EPA-600/4-77-047
October 1977
Environmental Monitoring Series
STATUS AND QUALITY OF
1DIATION MEASUREMENTS
Food and Human Urine
tai Monitoring and Support Laboratory
Office of Research and Development
Environmental Protection Agency
• Vegas, Nevada 89114
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RESEARCH REPORTING SERIES
Research reports of the Off ice of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL MONITORING series.
This series describes research conducted to develop new or improved methods
and instrumentation for the identification and quantification of environmental
pollutants at the lowest conceivably significant concentrations. It also includes
studies to determine the ambient concentrations of pollutants in the environment
and/or the variance of pollutants as a function of time or meteorological factors.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/4-77-047
October 1977
STATUS AND QUALITY OF RADIATION MEASUREMENTS
Food and Human Urine
by
D. G. Easterly, R. R. Kinnison, A. N. Jarvis, and R. F. Smiecinski
Monitoring Systems Research and Development Division
Environmental Monitoring and Support Laboratory
Las Vegas, Nevada 89114
ENVIRONMENTAL MONITORING AND SUPPORT LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
LAS VEGAS, NEVADA 89114
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DISCLAIMER
This report has been reviewed by the Environmental Monitoring and Support
Laboratory-Las Vegas, U.S. Environmental Protection Agency, and approved for
publication. Mention of trade names or commercial products does not constitute
endorsement or recommendation for use.
ii
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FOREWORD
Man and his environment must be protected from the adverse effects of
pesticides, radiation, noise, and other forms of pollution, and the unwise
management of solid waste. Efforts to protect the environment require a focus
that recognizes the interplay between the components of our physical environ-
ment - air, water, and land. The Environmental Monitoring and Support Labo-
ratory-Las Vegas contributes to this multidisciplinary focus through programs
engaged in
• developing and optimizing systems and strategies for
monitoring pollutants and their impact on the environment,
and
demonstrating new monitoring systems and technologies by
applying them to fulfill special monitoring needs of the
Agency's operating programs.
This summary report, "Status and Quality of Radiation Measurements-Food
and Human Urine," should be useful in evaluating the quality of environmental
radiation data. The data contained in this report should be of value to the
EPA, other Federal agencies, State agencies, and private laboratories. For
further information on the data contained in this publication contact the
Quality Assurance Branch, Environmental Monitoring and Support Laboratory,
Las Vegas, Nevada.
..,,,.. >*-
George B./ Morgan
Director
Environmental Monitoring and Support Laboratory
Las Vegas
iii
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ABSTRACT
As part of the radiation quality assurance program conducted by the
U.S. Environmental Protection Agency, calibrated radionuclide solutions
are distributed to participating laboratories for instrument calibration
and yield determinations. Laboratory performance studies involving the
analysis of radionuclides in environmental media are also conducted.
A summary is given of the results for the food and human urine cross-
check programs for 1972-1975. For tritium, which was the least difficult
to analyze, eighty-two percent of the laboratories were within the control
limits for accuracy and ninety-nine percent within the control limits
for precision over the 3-year period. For strontium-89, the most difficult
to analyze, thirty-three percent were within the accuracy control limits
and seventy-seven percent within the precision control limits.
iv
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CONTENTS
Page
Disclaimer ii
Foreword iii
Abstract iv
List of Figures and Tables vi
Introduction 1
Methods and Procedures 2
Analysis by Participants 4
Results and Discussion A
Summary 6
Appendix. Statistical Calculations 33
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LIST OF FIGURES
Number Page
1 Computer performance report 7
2 Control chart 9
3 Histogram of laboratory averages reported for
strontium-90 in food 11
4 Histogram of laboratory averages reported for
Btrontium-89 in food 13
5 Histogram of laboratory averages reported for
iodine-131 in food 15
6 Histogram of laboratory averages reported for
cesium-137 in food 17
r
7 Histogram of laboratory averages reported for
barium^140 in food 19
8 Histogram of laboratory averages reported for ...
potassium in food 20
9 Histogram of laboratory averages reported for
tritium in urine 22
LIST OF TABLES
1 Summary of Cross-check Programs 28
2 Summary of Food Analysis Data 29
3 Summary of Tritium in Human Urine Analysis Data 31
4 Summary of Laboratory Performance, 1972-1975
Interlaboratory Comparison Studies - Food
and Human Urine 32
vi
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INTRODUCTION
Environmental radiation measurements are made by international, Federal,
State, local, and private agencies. The data obtained from these measurements
are utilized by the U.S. Environmental Protection Agency (EPA) and other
agencies for such purposes as estimating dose and health effects, establishing
standards and guides, and conducting regulatory activities. It is therefore
imperative that the precision and accuracy of radioassay procedures be assured
so that policy decisions concerning environmental quality are based on valid
and comparable data.
The radiation quality assurance program of the EPA is designed to en-
courage the development and implementation of quality control procedures at all
levels of sample collection and analysis. As an integral part of the EPA's
program, the Quality Assurance Branch of the Environmental Monitoring and
Support Laboratory-Las Vegas (EMSL-LV) distributes calibrated radionuclide
solutions for instrument calibration and chemical yield determinations, de-
velops and tests analytical procedures for possible use as EPA-approved labo-
ratory methods, and conducts a number of laboratory performance studies in-
volving the analysis of radionuclides in environmental media.
The laboratory intercomparison studies program (performance studies)
enables participating laboratories to maintain checks on their analyses and
assists them in documenting the validity of their data. In addition, this
program enables EPA to obtain an overall estimate of the precision and accuracy
of currently implemented environmental radioassay procedures and the precision
and accuracy of currently used laboratory procedures for environmental samples.
Performance programs currently in progress involve samples of a variety of
environmental material and include milk, air, water, soil, diet, urine, and
noble gases. Table 1 is a summary of these programs. Participants include
private nuclear facilities, State, Federal, and international laboratories.
Because of the large and growing number of participants and the continuing
nature of the programs, sufficient data are generated to enable periodic
assessment of the quality of environmental data obtained from these labora-
tories.
Participating laboratories perform analyses on the cross-check samples and
return their data to the Quality Assurance Branch for statistical evaluation.
Comparisons are made between laboratories and within an individual laboratory
for accuracy and precision. A computer report and an updated performance chart
are returned to each participant. This enables each laboratory to document the
precision and accuracy of its radiation data, to identify instrumental and
procedural problems, and to compare their performance with other laboratories.
A preliminary report on the laboratory performance studies conducted for
1
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food and human urine is presented on the following pages.
METHODS AND PROCEDURES
Food and human urine samples containing known amounts of specific radio-
nuclides were prepared and distributed to a number of Federal, State, and
private laboratories. These samples were designed to test the ability of
participating laboratories to analyze human urine for tritium, and food for
strontium-90, strontium-89, iodine-131, cesium-137, barium-140, and potassium.
A distribution schedule for the food and urine samples is shown below.
YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
1972
1973
1974
1975
— — — — —
00-00
- 0 - X
- - 0 X -
_ _
0 0
0
0
_ _ _ _
0
X 0 - -
X 0 - -
0
0
H
H
Food: X Urine: 0 None: - Both:
The quantity and activity levels of each type of sample are described in
the following paragraphs.
FOOD SAMPLES
Three 4-liter simulated food samples containing known amounts of
radionuclides were sent to each participant. The samples were formulated to
include the dietary intake of the Standard Adult Man.* A chart depicting
these various radionuclides and the concentration ranges is shown below.
ISOTOPE CONCENTRATION RANGE
90Sr 60 - 198 pCi/kg
89Sr 0 - 204 pCi/kg
131I 0-216 pCi/kg
137Cs 65 - 205 pCi/kg
llt0Ba 0 - 207 pCi/kg
K 2216 - 2619 mg/kg
*See "Radiological Health Handbook" compiled and edited by the Bureau of
Radiological Health and the Training Institute Environmental Control Adminis-
tration, U.S. Department of Health, Education and Welfare, January 1970,
p. 216.
2
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A 4-liter food sample is composed of the following ingredients.
Soya flour 70.3 g/4 liter
Instant potatoes 563.0 g/4 liter
Milk powder 76.0 g/4 liter
White flour 113.0 g/4 liter
French dressing 225.0 g/4 liter
Formalin 28.2 g/4 liter
Distilled water 3208.7 g/4 liter
(aged 30 days)
The first four ingredients are dry-mixed in a 40-quart blender. The dry
mixture is then combined with distilled water in the blender using a propor-
tion of two parts water to one part dry mix. The liquid mixture is trans-
ferred to a 100-gallon plastic tank, which is resting on a 1000 pound capacity
portable platform scale, and stirred with a large commercial electric mixer.
After all the dry ingredients have been transferred, the French dressing and
the formalin are added directly to the mixture. Additional distilled water is
added until final sample weight is reached. The sample is stirred for at least
3 hours and aliquots are removed and counted for background determination.
Upon completion of this initial mixing, the sample has a density of 1.071
grams/milliliter and will yield approximately 4 grams of ash per kilogram of
food sample. Accurately measured amounts of the desired radionuclides are
added to the food sample, and it is then stirred for approximately 17 hours.
Three aliquots are analyzed for radioactivity, providing a check on homogeneity
and accuracy before the food is transferred into 4-liter cubitainers for dis-
tribution to the participating laboratories.
URINE SAMPLES
A 50-milliliter human urine sample, containing a known amount of tritium,
and a 50-milliliter background human urine sample were sent to each partici-
pant. Seventeen different samples were distributed between December 1972 and
December 1975. The concentrations ranged from 969 (June 1974) to 3432 (July
1973) pCi/liter.
Composite human urine is collected and utilized in the preparation of the
tritium in urine samples. The total urine sample is preserved with 7.5 ml of
formaldehyde solution per liter of urine and then divided into two parts. One
half is used in the preparation of the 50-ml background samples, while a pre-
calculated amount of tritium is added to the other half. The portion con-
taining the tritium is thoroughly mixed and then transferred to 60-milliliter
glass bottles for distribution. Before shipping to participants, random sam-
ples are analyzed and the batch checked for homogeneity.
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ANALYSIS BY PARTICIPANTS
Participating laboratories are instructed to conduct three independent
determinations for each radionuclide included in the particular cross-check
sample, and report the results to the Quality Assurance Branch. Control
limits previously established by the Analytical Quality Control Service*, are
used in analyzing the quality of the results obtained by these laboratories.
These limits are based on the purpose for which the data are being obtained and
on reasonable laboratory ability. Upon receipt of the reports from all par-
ticipating laboratories, the data are analyzed using a computer. For each
radionuclide, this analysis includes determination of the following parameters:
the experimental average and standard deviation for each laboratory, the nor-
malized range, the normalized deviation from the known and grand average, and
the experimental sigma and the grand average of all laboratories. Examples of
sample calculations to illustrate the computations performed by the computer
are shown in the Appendix.
A report is generated containing the data reported by all participating
laboratories, listed according to identity code, along with the results of the
data analysis. Examples are shown in Figure 1. In addition, a control chart
is generated for each radionuclide included in the sample (Figure 2). The
control charts are updated each time a laboratory participates in a cross-check
study, thus giving each laboratory a continuous record of its performance. A
copy of the computer printout and a control chart for each radionuclide are
mailed to each participant approximately 6 weeks following the report due date.
RESULTS AND DISCUSSION
A laboratory is considered accurate, for our purposes, if its normalized
deviation (known) is within ±3. A laboratory is considered precise if its
range analysis (R + SR) is less than or equal to 4.
The results of the radionuclides in food intercomparison studies are
summarized in Table 2 and Figures 3 to 8.
STRONTIUM-90 (Figure 3)
All six studies contained a strontium-90 spike. Forty-seven percent of
the laboratories reported accurate results and ninety-two percent reported
precise results during the 2-year period. For April and August of 1975 the
known and grand average values were equal or almost equal. No strontium-89
was added to these samples. In three of the other four studies where stron-
tium-89 was added, the grand average was less than the known value. This may
*Rosenstein, M., and A. S. Goldin, "Statistical Techniques for Quality Control
of Environmental Radioassay," AQCS Report Stat-1, U.S. Department of Health,
Education and Welfare, PHS, November 1964.
-------
be an indication that strontium-89 activity in the sample may cause the ana-
lytical results to be biased low.
STRONTIUM-89 (Figure 4)
Four of the six studies included this isotope. Thirty-three percent of
the laboratories 'reported accurate results and seventy-seven percent met the
precision requirements. In all four studies the laboratories' grand average
values were lower than the known values, possibly indicating a negative bias
for this analysis.
IODINE-131 (Figure 5)
This isotope was present in five of the six samples used in this study.
Fifty-nine percent of the laboratories reported results within the accuracy
limits, and eighty-seven percent of the laboratories reported replicate results
with a precision meeting the requirements of the study. A comparison of the
known and grand average values shows no indication of bias in the analysis.
CESIUM-137 (Figure 6)
Cesium-137 was present in all six samples. Seventy-one percent of the
laboratories reported data within the acceptable accuracy limits while ninety-
seven percent of the laboratories had acceptable precision in their measure-
ments. No bias was evident from the reported results. Some improvement can be
seen in the 1975 data over the 1974 data where the grand average values fell
closer to the known value.
BARIUM-140 (Figure 7)
Only two of six samples contained this isotope. Fifty-three percent of
the laboratories reported results within the control limits, and ninety-one
percent met the requirements for precision. More studies containing barium-
140 must be conducted before any conclusions can be made about bias or other
trends in laboratory performance.
POTASSIUM (Figure 8)
Since the potassium concentration occurs naturally in the food sample, all
six studies contained potassium. Sixty-eight percent of the laboratories met
the requirements for accuracy, and ninety-nine percent met the standards for
precision. In all six studies the laboratories' low grand average would imply
that the analyses may be biased.
TRITIUM
The results of the radionuclides in human urine studies are summarized in
Table 3 and Figure 9. Eighty-two percent of the laboratories reported results
within the 3 sigma control limits while ninety-nine percent reported results
with acceptable precision. No bias in the reported results was evident over
the 3-year period in which the data were collected.
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SUMMARY
Table 4 is a summary of the results for the six radionuclides analyzed in
the food cross-check samples and the one isotope analyzed in the human urine
cross-check sample. Using the percentage of laboratories reporting data within
the 3 sigma control limits as criteria, the radionuclides are listed in the
order of the ability of the laboratories to perform the radionuclide analysis.
The top chart refers to the ability of the laboratories to maintain the re-
quired accuracy, while the bottom chart is a measure of the laboratories'
ability to meet the precision requirements.
The conclusions drawn, of necessity, have been very general due to the
limited amount of available data. The tritium data show that eighty-two
percept of the laboratories were within the control limits for accuracy and
ninety-nine percent within the control limits for precision over the 3-year
period. Thirty-three percent were within the accuracy control limits and
seventy-seven percent within the precision control limits for strontium-89.
With the continuation of these studies, additional data will be collected
and compiled. When more data become available, such parameters as control
limits, methods of analysis, and instrument calibration must be critically
assessed in determining laboratory performance and improving it when necessary.
-------
EMSL-LV TRITIUM IN URINE CROSS-CHECK PROGRAM SEPTEMBER 1974
09/20/74 SAMPLE - A 3H
KNOWN VALUE = 3273 pCi/1
EXPECTED LABORATORY PRECISION (IS, 1 DETERMINATION) = 357 pCi/1
LAB RESULT
AN NO DATA PROVIDED
EXPERIMENTAL RNG ANLY
SIGMA (R + SR) AVERAGE
CF
CF
CF
CM
CM
CM
CO
D
D
D
J
J
J
P
Z
z
Z
3269
3522
3632
3261
3373
3362
NO DATA
3060
3060
3240
3255
3247
3294
NO DATA
3240
3340
3190
186.1
61.7
PROVIDED
103.9
25.1
PROVIDED
76.4
0.60
0.19
0.30
0.08
3474
3332
3120
3265
NORMALIZED DEVIATION
(GRAND AVG) (KNOWN)
0.9
0.2
1.0
0.3
-0.8 -0.7
-0.1
-0.0
0.25
3257
-0.2
-0.1
EXPERIMENTAL SIGMA (ALL LABS) = 149
GRAND AVERAGE
3290
Figure 1. Computer performance report.
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Explanation of terms in Figure 1:
Title:
Column 1:
Column 2:
Column 3:
Column 4:
Column 5:
Column 6:
Column 7:
Bottom of
Chart:
Program name, sample collection date, sample code letter,
analysis type, known concentration of radionuclide, expected
standard deviation of analysis - single determination.
Laboratory identification code (A, B, C, etc.).
Laboratory results (0-25 results listed down column).
Is (standard deviation) of the experimental results.
Normalized range value in "mean range + standard error of
the range" (R + a_) units for comparability. (See
R
Statistical Techniques for Quality Control of Environmental
Radioassay, AQCS Report Stat-1, November 1964, pages 4-8.)
(S = a for printing purposes.)
R R
Average value.
Normalized deviation from the grand average value of all
laboratories expressed in aM units.
Normalized deviation from the known value expressed in OM
units.
Is experimental error of all laboratories, and the grand
average of all laboratories.
-------
<
10
9
8
7
6
5
4
3
2
1
0
-1
-2
-3
-4
-5
-6
-7
-8
-9
-10
B+3
B+2
R+1
R+0
TRITIUM IN URINE CROSSCHECK PROGRAM
LAB - O 3H
NORMALIZED DEVIATION FROM KNOWN
1973
1974
CL
WL
WL
CL
JFMAMJJASOND JFMAMJJASOND
NORMALIZED RANGE
1973
1974
I
CL
WL
JFMAMJJASOND JFMAMJJASOND
Figure 2. Control Chart.
-------
Explanations of terms used in the control chart (Figure 2).
Title:
Upper Graph:
Lower Graph:
Name of program, laboratory code letter, and type of
analysis.
"Normalized deviation from known versus the month
of analysis." [The 95.0% (y ± 2aM) and the 99.7%
(Vi ± 3a..) confidence levels were chosen as the warning
M
levels and control limits respectively.]
"Normalized range values (R +
-------
CONTROL
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D OUTLIER
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Figure 3 (continued). Histogram of laboratory averages reported for
strontium-90 in
12
-------
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15-,
O
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LIMIT
D OUTLIER
MAY 1974
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Figure 4. Histogram of laboratory averages reported for strontium-89 in food
13
-------
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LIMIT
a OUTLIER
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DECEMBER!
x"
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Figure 4 (continued). Histogram of laboratory averages reported for
strontium-89 in food.
14
-------
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Figure 5. Histogram of laboratory averages reported for iodine-131 in food,
15
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LIMIT
n OUTLIER
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Figure 5 (continued). Histogram of laboratory averages reported for
iodine-131 in food.
16
-------
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LIMIT
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Figure 6. Histogram of laboratory averages reported for cesium-137 in food.
17
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Figure 6 (continued). Histogram of laboratory averages reported for
cesium-137 in food,
18
-------
CONTROL
LIMIT
a OUTLIER
15 -
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D
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AUGUST 1974
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Figure 7. Histogram of laboratory averages reported for barium-140 in food.
19
-------
15
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Figure 8. Histogram of laboratory averages reported for potassium in food
20
-------
CONTROL
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Figure 8 (continued)
Histogram of laboratory averages reported for
potassium in food.
21
-------
. CONTROL
M LIMIT
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UtLt/VABtK
3c
j
l
10OO 15OO 2OOO 25OO 3OOO 35OO
CONCENTRATION (pCi/liter)
4OOO
15-,
O
a
5 -
5OO
X
M.
1OOO
JANUARY 1973
-t-T
15OO
2OOO
2500
3OOO
FEBRUARY 1973
>
o
z 10 -
UJ
D
O R .
HJ O
(£
U.
o •
X
1
B
R
i
1OOO 15OO 2OOO 25OO 3OOO 35OO
CONCENTRATION (pCi/liter)
4OOO
Figure 9. Histogram of laboratory averages reported for tritium in urine
22
-------
u
|«H
S 5 H
o
Z
UJ
D
O
DC
U.
CONTROL
LIMIT
D OUTLIER
15 - APRIL 1973
r ' i- • r i • ' •
1OOO 15OO 2OOO 250O 3OOO 35OO 4OOO
CONCENTRATION (pCi/liter)
151 MAY 1973
x~
(
n
D 500
1OOO
I
15OO
1
2000
2500
30OO
CONCENTRATION (pCi/liter)
FREQUENCY
> « 0 W
1 1 1 1
X
A
• 1 — I ...-I—I II
JUNE 1973
i i
5OO 1OOO 15OO 2OOO 25OO 3OOO
CONCENTRATION (pCi/liter)
Figure 9 (continued). Histogram of laboratory averages reported for
tritium in urine.
23
-------
H
CONTROL
LIMIT
1OOO
IS-
IS -I
D OUTLIER
15 -,
>
U
Z 10-
UJ
D
O ,, .
UJ 5
K
u.
o -
JULY1973
x~
l
uT
i
X
_^ • • •
• , , I — , ^i H
15OO
2OOO
2500
3OOO
35OO
4OOO
CONCENTRATION (pCi/liter)
SEPTEMBER 1973
u
z
111
D
a
UJ
a:
u.
10-
5 -
X
1
N-
1
. ^
III
1OOO 15OO 2OOO 25OO 3OOO 35OO 4OOO
CONCENTRATION (pCi/liter)
DECEMBER 1973
o
z
UJ
D
O
UJ
K
u.
10-
5B
0 "I
M.
1
9»
7_r^
1OOO 15OO 2OOO 25OO
X
4-
- -• •-•
H . i
3OOO 35OO
1
4OOO
CONCENTRATION (pCi/liter)
Figure 9 (continued)
Histogram of laboratory averages reported for
tritium in urine-
24
-------
15 -,
1OOO
O
15-
1OOO
CONTROL
H LIMIT
n OUTLIER
MARCH 1974
u
2 10-
UJ
D
0 5 -
or
u.
O -
H.
I
• •
X
\
m i
i 1 * — i < * /
n
15OO
2OOO
2500
3OOO
3500
5000
CONCENTRATION (pCi/liter)
JUNE 1974
>
u
z
HI
D
a
m
£
u.
1O -
5 -
X
I
* II
i
-i
i_! 1 1 I i I
50O
1OOO
150O
2OOO
25OO
3OOO
CONCENTRATION (pCi/liter)
SEPTEMBER 1974
>
u
2 -JQ _
UJ
D
Of _
uj 5 -
K
u.
^ •• • • •• • w i mf fc> •%
X
\
H.
• L •
• I ii i ™ • 11
15OO
2OOO
25OO
3OOO
35OO
4OOO
CONCENTRATION (pCi/liter)
Figure 9 (continued).
Histogram of laboratory averages reported for
tritium in urine.
25
-------
. .CONTROL
H LIMIT
a OUTLIER
15-
>
U
Z 10-
ILI
D
a =
uj 5-
a:
LL
o-
DECEMBER1
x"
i
^
|4,
1
K J| • n
| 1 1
1OOO 15OO 2OOO 25OO 3OOO 35OO
CONCENTRATION (pCi/liter)
4OOO
15 -,
MARCH 1975
5OO
1OOO
15OO
2OOO
25OO
3OOO
CONCENTRATION (pCi/liter)
15 -,
O
Z 10-|
UJ
a = j
UJ 5 •
n
JUNE 1975
n
5OO 1OOO 2OOO 25OO 3OOO 35OO
CONCENTRATION (pCi/liter)
4OOO
Figure 9 (continued).
Histogram of laboratory averages reported for
tritium in urine .
26
-------
15 _
u.
CONTROL
LIMIT
D OUTLIER
SEPTEMBER 1975
15OO 2OOO 25OO 3OOO 35OO
CONCENTRATION (pCi/liter)
4OOO
IO -
>
U
Z 10 -
UJ
D
0 5 -
UJ 5
tr
u.
X
1
H.*
i
t
i^^H • n
DECEMBER
n
5OO
1OOD
15OO
2OOO
CONCENTRATION (pCi/liter)
Figure 9 (continued). Histogram of laboratory averages reported for
tritium in urine •
27
-------
TABLE 1. SUMMARY OF CROSS-CHECK PROGRAMS*
SAMPLE
Milk
Water
Gross a, 8*
Gamma
3H
239Pu*
Radium
Air
Gross a, 3*
239Pu*
Soil*
Diet
Urine
Gas
ANALYSIS
89Sr, 90Sr, 131I,
137Cs, lt(0Ba, K
Gross a, 3
60Co, 106RU, 13"Cs,
137Cs, 51Cr, 65Zn
3H
239pu
226Ra, 228Ra
a, 3. 90Sr, 137cs
239Pu
238pUf 239pu
228Th, 230Th, 232Th
89Sr, 90Sr,131 I,
137Cs, "°Ba, K
3H
85Kr
ACTIVITY
PER ISOTOPE
< 200 pCi/liter
< 100 pCi/liter
< 500 pCi/liter
< 3500 pCi/liter
< 10 pCi/liter
< 20 pCi/liter
< 200 pci/sample
< 2 pCi/sample
< 50 pCi/sample
< 200 pCi/kg
< 3500 pCi/liter
< 20 pCi/ml
QUANTITY
SUPPLIED
**» 4 liters
^ 4 liters
^ 4 liters
^ 50 ml
^ 4 liters
^ 4 liters
3 - 2" or 4"
diam. air filters
3 - 2" or 4"
diam. air filters
^35 grams
3 - 4-liter
samples
^ 50 ml
10 liters
PRESERVATIVE
Formalin
0.5N_ HNOa
0.5N_ HNO3
none
0.5N HNO3
0.5N HN03
none
none
none
Formalin
Formalin
none
DISTRIBUTION
Bimonthly
Bimonthly
Bimonthly
Bimonthly
Semiannually
Quarterly
Quarterly
Quarterly
Semiannually
Quarterly
Quarterly
Quarterly
TIME FOR
ANALYSIS
S REPORT
6 weeks
4 weeks
4 weeks
4 weeks
8 weeks
6 weeks
6 weeks
6 weeks
8 weeks
8 weeks
4 weeks
6 weeks
* Laboratories are required to have the necessary licenses before receiving these samples.
-------
TABLE 2. SUMMARY OF FOOD ANALYSIS DATA
May 1974
N
y (pCi/kg)
x (pCi/kg)
a (pCi/kg)
s (pCi/kg)
(a/y) 100 (%)
(s/y) 100 (%)
90Sr
5
60
67
3
8
5
13
89
Sr 131I
8 17
53
48
5
28
9
53
47
56
5
17
11
36
137Cs
18
65
72
5
7
8
11
140Ba K
17
0 2330 mg/kg
2291 mg/kg
117 mg/kg
151 mg/kg
5
6
August 1974
N
y (pCi/kg)
x (pCi/kg)
a (pCi/kg)
s (pCi/kg)
(a/y) 100 (%)
(S/y) 100 (%)
90Sr
9
198
183
9.9
46
5
23
89
7
204
174
10
35
5
17
Sr 131I
18
216
216
.2 10.8
27
5
13
137Cs
19
205
205
10.3
20
5
10
140Ba K
16 17
207 2389 mg/kg
196 2255 mg/kg
10.3 119 mg/kg
26 207 mg/kg
5 5
13 9
December 1974
N
y (pCi/kg)
x (pCiAg)
a (pciAg)
s (pciAg)
(a/y) 100 (%)
(s/y) 100 (%)
90Sr
10
175
166
8.8
17
5
10
89
6
180
170
9
18
5
10
Sr 131I
14
175
189
8.8
18
5
10
137Cs
18
176
177
8.8
14
5
8
ltf°Ba K
16
0 2619 mg/kg
2549 mg/kg
131 mg/kg
176 mg/kg
5
7
N, number of laboratories; y, known value; xf grand average; a, expected
precision; s, standard deviation.
29
-------
TABLE 2 (Continued).
April 1975
N
y (pciAg)
x (pCi/kg)
a (pciAg)
s (pciAg)
(a/u) x loo (%)
(s/y) x 100 (%)
90Sr
12
150
151
7.5
11
5
7
89gr ISlj.
15
0 149
151
7.5
8
5
5
137Cs
16
150
151
7.5
7
5
5
'""Ha K
14
0 2216 mg/kg
2093 mg/kg
111 mg/kg
170 mgAg
5
8
August 1975
N
y (pciAg)
x (pciAg)
a (pci/kg)
s (pciAg)
(a/p) x 100 (%)
(S/y) X 100 (%)
90Sr
10
101
101
5.1
8
5
8
89Sr isij.
-
0 0
-
-
-
-
-
137Cs
13
121
120
6.1
6
5
5
llt0Ba K
12 14
145 2352 mg/kg
147 2227 mg/kg
7.3 118 mg/kg
21 179 mg/kg
5 5
14 8
December 1975
N
y (pciAg)
x (pciAg)
a (pci/kg)
s (pciAg)
(a/p) x 100 (%)
(S/y) X 100 (%)
90Sr
7
125
107
6.3
12
5
10
89gr 131j
5 10
124 127
104 129
6.2 6.4
25 5
5 5
20 4
137Cs
11
101
100
5.1
6
5
6
l*°Ba K
12
0 2414 mg/kg
2330 mg/kg
121 mg/kg
129 mg/kg
5
5
30
-------
TABLE 3. SUMMARY OF TRITIUM IN HUMAN URINE ANALYSIS DATA
N
y (pCi/liter)
x (pCi/liter)
a (pCi/liter)
s (pCi/liter)
(a/y) 100 (%)
(s/y) 100 (%)
N
y (pCi/liter)
x (pCi/liter)
a (pCi/liter)
s (pCi/liter)
(a/y) 100 (%)
(s/y) 100 (%)
N
y (pCi/liter)
x (pCi/liter)
a (pCi/liter)
s (pCi/liter)
(a/y) 100 (%)
(s/y) 100 (%)
December
1972
3
2270
2308
341
333
15
15
July
1973
3
3432
3485
347
379
10
11
December
1974
6
2546
2455
349
349
14
14
January
1973
3
1048
1024
325
99
31
9
September
1973
3
1641
1704
333
97
20
6
March
1975
7
1504
1327
331
414
22
28
February
1973
3
2080
1796
333
439
16
21
December
1973
3
2391
2833
340
374
14
16
June
1975
7
2793
2829
356
330
13
12
April
1973
3
1724
1749
336
422
19
24
March
1974
3
2012
2356
350
785
17
39
September
1975
8
2004
2105
345
536
17
27
May
1973
1
1148
1200
329
100
29
9
June
1974
4
969
885
324
81
33
8
December
1975
6
1001
1077
324
224
32
22
June
1973
2
1357
1283
332
306
24
23
September
1974
5
3273
3290
357
149
11
5
31
-------
TABLE 4. SUMMARY OF LABORATORY PERFORMANCE
1972-1975 INTERLABORATORY COMPARISON STUDIES - FOOD AND HUMAN URINE
% of Laboratories within ± 3o
Radionuclide Analysis (99.7% Control Limits)
1972-73 1974 1975 1972-75
Tritium (urine) 88 85 75 82
Cesium-137 - 63 82 71
Potassium - 75 60 68
Iodine-131 - 47 81 59
Strontium-90 - 41 51 47
Barium-140 - 47 62 53
Strontium-89 - 32 40 33
% of Laboratories within R + 3a
Radionuclide Analysis (100 % Control Limits)
1972-73 1974 1975 1972-75
Tritium (urine) 100 100 97 99
Potassium - 100 98 99
Cesium-137 - 96 98 97
Strontium-90 - 90 94 92
Barium-140 - 95 85 91
Iodine-131 - 83 94 87
Strontium-89 - 73 100 77
32
-------
APPENDIX. STATISTICAL CALCULATIONS
To illustrate the computations performed by the computer, an example
of range analysis calculations are given using data for only one laboratory
(Laboratory D, see Figure 1) .
The experimental data are listed and the mean, experimental sigma and
range are computed. These statistics provide measures of the central ten-
dency and dispersion of the data.
The normalized range is computed by first finding the mean range, R,
the control limit, CL, and the standard error of the range, aR- The nor-
malized range measures the dispersion of the data (precision) in such a form
that control charts may be used. Control charts allow one to readily compare
past analytical performance with present performance. In the example, the
normalized range equals 0.3 which is less than 3, which is the upper warning
level. The precision of the results is acceptable.
The normalized deviation is calculated by computing the deviation and
the standard error of the mean, a • The normalized deviation allows one to
readily measure central tendency (accuracy) through the use of control charts.
Trends in analytical accuracy can be determined in this manner. For this
example, the normalized deviation is -0.7 which falls between +2 and -2,
which are the upper and lower warning levels. The accuracy of the data is
acceptable.
Finally, the experimental error of all laboratories, the grand average,
and the normalized deviation from the grand average are calculated in order
to ascertain the performance of all the laboratories as a group. Any bias in
methodology or instrumentation may be found from these results.
EXAMPLE CALCULATIONS (Laboratory D Data, see Figure 1)
Experimental data:
Known value = u = 3273 pCi 3H/liter urine on September 24, 1974
Expected laboratory precision = o = 357 pCi/liter
Laboratory Sample Result
D xi 3060 pCi/liter
D x2 3060 pCi/liter
D x3 3240 pCi/liter
33
-------
Mean = x
N
x = i=i = 2|§2. = 3120 pci/iiter
N 3
where N = number of results = 3
Experimental sigma = s
V(3060)2 + (3060) 2 +
(3240)2 - (306° + 306° + 3240)2
= 103.9 pCi/liter
Range = r
r = (maximum result - minimum result]
= |3240 - 3060| = 180 pCi/liter
Range Analysis (RNG ANLY)*
Mean range = R
R = d2a where d2* = 1.693 for N = 3
= (1.693)(357)
= 604.4 pCi/liter
* Rosenstein, M., and A. S. Goldin, Statistical Techniques for Quality Control
of Environmental Radioassay, AQCS Report Stat-1, U.S. Department of Health,
Education and Welfare, PHS, Nov 1964.
34
-------
Control limit = CL
CL = R + 3a
R
= Di+R where D^* = 2.575 for N = 3
= (2.575)(604.4)
= 1556 pCi/liter
Standard error of the range = a
a = (R + 30,, - R) * 3
R R
= (DifR - R) * 3
= (1556 - 604.4) r 3
= 317.2 pCi/liter
Let range = r = wR + xa = 180 pCi/liter
Define normalized range = w + x
for r > R, w = 1
then r = wR + xa = R + xa
iv i\
r - R
X - —
r "~ R
therefore w+x = 1 + x = 1+
for r <_ R, x = 0
then r = wR + xa = wR
R
or w = ^
R
therefore w+x = w+0 = —
R
since r < R (180 < 604.4)
180
W + X 604.4
= 0.30
* Rosenstein, M., and A. S. Goldin, Statistical Techniques for Quality
Control of Environmental Radioassayf AQCS Report Stat-1, U.S. Department
of Health, Education and Welfare, PHS, Nov 1964.
35
-------
Normalized deviation of the mean from the known value = ND
Deviation of mean from the known value = D
D = x - y
= 3120 - 3273
= - 153 pCi/liter
Standard error of the mean = a
m
a = 2_
ft
357
/3
= 206.1 pCi/liter
ND = —
a
m
- 153
206.1
= - 0.7
Experimental sigma (all laboratories) = s (See Figure 2)
N
. , <*i>2 -
•t "l=1
X
Grand average = GA
N
N
49345
15.
3290 pCi/liter
36
-------
Normalized deviation from the grand average = ND1
Deviation of the mean from the grand average = D1
D' = x - GA
= 3120 - 3290
= - 170 pCi/liter
ND' = 21
a
m
- 170
206.1
= - 0.8
«U.S. GOVERNMENT PRINTING OFFICE: 1977-786-181 37
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
. REPORT NO.
EPA-600/4-77-047
3. RECIPIENT'S ACCESSION-NO.
. TITLE AND SUBTITLE
STATUS AND QUALITY OF RADIATION MEASUREMENTS
Food and Human Urine
EPORT DATE
October 1977
6. PERFORMING ORGANIZATION CODE
.AUTHOR(S)
G Easterly, R. R> Kinnison,
A. N. Jarvis, and R. F. Smieclnski
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Environmental Monitoring and Support Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Las Vegas, Nevada 89114
10. PROGRAM ELEMENT NO.
1HD621
11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
U.S. Environmental Protection Agency-Las Vegas, NV
Office of Research and Development
Environmental Monitoring and Support Laboratory
Las Vegas. NV 89114
13. TYPE OF REPORT AND PERIOD COVERED
Preliminary. 1Q72-1975
14. SPONSORING
EPA/600/07
NCY CODE
16. SUPPLEMENTARY NOTES
16. ABSTRACT
As part of the radiation quality assurance program conducted by the U.S. Environ-
mental Protection Agency, calibrated radionuclide solutions are distributed to
participating laboratories for instrument calibration and yield determinations.
Laboratory performance studies involving the analysis of radionuclides in environ-
mental media are also conducted.
A summary is given of the results for the food and human urine cross-check
programs for 1972-1975. For tritium, which was the least difficult to analyze,
eighty-two percent of the laboratories were within the control limits for accuracy
and ninety-nine percent within the control limits for precision over the 3-year
period. For strontium-89, and most difficult to analyze, thirty-three percent were
within the accuracy control limits and seventy-seven percent within the precision
control limits.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
barium-140
cesium-137
food analysis
human urine analysis
iodine-131
isotopes
L
potassium
quality assurance
quality control
radiation chemistry
strontium-89
strontium-90
tritium
b.IDENTIFIERS/OPEN ENDED TERMS
laboratory performance
intercomparison studies
cross-check
13. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS (This Report)
20. SECUBi!TYia.7SS (This page)
UNCLASSIFIED
c. COS AT i l-'icld/Group
07E
12B
14D
18B.D.H
21. NO. OF PAGES
44
22. PRICE
EPA Form 2220-1 (9-73)
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