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evidence that smoke might be more important than sulphur. This work has never been published
in full, and only briefly in the transactions of the Association of Industrial Medical Officers. He
agreed that the only way of determining the effect of sulphur gas would be by prospective surveys
over the next decade, during which smoke will doubtless be reduced while sulphur pollution will
remain relatively constant.
3. The comments set out above summarise in effect the conclusions to be derived from the
technical observations of Mr. Engineer and the Medical Officer; in short, that sulphur alone is
not a proven danger. They are brought into this introduction so that Your Worshipful Committee
may be aware of the inevitable scientific deduction which is to be drawn from the reviews of your
Technical Officers.
4. In seeking to obtain legislative powers to control a nuisance, it is essential that it is
possible clearly to define the nuisance, and to prove that such nuisance exists as a hazard to
health or welfare, and finally to set out in the powers sought a practical manner of controlling
such a nuisance. Mr. Remembrancer has kept these requirements in mind when reading the
opinions of the experts in this field.
The Medical Officer would say:—
5. The magnitude of the London Fog in December, 1952, focussed public attention upon the
serious effect of atmospheric pollution on health. The Minister of Housing and Local Government
appointed in July, 1953, the Committee on Air Pollution, with the following terms of
reference:—
"To examine the nature of causes and effects of air pollution, and the efficacy of present
preventative measures; to consider what further preventative measures are practicable, and to
make recommendations." Both the interim report issued in November, 1953, and the final report
of the Committee indicated that the sulphur content of British fuels varies considerably. When
the fuel is burnt, whether in industrial or domestic appliances, most of the sulphur is also burnt,
being converted into twice its weight of sulphur dioxide, a gas of acidic properties which is
discharged with the chimney gases. An estimate was given of 5 million tons of sulphur dioxide
per annum from the use of solid fuels used throughout the Country in 1952. From the burning of
4.5 million tons of fuel and gas fuel oils, together with 0.6 million tons of creosote pitch mixtures
in 1952, there would be little smoke given efficient combustion, but assuming an average sulphur
content of 2 to 4%, the burning of 5.1 million tons would result in about 0.3 million tons of sulphur
dioxide being discharged with the chimney gases. Diesel engines (road transport and others)
use about 2 million tons of oil per year, and produce from 20,000 to 40,000 tons of sulphur dioxide.
Some 5.3 million tons of motor spirit (including motor benzole) were used in transport in
1952. The amount of sulphur dioxide produced in this source is negligible.
6. The only recommendation of the Committee, so far as the emission of sulphur dioxide is
concerned, related to the washing of gases at power stations to remove at least 90% of that
pollution. The comment is made "that there remain many uses of fuel for which the more expensive
refined sources of energy will be too costly. There is thus no present prospect of substantially
reducing the emission of sulphur dioxide from general industry or domestic fires. An
intensive research is recommended." In this connection, the standing Advisory Committee to the
Medical Research Council has a Sub Committee on Atmospheric Pollution with working parties
engaged on various aspects; e.g. chronic bronchitis in relation to atmospheric pollution; the constituents
of atmospheric pollution and means of prevention,mortality and morbidity statistics,etc.
7. So far as the City of London is concerned, in 1953 the approximate consumption of solid
fuel was 72,300 tons. The amount of sulphur in these fuels varied between 0.5% and 3%. Assuming
the average sulphur content to be 1.5% by weight the sulphur dioxide emitted would have been
2,169 tons. In 1954 the annual consumption of fuel oils was 20,000 tons, and if all the oil burnt
in that year had contained an average of 3% of sulphur, (light or 200 seconds oil) the total sulphur
dioxide pollutant would have been 1,200 tons. If it had all contained 3.7% (medium or 950 seconds
oil) the total would have been 1,480 tons, and if it had all contained 4% (heavy or 3,500
seconds oil) the total would have been 1,600 tons. Unfortunately no figures were actually available
which subdivide the various grades of oil into their sulphur content, but figures have
recently been obtained from one large oil company from the quantities which they are now
supplying.
Heating oil 35 seconds 1% sulphur 324 tons
Light oil 200 " 3.0% " 2,260 "
Medium oil 950 " 3.7% " 1,400 "
This company does not supply any heavy grade oil in the City, and in any case, only the largest
installations in buildings of many storeys would burn the heaviest grade of fuel oil, and the
height of the chimneys would assist in the greater dispersal of the flue gases, with a consequent
decrease of the ground level concentration of sulphur dioxide.
8. Thus it will be seen from the figures of the particular company referred to above that if the
950 seconds viscosity oil with a sulphur content of 3.7% was substituted by 200 seconds oil
with a sulphur content of 3 0% the total annual sulphur dioxide would be reduced by only 0.7% of
1,400 tons; i.e., 9.8 tons, which is not a significant figure compared with the total emission. It
should, however, be remembered that oil consumption for central heating in the City must have
risen steeply since 1954, but the actual increase is not known.
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