London's Pulse: Medical Officer of Health reports 1848-1972
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Hints from the Health Department. Leaflet from the archive of the Society of Medical Officers of Health. Credit: Wellcome Collection, London
Leyton 1950
[Report of the Medical Officer of Health for Leyton]
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51
The following observations of the weather are also made—
of wind speed and direction, visibility, air temperature and rainfall.
All observations are recorded; and monthly returns are submitted
to the Superintendent of Observations, the figures being included
in the monthly Atmospheric Pollution Bulletin published by the
Department of Scientific and Industrial Research.
The following table shows the results recorded during the ten
months ended 31st December, 1950:—
CONCENTRATION OF SMOKE AND SULPHUR DIOXIDE EXPRESSED IN MILLIGRAMS PEP 100 CUBIC METRES.
| SMOKE | SULPHUR DIOXIDE | |||||
|---|---|---|---|---|---|---|
| Month 1950. | Monthly average | Highest daily average | Lowest daily average | Monthly average | Highest daily average | Lowest daily average |
| March | 44.3 | 127.4 | 10.1 | 29.2 | 82.6 | 10.0 |
| April | 24.6 | 39.1 | 13.8 | 16.0 | 31.5 | 5.1 |
| May | 11.8 | 30.8 | 0.5 | 4.9 | 13.4 | 0.3 |
| June | 5.6 | 9.5 | 1.1 | 5.6 | 12.6 | 0.6 |
| July | 5.7 | 11.7 | 2.4 | 6.3 | 14.6 | 1.4 |
| August | 6.4 | 9.8 | 3.4 | 8.3 | 12.6 | 4.0 |
| September | 8.9 | 20.0 | 3.3 | 8.6 | 16.9 | 1.7 |
| October | 24.8 | 57.8 | 9.3 | 18.0 | 41.2 | 7.7 |
| November | 36.5 | 92.9 | 15.2 | 27.2 | 57.2 | 11.2 |
| December | 47.4 | 102.7 | 14.1 | 36.0 | 62.3 | 12.9 |
There was a very great variation in the amount of pollution
from day to day, as can be seen from a comparison of the highest
and lowest daily averages in the above table. It was found that
this variation had a close connection with the varying weather
conditions, important factors being the speed and direction of the
wind and the degree of turbulence of the air—that is, the readiness
with which air mixes with itself. For example, the highest daily
average smoke concentration during eight of the ten months under
review occurred on days when the air was almost completely calm,
with accompanying fog or haze—conditions which indicate a low
turbulence. On the other hand, eight of the lowest daily average
sulphur dioxide readings were obtained when a moderate northeasterly
wind was blowing.
In addition to the irregular daily variations in the amount of
pollution, there was a well defined and much more regular variation