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104
a considerable improvement in the level of atmospheric pollution in the neighbourhood
of the works. In the case of the glass works, the chimney will be 131 ft. high and
is designed with a removable constriction at the outlet so as to maintain a suitable
efflux velocity with one bath working. When a second bath is brought into
commission the constriction will be removed. This adaptation was made following
representations from the Department and is a good illustration of the benefits of
notification and consultation. The well-known weakness of the Act concerning
boilers and chimneys for shops and offices, to which Section 10 of the Act does not
apply, has not yet been remedied.
MEASUREMENT OF ATMOSPHERIC POLLUTION
Shortly after the amalgamation of the three Boroughs, consultations were held
with representatives of the Warren Spring Laboratory, Ministry of Technology, to
establish the number and siting of the various instruments necessary to give adequate
information as to atmospheric pollution in the Borough. It was decided that this
object could best be obtained as follows:—
(1) By retaining five standard deposit gauges at Bashley Road, Acton;
Longfield Depot, Ealing; Birkbeck Avenue, Greenford; Hortus Cemetery,
Southall; and Park Avenue, Southall.
These are for monitoring local emissions in the vicinity of the sites and for
measuring local fall-out of larger particles.
(2) By continuing the use of six volumetric instruments at Acton Lane,
Acton; Friars Place Lane, Acton; Chase Road, Acton; Town Hall Annexe,
Ealing; Eliots Green Grammar School, Northolt; and Walpole Grammar
School, Ealing.
The function of these is to measure smoke and sulphur dioxide in the
atmosphere.
(3) The eventual establishment of a new volumetric instrument at Northcote
Clinic, Southall.
This regrouping resulted in the reduction of the former volumetric sites by one
and the abolition of all the lead peroxide sites. The modern daily volumetric
instrument gives a more reliable and useful figure for atmospheric sulphur.
Examination of former figures for the lead peroxide instruments which have now
been discontinued shows that the amount of sulphur in the air in the past few years
has been decreasing steadily at all the sites with the exception of the one used at
Longfield Depot; the trend line of this station, obtained by using a five-year moving
average, shows a slow rise.
The standard deposit gauge figures follow a similar pattern with the exception
of those at Bashley Road and Longfield Depot, both of which show a slight rise
over the past three years.
As the volumetric instruments have not been in use for such long periods as the
other types, it is not possible to establish reliable trends but, from the information
available, it appears that the amount of smoke in the air each day is getting less
whilst the amount of sulphur dioxide is increasing slightly.
The monthly averages of the daily figures for smoke and sulphur dioxide obtained
from the six volumetric instruments are shown graphically in the first three diagrams
on pages 137 and 138. The monthly analysis of insoluble deposits from the deposit
gauges is shown in the last three diagrams on pages 138 and 139. (The White Street,
Southall, deposit gauge is operated by the North Thames Gas Board.) The complete
results for the year are given in Tables Nos. 20, 21 and 22 (immediately preceding
the graphs) on pages 134, 135 and 136.