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43
CLEAN AIR ACT, 1956.
Recording of Atmospheric Pollution.
Five instruments for the measurement of atmospheric pollution
are installed within the district. There are two deposit gauges, two
sulphur dioxide candles and a volumetric apparatus for measuring
sulphur dioxide and tarry matter.
Volumetric Apparatus.
This instrument functions in the Public Health Department's
office. A sample of the atmosphere is constantly being drawn
through and readings are taken daily, throughout the year.
It serves two functions. Firstly, to record the amount of the
gas, sulphur dioxide present. This represents the irritant factor in
pollution which, incidentally, will not be directly improved by the
programme of Smoke Control Areas. Secondly, this daily recording
gives an indication of the density of the suspended tarry matter
in the air. It is at this substance, which mainly originates from
domestic chimneys, that the smoke control programme is aimed.
Both the sulphur dioxide and the tarry matter are virtually negligible
in summer, but increase many times when foggy conditions
obtain.
Records show that pollution in 1960 did not reach a high level.
The latter part of the winter was characterised by a few fairly high
readings, whereas the autumn was relatively free from fog.
Sulphur Dioxide Candles.
The two candles are set at the Foootscray County Primary
School, Sidcup (Riverside Road), and at the County Primary Roman
Catholic School, Sidcup (Lamorbey). They again indicate the
quantity of sulphur dioxide pollution, but are read monthly.
Deposit Gauges.
The two deposit gauges are situated alongside the sulphur
dioxide candles and also give monthly readings.
They are designed to measure the content of the solid matter
in aerial pollution and are of importance in indicating the quantity
of calcareous material, most of which has its origin in the cement
flue dust emanating from cement works at Dartford and other places
in the Thames Estuary.
The problem of cement flue dust deposits in the area and in
fact, in the whole of North West Kent, is one which has concerned
the Council for many years. The Council is represented on the