for a good extensive sampling network, with emphasis,
whereverfeasible, on the larger centers of population. Various distinctive soil regions of the U.S.—asclassified by the
Department of Agriculture—were also included, since soil
conditions may be considered as the integrated end-products of climatic, topographical, and geologic effects—all of
which are important in affecting the strontium-90 content
CONCENTRATIONS
OF STRONTIUM-90 IN MILK
PUBLIC
CITIES WHERE SAMPLES
WERE TAKEN
ALABAMA
ALASKA
ARIZONA
CALIFORNIA
of soil, which in turn affects the strontium-90 content of
pasture, cow, milk, and man.
,
All areas whose soils had been found by AEC studies to
be high in strontium-90 also were included, as well as sev-
eral sites whose milk had been tested previously by the
PHSand the AEC.
At each of the cities selected, CU shoppers purchased
COLORADO
0. c.
FLORIDA
eight quarts of fluid milk each week, for a period of four
weeks. Generally, two separate across-the-counter purchases
were made each week of one quart from each of four major
local dairies, Four-ounce portions from each of the 32
quarts thus purchased were composited to provide a total
of one gallon of milk for testing from each samplingsite.
The pooled composites thus obtained represented a major
part of the milk supply of each of the cities sampled for
the period from mid-July to mid-August, 1958. A total of
approximately 1600 quarts were purchased for these tests.
Analyses for strontium-90 were made for CU by a con-
sulting laboratory which specializes in such work, and
whosereliability had been established by check-sample data
provided by the AEC as well by CU.
In drawing up its program for sampling and testing milk,
not, of course, be noted by a one-period sampling and
analysis. The best data available for observing the progressive change in milk’s strontium-90 content probably are the
monthly figures of the PHS.
From these and other studies, there is incontrovertible
evidence that the strontium-90 content of milk has been increasing since 1954. The average rate of increase wasesti-
mated by the AEC in 1957 to be between 0.5 to 1.0 8.U. per
year for past years. The overall average of 48 U.S. cities
sampled by CU is 8.0 S.U.; the average of the 10 cities covered by the PHS for approximately the same period is 7.6
S.U., a figure that is in good agreement with that found by
CU considering the differences in the sites sampled and in
the nature of the samples. For purposes of noting change,
an overall estimate of the strontium-90 content of milk
in 1957 may be obtained by averaging figures published by
the PHSforfive cities sampled that year (4.35 $.U.) or by
taking the average which was published by Lamont (6.1
S.U.). It would appear from these figures that the stron-
tium-90 content of milk in mid-1958 was more than two
Miami
4s
7.6
10.6
KANSAS
MASSACHUSETTS
MICHIGAN
MINNESOTA
MISSISSIPPI
MISSOURI
MONTANA
NEBRASKA
NEW YORK
breadth rather than depth of coverage. Any trend or variation of strontium-90 content with time or other factors can-
5.9
9.8
Indianapolis
Des Moines
acknowledges the suggestions made by these organizations.
The data obtained by CU, together with somerelated re-
Denver
Washington
INDIANA
1OWA
culture, and the U.S. Public Health Service, and gratefully
sults from other laboratories, are shown in the Table on
this page. CU’s data, it should be emphasized, provide
2.6
7.3
6.1
12.6
KENTUCKY
LOUISIANA
MAINE
NORTH
7.4
4.9
3.3
1.9
Atlanta
Boise
Chicago
NEVADA
NEW MEXICO
RESULTS
Birmingham
Juneau
Phoenix
Los Angeles
Sacramento
San Francisco
Wichita
9.8
15.6
7.1
Boston
Sault Ste. Marie
Ouluth
Minneapolis
13.9
§.4
11.5
9.2
St. Louis
Great Falls
North Platte
Las Vegas
Sante Fe
Buffalo
Perry
N.Y. CG.
6.6
10.5
9.5
141
Fargo
Mandan
SOUTH CAROLINA
SOUTH DAKOTA
TENNESSEE
TEXAS
UTAH
VIRGINIA
WASHINGTON
WEST VIRGINIA
WISCONSIN
WYOMING
CANADA
Tulsa
6.5
11.8
8.8
6.6
5.0
13.7
Columbia
Rapid City
6.8
11.2
Memphis
Austin
EI Paso
Houston
13.6
2.5
3.3
4.4
Salt Lake City
Norfolk
§.2
10.6
Seattle
10.1
Spokane
6.2
Charleston
Columbus
Casper
7.3
3
4
Jan.-Mar./56
Jan.-Mar./58
20-30 Get.-Dec./57
15
Jan.-Mar./56
5-6
Anr.-June/56
9.4
8.7
Portland
Philadelphia
Pittsburgh
Quebec
Winnipeg
13.4
9.4
Sismarck
OKLAHOMA
7.6
2.3
5.1
Charlotte
OREGON
PENNSYLVIANA
9.4
4-6 May-Sept./56
Wt
8.8
CAROLINA
Cincinnati
Cleveland
Sampling
period
4.6
8.6
NORTH DAKOTA
OHIO
§.U.
8.1
Louisville
New Orleans
Bangor
Jackson
State College
ATOMIC
ENERGY
COMMISSION
HEALTH
SERVICE
July-August 1958
$.U.
S.U.*
GEORGIA
IDAHO
ILLINOIS
CU consulted the Lamont Geological Observatory, the
Atomic Energy Commission, the U.S. Department of Agri-
CONSUMERS
UNION
3.0
44
5.9 (Aug. only}
4
7.8
Jan.-Mar./58
13.6
9.5
*Figures were obtained by averaging the July and August single-day
samples, and have been converted from the micromicrocuries of
strontium per liter in which the PHS data originally appeared.
_
aN, . Ye,
oy
CONSUMER REPORTS
109