Human exposure to fumonisins from home grown maize in Tanzania

Fumonisins contaminate maize worldwide resulting in unacceptable fumonisin exposures in people relying on maize as staple food. This study determined fumonisins B(1) (FB(1)) and B(2) (FB(2)) in maize from 120 rural households: 30 from each of four main maize producing regions of Tabora, Ruvuma, Iringa and Kilimanjaro in Tanzania in order to estimate total fumonisin (FB(1) + FB(2)) exposures to adult individuals in the households. The average daily per capita maize consumption of 771 g, recommended by the Tanzania Food and Nutrition Centre (TFNC) for an adult relying on it as a main meal, and also average daily per capita maize consumptions of 129, 308 and 356 g documented for Tanzania, were used in the exposure estimation. The fumonisins were determined by HPLC using fluorescence detection. Total fumonisins exposure (mu g/kg body weight (bw)/day) was determined by multiplying average daily per capita maize consumption (kg) by fumonisin level in maize (mu g/kg) from a given household and then dividing by an average bw of an adult of 60 kg. Of the 120 samples, 52% were contaminated with fumonisins at levels of up to 11,048 mu g/kg (median; 363 mu g/kg). Based on the recommended maize consumption of 771 g/person/day, fumonisin exposures to adult individuals in 38% of the households would exceed the provisional maximum tolerable daily intake (PMTDI) of 2 mu g/kg bw, recommended by the Joint FAO/WHO Expert Committee on Food Additives. At the least documented maize consumption of 129 g/person/day, fumonisin exposures in 16% of the households were still above the PMTDI. Reduction of the maize consumption level to 40 g/person/day is an impractical, and reduction of the maximum contamination level to 155 mu g/kg is a possibly practical, option for effective minimisation of fumonisin exposures in these communities. A relatively larger study is needed in order to generate comprehensive data for the formulation of appropriate strategies to minimise fumonisin exposures in Tanzania.