Aflatoxin B1 in walnuts: a probabilistic cancer risk assessment for Iranians

Abstract

Abstract On a global basis, walnuts rank second behind almonds in nut production and China, the United States and Iran are, respectively top producers of this nut. Generally, the nuts are exposed to relatively high temperatures and high humidity which predispose fungal growth. Hence, it is of crucial importance to regularly check the levels of toxins produced by fungi in these products, and subsequently, assess possible risk posed to human health via exposure to such toxins. Aflatoxin B1 as a secondary fungal metabolite widely found in many foodstuffs is considered a public health concern worldwide due to its genotoxic and carcinogenic properties. In this study, walnut samples collected from five different orchards located in five cultivation zones in Iran, were evaluated for aflatoxin B1 concentrations using high performance liquid chromatography with fluorescence detection. Aflatoxin B1 were found in more than half of the samples and its level ranged from 0.8–14.5 µg/kg. The present analysis showed a low lifetime carcinogenic risk for walnut consumption in Iranian consumers. The annual cancer risks (individual lifetime hepatic cancer risk) posed by consumption of walnuts were 1.0 × 10−4 and 3.4 × 10−6 in 105 persons (for hepatitis B positive and hepatitis B negative, respectively).