Quantitative Risk Assessment of Aflatoxin B1 Exposure Through Groundnut Consumption in Kano State, North West Nigeria

Aflatoxin B1 is a Group 1 human carcinogen produced by Aspergillus species in improperly stored groundnuts, and chronic dietary exposure is associated with hepatocellular carcinoma and child growth impairment. North West Nigeria, particularly Kano State, is characterised by both high groundnut production and consumption, yet quantitative risk assessments of aflatoxin B1 exposure through this food are largely absent. This study conducted a probabilistic quantitative dietary exposure risk assessment for aflatoxin B1 in Kano State groundnut consumers. Aflatoxin B1 concentration data were derived from analysis of 180 groundnut samples collected from three major markets in Kano Metropolis using high performance liquid chromatography with fluorescence detection. Groundnut consumption data were obtained from a 24-hour dietary recall survey with 320 adults and 150 children aged 3 to 10 years. Exposure was estimated using a Monte Carlo simulation approach in @Risk software. Liver cancer risk was estimated using a potency factor approach adjusted for hepatitis B surface antigen prevalence. Results showed median aflatoxin B1 concentration of 4.8 micrograms per kilogram. Estimated daily intake for children exceeded adult exposure by 2.3-fold on a body weight basis. Liver cancer risk estimates for the general population were 1.8 cases per 100,000 persons per year, increasing to 6.4 cases per 100,000 per year among hepatitis B-infected consumers. The study provides the first quantitative risk assessment for this exposure route in Kano State and recommends urgent aflatoxin reduction interventions. Keywords: aflatoxin B1, risk assessment, groundnut, hepatocellular carcinoma, Kano.