Findings In control villages mean aflatoxin–albumin concentration increased postharvest (from 5·5 pg/mg [95% CI 4·7–6·1] immediately after harvest to 18·7 pg/mg [17·0–20·6] 5 months later). By contrast, mean aflatoxin–albumin concentration in intervention villages after 5 months of groundnut storage was much the same as that immediately postharvest (7·2 pg/mg [6·2–8·4] vs 8·0 pg/mg [7·0–9·2]). At 5 months, mean adduct concentration in intervention villages was less than 50% of that in control villages (8·0 pg/mg [7·2–9·2] vs 18·7 pg/mg [17·0–20·6], p