Risk of exposure to aflatoxin M1 through consumption of cow's milk among children in Magadu, Morogoro.

Abstract

Aflatoxin M1 (AFM1) contamination of milk affects the general population with particular attention to children who frequently consume milk as part of complementary food. This study determined AFM1 contamination of cow's milk and estimated the health risk of dietary AFM1 through consumption of cow's milk among children (6 to 36 months) in the Magadu ward of Morogoro region in Tanzania. A total of 165 mother-baby pairs were recruited and interviewed on child feeding practices with a focus on feeding of cow's milk in the past 24 h. Alongside the interview, 100 raw cows' milk samples were collected from subsampled respondent households and were analyzed for AFM1 using enzyme-linked immunosorbent assay (ELISA). The results showed that about 35% of the surveyed children consumed cow's milk in the form of plain milk, incorporated in porridge and/or tea. The amount consumed varied from 62.5 to 500 mls with a median of 125 (125, 250) mls at a frequency of 1 to 2 times a day. All raw cows' milk (100%) samples (n = 100) were found contaminated with AFM1 at concentrations ranging from 0.052 to 9.310 µg/L and median of 2.076 µg/L (1.27, 2.48). All samples were contaminated by AFM1 at levels above the limits of 0.05 µg/L of raw milk set by the Tanzania Bureau of Standard and the European Union, while 97% exceeded 0.5 µg/L set by the US Food and Drug Administration. Exposure to AFM1 due to consumption of cow's milk ranged from 0.0024 to 0.077 µg/kg bw per day with a median of 0.019 (0.0016, 0.026) µg/kg bw per day, while the margin of exposure (MOE) ranged from 5.19 to 166.76 and median 20.68 (15.33, 25.40) implying high risk of public health concern. This study recommends that advocacy on consumption of cows' milk to combat undernutrition in children should consider a holistic approach that considers the milk's safety aspect.