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ATMOSPHERIC POLLUTION
There are established in the City of London four stations for the measurement of atmospheric
pollution by the volumetric method; one at the City Mortuary which is attended by the
Superintendent of the Mortuary and Disinfecting Station and three at Police Stations which are
operated with the kind assistance of the City Police. Daily readings are taken at these stations
and the information is collated at the central office in Guildhall where the smoke stains are
'read' on a photo-electric reflectometer and forms are completed and returns made to the Department
of Scientific and Industrial Research who collate similar information from all over the
country.
The success of atmospheric pollution measurements relies upon the keenness and efficiency
of the operators of the volumetric apparatus. In order to give the operators a further interest in
the measurement of atmospheric pollution, Mr. J.W. Campbell, the Public Health Inspector responsible
for measurement in the City, arranged for a visit to the Air Pollution Research Unit at St.
Bartholomew's Medical College and a further visit was made to the Department of Scientific and
Industrial Research Laboratories at Warren Spring where a technical officer explained the various
types of equipment which are used all over the country and explained the object of and the necessity
for the measurement of atmospheric pollution. Both these visits were much appreciated by
the City operators and they asked many searching and pertinent questions which reflects their
keenness.
In the winter months when 'smog' is likely to occur, more frequent readings are required to
get an accurate reading as to the extent of atmospheric pollution. The resident Superintendent
of the City Mortuary and Disinfecting Station has frequently carried out four-hourly readings
during such periods in the past and if the 'smog' is prolonged this duty could be quite onerous.
With this in mind it was recommended that a semi-automatic sequential smoke and SO2 sampling
instrument be purchased. This machine can be set to take readings at either three or twenty-four
hour intervals. Delivery of the machine was too late for it to be put into operation for the winter
period of this year but it is hoped that it will be in use for any 'smog' occurring in the winter of
1964/65.
There are two deposit gauges in the City one on the roof of the Guildhall Office Block and
one at the City Mortuary. The rainwater and deposited matter are collected during the month
by means of a bowl which has been scientifically measured. On the 1st of the month it is taken
to the Public Analyst for general analysis and the results are forwarded to the Department of
Scientific and Industrial Research. A similar procedure is carried out. in connection with lead
peroxide method. The lead peroxide candles are exposed to the atmosphere for 1 month and then
analysed by the Public Analyst.
The results of these investigations are set out in the tables which follow.
TABLE I — Deposit Gauge
The rainwater collected was slightly less than the average for the previous five years.
There was a considerable increase in the amount of soluble matter in the rainwater collected at
Golden Lane during the year. Dr. H.A. Williams, Public Analyst reported on the March analysis
that 'the deposit contained an abnormal amount of dissolved organic matter and salt, and a
considerable growth of micro organisms'.
TABLE II — Smoke concentrations by the volumetric method
The concentration of smoke recorded in 1963 was above the average for the past five years
at three of the stations but recordings at Bishopsgate showed a slight decrease.
TABLE III — Sulphur measurement by the volumetric and lead peroxide methods
The concentrations of sulphur recorded in 1963 was above the average for the past five
years at three of the stations but recordings at Bishopsgate showed a slight decrease.
Recordings of sulphur pollution by the lead peroxide method were slightly below the average
for the past five years.
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