The risk of exposure to aflatoxins through consumption of nshima made from maize meal in selected areas of Lusaka district.

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Musonda, Mumba
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The University of Zambia
Maize and its products, such as maize meal, are susceptible to aflatoxin contamination. Maize is the staple crop of Zambia and is widely consumed as thick porridge, commonly called nshima. Previous studies have reported high levels of AFs in maize produced in Zambia. However, no study has determined the risk of exposure to AFs through the consumption of maize nshima. This cross-sectional study was designed to determine the risk of exposure to aflatoxins through the consumption of maize nshima in households in the Lusaka District. A questionnaire was administered to households to investigate dietary consumption patterns and revealed that most Zambians consumed nshima twice a day, prepared from either breakfast or roller maize meal. It was also noted that males aged 18 years and above consumed more nshima per day (360 – 980g) than children and female adults. The Zambia Bureau of Standards Laboratory recorded aflatoxin concentrations ranging from 0.2 μg/kg to 150 μg/kg in breakfast (flour from polished maize grain) and roller (flour from whole maize grain) meal samples from 2019-2022. This was used as secondary data for determining the risk of exposure to aflatoxins during this study. The risk of exposure was estimated using the Model Risk Software® using the estimated daily intake of maize nshima and secondary aflatoxin data as input parameters. The maximum exposure of 80.2 to aflatoxins was highest for the males compared to other age groups. The risk was further characterized using the margin of exposure (MOE). The MOE was < 10000 for age categories, thus indicating potential adverse health effects, with the highest MOE of 0.005 recorded for the males. The high levels of AFs in maize meal and high exposures accentuate the need for preventive measures. Particular attention should be given to raising awareness of the impact of aflatoxin risk exposure and setting maximum allowable limits in maize meal considering maize product consumption patterns in Zambia
Thesis of Master of Science in Food Safety and Risk Analysis