Persistence of lindane in rice and maize ecosystems in Nigeria

A three year field study was undertaken to examine the fate of residues of lindane in soil and crops after repeated seasonal applications of lindane to soil in which maize and rice crops were grown. In the 1993 rice study, the lindane residues in the treated soil were 0.6 mgkg-1 (1day) and 0.04 mgkg-1 (2 months) after application respectively. In the soil from the maize plots, lindane residues were 0.19 mg kg-1 (1 day) and 0.16 mg kg-1 (1 month) after application and not detectable after 6 months. In the 1994 maize study, the lindane residues in the soil were 0.12 (1 day), 0.10 (1 month) and 0.033 mg kg-1 (2 months) after application respectively while in the crop they were 0.19 (1 day), 0.105 (2 weeks) and 0.05 (4 weeks) mg kg-1, respectively. In general, lindane residues were not detected in the soil one year after application indicating that there was no accumulation of lindane in the soil during the period 1992-1994 and therefore unlikely to be any long term effects on soil fauna. Lindane residues in rice and maize crops continued to decrease during the period up to harvest. (author). 6 refs, 2 tabs