Implications of seasonal variations in aflatoxin B1 levels in Nigerian market foods.

Aflatoxin B1 levels were determined in Nigerian rural and urban market foods from 1977 to 1978. In general, levels were found to be highest during the peak rainy season, and the data suggest that livestock and humans are at highest risk from aflatoxicosis during this time. The incubation period for humans and nonhumans varies, and the risk to man from seasonal exposure to aflatoxin is assessed and reviewed. Primary hepatocellular carcinoma patients showed first symptoms of tumors during the dry season.