THE AREA DISTRIBUTION OF AN INSECTICIDE (FENTHION) SPRAYED INSIDE THE HUTS OF AN AFRICAN VILLAGE.

In the course of a village-scale trial of fenthion, carried out in a village near Lagos, Nigeria, 40% fenthion water-dispersible powder was used at a 3.75% concentration. This was applied by Galeazzi "OM" sprayers with constant-pressure assemblies. The target concentration was 1.5 g/m(2). Filter-papers were placed on walls, ceilings and roof beams to determine the actual average rate of application, and glass plates were placed on the floors to determine the rate of "bounce-off" from the walls or of "drop-out" from the ceilings. The results of chemical tests show that the rate actually applied came closest to the target concentration on the walls, followed, in that order, by ceilings and roof beams. There were heavy deposits on the floors up to 30 cm away from the walls. The authors analyse the causes for the variations encountered.