issible
nuous
ordine
issivnle
r sugconre, so
ld be
served
7aters.
a than
om has
Inited
1uman
tivity
ild be
de by
mean
t least
wn to
30 the
in the
wuman
many
reting
ations
daily
me to
tivity
From the latest figures available (for the first half
of 1959) we calculate the mean contents of strontium90 and cesium-137 in surface waters as 0-75 uyuc./litre
and 0-20 uue./litre, respectively. The mean daily
intakes of populations ingesting such drinking waters
would therefore be 1-9 uuc. and 0-5 unc. of the two
nuclides, respectively.
For large populations the International Commission
on Radiological Protection suggests 33 uyuc./litre and
6,000
yye./litre
in
water,
respectively,
for
these
materials as the maximum permissible concentrations.
It will be seen that the observed values are very
small in comparison to these permissible levels.
Note added in proof. Since these investigations
were completed, we have had the opportunity of
examining specimens of drinking waters supplied to
Horrabridge, Devon.
The radioactivity of these
particular waters has been the subject of recent communications®*.23 concerning the incidence of cancer
in the area. We find the long-lived natural activity
of the Sampford Spiney supply to be 0:6 puc./litre,
and its content of radon + daughters 2,500—5,000
uuc./litre. It will be seen that these values are well
within the range reported in Table 1 above for waters
in south-west England.
Many of the water samples were obtained through
the goodwill and co-operation of Mr. A. W. Kenny,
of the Ministry of Housing and Local Government,
who kindly approached on our behalf the chief
engineers of numerous water undertakings, to all of
whom we would like to express our sincere thanks.
Our thanks are also due to Mr. J. Crookall, of this
Department, for chemical estimations carried out on
a number of the samples.
1 Turner, RB. C., Radley, J. M., and Mayneord, W. V., Health Phys., 1,
263 (1958).
* Stehney, A. F., deta Radiol., 43, 43 (1955).
* Hursh, J. B., and Gates, A. A., Univ. Rochester Rep. OR, 257 (1953).
4 Lucas, H. F.. and Itcewiez, F. H., J. Amer. Waterworks Assoc., 50,
1523 (1958}.
* Krause, D. P., A.N.L. Rep. 5967 (Dec, 1958).
* Lucas, H. F., and Krause, D. P., Radiology, 74, 114 (1960).
7 Rajewsky, B., Muth, H., Hantke, H. J., and Aurand, K., Strahlentherapre, 104, 157 (1957).
4 Jacobi, R. B., J, Chem. Soc., 3, 314 (1949).
* Thomson, J. J., Phil. Mag., 4, 352 (1902).
Turner, R, C., Radley, J. M., and Mayneord, W. V., Brit. J. Radiol.,
$1, 397 (1958).
1 Rosholt, J. N., Anal, Chem., 29, 1398 (1957).
‘1 Mayneord, W. V., Turner, R. C., and Radley, J. M., Vature, 187,
208 (1960).
ta Smith. H., and Chandler, T. BR. D., United Nations Conf., P/298
4 Rona, E., and Urry, W. D., Amer. J. Set,, 250, 241 (1952).
15 Scott, R. C., and Barker, F. B., United Nations Conf., P/778 (1958).
16 Recommendations of the International Commission on Radiological
Protection, rit, J. Radioel., Supp. No. 6 (1955).
"7 Meyer, 5., Mitt. Des Instituts far Radium Forschung, No. 238,
Wien (1929),
18 International Commission on Radiological Protection, Report of
Committee IL (Pergamon Press, London, 1959).
'® Marineili, L, D., dimer. J. Roentgenol,, 90, 729 (1958).
20 Mayneord, W. V., Radley, J. M., and Turner, R. C., Ade. Sei,
No. 64, 363 (March 1060),
21 Crooks, R. N., Osmond, R. G. D., Owers, M. J., Fisher, E. M. B.,
and Evett, T. W., A.E.R.E.—R 3127, London (H.M,8.0., 1959).
*? Allen-Price, E. D., Lancez, i, 1235 (1960).
33 Ane I)., Lakey, J. R. A., and Mathias, D. J., Lancet, ii, 1272
100 or
icular
re the
ugher
ntake
range
atural
yution
nking
aving
food
ice of
retain,
1 form
nents,
food,
made
zation
actors
e the
‘in
daily
on to
tivity
n-137
iduets
iivity,
irface
itents
values
Printed in Great Britain by Fisher, Knight & Co.. Ltd., St. Albans,