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
Hackney 1968
[Report of the Medical Officer of Health for Hackney]
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| Lead content (mg/1 Pb) | Samples of water standing in lead pipe overnight | Samples of water after running the tap |
|---|---|---|
| Less than 0.01 | 10 | 37 |
| 0.01 | 31 | 57 |
| 0.02 | 21 | 4 |
| 0.03 | 8 | 1 |
| 0.04 | 9 | 0 |
| 0.05 | 5 | 0 |
| 0.06 | 5 | 0 |
| 0.07 | 4 | 1 |
| 0.08 | 1 | 0 |
| 0.09 | 3 | 0 |
| 0. 10 | 1 | 0 |
| 0.12 | 1 | 0 |
| 0. 16 | 1 | 0 |
| 100 premises | 100 premises |
The above results are very satisfactory and the figures are within the
limits of the World Health Organisation European Standards for Drinking Water
Quality. This states that the upper limit for lead in running water in the
supply should not be more than 0.1 mg/1 (Pb); but where water undertakings
continue to use lead piping the concentration of lead (as Pb) should not
exceed 0.3 mg/1 after 16 hours contact with the pipes.
| Source of supply | No. of samples | Agar Plate count per ml. after 20-24 hours at 37°C | Coliform count per cent samples negative in 100 ml. | E. Coli count per cent samples negative in 100 ml. |
|---|---|---|---|---|
| Stoke Newington | 257 | 18.9 | 100.0 | 100.0 |
| All Thames derived | 3,651 | 11.4 | 99. 86 | 99.97 |
| Stoke Newington | All Thames derived | |
|---|---|---|
| Number of samples | 52 | 363 |
| Ammoniacal Nitrogen | 0.014 | 0.020 |
| Albuminoid Nitrogen | 0.062 | 0.083 |
| Nitrate Nitrogen | 4.8 | 3.9 |
| Oxygen abs. from KMn04 4 hrs. at 27°C | 0.69 | 1.20 |
| Hardness (total) CaC03 | 308 | 280 |
| Hardness (non-carbonate) CaCO3 | 78 | 76 |
| Magnesium as Mg | 5 | 4 |
| Sodium as Na | 29.9 | 23.2 |
| Potassium as K | 5.2 | 5.3 |
| Chloride as CI | 40 | 32 |
| Phosphate as PO4 | 1.7 | 2.0 |
| Silicate as Si02 | 10 | 10 |
| Sulphate as S04 | 66 | 62 |
| Natural Fluoride asF | 0.30 | 0.30 |
| Surface-active material as Manoxol OT | 0.01 | 0.02 |
| Turbidity units | 0.1 | 0.1 |
| Colour (Burgess units) | 7 | 14 |
| pH Value | 8.0 | 7.9 |
| Electrical Conductivity (microhms) | 630 | 570 |