Abstract: Objective To investigate the contamination status of aflatoxin B₁ in foodstuffs in Yunfu City,and preliminarily assess the dietary exposure and health risk. Methods Based on the determination results of random sampling foodstuffs in Yunfu City from 2019 to 2022,the Monte Carlo probability model was used to assess the dietary exposure of aflatoxin B₁ in different population groups by region,gender,and age. The risk of liver cancer was described by using the point estimation method and the margin of exposure method. Results The mean content of aflatoxin B₁ in 1 239 samples of 10 types of foodstuffs was 3.98 µg/kg,with peanut oil （5.89 µg/kg）,brewed sauce （1.75 µg/kg）,and corn oil （1.10 µg/kg） ranking among the top three. The overall detection rate was 31.9%,with the top three being brewed sauce,peanut oil,and corn oil,which were 60.0%,44.4%,and 29.4%,respectively. The overall exceeding rate was 3.8%,and all unqualified products were peanut oil. At the 50 and 95 percentiles （representing mean and high exposure levels respectively）,for urban and rural populations,the aflatoxin B₁ exposure were 1.41 and 18.33 ng/（kg·d）,respectively; the MOE values both were much lower than 10 000.The incidence risk of liver cancer was 0.039 and 0.513 cases per 100 000 individuals per year,respectively. The main sources of aflatoxin B₁ were vegetable oils,rice,and wheat flours,accounting for 82.3%,9.2%,and 6.4% of dietary exposure,respectively. The exposure and health risks in rural areas were higher than those in urban areas. There was a trend that the younger the age,the higher the exposure and health risk,with the 3-5-year-old group being the highest. Conclusions Foodstuff in Yunfu City is contaminated with aflatoxin B₁ to a certain extent,and the health risk of dietary exposure should be paid attention to and priority should be paid to rural areas and young people. It is suggested to strengthen the supervision of foodstuffs with high detection rate.

Key words: Aflatoxin B₁, Contamination status, Dietary exposure, Carcinogen risk assessment