Multi-mycotoxin exposure of children (0-24 months) in rural maize-subsistence farming areas of the Eastern Cape Province, South Africa

Abstract

In South Africa, child malnutrition is highly prevalent among children from in rural areas mostly at risk. In the Eastern Cape (EC) Province, maize is commonly used as complementary and weaning food. Previous studies conducted in parts of EC have indicated high levels of fumonisin B (FB) mycotoxins in home-grown maize, as well as the co-occurrence of otherFusarium mycotoxins, such as deoxynivalenol (DON) and zearalenone (ZEN). A cross-sectional study of children below 24 months was conducted in rural maize-subsistence farming areas in Centane, EC to determine mycotoxin exposure. Home-grown maize samples (n=171) were collected from households in the study area and analysed by LC-MS/MS for FB, DON and ZEN. Food intakes of 129 children were quantified using a validated quantitative food frequency questionnaire (QFFQ). Individual raw maize consumption was calculated using recipes from the QFFQ. Probable daily intakes (PDIs) for each mycotoxin were determined using a deterministic approach and were compared to the respective mycotoxins’ provisional maximum tolerable daily intake (PMTDI). The numerical means for total FB (sum of fumonisin B1, B2 and B3), DON and ZEN levels in home-grown maize were 1,035, 24.5 and 31.0 μg/kg, respectively. Mean daily maize intakes of children ranged from 2-321 g/day and increased with age. The mean PDIs for total FB, DON and ZEN were 8.4, 0.2 and 0.3 μg/kg body weight (bw)/day, respectively. Exposures stratified by age indicated persistent high mean PDIs for total FB, above the PMTDI of 2 μg/kg bw/day, ranging between 5.0-11.6 μg/kg bw/day. Mean exposure to DON and ZEN were below their relevant PMTDIs (1 and 0.5 μg/kg bw/day, respectively). Individually, 81 and 13% of children had exposures above the PMTDI for total FB and for ZEN, respectively. Results confirm the magnitude of FB exposure among vulnerable groups from rural maize subsistence farming areas in EC.