Exposure of children 4 to 6 months of age to aflatoxin in Kisumu County, Kenya

摘要

Contamination of foods by aflatoxins is a global health problem in both developed and developing countries. Exposure to the toxins is associated with a range of effects on health including stunting in children. Commodities at high risk of aflatoxin contamination include cereals, legumes, milk, fish and meats. Children are more vulnerable to effects of aflatoxin exposure compared to adults. Being genotoxic, levels of aflatoxins in foods should be kept as low as possible, given that there is no known threshold at which they may pose a health risk. This study investigated the potential exposure of young children to aflatoxin contamination in Kisumu County, Kenya. Kisumu County may have the potential for low to high levels of aflatoxin contamination due to prevailing weather conditions as well as reliance on maize, sorghum, cassava and rice as the main staple foods, groundnuts as snack and omena (Rastrienobola argentea) and milk as cheap sources of protein. These foods are also used as weaning foods in the County. Samples of omena, rice, groundnuts, cassava, maize, and sorghum were collected from Kibuye wholesale market, Kibuye open air market, Ahero market, Oile market and Mamboleo market in Kisumu County using a combination of cluster and systematic sampling. Processed cow’s milk samples were collected from supermarkets and raw cow’s milk samples from 3 market milk bazaars in the County. Analysis of solid foods was done using HELICA Total Aflatoxin Assay, intended for quantitative detection of aflatoxin B1, B2, G1 and G2. Milk sampling was done using the European model outlined in the Codex Alimentarius. Aflatoxin M1 levels in milk were analyzed using HELICA Aflatoxin M1 Assay. Aflatoxin levels in the foods ranged from 0 to 34.5 ppb aflatoxin B1, 0.012 to 0.127 ppb aflatoxin M1 in processed milk and 0.0002 to 0.013 ppb aflatoxin M1 in raw milk. All the food products, except cassava, had samples with detectable aflatoxin levels. Daily aflatoxin consumption ranged from 35 ng (4.43/kgBw/day) to as high as 872 ng (110.4 ng/kgBW). These findings indicate that weaning children in Kisumu County are potentially exposed to levels of aflatoxins above the permissible amounts, given that the food stuffs that were analyzed are the commonly used weaning food items. Its effects on their health should be assessed and efforts taken to reduce potential exposure both from the commonly suspected sources as well as from milk.