Exposure of school children to aflatoxins and fumonisins through maize-based diets in school meals programme in Salima District, Malawi

Abstract

Exposure to aflatoxins and fumonisins contaminated food poses threats to human health, including causation of cancer,  immunosuppression, impaired growth, respiratory problems, diarrhea, among others. This study was carried out to evaluate the levels of aflatoxins and fumonisins in maize-based porridge and the estimated intake levels of the contaminants among school going children in selected primary schools in Salima District, Malawi. A total of 496 children and 124 food handlers from 31 primary schools within three Extension Planning Areas(EPAs) under the School Meals Programmes were involved. Consumption and meal preparation data were collected from the respondents using pre-tested questionnaires. Reveal Q+ Kits were used to quantify aflatoxins and fumonisins in sampled meals. Monte Carlo risk simulation using @RiskPalisade software (UK) was used to generate exposure data. All porridge samples had varying detectable levels of mycotoxins. However, there were no significant (P < 0.05) differences in the aflatoxins and fumonisins levels for samples from different EPAs indicating the endemic presence of mycotoxins within the district. Over 95% of the schools used maize as the main ingredient in preparing the porridge with relatively high quantities consumed 610 grams/child/day equivalent to 0.019 kg/kg bodyweight/day regardless of the gender (χ2 = 5.624, P = 0.286) or the age (r = 0.033, P = 0.459) of the respondents. The levels of aflatoxins and fumonisins in the samples ranged from 2.13 to 33.37 µg/kg and < 0.3 to 1.0 ng/kg,  respectively. The mean and the 95th percentile intake levels for aflatoxins ranged from 0.2 - 0.60 ng/kg bodyweight/day and 6 – 9.2 µg/kg bodyweight/day for fumonisins, which exceeded the recommended safety levels for children according to standards of European Food Safety Authority (2007) and Joint Food and Agriculture Organization/World Health Organization Committee on Food Additives (2008), respectively. The consumption of maize-based porridge was found to expose school-going children to unacceptable levels of mycotoxins whose effects on their health, education and well-being remain unknown. There is a need to educate food handlers on mycotoxins intoxication and proper postharvest handling practices of maizebased foods to prevent exposure. Furthermore,  diversification to reduce overreliance on maize-based diets should be promoted.

Key words: Aflatoxins, Fumonisins, Exposure, School children, School Meals, Maizebased-porridge