View report page

52
In three instances re-infestation occurred during the year, in a block of three
houses, all of which became re-infested. The three families concerned were very
friendly and it was found that a good deal of interchange of furniture went on between
them, not an unusual practice, but one which leads to unfortunate results when
one of them purchases secondhand bug-infested furniture and it also becomes the
subject of exchange.
Regulations, known as the Hydrogen Cyanide (Fumigation of Buildings),
Regulations, and dated December, 1938, have been made by the Secretary of State
and come into operation on the 1st February, 1939. All fumigation of buildings
with hydrogen cyanide after that date will have to comply with these Regulations.
(c) In cases of light infestation, or where for any reason it was not practicable
to seal off a room, other fumigants or contact sprays were used on 106 occasions,
with 4 primary failures.
(d) Washed heavy naphtha was used for 33 houses, 6 of which were furnished
and 24 of which belong to the Council. In four instances the primary treatment
was not successful, 2 of these being furnished houses.
As our knowledge of washed heavy naphtha grows it is becoming more and
more clear that it will replace hydrogen cyanide as a fumigant in houses, but as
yet we have not been able to work out a thoroughly satisfactory method of using
this chemical in furnished houses, although the method for use in empty houses
is quite efficient.
(e) In addition to the above, 103 houses in Clearance Areas were disinfested
with a mixture of equal parts of orthodichlorbenzene and paraffin before demolition.
3. The methods employed for ensuring that the belongings of tenants are free
from vermin before removal to Council houses.—The Sanitary Inspector in charge
of disinfestation inspects the furniture of all persons provisionally selected as tenants
for the Council's houses, decides when disinfestation is necessary and makes the
necessary arrangements. During the year he visited 506 houses in this connection.
In all cases where vermin are found, the removal is carried out under the supervision
of the Health Department, either in the Council's special pantechnicons, of which
there are now three, or in hired vans. During the year 215 removals were carried
out in this way, each van load being disinfested with Zyklon B, at one of the Council's
depots.
As a matter of interest it may be stated that of the 506 tenants inspected during
the year 252 were in slum clearance houses and 254 were in other houses. Eighty
per cent. of the slum clearance houses were bug infested, compared with 52 per
cent. of the others.
Recent work by the London County Council and by the Enfield Urban District
Council has shown that heavy naphtha can be effectively used in vans for the
disinfestation of furniture in transit. It appears that at a temperature of 100ºF.