Concentration of aflatoxin B₁ in Iranian rice and human health risk assessment

Contamination of food products such as rice with mycotoxins, especially aflatoxins (AFs), can endanger human health and cause economic problems. Dietary exposure to aflatoxin B1 (AFB1) is a public health concern, especially in countries where rice is a staple food, due to its carcinogenic, acute, and chronic effects. Therefore, the aim of this study was to determine the occurrence and concentration levels of AFB1 in domestic (Iranian) rice samples. The presence and mean concentration of AFB1 in 70 Iranian rice samples collected from local markets in Tehran, Iran were measured using a competitive ELISA method. Furthermore, a health risk assessment was performed based on estimated daily intake (EDI) of AFB1 from rice consumption, margin of exposure (MOE), and liver cancer risk in Iranian children and adults. AFB1 was detected in 26 samples (37.1%) with the mean concentration levels of 1.86 ± 0.67 ng/g (ranges from 1.12 to 4.26); of these, 7 samples (26.9%) had values exceeding the limit set by European Union regulations (2 ng/g). Additionally, AFB1 contamination in no rice sample exceeded the maximum limit accepted by Iranian National Standardisation Organisation (5 ng/g). This study showed that the mean EDI of AFB1 was 9 and 3 ng/kg bw/day for children and adults, respectively. In addition, the mean MOEs for children and adults were 18 and 64, respectively, indicating a public health concern. In addition, the present study showed that the risks of liver cancer associated with rice consumption among Iranian children and adults were 0.13 and 0.04 cancer cases/year/per 10⁵ people, respectively. This study showed that monitoring AFB1 levels in rice is essential for assessing food safety and protecting public health, particularly in developing countries where rice is a staple food.