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
Croydon 1937
[Report of the Medical Officer of Health for Croydon]
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bacteriological examination to the Borough Pathologist:
(ContinuedT)
| Date taken. | Time taken. P.M. | Temp, of water. Degrees FAHR. | No. of bathers during the day up to time of sampling. | Weather Conditions. | Remarks. | Result. |
|---|---|---|---|---|---|---|
| 18/8/37 | 7.15 | 68 | 1,220 | Blue sky and clouds, sunny. | New ozone plant in operation. | B. Coli present in 0.1 cc., but not in 0.01 cc. No staph, aureus or strept. present. Organisms : per l/100th of a cc. were too numerous to count. |
| 25/8/37 | 7.20 | 69 | 3,035 | Overcast, warm. | New ozone plant working all day. | B. Coli present in 1 cc. and over. Absent in 0.1, 0.01, and 0.001 cc. No staph, aureus, but a few haemolytic streptococcal colonies present on plates. Organisms : 56,000 per 1 cc. |
| 1/9/37 | 7.10 | 66.5 | 721 | Overcast. | Filtering from 7 a.m. Ozone on all day. | B. Coli present in 10 cc., but not in 1 cc. or under. No staph, aureus or streptococci present. Organisms : 16,400 per 1 cc. |
| 8/9/37 | 7.10 | 67 | 1,107 | Clouds and sun. | Continuous filtration, and ozone on. | B. Coli present in 10 cc. and over but absent in 1 cc. and under. No staph, aureus or strept. present. Organisms : 1,500 per 1 cc. |
| 15/9/37 | 7.15 | 65 | 77 | Overcast and cloudy. | Ozone on all day. | No B. Coli in 50 cc. or under. No staph, aureus or strept. present. Organisms : 400 per 1 cc. |
| 22/9/37 | 7.15 | 67 | 74 | Overcast. | Ozone on all day. Filtering continuous. | B. Coli absent in 50 cc. and under. No staph, aureus or strept. present. Organisms : 240 per 1 cc. |
COMMENTS.—The above results appear to show that ozone alone will not keep the pool water in a reasonable state of purity,
especially when the load is heavy. The Chloramine process, however, proved to be efficient. In this connection, the results
obtained on August 11th, 1937, when chloramine only was used, and the result obtained on August 18th with a lighter load and
lower temperature, and on August 25th with a comparable load and temperature when ozone only was being utilised, should be
contrasted. The tacteriological results obtained with chloramine were satisfactory throughout.