They are unique among the mycotoxins in being almost exclusively contaminants of maize, particularly when grown in warmer regions. Maize is a major human dietary staple that has been in the diet of Nigeria and the African region for centuries. It started as a subsistence crop and has gradually become a major and the most frequently consumed crop in Nigeria. Fumonisins are also detected in symptomless maize kernels, and surveys of good quality maize and maize based products have revealed the natural presence of fumonisins at very low levels.

Because of concerns about mycotoxin contamination in the food and feed supply in developing countries, the International Atomic Energy Agency (IAEA) Technical Cooperation (TC) Department, in collaboration with the Food and Environmental Protection Subprogramme of the Joint FAO/IAEA Joint Centre of Nuclear Techniques in Food and Agriculture, developed a number of international capacity building projects aimed at the establishment of analytical infrastructures to monitor import/export agricultural products for consumer health protection and to support food trade between member states. Within the framework of the IAEA TC Project NIR/5/030 entitled Regulatory Control and Monitoring of Contaminants and Residues in Fresh Produce, staff members from the National Agency for Food and Drug Administration and Control (NAFDAC, Nigeria) were trained on the use of analytical methodologies to detect, monitor and control fumonisins in maize.

The study indicated that fumonisin B1 is a widespread contaminant of maize kernels in Nigeria. Various contamination levels were encountered across the five different areas and the overall results revealed relatively low levels of contamination. These findings were consistent with results reported worldwide confirming the widespread presence of the fumonisins in maize, and demonstrate the potential risk of chronic exposure of the consumer to fumonisin, especially through the ingestion of poor food quality grade grain.

Since maize has become Africa’s most important staple food crop, being consumed up to three times a day and used as weaning food for babies, the enforcement of good agricultural practices, including the disposal of visibly damaged kernels through cleaning procedures and wet food processing, is strongly recommended to reduce the fumonisin B1 content, thus preventing exposure of consumers to harmful toxins in food.

These research findings were presented to the 3rd Session of the Codex Committee on Contaminants in Foods (CCCF), (Rotterdam, the Netherlands, 23-27 March 2009), at which the CCCF agreed to initiate work on establishing maximum levels. In discussing the potential establishment of proposed draft maximum levels in maize and maize products and associated sampling plans at the subsequent 4th Session of the CCCF (Izmir, Turkey, 26-30 April 2010), the Committee noted that fumonisins in maize and maize products were proposed for evaluation by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) and therefore, the Committee agreed to suspend work on the establishment of maximum levels until the completion of the JECFA evaluation. The JECFA assigned a high priority to the evaluation of fumonisins, including the consideration of occurrence data generated and submitted by Nigeria under TC Project NIR/5/030.

Joint FAO/WHO Food Standards Programme, Report of the Fourth Session of the Codex Committee on Contaminants in Foods (ALINORM 10/33/41), Izmir, Turkey, 26-30 April 2010. Proposed Draft Maximum Levels for Fumonisins in Maize and Maize Products and Associated Sampling Plans (CX/CF 10/4/8) and Comments Submitted at Step 3 by Egypt, the European Union, Ghana, Japan, Kenya, Norway, the Philippines, Thailand, COCERAL and the IAEA (CX/CF 10/4/8 - Add. 1).