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79
Investigation of Atmospheric Pollution—Department of Scientific and
Industrial Research.— In view of the work undertaken by the City Council
in relation to the investigation of atmospheric pollution, the Department
mentioned invited the Council to appoint members to the Standing
Conference of Co-operating bodies. This body consists of representatives
of Local Authorities, industrial undertakings, scientific societies, etc.,
actively interested in such investigations. The Council appointed your
.Medical Officer of Health and Mr. C. H. Cribb, one of the City's Public
Analysts, as their representatives. They attended the bi-annual meeting
in October when matters relating to administration of smoke legislation
and research were discussed.
Sulphur gas—measurement of .—The deleterious effects of sulphurous
and sulphuric acids in the air on the health of the community and on
buildings is now fully recognised. A method has been devised by the
Department of Scientific and Industrial Research for the determination of
the amount of this pollution present in the atmosphere. A measured
volume of air is bubbled through a solution of hyperol, the acidity of
which can be easily measured. All the sulphur compounds in the air
passed through the apparatus are absorbed by this solution, and can be
identified and measured by chemical analysis.
Mr. Cribb, who has been carrying out laboratory investigations of
atmospheric pollution on behalf of the Council, was authorised to proceed
with this new line of investigation. Apparatus of the type recommended
by the Department but modified by Mr. Cribb in such a manner as to
enable a larger volume of air to be examined with increased accuracy
was installed at the City Hall at the end of the year. The results obtained
by experiment are appended herewith as a matter of interest:—
Date
Volume of air
examined.
Time of
Experiment.
Sulphur dioxide in parts
per million.
Volumetric
analysis.
Gravimetric
analysis.
12 December,
1931
75 cubic feet
8 hours
0.37
0.48
The diagram on the opposite page indicates in graphic form the varying
amounts of suspended dirt as recorded by the automatic air filter installed
at the City Hall. Readings are taken hourly throughout the 24 hours
and the average pollution for the month is shown, worked out as an
average day during that month from these readings.