Control of health hazards likely to arise from the use of organo-phosphorus insecticides in vector control.

The widespread use of DDT and the chlorinated hydrocarbon group of insecticides for the control of mosquitos and flies has led to the emergence of resistant strains of flies. Where the DDT group of insecticides is ineffective for the control of resistant insects, it appears that the use of the organo-phosphorus group of insecticides may be an alternative. However, it seems probable that their introduction and application under the same conditions in which DDT has been safely used might carry serious risks to the health of the men who apply them. In this paper, the authors indicate what these dangers are, how they manifest themselves, and how they might be controlled. Four methods of blood-cholinesterase determinations, carried out in the laboratory and in the field, are described in an annex.