposure to multiple mycotoxins elevates the associated health risks. Millet grains, which were the least contaminated, can provide an alternative to sorghum. However, to tackle the mycotoxin problem, other control and prevention mechanisms, e.g. good agricultural practices and optimized storage must be further explored and implemented in sub-Saharan Africa.