Dietary Practices, Nutritional status, Risk of exposure to aflatoxins and Pesticide among adolescents in Boarding - high schools in Kilimanjaro, Tanzania

Abstract

School feeding in low income countries relies mainly on cereals and legumes. Cereals are low in nutrients and its overdependence can lead to poor nutrient intake. Cereals and legumes are susceptible to aflatoxins contamination, causing both acute and chronic toxicity in human. The use of pesticide has been one of the measures to control aflatoxins. Inappropriate pesticides use may result to unacceptable residues in grains. A cross sectional study was conducted to assess dietary practices, nutrition status, the risks of exposure to aflatoxins and pesticide among adolescents through consumption of school meals in Kilimanjaro region. Food frequency questionnaires and 24 hours’ dietary recalls were used to collect food consumption information. Nutrition status was assessed using anthropometry and test of hemoglobin levels. World Health Organization. Arthro plus and Nutri survey software were used to analyze anthropometry and dietary data respectively. Aflatoxin and pesticide residues were analyzed using High Performance Liquid chromatography (HPLC), and Gas Chromatography Mass spectrometer (GC-MS), respectively. Results shows that, maize based food and beans were consumed on daily basis with low intake of animal sources, vegetables and fruits. Mean intake of Vitamin C, iron, calcium and zinc were below the Recommended Daily Allowance (RDA). The average carbohydrates, fats and proteins intake were slightly higher than RDA for adolescents. Overall 23.1% of the adolescents were anemic, 25% overweight and 6.1% obese. Total aflatoxins contamination ranged from 0.20 - 438.53 μg/kg and aflatoxin B1 (AFB1) ranged from 0.44 μg/kg to 35.89 μg/kg. The highest exposure to total aflatoxins ranged from 0.70-973.45 ng/kg/bw/day and AFB1 ranged from 0.05-81.06 ng/kg/bw/day. Pesticide residues in all samples were below the detection limits, implying no risk to pesticide exposure among the studied individuals. Inadequate nutrients intake and the pronounced risk of exposure to aflatoxins could have been contributed by a monotonous cereal and legume based diet in boarding schools. The no detects of pesticide residues might have been contributed by degradation of pesticide due to the prolonged storage, milling process, and uses of silos for storage. The relevant ministries should consider food diversification and routine risk assessments of the susceptible crops throughout the value chain as a long-term intervention plan.