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61
It was pointed out in the report for 1962 that householders on an
average spent on adaptation about double the amount of money they
received by way of Grant and it will be seen from the above figures that
this trend continues.
Industrial Premises.
During May the Minister of Housing and Local Government issued
a memorandum on chimney heights for industrial plants. This contained
the long awaited official recommendations on the height at which flue
gases can be discharged into the atmosphere to give an acceptable amount
of pollution at ground level. The issue of this guide was welcomed by all
who have to make recommendations in respect of Section 10 of the Clean
Air Act 1956 on plans submitted for new boiler house installations.
A shortcoming of the Clean Air Act in respect of chimney heights is
that while Section 10 gives some control over new structures there is no
control over the discharge of flue gases into an existing chimney or over
plant where the management decide at a later date to use an alternative fuel.
In July a temporary exemption permitted by Section 2 of the Clean
Air Act 1956 which allowed as a defence against prosecution for the
emission of dark smoke due to the inability to remedy faulty buildings and
equipment came to an end. Industrialists in the district known to be
using old types of plant were advised prior to July of the position and
(luring the early months of the year two coal fired plants changed over to
oil burning.
NATIONAL SURVEY OF AIR POLLUTION
The four Harrow Stations supplying information to the Warren
Spring Laboratory of the Department of Scientific and Industrial Research
for the National Survey have continued in operation. Station No. 1 at the
offices of the Health Department, Harrow Weald is in an area of light
development on the edge of the Green Belt, Station No. 2 is situated at a
factory in Wealdstone in a heavily developed area including dwelling
houses and industrial premises, Station No. 3 is at a school in Roxeth in
a residential area subject to Smoke Control Orders and Station No. 4 is
at a school in a similar area in Stanmore which is not smoke controlled.
Some difficulty has been experienced in obtaining the necessary
Minimum of 21 valid daily readings in each period of 28 days, particularly
at holiday times and it has been decided to install at least one 8 port air
sampling device which automatically carries out the eight-day sequence
of changing re-agent bottles and filter papers.
The highest sulphur dioxide concentrations have been at Station
No. 2 with a particularly high peak during February of 1,178 micrograms
per cubic meter and an average daily figure for six months of 600.