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The following report gives details of the trials carried out.
TRIALS WITH D.D.T. FOR THE PREVENTION AND
ELIMINATION OF BED BUGS (1st INTERIM REPORT).
Introduction.
In July, 1945, the Medical Officer of Health obtained a supply of D.D.T.
through the Ministry of Supply for experimental use against the bed bug.
It was agreed that the local Health Department would carry out the trial
(supplying labour, transport, etc). On 24th July, 1945, the interested
parties met at Tottenham and planned the following trials.
(1) Prevention of Bug-Infestation of Pre-fabricated Houses by PreTreatment
with D.D.T.
(a) Project.
Prefabricated houses to be treated with D.D.T. shortly after completion
and before entry of the new tenants. Alternate houses to be left
untreated as "controls." Both groups to be inspected at fairly long
intervals (3—6months) to determine the proportions of each which are
found to become infested. Further proposed to extend this trial elsewhere
in conjunction with the Ministry of Works.
(b) Collaboration Arranged.
The D.D.T., kerosene and labour to be supplied by the Tottenham
Health Department, and subsequent inspections made by their Sanitary
Inspectors, spraying of the first group of houses to be supervised by a Ministry
official.
(c) Methods Employed.
Treatment is rapid; a team of two men (one sprayer and one relief) can
treat the two bedrooms of a prefabricated house in approximately ten
minutes. About 1J gallons of kerosene containing J lb. of D.D.T. are
used per house. For convenience, the solution is prepared from a
cyclohexanene concentrate (supplied by Geigy, Ltd.) which contains 33 per
cent D.D.T. This is simply diluted with the appropriate amount of
kerosene.
(id) Progress.
Eight houses treated and occupied and a further eight occupied without
treatment.
(2) Eradication of Bugs from Old Infested Houses. Comparison of
Different Methods of Applying D.D.T.
(a) Project.
The following four types of treatment were each carried out in four to
seven bug-infested houses:—
(1) D.D.T. solution in kerosene (5 per cent). This was prepared by
adding one part of the Geigy Concentrated D.D.T. in cyclohexanene
to five parts of odourless kerosene.
(2) D.D.T. emulsion in water (5 per cent). A rejected batch of
A.T.S.O. No. 1 was used, with the composition:—
Sulphonated castor oil .. 24.5 per cent.
Cresylic acid 6.0 per cent.
D.D.T. 15.5 per cent.
Heavy solvent naphtha 54.0 per cent.
This was diluted with two parts of water before use.
This Treatment resulted in the formation of pools of milky emulsion
on the floors and the heavy naphtha present occasionally caused paint to
soften and run. It was found to be unpopular.