Led by Johanna Lindahl of the International Livestock Research Institute (ILRI), the scientists confirmed high levels of aflatoxin in maize and sorghum flours, and milk fed to children.
41% of children fed on these diets in Dagoretti and Korogocho estates were found stunted and having poor growth. The findings come only months after the Kenyan Medical Research Institute (Kemri) confirmed that a quarter of pregnant women in Kisumu County were consuming dangerous levels of aflatoxin.
Aflatoxin is also a carcinogen.
In Nairobi, the researchers had collected 403 samples of milk, maize and sorghum flours from households and retailers in Dagoretti and Korogocho.
Aflatoxin was detected in all milk and sorghum samples and 95 per cent of the maize. Out of which 63% of the milk samples, 16% of maize and 1% of sorghum exceeded allowable levels of aflotoxin.
The study found 41% of the 204 children fed on these diets to be stunted. Those from Korogocho were worse off than their Dagoretti counterparts while 17% of all children were underweight.
The children were aged between one and three years, many of them still breastfeeding. Aflatoxin has been confirmed in breast milk. But the researchers warn Nairobi residents that aflatoxin exposure is not just for the poor and cite a recent urban study where 99 per cent of pasteurized milk had tested positive.