Methods We undertook an intervention study at subsistence farms in the lower Kindia region of Guinea. Farms from
20 villages were included, ten of which implemented a package of postharvest measures to restrict aflatoxin
contamination of the groundnut crop; ten controls followed usual postharvest practices. We measured the
concentrations of blood aflatoxin–albumin adducts from 600 people immediately after harvest and at 3 months and
5 months postharvest to monitor the effectiveness of the intervention.