-------
Table 6-138 gives a summary of the control block data. The
zero SD estimates for Machines 41 and 42 at 0.0 mg/cm2 reflect
the fact that all of the readings for these two machines on bare
substrate were zeros. Like the field sample data, this
predominance of zero readings on the wood control blocks was not
exhibited on other substrates. The fact that zero readings were
less prevalent with Machine 40 on the control blocks, which was
also the case on the field samples, points to a machine effect,
since the same operator (J) used both Machines 40 and 42.
Machine 42 exhibited increasing, but not substantial bias as the
lead level increased, while the bias for Machines 40 and 41
became increasingly negative and substantial.
It is possible to see a mild operator effect within Machine
41, which was the only machine used by two operators. Figure
6-63 gives XRF-ICP scatterplots for the two operators of this
machine. The scatterplot for Operator J suggests a greater slope
(responsiveness to change in the lead level) than that for
Operator K. The possibility that other factors, such as paint
thickness, may explain the apparent operator difference cannot be
dismissed.
6.4.4.8.7 XL: Summary of Analysis
The model did not adequately capture certain aspects of the
performance of the XL prototype. This is demonstrated
graphically in Figures 6-57, 6-58, and 6-60, where the
nonparametric response at the 1.0 mg/cm2 ICP level is appreciably
higher than the model response. The nonparametric estimates
indicate less bias than the model at the 1.0 mg/cm2 lead level.
Although the nonparametric estimates did not account for the
combined effect of spatial variation and laboratory error in ICP
measurements, it is highly unlikely that provision for it would
change this conclusion. On brick, concrete, metal and plaster,
the response of the instrument seemed to change at or near a lead
level of 1.0 mg/cm2.
The XL produced readings on the field samples near the 1.0
mg/cm2 ICP level that had less bias than readings from the other
L-shell instruments evaluated. This finding agrees with the
classification results presented in section 6.5, which show that
the XL gave higher readings than the other L-shell instruments at
lead levels above 1.0 mg/cm2. But like the other L-shell
instruments, the XL was also capable of giving readings less than
1.0 mg/cm2 at ICP measurements in excess of 10.0 mg/cm2. Of the
38 instances where the ICP measurement exceeded 10.0 mg/cm2, 2 of
the XL readings were below 0.4 mg/cm2, and 1 was equal to 0.4
6-276
-------
XL on wood, Machine 41: Operator J
2.5
it,
1.5-
0.5 -
ICP
XL on wood, Machine 41: Operator K
2.5
1.5
0.5
ICP
Figure 6-63.
XL on Wood, Operators K versus J scatterplots on
MACHINE 41.
6-277
-------
mg/cm2. The corresponding sample locations usually were found in
older buildings, with thick layers of paint. The K-shell
instruments were more consistent in giving readings above 1,0
mg/cm2 in the presence of high lead levels.
Machine effects are an important factor to consider in
evaluating the performance of the XL. These effects were
apparent in (1) the model and nonparametric estimates derived
from'the field sample data; (2) the frequency of zero readings at
very low (less than 0.1 mg/cm2) ICP measurements; (3) the control
block data summary statistics. All three sets of results point
to Machine 40 as giving higher readings than either Machines 41
or 42 for lead levels less than 1.0 mg/cm2. Machine 40 also
produced fewer zero readings at low lead levels on painted
samples than the other two machines. The same operator (J) used
both Machines 40 and 42 in the study, including on the control
blocks where lead levels and other factors that may have affected
performance were controlled. It therefore is reasonable to
attribute the higher Machine 40 readings to a machine effect.
This does not rule out the possibility that other effects, such
as those attributable to operators or related to the field
samples, were present in conjunction with those attributable to
machines.
On drywall and plaster, a pattern is present in the SD
estimates obtained from the control block data, where the SD is
substantially larger at 0.0 mg/cm2 than at 1.02 mg/cm2. A large
positive bias at 0.0 mg/cm2 can also be seen where this pattern
is present. It was possible to reproduce the same pattern
directly for the field sample data obtained with Machine 40 on
several substrates, for which there were ample readings at very
low ICP measurements. Standard deviations were computed for
field sample readings with ICP measurements less than 0.005
mg/cm2, and for readings with ICP measurements between 0.005
mg/cm2 and 0.5 mg/cm2. On all substrates except wood, Machine 40
had a higher SD estimate for the lower ICP range. A similar
pattern was not seen in Machine 41 data taken on painted samples.
This result suggest that, for certain XL machines or operators,
readings at very low or zero lead levels were more variable than
at somewhat higher lead levels.
6.4.5 Use of the First XRF Reading Versus the Average of
Three Readings
In the full study, three successive, nominal 15-second
readings were made with each XRF instrument, at each sampled
location. In section 6.5 it is demonstrated that the use of the
6-278
-------
average of three readings did not significantly improve the
classification accuracy obtained by using the first reading
alone. The purpose of this section is to elaborate on this
finding in the context of the XRF measurement model, and to
explain why using the average of three readings was not found to
substantially reduce the variability of XRF measurements on
painted surfaces under field conditions.
Basic statistical reasoning suggests that the average of
three readings should be more accurate than one reading, since
the standard error of the average is smaller than the standard
deviation of one reading. If the successive readings are
statistically independent, the standard deviation of the average
is approximately 0.58 (one divided by the square root of 3) times
the standard deviation of one reading. In practice, however,
this level of improvement was demonstrably absent. In section
6.4.5.1 it is shown that the standard deviation of the average
was usually at least 0.70 times the standard deviation of one
reading, and in some cases 1.00 times (no improvement) when the
lead level was 1.0 mg/cm2 or greater.
Further analyses suggest two reasons why the average of
three readings fell short of the performance suggested by the
0.58 multiplier. The first is that the assumption of
independence was not valid, with the possible exception of the
MAP-3 K-shell. Estimated correlations between successive readings
on the control blocks revealed, with the exception of the MAP-3,
that successive readings were dependent to a substantial degree.
The information obtained from three successive (but dependent)
readings was less than if the readings were independent. The
estimated correlations are presented in section 6.4.5.2, where
this issue is discussed in more detail.
The second, and possibly more important reason why averaging
three readings did not yield a large reduction in variability, is
the existence of non-instrumental sources of variability, that
replication cannot diminish. Factors associated neither with the
level of lead in paint nor the instrument contributed to
variation in XRF readings. In section 6.4.5.3, a nonparametric
residual analysis demonstrates that the K-shell instruments were
moderately intercorrelated, with above-average readings from the
MAP-3 associated with above-average readings from the Microlead
I, for example. The same was also true for the L-shell
instruments. These results suggest that instruments of the same
shell were sensitized to factors other than lead that were
associated with the sample locations.
6-279
-------
Using the triplicate measurements from the full study and
the correlations obtained in section 6.4.5.2, it was possible to
partition the observed XRF variability into instrumental and non-
instrumental components. This was done on the K-shell
instruments for metal and wood substrates, and the results are
presented in section 6.4.5.4. It is demonstrated that non-
instrumental sources of variability were substantial, and
exceeded instrumental variability as the lead level increased.
6.4.5.1 XRF Estimation With the Average of Three Readings
Section 6.4.2 describes the XRF measurement model that was
applied to the first regular paint reading. The same model was
also applied to the average of three readings. Estimated
standard deviations at lead levels of 0.0 mg/cm2 and 1.0 mg/cm2
can be compared to similar quantities obtained using only the
first reading. Tables 6-139 through 6-146 give estimated
standard deviations by machine for each instrument, resulting
from the model. Results for bias are not presented, because they
were not noticeably affected by the change in number of readings.
The ratios reported in the tables are the standard
deviations of the average divided by the standard deviations of
the first XRF reading. Ratios close to, or in some cases larger
than one due to sampling variability, indicate little or no
accuracy gain from using the average of three readings. A ratio
of 0.58 corresponds to the reduction in variability that would be
obtained if the three readings were independent, and if only
instrumental error contributed to the variability of XRF readings
at a fixed level of lead. Table 6-147 is a summary of the
information in Tables 6-139 through 6-146, obtained by pooling
data across substrates and machines.
The MAP-3 K-shell (Table 6-141) exhibited the greatest
improvement with the use of three, as opposed to one reading.
Still, the standard deviation ratios were larger than 0.58, and
some were substantially larger. The L-shell instruments (Tables
6-140, 6-142, 6-144, and 6-146) benefitted the least from using
three measurements. The ratios for both the K- and L-shell
instruments usually increased as the lead level increased from
0.0 mg/cm2 to 1.0 mg/cm2, where they often became close to or
even exceeded 1.0. Correct classification of sites having high
lead levels improved only minimally with the use of three
averaged readings, as demonstrated in section 6.5.
The results presented in Table 6-139 through 6-146
demonstrate that taking three successive readings at a fixed
6-280
-------
Table 6-139.
Change in Standard Deviations: One Versus Three Paint
Readings for Lead Analyzer K-shell.
SUBSTRATE
Brick
Concrete
Concrete
Drywall
Metal
Metal
Plaster
Plaster
Wood
XRF
CODE
NO.
1
1
2
1
1
2
1
2
1
Pb = 0.0 mg/cm2
ONE
0.167
0.113
0.127
0.076
0.169
0.242
0.142
0.123
0.082
THREE
0.173
0.072
0.080
0.048
0.148
0.164
0.145
0.071
0.067
RATIO
1.04
0.63
0.63
0.62
0.87
0.68
1.03
0.58
0.82
Pb = 1.0 mg/cm2
ONE
0.226
0.366
0.328
0.354
0.421
0.242
0.241
0.250
0.440
THREE
0.220
0.369
0.182
0.300
0.387
0.164
0.223
0.328
0.429
RATIO
0.97
1.01
0.56
0.84
0.92
0.68
0.93
1.31
0.98
Table 6-140.
Change in Standard Deviations: One Versus Three Paint
Readings for Lead Analyzer L-shell.
SUBSTRATE
Brick
Concrete
Concrete
Drywall
Metal
Plaster
Plaster
Wood
XRF
CODE
NO.
1
1
2
1
1
1
2
1
Pb = 0.0 mg/cm2
ONE
0.057
0.011
0.014
0.006
0.014
0.005
0.014
0.012
THREE
0.059
0.012
0.013
0.007
0.012
0.006
0.008
0.012
RATIO
1.04
1.09
0.93
1.08
0.87
1.04
0.58
1.00
Pb = 1.0 mg/cm:
ONE
0.060
0.109
0.021
0.172
0.232
0.159
0.035
0.188
THREE
0.061
0.104
0.021
0.167
0.245
0.179
0.044
0.205
RATIO
1.02
0.95
1.00
0.97
1.06
1.13
1.26
1.09
location did not, typically, realize the gain anticipated for
three independent readings under variable sampling conditions.
The following three sections explain why this occurred.
6.4.5.2 Dependence of Successive XRF Measurements
One reason why the average of three successive XRF readings
did not yield a large improvement is that the three successive
readings were substantially correlated. Obtaining an unusually
high first reading made it more likely that the second reading
would also be high, and similarly for the third reading. Three
successive readings were therefore less informative than three
6-281
-------
Table 6-141.
Change in Standard Deviations:
Readings for MAP-3 K-shell.
One Versus Three Paint
SUBSTRATE
Brick
Brick
Concrete
Concrete
Concrete
Drywall
Drywall
Metal
Metal
Metal
Plaster
Plaster
Plaster
Wood
Wood
Wood
XRF
CODE
NO.
10
11
10
11
12
10
11
10
11
12
10
11
12
10
11
12
Pb = 0.0 mg/cm2
ONE
0.762
1.012
0.751
1.078
0.987
0.324
0.380
0.330
0.445
0.374
0.702
1.048
0.754
0.449
0.528
0.525
THREE
0.524
0.685
0.469
0.788
0.613
0.206
0.283
0.245
0.343
0.245
0.513
0.658
0.482
0.375
0.497
0.393
RATIO
0.69
0.68
0.62
0.73
0.62
0.64
0.74
0.74
0.77
0.66
0.73
0.63
0.64
0.84
0.94
0.75
Pb = 1.0 mg/cm2
ONE
0.771
1.018
0.890
1.158
0.987
0.324
0.380
0.481
0.445
0.620
0.781
1.070
0.782
0.629
0.530
0.999
THREE
0.547
0.694
0.714
0.893
0.613
0.206
0.283
0.388
0.349
0.451
0.608
0.774
0.555
0.586
0.498
0.780
RATIO
0.71
0.68
0.80
0.77
0.62
0.64
0.74
0.81
0.78
0.73
0.78
0.72
0.71
0.93
0.94
0.78
independent readings.
The average of the correlations between first and second, first
and third, and second and third readings determines the reduction
in variability gained by using the average of three successive
readings, as opposed to using only the first. For three
independent readings, the correlations are each equal to zero,
and the standard deviation of the average is (1/3) °'5 = 0.58 times
as large as the standard deviation of one reading. Generally,
the standard deviation of the average of three readings is the
square root of the quantity one-third plus two-thirds times the
average correlation multiplied by the standard deviation of a
single reading:
SD
three
[1/3 + 2-C/3]
0.5
SD0
For example, suppose that the first and second readings have a
correlation of 0.28, the first and third readings 0.23, and the
second and third readings 0.21. The average of the three
correlations is C = 0.24, and the multiplier is
[1/3 + 2- (0.24)/3]°-5 = 0.70,
which is equivalent to the statement that the ratio of SD
three
to
6-282
-------
Table 6-142.
Change in Standard Deviations:
Readings for MAP-3 L-shell.
One Versus Three Paint
SUBSTRATE
Brick
Brick
Concrete
Concrete
Concrete
Drywall
Drywall
Metal
Metal
Metal
Plaster
Plaster
Plaster
Wood
Wood
Wood
XRF
CODE
NO.
10
11
10
11
12
10
11
10
11
12
10
11
12
10
11
12
Pb = 0.0 mg/cm2
ONE
0.237
0.219
0.087
0.094
0.075
0.039
0.041
0.381
0.437
0.165
0.081
0.100
0.077
0.095
0.086
0.147
THREE
0.229
0.238
0.066
0.114
0.058
0.029
0.059
0.384
0.428
0.122
0.065
0.086
0.065
0.085
0.086
0.158
RATIO
0.97
1.09
0.76
1.21
0.77
0.74
1.44
1.01
0.98
0.74
0.80
0.86
0.84
0.89
1.00
1.07
Pb = 1.0 mg/cm2
ONE
0.239
0.228
0.161
0.230
0.093
0.255
0.247
0.475
0.540
0.263
0.161
0.185
0.099
0.282
0.253
0.192
THREE
0.231
0.246
0.170
0.221
0.080
0.232
0.379
0.478
0.533
0.232
0.163
0.194
0.090
0.300
0.301
0.166
RATIO
0.97
1.08
1.06
0.96
0.86
0.91
1.53
1.01
0.99
0.88
1.01
1.05
0.91
1.06
1.19
0.86
SD^ is equal to 0.70. This is more than the 0.58 multiplier
that would apply if the three readings were independent. In
fact, a multiplier of 0.70 suggests that three successive (but
correlated) readings have approximately the same information as
two independent (uncorrelated) readings with the same instrument.
Table 6-148 reports average correlations for the eight XRF
instrument types estimated from the control block data.
Triplicate XRF readings were used to estimate the correlations
between the first and second, first and third, and second and
third readings. The advantage of using the control block data
instead of the field sample data is that the lead levels were
fixed at known values on the control blocks, which removed a
potential source of spurious correlation. SD ratios were
calculated from the correlations in the same manner as the above
example, and are alternatives to the estimates presented in
Tables 6-139 through 6-147.
Only the MAP-3 K-shell gave nearly uncorrelated successive
readings. The L-shell instruments produced more highly
correlated readings than the K-shell instruments. The MAP-3 L-
shell, however, had correlations more similar to the K-shell
instruments than to the other L-shell instruments. The L-shell
instruments had higher correlations at 0.0 mg/cm2 than at higher
6-283
-------
Table 6-143.
Change in Standard Deviations:
Readings for Microlead I.
One Versus Three Paint
SUBSTRATE
Concrete
Concrete
Concrete
Concrete
Concrete
Drywall
Drywall
Drywall
Metal
Metal
Metal
Metal
Metal
Plaster
Plaster
Plaster
Plaster
Wood
Wood
Wood
Wood
Wood
XRF
CODE
NO.
20 (Den)
20 (Phi)
21
22
23
20
21
22
20
21
22
23
24
20
21
22
23
20
21
22
23
24
Pb = 0.0 jng/cm2
ONE
0.559
0.543
0.724
1.244
0.483
0.345
0.351
0.534
0.617
0.732
0.808
0.366
0.723
0.510
0.660
1.013
0.370
0.624
0.663
0.831
0.500
0.578
THREE
0.370
0.386
0.635
1.306
0.346
0.235
0.244
0.538
0.563
0.685
0.850
0.223
0.691
0.350
0.484
0.579
0.322
0.499
0.602
0.800
0.419
0.568
RATIO
0.66
. 0.71
0.88
1.05
0.72
0.68
0.70
1.01
0.91
0.94
1.05
0.61
0.96
0.69
0.73
0.57
0.87
0.80
0.91
0.96
0.84
0.98
Pb = 1.0 mg/cm2
ONE
0.708
0.543
0.790
1.309
0.483
0.345
0.351
0.534
0.684
0.790
0.808
0.545
0.723
0.584
0.807
1.013
0.531
0.915
0.758
0.851
0.550
0.578
THREE
0.549
0.488
0.706
1.306
0.607
0.387
0.395
0.538
0.630
0.744
0.850
0.467
0.691
0.448
0.670
0.579
0.415
0.867
0.740
0.835
0.645
0.568
RATIO
0.78
0.90
0.89
1.00
1.26
1.12
1.13
1.01
0.92
0.94
1.05
0.86
0.96
0.77
0.83
0.57
0.78
0.95
0.98
0.98
1.17
0.98
Table 6-144.
Change in Standard Deviations:
Readings for X-MET 880.
One Versus Three Paint
SUBSTRATE
Concrete
Drywall
Metal
Metal
Plaster
Wood
XRF
CODE
NO.
50
50
50
51
50
50
Pb = 0.0 mg/cm2
ONE
0.027
0.013
0.141
0.278
0.022
0.024
THREE
0.027
0.013
0.141
0.260
0.022
0.022
RATIO
1.00
1.00
1.00
0.94
1.00
0.90
Pb = 1.0 mg/cm2
ONE
0.067
0.133
0.238
0.278
0.083
0.289
THREE
0.066
0.134
0.237
0.260
0.082
0.296
RATIO
0.99
1.01
1.00
0.94
0.99
1.02
6-284
-------
Table 6-145.
Change in Standard Deviations:
Readings for XK-3.
One Versus Three Paint
SUBSTRATE
Brick
Brick
Concrete
Concrete
Concrete
Drywall
Drywall
Metal
Metal
Plaster
Plaster
Plaster
Wood
Wood
Wood
XRF
CODE
NO.
30
31
30
31
32
30
31
30
32
30
31
32
30
31
32
Pb = 0.0 mg/cm2
ONE
0.591
0.320
0.636
0.847
0.508
0.356
0.206
0.517
0.607
0.546
0.404
0.521
0.486
0.313
0.488
THREE
0.493
0.173
0.506
0.255
0.478
0.203
0.182
0.435
0.465
0.474
0.359
0.352
0.376
0.269
0.304
RATIO
0.83
0.54
0.80
0.30
0.94
0.57
0.88
0.84
0.77
0.87
0.89
0.68
0.77
0.86
0.62
Pb = 1.0 mg/cm2
ONE
0.591
0.320
0.636
0.847
0.508
0.562
0.547
1.058
0.992
0.633
0.404
0.645
0.686
0.444
1.152
THREE
0.493
0.719
0.506
0.255
0.478
0.845
0.361
0.962
0.912
0.547
0.360
0.452
0.679
0.503
1.010
RATIO
0.83
2.25
0.80
0.30
0.94
1.50
0.66
0.91
0.92
0.86
0.89
0.70
0.99
1.13
0.88
Table 6-146.
Change in Standard Deviations:
Readings for XL.
One Versus Three Paint
SUBSTRATE
Brick
Concrete
Concrete
Drywall
Metal
Metal
Metal
Plaster
Plaster
Wood
Wood
Wood
XRF
CODE
NO.
41
41
42
41
40
41
42
40
42
40
41
42
Pb = 0.0 mg/cm2
ONE
0.056
0.050
0.083
0.049
0.196
0.158
0.124
0.123
0.046
0.120
0.123
0.119
THREE
0.043
0.044
0.066
0.058
0.192
0.107
0.110
0.095
0.039
0.088
0.052
0.097
RATIO
0.77
0.88
0.80
1.18
0.98
0.68
0.89
0.77
0.85
0.73
0.42
0.82
Pb = 1.0 mg/cm2
ONE
0.167
0.312
0.211
0.266
0.280
0.158
0.396
0.123
0.205
0.276
0.243
0.325
THREE
0.176
0.349
0.200
0.225
0.278
0.107
0.391
0.095
0.182
0.271
0.217
0.305
RATIO
1.05
1.12
0.95
0.85
0.99
0.68
0.99
0.77
0.89
0.99
0.89
0.94
6-285
-------
Table 6-147.
Standard Deviation (SD) Ratios, Pooled by Instrument.
Instrument
Lead Analyzer K- shell
Lead Analyzer L- shell
MAP-3 K-shell
MAP-3 L-shell
Microlead I
X-MET 880
XK-3
XL
Pb=0 . 0 mg/cm2
SD Ratio
0.84
1.02
0.71
0.98
0.86
0.98
0.77
0.79
Pb=1.0 mg/cm2
SD Ratio
0.95
1.06
0.78
1.05
0.93
1.01
0.93
0.96
levels of lead. The high correlation for the XL at 0.0 mg/cm2
may be explained by the fact that it often gave three successive
zero readings at lower lead levels, due to its lower truncation
property.
The SD ratios reported in Table 6-148 are generally smaller than
those reported in Table 6-147. Since a smaller ratio implies a
greater reduction in variability using the average of three
readings, XRF readings on the field samples (the data used to
derive Table 6-147) were affected by sources of variability that
averaging did not reduce, and that were absent from XRF readings
on the control blocks. Thus, correlations between successive
readings alone did not account for the small reduction in
standard deviations obtained from the XRF measurement model,
implying the existence of non-instrumental factors that affected
XRF variability.
6.4.5.3 Correlation of XRF Readings Across Instruments
Non-instrumental factors that affected the variability of XRF
readings were associated with the locations at which measurements
were made. Non-instrumental factors have the potential to affect
readings made with all instruments at a given location, although
the impact can vary with the instrument. If several instruments
are affected in a similar manner, these factors may be detectable
as correlations across instrument readings.
Correlations across instruments were estimated using the
nonparametric standardized residuals defined in section 6.3. The
nonparametric standardized residuals were obtained by subtracting
6-286
-------
Table 6-148.
Correlations for Successive Readings, Estimated From the Control Block Data.
INSTRUMENT
Lead Analyzer K-shell
Lead Analyzer L-shell
MAP-3 K-shell
MAP-3 L-shell
Microlead I
X-MET 880
XK-3
XL
NUMBER OF
READINGS
1255
1245
1206
1202
636
1145
1179
1305
BARE
0.0 mg/cm2
0.12
0.96
0.05
0.46
0.32
0.97
0.33
0.96
RED NIST SRM
1.02 mg/cm2
0.12
0.73
-0.06
0.13
0.41
0.83
0.42
0.74
YELLOW NIST
SRM
3 . 53 mg/cm2
0.34
0.77
0.06
0.14
0.31
0.84
0.36
0.83
AVERAGE
0.19
0.82
0.02
0.24
0.34
0.88
0.37
0.85
SD
RATIO
0.68
0.94
0.59
0.70
0.75
0.96
0.76
0.95
6-287
-------
from the XRF readings a nonparametric estimate of their mean
relationship with the ICP measurements, and dividing the
differences by a nonparametric estimate of the standard
deviation. The resulting quantities can be viewed as the XRF
readings with their dependence on the ICP-measured lead level
separated out. Thus, although the nature of an XRF-ICP
relationship changed substantially across instruments and
substrates, the nonparametric standardized residuals exhibited
comparable behavior, and their derivation did not require the use
of a model.
The 8 measurement modes, obtained from the 6 instruments and
2 shells, were grouped into 12 field classifications. Each
field classification represented a full set of XRF measurements
on all sample locations. Since each sample location had 12
associated XRF readings, it was possible to calculate the 12 by
12 correlation matrix of nonparametric standardized residuals.
This was done for 333 sample locations on wood substrates. The
correlations are presented graphically in Figures 6-64 through
6-75. The K-shell instruments are shown with dark shading, and
the L-shell instruments with light shading. The Lead Analyzer
and two MAP-3 instrument field classes, which made measurements
using both shells, are shown side by side.
The correlations exhibit an interesting pattern: the
K-shell instruments were more correlated with other K-shell
instruments than with the L-shell instruments, and similarly for
the L-shell instruments. The Lead Analyzer K-shell, for
instance, exhibited higher correlations with other K-shell
instruments than with its own L-shell, as did the MAP-3. The XL
and Lead Analyzer L-shell exhibited weaker correlations than the
other two L-shell instruments, but both were more correlated with
L-shell than with K-shell instruments.
The process that was used to derive the residuals eliminated
the contribution of the ICP-measured lead levels to the
correlations. Instrumental variability, which by definition is
independent across different machines at a fixed level of lead,
was likewise not a contributing factor to the correlations.
Therefore, the substantial correlations that these residuals
exhibited across instruments reflect the influence of non-
instrumental factors, related to the locations where instrument
readings were made, that contributed to XRF performance. These
non-instrumental factors affected the performance of the K-shell
and L-shell instruments in different ways.
6-288
-------
1 -r
0.8 --
0.6 --
0.4
0.2 -
0.469
0.371
0.273 0.264
0.191
0.436
0.203
0.397
0.311
-O.047
X-MET880 XK-30) XK-3(IT) MAP-3(I) MAP-3(IT) Lead Microlead Microlead
Analyzer 1(1) I(IT)
-0.2 -
Figure 6-64. XL: Correlation of nonparametric standardized
residuals with other instruments. Substrate=WOOD
1 -
0.8 -
0.6 -
0.4 -
0.2 -
0 -
-0.2 -
0.371
0.008
XL XK-3(I)
0.758 °'7
ITT7T
:
0.087
„__. 0.046
i
i
0.116
78
"
m
: :
:
0.055J
93
BE K-Shell
SI L-Shell
0.081
XK-3(I1) MAP-3(I) MAP-3(IT) Lead Microlead Microlead
Analyzer I (I) I (II)
Figure 6-65. X-MET 880: Correlation of nonparametric
standardized residuals with other instruments.
Substrate=WOOD
6-289
-------
1
0.9
0.8
0.7
0.6
0.5
0.4
0.392
0.415
0.35
0.328
0.187
XL X-METS80 XK-3 (II) MAP-3 (I) MAP-3 (II) Lead Microlead Microlead
Analyzer I (I) I (II)
Figure 6-66.
XK-3 (I) : Correlation of nonparametric
standardized residuals with other instruments.
Substrate=WOOD
XL X-MET880 XK-3(1) MAP-3 (1) MAP-3 (II) Lead Microlead Microlead
Analyzer 1 (I) 100
Figure 6-67. XK-3 (II): Correlation of nonparametric
standardized residuals with other instruments.
Substrate=WOOD
6-290
-------
X-MET XK-3(1) XK-3(1I) MAP-3 (1) MAP-3 (11) Lead Microlead Microlead
880 Analyzer 1(1) 1(11)
Figure 6-68. MAP-3 (I) K-shell: Correlation of nonparametric
standardized residuals with other instruments.
Substrate=WOOD.
1 -
0.9 -
0.8 -
0.7
0.6 -
0.5 -
0.4 -
0.3 -
0.2 -
0.1 -
0.758
- 0.469
0.772
0.223
0.102
0.022
1
1
H XL-Shell
°-425 M L-Shell
0.147
BO OS3
0.061
•
: i . i i
XL X-MET XK-3(I) XK-3(II) MAP-3 (1) MAP-3 (II) Lead Microlead Microlead
880
Analyzer 1 (1) 1 (11)
Figure 6-69. MAP-3 (I) L-shell: Correlation of nonparametric
standardized residuals with other instruments.
Substrate=WOOD
6-291
-------
1 --
0.9 --
0.8 --
0.7
0.6 -
0.5 --
0.4
0.3 --
02.--
0.1 -
0 --
0.562
0.517
0.303 0.304
0.203
0.436
0.315
10.167
0.116
0.408
XL X-MtT XK-3(I) XK-3{II) MAP-3 (I) MAP-3 (II) Lead Microlead Microlead
880 Analyzer 1(1) I (IT)
Figure 6-70. MAP-3 (II) K-shell: Correlation of nonparametric
standardized residuals with other instruments.
Substrate=WOOD.
1 -
0.9 -
0.8 -
0.7-
0.6
0.5 -
0.4 -
0.3 -
0.2
0.1 -
0.778 0.772
0.436
XL
] 1
1
i
j
0.144 0.15
m 0.077 |j|
m
I H!
05 K-Shell
°'426 H L-Shell
0.315
HHHfE
0.195
Iffif 0.145
|H HH 0.095
1 . . ml , 1
X-MET XK-3(1) XX-3(11) MAP-3 (I) MAP-3 (11) Lead Microlcad Microlcad
880 Analyzer 1(1) 1(1')
Figure 6-71.
MAP-3 (II) L-shell: Correlation of nonparametric
standardized residuals with other instruments.
Substrate=WOOD
6-292
-------
XL X-MfcT XK-3(I) XK-3(II) MAP-3 (I) MAP-3 (II) Lead Microlead Microlead
880 Analyzer 1(1) I (IT)
Figure 6-72. Lead Analyzer K-shell: Correlation of
nonparametric standardized residuals with other
instruments. Substrate=WOOD.
1 -r
0.8 -r
0.6
0.4 --
0.2 --
0 --
-0.2-1-
0.493
0.397
XL X-MET XK-3(I) XK-3(II) MAP-3 (I) MAP-3 (II) Lead Microlead Microlead
880 Analyzer 1(1) I (IT)
Figure 6-73. Lead Analyzer L-shell: Correlation of
nonparametric standardized residuals with other
instruments. Substrate=WOOD
6-293
-------
XL X-MET880 XK-30) XK-3(II) MAP-SO) MAP-3 (II) Lead Microlead
Analyzer I (11)
Figure 6-74. Microlead I (I): Correlation of nonparametric
standardized residuals with other instruments.
Substrate=WOOD.
1 T
0.8 -
0.6 T
0.4 --
02 -
-0.2 -
0.408
0.322
-0.047, -O.01
0.187
ililiiiii
XL X-MET880 XK-3(I) XK-3(U) MAP-3 (1) MAP-3 (11) Lead Microlcad
Analyzer 1(1)
Figure 6-75. Microlead I (II): Correlation of nonparametric
standardized residuals with other instruments.
Substrate=WOOD.
6-294
-------
Repeated readings at the same location with the same
instrument repeated the realization of location-specific factors
that affected XRF performance. Therefore, averaging repeated
readings did not reduce the variability that these factors
imparted to XRF measurements. The MAP-3 K-shell, for instance,
was clearly correlated with the other K-shell instruments, which
suggests that non-instrumental factors contributed significantly
to the variability of its readings on painted surfaces under
field conditions. Although it was established in section 6.4.5.2
that its three successive readings were essentially uncorrelated,
using the average of three readings instead of the first could
not achieve a commensurate reduction in variability, as seen in
Table 6-141.
6.4.5.4 Separating Instrumental and Non-instrumental
Variability
Separation of instrumental and non-instrumental components
of variability in XRF measurements illustrates the relative
contribution of each component to total variability. This was
done explicitly with the full study data. The triplicate
measurements taken at each sample location were used to estimate
the SD due to instrumental factors, taking into account the
correlations presented in Table 6-148. Estimation of the XRF-ICP
relationship was used to estimate the full SD due to both
instrumental and non-instrumental factors. The SD due to non-
instrumental factors was estimated by taking the square root of
the full SD squared minus the instrumental SD squared. In cases
where, due to small sample variability, the estimated
instrumental SD exceeded the estimated full SD, the non-
instrumental SD estimate was set to zero.
Figures 6-76 through 6-83 illustrate the effect of
separation with the four K-shell instruments, on metal and wood
substrates. The solid line in each graph shows the full SD for a
single reading, as a function of the ICP level (mg/cm2) . The
full SD was estimated using monotone regression of the first XRF
reading against the ICP measurement. The dashed line shows the
instrumental SD, which was estimated using monotone regression on
the variances calculated from the three readings at each sample
location, and then taking the square root. Since the variances
based on three readings were underestimates of the true
variances, they were adjusted upward using the correlations in
Table 6-148.
6-295
-------
0 9
0 8
0.7
o °'6
•+-•
o
'I 0.5
T3
o 0.4
TJ
0
0.3
0.2
0.1
C
Lead Analyzer, K-shell on metal, N = 188
/
/ '"*
/.-.-.- i i
// ' \^ / i
n \
/; \ /
//
ii / \
/' '' 'N
/
r — — —
/
/
.u t
!'!'•-: i
.! i i
li r-
1
* 1 1 1 t 1 1
) 1 23456:
ICP (MG/CM2)
Solid line = Full SD, Dashed line = Instrumental SD, Dot-dashed = Non-instrumental SD
7
Figure 6-76.
XRF variability: instrumental versus non-instrumental components
Analyzer K-shell on metal.
Lead
6-296
-------
3C
.D
3
C
O 0 (-
•^ 2.5
o
0)
Standard d
ui ro
1
i
0.5
C
MAP-3, K-shell on wood, N = 344
L
/' X
//
r- I
f _J :
/: ,'
/
) 5 10 15 20 25 30 3
ICP (MG/CM2)
Solid line = Full SD, Dashed line = Instrumental SD, Dot-dashed = Non-instrumental SD
5
Figure 6-77
XRF variability: instrumental versus non-instrumental components.
Analyzer K-shell on wood.
Lead
6-297
-------
1
0.8
c
0
Is 0-6
OJ
•o
T3
O
? 0.4
D
(/)
0.2
n
u
C
j
MAP-3, K-shell on metal, N = 188
/
//' 'V
/ •'
/ 1
/.''"' \ '
II
It
1 i
1 i
1 1
1 '
;
1 1 -'
i /
:
1 r
1 •
r_T .'
1. _ J
1 1 1 1 1 1
) 1 2 3 4 5 6 ~t
ICP (MG/CM2)
Solid line = Full SD, Dashed line = Instrumental SD, Dot-dashed = Non-instrumental SD
7
Figure 6-78.
XRF variability: instrumental versus non-instrumental components.
shell on metal.
MAP-3 K-
6-298
-------
A
3c
.0
3
c
§ 2.5
o
>
^ 2
i_
D
o 1.5
GO
1
I
0.5
n
u
C
MAP-3, K-shell on wood, N = 344
/.
// \
/' *
/' N
A '*
it
n
Ij I
•_T I :
r '
r
-II x
/'
-TL— '
1 1 1 1 1 1
) 5 10 15 20 25 30 3
ICP (MG/CM2)
Solid line = Full SD, Dashed line = Instrumental SD, Dot-dashed = Non-instrumental SD
5
Figure 6-79.
XRF variability: instrumental versus non-instrumental components.
shell on wood.
MAP-3 K-
6-299
-------
c
O
f
0)
T>
O
C
O
CO
0.6
0.5
0.4
0.3
0.2
0.1
0
i
0
ML I Revision 4 on metal, N = 62
1 1
0.5
1
1.5
2.5
ICP (MG/CM2)
Solid line = Full SD, Dashed line = Instrumental SD, Dot-dashed = Non-instrumental SD
Figure 6-80.
XRF variability: instrumental versus non-instrumental components,
Revision 4 on metal.
ML-1
6-300
-------
o
f.
1.5
o
'>
\ '
o
C
0
O-J
(/I
n ^
Vy. J
A
U
C
ML 1 Revision 4 on wood, N = 297
i i i i i i
/
fj
/ 1
J........
I
i i i i i i
) 5 10 15 20 25 30 3
ICP (MG/CM2)
Solid line = Full SD, Dashed line = Instrumental SD, Dot-dashed = Non-instrumental SD
5
Figure 6-81.
XRF variability:
Microlead I on wood.
instrumental versus non-instrumental components
6-301
-------
c
,0
v^
.2
•2
o
T3
c
D
•4->
in
3.5
2.5
1.5
0.5
0
0
XK-3 on metal, N = 187
1
ICP (MG/CM2)
Solid line = Full SD, Dashed line = Instrumental SD, Dot-dashed
Non-instrumental SD
Figure 6-82.
XRF variability:
metal.
instrumental versus non-instrumental components. XK-3 on
6-302
-------
1 fi
1.4
1 9
c
•- 1
•*-> '
O
0)
08
~o
0
c
o 0.6
CO
Oyl
.4
0.2
0
C
<
XK-3 on wood, N = 342
i i i i i i i i
/
/ .-'"
..'•'
' ! /
1
_t , ;
i
i
I i
Hi"1
i
-TJ •
) 1 2 3 4 5 6 7 8 £
ICP (MG/CM2)
Solid line = Full SD, Dashed line = Instrumental SD, Dot-dashed = Non-instrumental SD
)
Figure 6-83.
XRF variability: instrumental versus non-instrumental components.
wood for ICP less than 10 mg/cm2.
XK-3 on
6-303
-------
The dot-dashed line shows the non-instrumental SD. The non-
instrumental SD was estimated as zero over a narrow ICP range for
the Lead Analyzer (Figures 6-76 and 6-77) where the estimated
instrumental SD exceeded the estimated full SD, as explained
above.
The full SD estimates are not the same as those presented in
section 6.4.4, because they were not derived from the XRF
measurement model, which takes into account the combined effect
of spatial variation and laboratory error in ICP measurements.
The relationship of XRF to ICP measurements, unlike the
relationship of XRF measurements to the true lead level, was
directly observable, and gave an approximate basis upon which the
change in response to the lead level of the different components
of variability could be expressed.
Usually, the non-instrumental components of variability were
larger than the instrumental components, especially at higher
levels of lead. These figures demonstrate that non-instrumental
sources of variability, which were not reduced by taking repeated
readings at the same place, dominated the XRF measurement error
process as the lead level in the paint increased. Combined with
the high instrumental correlation between successive readings
observed for all instruments with the exception of the MAP-3,
repeated readings can be expected to result in only a modest
improvement in the precision of measurement. As an example,
suppose that the instrumental and non-instrumental SDs are each
equal to 0.7 mg/cm2, and that the average correlation between
successive readings is 0.35. This is a fairly typical case.
Then the full SD of a single reading is (0.72 + 0.72)0-5 = 0.99
mg/cm2. The full SD of the average of three readings taken at a
single location is [0.72 + 0.72- (1/3 + 0.35/3 + 0.35/3)]0-5 = 0.88
mg/cm2, a reduction of only 11 percent.
6.4.5.5 Conclusions
Sections 6.4.5.2 through 6.4.5.4 illustrate in different,
but related ways, that using the average of three successive XRF
readings did not substantially reduce the variability compared to
using only the first reading. This is the result seen from
fitting the XRF measurement model to the average, and comparing
SD estimates with those from fitting the model to the first
reading. There are two distinct reasons for this: (1)
successive readings were not independent, except possibly for the
MAP-3 K-shell; (2) instrumental variability, which is the only
kind that can be reduced by taking repeated measurements, was not
the only kind that was exhibited. Non-instrumental sources of
6-304
-------
variability, which were specific to the sample locations, were
substantial and dominated instrumental variability as the level
of lead in paint increased.
Most instruments exhibited little or no improvement using
the average of three readings. Improvements, when realized, were
typically less than expected from three independent readings
taken under variable field conditions. The ability of an XRF
instrument to correctly classify the lead level in paint with
respect to the 1.0 mg/cm2 federal standard would therefore not be
expected to improve appreciably by taking the average of three
readings.
6.4.6 Correction of XRF Measurements for Bias
The analyses presented in section 6.4.4 demonstrate that
every XRF instrument, with the exception of the Lead Analyzer
K-shell, was prone to exhibit bias on at least some substrates,
or under certain conditions. The L-shell instruments were
generally under-responsive to the level of lead in paint: an
increase in the lead level by a certain amount led to a smaller
increase in the expected XRF reading. This under-responsiveness
is reflected in model slope estimates that were less than 1.0,
leading to negative bias that became more prominent as the lead
level increased. The K-shell instruments, by contrast, usually
had slope estimates near 1.0, and exhibited bias mainly as "add-
on" effects that are indicated by intercept estimates that
differed significantly from 0.0. These effects varied markedly
between different machines of the same instrument type, between
substrates, and possibly between other factors such as operators,
substrate or paint composition.
The use of XRF readings taken on NIST SRM films, with known
lead levels, was considered as a means for correcting bias in the
regular measurements. Readings on NIST SRM films over control
blocks were made at the beginning and end of testing in each
unit, and whenever the substrate changed, at lead levels of 1.02
mg/cm2 (red) and 3.53 mg/cm2 (yellow), and also on the bare
control block. In the full study, paint was removed from the
substrate at sampled locations, and readings were made with the
red NIST SRM film placed over the bare substrate.
Three strategies for bias correction using red NIST SRM
readings were considered. Each used the average of three nominal
15-second readings on the red NIST SRM film as a single
measurement:
6-305
-------
(1) Control correction used the red NIST SRM measurements for
beginning, continuing, and end of day control blocks to
calculate a correction factor specific to the unit and the
substrate. The average of these measurements minus 1.02
mg/cm2 was used to correct the regular XRF measurements made
in the same unit on the same substrate. For example, if the
average of the red NIST SRM measurements on metal control
blocks in a particular unit was 1.54 mg/cm2, the correction
factor was 1.54 - 1.02 = 0.52 mg/cm2. A regular XRF reading
of 4.77 mg/cm2 on metal substrate in the same unit would be
corrected to read 4.77 - 0.52 = 4.25 mg/cm2.
(2) Full correction used the red NIST SRM measurements at each
bared sampled location to correct the regular XRF readings
individually. Unlike control correction, full correction
had the potential to reflect site-specific attributes. It
was, however, a destructive and labor-intensive procedure,
and is considered here for the sake of comparison. Full
correction is not a practical field procedure.
(3) Red NIST SRM average correction was a compromise between
control block and full correction. The red NIST SRM
measurements at each bared sample locations were averaged by
unit and substrate to calculate the correction factors.
As described, red NIST SRM average correction requires the
same physical effort as full correction, and is therefore not
practical for field use. It was considered because of its
similarity to a more practical method that has been proposed,
which consists of randomly selecting at most three locations per
unit for a given substrate, removing the paint, and making red
NIST SRM readings over the bare substrate. There is no
appreciable difference between the two methods in their ability
to reduce bias, the distinction being that the red NIST SRM
average correction factor is based on a potentially larger
sample, and should therefore contribute less variability to the
corrected XRF measurements than the randomized procedure.
Tables 6-149 through 6-156 show the effects of bias
correction, by machine and substrate, for the eight types of XRF
instruments considered in the full study. It is immediately
apparent that none of the three correction methods were effective
on the L-shell readings. This is not surprising, because the
corrections are additive in nature, while the bias of the L-shell
instruments consisted primarily in deficient responsiveness to
the lead level. Only the K-shell instruments stood to benefit
from the three techniques that were considered.
6-306
-------
Table 6-149.
Effect of Bias Correction Methods on Lead Analyzer, K-shell.
b(0) = bias at 0.0 mg/cm2, b(l) = bias at 1.0 mg/cm2.
Model Estimates of Bias:
SUBSTRATE
Brick
Concrete
Concrete
Drywall
Metal
Metal
Plaster
Plaster
Wood
XRF
CODE
NUMBER
1
1
2
1
1
2
1
2
1
CORRECTION METHOD (results in mg/cm2)
NONE
b(0)
0.080
0.010
0.066
-0.018
0.075
0.096
0.022
0.060
0.013
b(l)
-0.219
-0.016
-0.069
0.178
0.037
-0.152
-0.116
-0.101
0.282
CONTROL
b(0)
-0.100
-0.054
-0.039
-0.095
-0.018
-0.019
-0.060
-0.128
-0.049
b(l)
-0.416
-0.032
-0.121
0.015
0.022
-0.194
-0.133
-0.243
0.229
FULL
b(0)
0.003
-0.017
0.017
-0.106
-0.023
0.104
-0.041
0 . 020
-0.057
b(l)
-0.325
-0.018
-0.138
0.143
-0.001
-0.136
-0.009
-0.118
0.120
RED NIST AVERAGE
b(0)
-0.004
-0.026
0.020
-0.129
-0.076
0.085
-0.046
0.005
-0.090
b(l)
-0.312
-0.040
-0.123
0.188
-0.005
-0.121
-0.059
-0.097
0.141
6-307
-------
Table 6-150.
Effect of Bias Correction Methods on Lead Analyzer, L-shell. Model Estimates of Bias:
b(0) = bias at 0.0 mg/cm2, b(l) = bias at 1.0 mg/cm2.
SUBSTRATE
Brick
Concrete
Concrete
Drywall
Metal
Metal
Plaster
Plaster
Wood
XRF
CODE
NUMBER
1
1
2
1
1
2
I
2
1
CORRECTION METHOD (results in mg/cm3}
NONE
b(0)
0.035
0.008
0.016
-0.006
0.013
0.019
0.000
0.017
-0.019
b(l)
-0.928
-0.818
-0.935
-0.704
-0.724
-0.878
-0.756
-0.918
-0.730
CONTROL
b(0)
-0.003
-0.020
0.011
-0.047
-0.031
-0.024
-0.039
0.007
-0.062
b(l)
-0.963
-0.921
-0.978
-0.659
-0.826
-0.867
-0.872
-0.907
-0.789
FULL
b(0)
0.043
0.042
0.063
-0.023
0.050
0.157
0.027
0.058
-0.020
b(l)
-0.920
-0.893
-0.909
-0.595
-0.825
-0.907
-0.826
-0.856
-0.776
RED NIST AVERAGE
b(0)
0.043
0.044
0.061
-0.022
0.050
0.101
0.034
0.061
-0.017
b(l)
-0.919
-0.898
-0.906
-0.611
-0.826
-0.797
-0.846
-0.863
-0.767
6-308
-------
Table 6-151.
Effect of Bias Correction Methods on MAP-3, K-shell.
b(0) = bias at 0.0 mg/cm2, b(l) = bias at l.O mg/cm2.
Model Estimates of Bias:
SUBSTRATE
Brick
Brick
Concrete
Concrete
Concrete
Drywall
Drywall
Metal
Metal
Metal
Plaster
Plaster
Plaster
Wood
Wood
Wood
XRF
CODE
NUMBER
10
11
10
11
12
10
11
10
11
12
10
11
12
10
11
12
CORRECTION METHOD (results in mg/cm2)
NONE
b(0)
-0.554
-0.616
-0.590
-0.722
-0.766
-0.058
0.112
0.311
0.381
0.292
-0.602
-0.550
-0.975
-0.044
-0.039
-0.246
b(l)
-0.733
-0.847
-0.325
-0.616
-0.513
0.209
-0.500
0.455
0.666
0.316
-0.438
-0.509
-0.709
0.383
0.217
0.546
CONTROL
b(0)
-0.515
-0.396
-0.540
-0.359
-0.378
-0.112
0.036
0.171
0.114
0.178
-0.291
-0.059
-0.413
0.048
0.102
-0.177
b(l)
-0.698
-0.631
-0.241
-0.277
-0.015
0.039
-0.563
0.319
0.423
0.223
-0.169
0.008
-0.119
0.445
0.347
0.653
FULL
b(0)
-0.775
-0.879
-0.641
-0.786
-0.562
-0.219
-0.150
0.022
0.058
0.074
-0.617
-0.602
-0.731
-0.134
-0.252
-0.324
b(l)
-0.997
-1.131
-0.463
-0.863
-0.229
0.258
-0.374
0.094
0.147
-0.005
-0.394
-0.498
-0.452
0.066
-0.098
0.123
RED NIST AVERAGE
b(0)
-0.787
-0.887
-0.671
-0.854
-0.549
-0.254
-0.169
-0.058
-0.037
-0.023
-0.597
-0.593
-0.712
-0.255
-0.338
-0.610
b(l)
-1.002
-1.143
-0.442
-0.834
-0.247
0.215
-0.416
0.095
0.271
0.002
-0.457
-0.532
-0.478
0.087
-0.101
0.168
6-309
-------
Table 6-152,
Effect of Bias Correction Methods on MAP-3, L-shell.
b(0) = bias at 0.0 mg/cm2, b(l) = bias at 1.0 mg/cm2.
Model Estimates of Bias:
SUBSTRATE
Brick
Brick
Concrete
Concrete
Concrete
Drywall
Drywall
Metal
Metal
Metal
Plaster
Plaster
Plaster
Wood
Wood
Wood
XRF
CODE
NUMBER
10
11
10
11
12
10
11
10
11
12
10
11
12
10
11
12
CORRECTION METHOD (results in mg/cm2)
NONE
b(0)
0.034
0.025
-0.117
-0.130
-0.195
-0.123
-0.097
0.054
0.252
-0.109
-0.112
-0.112
-0.180
-0.084
-0.074
-0.051
b(l)
-0.864
-0.863
-0.892
-0.812
-1.057
-0.615
-0.656
-0.662
-0.290
-0.868
-0.911
-0.842
-1.010
-0.630
-0.607
-0.886
CONTROL
b(0)
-0.158
-0.157
-0.334
-0.318
-0.333
-0.284
-0.275
0.015
0.178
-0.115
-0.313
-0.273
-0.305
-0.176
-0.211
-0.143
b(l)
-1.052
-1.046
-1.095
-1.021
-1.209
-0.786
-0.789
-0.702
-0.361
-0.878
-1.093
-1.063
-1.156
-0.733
-0.751
-0.971
FULL
b(0)
-0.227
-0.189
-0.339
-0.255
-0.331
-0.313
-0.277
-0.090
0.063
-0.156
-0.333
-0.261
-0.327
-0.275
-0.262
-0.190
b(l)
-1.131
-1.084
-1.127
-1.074
-1.188
-0.711
-0.799
-0.791
-0.632
-0.868
-1.174
-0.956
-1.155
-0.864
-0.830
-1.037
RED NIST AVERAGE
b(0)
-0.228
-0.191
-0.344
-0.294
-0.328
-0.310
-0.289
-0.099
0.006
-0.126
-0.328
-0.257
-0.331
-0.294
-0.274
-0.211
b(l)
-1.131
-1.083
-1.125
-0.971
-1.187
-0.724
-0.729
-0.790
-0.565
-0.891
-1.186
-0.980
-1.150
-0.853
-0.819
-1.033
6-310
-------
Table 6-153,
Effect of Bias Correction Methods on the Microlead I.
b(0) = bias at 0.0 mg/cm2, b(l) = bias at 1.0 mg/cm2.
Model Estimates of Bias:
SUBSTRATE
Concrete
Concrete
Concrete
Concrete
Concrete
Drywall
Drywall
Drywall
Metal
Metal
Metal
Metal
Plaster
Plaster
Plaster
Plaster
Wood
Wood
Wood
Wood
XRF CODE
NUMBER
20 (Den)
20 (Phi)
21
22
23
20
21
22
20
21
22
23
20
21
22
23
20
21
22
23
CORRECTION METHOD (results in ing /cm2)
NONE
b(0)
-0.030
0.589
0.670
0.892
0.110
0.004
0.202
0.658
0.351
-0.381
1.080
-0.415
-0.043
-0.035
-0.081
0.217
0.001
0.505
0.601
0.329
b(l)
-0.008
0.457
0.595
1.230
0.152
0.183
0.162
1.787
0.451
-0.174
1.361
-0.174
-0. 098
0.177
-0.316
0.010
0.425
0.896
0.740
0.743
CONTROL
b{0)
-0.649
-0.426
0.231
-0.653
-0.369
0.384
0.084
0.464
-1.946
0.399
0.748
0.043
-0.513
0.001
-1.263
-0.175
-0.490
0.598
-0.033
0.106
b{l)
-0.671
-0.520
0.198
-0.457
-0.350
0.450
-0.161
1.562
-2.307
0.664
1.038
0.256
-0.625
0.092
-1.073
-0.393
-0.424
0.968
0.115
0.830
FULL
b(0)
0.248
0.253
-0.237
0.067
-0.036
-0.061
0.035
-0.229
0.084
-0.020
-0.242
-0.225
0.110
0.046
-0.173
0.012
-0.028
0.015
-0.104
-0.047
b(l)
0.085
0.068
-0.366
0.301
0.162
-0.194
0.189
-0.386
0.057
-0.299
-0.178
0.037
0.121
0.040
0.199
-0.097
0.071
0.067
-0.062
0.115
RED NIST AVERAGE
b(0)
0.174
0.228
-0.267
-0.009
0.014
-0.145
0.053
-0.330
-0.133
-0.238
-0.283
-0.266
0.120
0.017
-0.250
0.036
-0.172
-0.108
-0.159
-0.448
b(l)
0.101
0.107
-0.388
0.438
0.061
0.083
0.102
-0.321
0.040
-0.119
-0.095
-0.024
0.050
0.051
-0.325
-0.135
0.087
0.072
-0.063
0.167
6-311
-------
Table 6-154.
Effect of Bias Correction Methods on the X-MET 880. Model Estimates of Bias;
b(0) = bias at 0.0 trig/cm2, b(l) = bias at 1.0 mg/cm2.
SUBSTRATE
Concrete
Drywall
Metal
Plaster
Wood
XRF
CODE
NUMBER
50
50
50
50
50
CORRECTION METHOD (results in mg/cm2)
NONE
b(0)
0.045
0.038
0.112
0 .048
0.042
b(l)
-0.890
-0.739
-0.769
-0. 880
-0.699
CONTROL
b(0)
0.002
-0.007
0.066
0.119
-0.031
b(l)
-0.909
-0.894
-0.799
-0.838
-0.826
FULL
b(0)
0.002
-0.034
0.036
0.004
-0.031
b(l)
-0.883
-0.851
-0.815
-0.809
-0.772
RED NZST
b(0)
0.001
-0.024
0.004
0.014
-0.031
AVERAGE
b(l)
-0.909
-0.918
-0.867
-0.885
-0.821
6-312
-------
Table 6-155,
Effect of Bias Correction Methods on the XK-3. Model Estimates of Bias:
b(0) = bias at 0.0 mg/cm2, b(l) = bias at 1.0 mg/cm2.
SUBSTRATE
Brick
Brick
Concrete
Concrete
Concrete
Drywall
Drywall
Metal
Metal
Metal
Plaster
Plaster
Plaster
Wood
Wood
Wood
XRF CODE
NUMBER
30
31
30
31
32
30
31
30
31 (Den)
32
30
31
32
30
31
32
CORRECTION METHOD (results in mg/cm3)
NONE
b(0)
1.001
0.472
1.083
0.660
1.837
-0.327
0.245
0.451
1.090
1.480
0.538
0.382
1.675
-0.065
0.339
0.933
b(l)
1.329
0.653
1.751
0.230
2.569
-0.093
0.184
0.856
1.611
1.685
0.571
0.217
1.627
0.352
0.765
1.227
CONTROL
b(0)
0.100
-0.269
0.559
0.049
0.150
-0.392
-0.285
-0.617
-0.467
-0.043
-0.210
-0.095
0.355
-0.476
-0.276
0.285
b(l)
0.097
-0.031
0.725
-0.628
0.680
-0.097
-0.589
-0.047
0.081
0.073
-0.128
-0.249
0.162
0.044
0.153
0.565
FULL
b(0)
0.110
-0.057
0.382
0.122
0.255
-0.243
-0.083
-0.029
-0.138
-0.055
0.030
-0.080
0.454
-0.136
-0.093
0.287
b(l)
0.320
-0.307
0.076
-0.652
0.453
-0.209
-0.219
0.186
0.166
0.015
-0.073
-0.172
0.260
0.095
0.227
0.438
RED NIST AVERAGE
b(0)
0.167
-0.100
0.286
0.100
0.159
-0.259
-0.124
-0.193
-0.226
-0.120
0.012
-0.068
0.434
-0.250
-0.120
0.195
b{l)
0.074
-0.101
0.262
-0.644
0.691
-0.069
-0.024
0.247
0.297
0.041
-0.074
-0.222
0.286
0.146
0.273
0.430
6-313
-------
Table 6-156.
Effect of Bias Correction Methods on the XL. Model Estimates of Bias:
b(0) = bias at 0.0 mg/cm2; nonparametric estimates of b(l) = bias at 1.0 mg/cm
SUBSTRATE
Brick
Concrete
Concrete
Drywall
Metal
Metal
Metal
Plaster
Plaster
Wood
Wood
Wood
XRF
CODE
NUMBER
41
41
42
41
40
41
42
40
42
40
41
42
CORRECTION METHOD (results in mg/cm2)
NONE
b(0)
0,038
0.039
0. 054
0.014
0.163
0.031
0.054
0.097
0. 048
0.080b
0.022"
0 , 092
b(l)'
-0.337
-0.378
-0.191
-0.564
-0.480
-0.623
0.517
-0.481
-0.255
-0.044
-0.363
-0.483
CONTROL
b{0)
0.107
0.042
-0.062
0.032
0.112
0.052
-0.043
0.021
-0.087
0.056b
0.058b
0.006
b(D*
-0.276
-0.384
-0.259
-0.657
-0.494
-0.599
0.451
-0.614
-0.408
-0.042
-0.330
-0.563
FULL
b(0)
0.119
0.112
-0.033
0.160
0.186
0.060
-0.005
0.166
-0.049
0.073"
0.218"
0.032
b(l)'
-0.284
-0.349
-0.280
-0.357
-0.522
-0.527
0.453
-0.447
-0.337
0.001
-0.276
-0.577
RED NIST
b(0)
0.104
0.105
-0.023
0.163
0.188
0.057
-0.019
0.160
-0.051
0.078"
0.187"
0.013
AVERAOE
b(l)'
-0.275
-0.379
-0.292
-0.378
-0.516
-0.562
0.461
-0.405
-0.354
-0.011
-0.283
-0.560
• Nonparametric estimates reported, except for drywall, for which model estimates are reported
b Estimates based on sample averages for ICP measurements less than 0.1 mg/cm2
6-314
-------
The Lead Analyzer K-shell (Table 6-149) exhibited little
bias without correction, and was neither helped nor harmed
appreciably with correction. The MAP-3 K-shell (Table 6-151)
exhibited large negative bias on brick, concrete and plaster, and
large positive bias on metal and wood, at a lead level of 1.0
mg/cm2. Control correction was most effective on plaster, mildly
beneficial on concrete and metal, and not effective on the other
three substrates. Full correction was beneficial on metal and
wood, especially at a lead level of 1.0 mg/cm2. Red NIST SRM
average correction mirrored the performance of full correction.
The Microlead I (Table 6-153) exhibited bias on all
substrates (with the possible exception of plaster), that varied
by machine. The bias was usually positive at a lead level of 1.0
mg/cm2. Control correction did not reduce the estimated bias,
but both full and red NIST SRM .average corrections did reduce the
bias across both machines and substrates. A reduction of
positive bias should help to decrease the frequency of
misclassifying paint as over a 1.0 mg/cm2 threshold when the true
paint level is less than that amount.
The XK-3 (Table 6-155) exhibited high, positive bias that
varied more between machines than between substrates. Control
correction was generally effective in reducing the bias,
sometimes substantially. The reduction of high, positive bias
should help to reduce the misclassification of paint with low
lead levels. Both full and red NIST SRM average correction
reduced the estimated bias to a similar extent.
Control correction appeared to benefit the XK-3, and the
MAP-3 K-shell on painted metal and plaster surfaces. Full and
red NIST SRM average correction performed similarly for the MAP-3
K-shell, Microlead I and XK-3, and appeared to benefit the
Microlead I, XK-3, and, on metal and wood, the MAP-3 K-shell.
One aspect of the comparison that was omitted from the
analysis is the effect that bias correction had on the
variability of XRF measurements. The quantities used in control
block and red NIST SRM average correction were sample averages
that introduced both additional variability and dependence across
readings on the same substrate-unit pair. Accounting for these
factors in deriving valid estimates of variability was made
difficult by the substitution of ICP measurements for true lead
levels. Ignoring the combined effect of spatial variation and
laboratory error in ICP measurements, experience with generalized
least squares regression showed that the standard deviations of
the corrected XRF readings were sometimes substantially larger
6-315
-------
than those of the uncorrected readings. Cases where bias
correction appeared to have minimal effect were possibly worsened
by the increase in variability. Although this issue was not
fully explored, it should be considered if the use of a bias
correction methodology is contemplated.
6.4.7 XRF Measurement Accuracy; Conclusions
The analyses presented in section 6.4 were aimed at
addressing the following two study objectives:
• To characterize the performance (precision and accuracy) of
portable XRF instruments under field conditions;
• To evaluate the effect on XRF performance of interference
from the material or substrate underlying the paint.
The six XRF instruments evaluated in the full study on two
different shells (K and L) gave eight instrument-she11 groupings.
In section 6.4.4, the accuracy of XRF readings for each of the
eight groupings was considered separately, by substrate. Data
from the full study established that the K-shell and L-shell
instruments shared important similarities within, but not between
these classes.
The K-shell instruments were distinguished from the L-shell
instruments primarily by their responsiveness to the lead level
in paint under field conditions. Responsiveness refers to the
property that changes in the lead level are reflected in changes
of similar magnitude in XRF readings. Even K-shell instruments
that exhibited substantial bias did not exhibit much change in
the bias as the lead level changed. The L-shell instruments, by
contrast, were under-responsive to the lead level, although
certain qualifications apply to the XL, which are summarized
below. This ensured that, typically, the L-shell instruments
became progressively more biased as the lead level increased.
Control block readings for L-shell instruments did not, however,
exhibit under-responsive behavior, and created a very different
impression of the accuracy of these instruments than what was
realized under field conditions.
A factor that was not considered in the analyses is the mass
of the paint samples, which affected the performance of the
L-shell instruments to a significant degree. The reason for not
including paint mass in the analyses is explained in section
6.4.8.1.1. The L-shell instruments were less responsive to
changes in the lead level on heavier than on lighter samples, an
6-316
-------
effect that was not seen with the K-shell instruments. This
factor may explain some of the discrepancy between the
performance of the L-shell instruments on the field samples and
on the control blocks, and it may also explain the emergence of
certain other factors (e.g. city) that were confounded with paint
mass to various degrees.
The following is a brief description of each of the
instrument-shell groupings:
(1) Lead Analyzer K-shell: This performance of the K-shell of
this instrument had a number of important distinguishing
features. It exhibited the least bias across a wide range
of lead levels over all of the instruments, K-shell and
L-shell. The magnitude of the bias was typically less than
0 .1 mg/cm2 at the 0 . 0 mg/cm2 lead level. At 1. 0 mg/cm2 the
bias was a little larger, but usually less than 0.3 mg/cm2.
The variability of its readings, as measured by the standard
deviation (SD), was the lowest among all K-shell
instruments. Estimates of the SD were typically in the 0.1
to 0.2 mg/cm2 range at 0.0 mg/cm2, and 0.2 to 0.4 mg/cm2 at
the 1.0 mg/cm2 lead level. The performance of this
instrument was also the most stable across substrates of all
K-shell instruments.
Only two Lead Analyzer machines were used by the same
operator, which made it difficult to assess the stability of
its performance with respect to machine differences. There
was, however, no evidence that the machines performed
differently, or that a pronounced difference existed between
their use in Denver and Philadelphia.
(2) Lead Analyzer L-shell; The performance of the L-shell of
this instrument was typical of the L-shell instruments
evaluated in the study. It was minimally biased and
exhibited low variability when lead was absent, but it was
under-responsive to the lead level as the amount of lead
increased. At the 1.0 mg/cm2 lead level, bias on the order
of -0.7 mg/cm2 to -0.9 mg/cm2 was exhibited with this
instrument on all substrates. Control block readings,
however, only became noticeably biased at 3.53 mg/cm2. Both
the control block and field sample data indicated a
flattening of the response at lead levels not much greater
than 1.0 mg/cm2, with increases in the lead level beyond
that point reflected in minimal or even no change in the XRF
readings, on average. Readings less than 1.0 mg/cm2 were
obtained on field samples with ICP measurements greater than
6-317
-------
10.0 mg/cm2 on all substrates for which such samples were
represented in the full study.
The Lead Analyzer L-shell was moderately more responsive to
the lead level in Denver than in Philadelphia, and the bias
estimates at 1.0 mg/cm2 obtained for Denver readings were
consequently lower. Building or substrate characteristics
that distinguish these two cities may have played a role,
and may also shed light on the disparity in performance of
this instrument on the field samples and on the control
blocks.
(3) MAP-3 K-shell: The K-shell of this instrument exhibited
prominent negative bias, both on the field samples and on
the control blocks, on brick, concrete and plaster
substrates. On these substrates the bias was estimated at
about -0.5 from the field sample data, with somewhat higher
or low bias estimates attributed to specific machines or
operators. On metal, the bias was positive and increased
with the lead level. At a lead level of 1.0 mg/cm2, the
bias on metal and wood was about 0.4, which again does not
account for machine or operator differences. The control
block data gave estimates of the bias that were negative and
larger in magnitude than those obtained from the field
sample data on brick, concrete, and plaster. On metal the
control block data, like the field sample data, indicated
positive bias. The MAP-3 K-shell had SD estimates in the
0.4 to 0.8 range at 0.0 mg/cm2, and 10 to 20 percent larger
at a lead level of 1.0 mg/cm2.
Three different MAP-3 machines were used in the study, each
by a different operator. It was therefore not possible to
separate machine from operator effects. On several
substrates differences between the performance of the
machines or operators were discerned, which could possibly
be attributable as well to effects associated with non-lead
factors in the paint samples. The control block data did
not exhibit large differences between the machines. The
benefit of correcting MAP-3 K-shell readings with the
control block data was seen on concrete, metal and plaster,
but not on the other substrates. Red NIST SRM average
correction was effective on metal and wood.
(4) MAP-3 L-shell: The performance of the L-shell of the MAP-3
resembled that of the other L-shell instruments. It was
minimally biased in the absence of lead, although it was
somewhat more variable than the other L-shell instruments,
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with SD estimates in the range 0.1 to 0.4. At increasing
levels of lead the instrument was under-responsive, to the
effect that the bias became negative and progressively
larger in magnitude. At a lead level of 1.0 mg/cm2 the bias
was about -0.6 in Denver, and -0.8 to -1.0 in Philadelphia.
Variability of the measurements also increased slightly as
the lead level increased.
The MAP-3 L-shell failed almost completely to indicate the
presence of high levels of lead. This was true especially
of plaster substrates, on which highly leaded paint was
found in an old house in Denver. None of the L-shell
instruments were able to accurately measure the lead levels
in the samples taken. A more general city effect was also
seen, with the instrument exhibiting greater responsiveness
to lead in Denver than in Philadelphia across a number of
substrates, the problem with plaster notwithstanding.
(5) Microlead I revision 4: The Microlead I exhibited prominent
bias that was usually positive. The Microlead I, like all
of the K-shell instruments, was responsive to lead,
suggesting that the bias remained relatively constant over a
wide range of lead levels. The Microlead I had SD estimates
in the 0.4 to 0.8 range at 0.0 mg/cm2 of lead that increased
slightly as the lead level increased.
Five different Microlead I machines were used by four
different operators, with some crossing between machines and
operators. These factors, together with substrate and city,
substantially affected the bias exhibited by the Microlead I
on the field samples, to the extent that broad
generalizations about bias having practical value are
difficult to make. Both field sample and control block data
exhibited bias, but there was little congruity between the
two measurement situations in this respect. Consistent
differences between machines and/or operators were detected
across substrates on the field samples. Differences between
machines were also evident in the control block data, but
the pattern did not match that seen in the field sample
data. Consequently, there was no indication that the
control block data could be effectively used to reduce bias.
Full and red NIST SRM average corrections did, however,
appear to be effective across machines and substrates with
this instrument.
(6) X-MET 880: The performance of this L-shell instrument was
similar to that of other L-shell instruments in the full
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study. Its most important attribute was its under-
responsiveness to lead on the field samples, which ensured
that readings of the X-MET 880 were more biased at higher
lead levels. A significant difference was evident in the
responsiveness of the instrument between Denver and
Philadelphia. Although the X-MET 880 was more responsive in
Denver, the bias remained large, at nearly -0.5 when the
true lead level was 1.0 mg/cm2. The Louisville pilot study
evaluated the X-MET 880 with a different radioactive source,
and found the instrument to be much more responsive than in
the full study. On metal, the bias estimated from the
Louisville data was on the order of -0.2 at 1.0 mg/cm2,
which was unusually small for the L-shell instruments that
were evaluated in the study. The X-MET 880 exhibited
minimal bias on the control blocks, as did the other L-shell
instruments.
Only one X-MET 880 machine was used in the full study, by
two different operators. Both operator and city effects
were evident in the full study field sample data. These
effects were exhibited in the responsiveness of the machine
to the lead present in paint.
(7) XK-3: This K-shell instrument exhibited substantial
positive bias on both the field samples and the control
blocks, and the bias increased moderately with the lead
level in both measurement situations. The bias varied
markedly between both substrates and machines. On brick,
concrete, metal, and plaster the XK-3 was prone to exhibit
bias as large as 1.0 or more. Bias was exhibited to a
lesser extent on drywall and wood. Unlike the other bias-
prone K-shell instruments, the XK-3 showed congruity in
performance between the control blocks and field samples, to
the extent that using the control blocks to correct for bias
had demonstrable merit. Full and red NIST SRM average
correction also were effective in reducing bias, with
performance that was similar to control correction. The
XK-3 had SD estimates in the 0.4 to 0.8 range at 0.0 mg/cm2,
that increased moderately as the lead level increased.
Three XK-3 machines were used by three different operators
in the full study, with limited crossing of machines and
operators. Prominent effects due to machines or operators
emerged, which were consistent across substrates. The
control block data reflected similar patterns when
summarized by machines within substrates.
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(8) XL: This L-shell instrument was different from the other
L-shell instruments in several important respects. The XL
truncated its readings at 0.0 and at 5.0, and many readings
of 0.0 were obtained at low lead levels as a result. The XL
was more responsive than other L-shell instruments at lead
levels near 1.0 mg/cm2. Like all L-shell instruments that
were evaluated, however, the XL was capable of giving very
low readings at high lead levels, in which respect the
instrument failed to match the performance of the K-shell
instruments that were evaluated.
Three XL machines were used by two operators, with limited
crossing between machines and operators. Machine or
possibly operator effects emerged from the field sample
data, and were exhibited in the control block data as well.
Although the performance of the Lead Analyzer K-shell
clearly distinguished itself, the use of its two machines by the
same operator may have given it an advantage with respect to the
other K-shell machines, where operator effects (or machine
effects that are truly operator effects) were exhibited. It is
still noteworthy that the low-bias, low-SD performance of the
Lead Analyzer was consistent across substrates, and between
machines.
The other K-shell instruments exhibited prominent bias. The
consequences of bias for classifying painted locations as above
or below 1.0 mg/cm2 are different depending on whether the bias
is positive or negative. In the full study, the distribution of
lead levels, as indicated by ICP measurements, was heavily skewed
toward the lower end, with lead levels at most locations below
1.0 mg/cm2. Levels above 1.0 mg/cm2 were highly dispersed. A
negative XRF bias on the order exhibited by the MAP-3 does not
affect the correct classification of locations with low lead
levels, and with a high dispersion in lead levels above 1.0
mg/cm2, only marginally diminishes the correct classification
rate of those above. From a classification point of view, only
lead levels slightly higher than 1.0 mg/cm2 are adversely
affected by small to moderate negative bias. Positive bias of
the kind exhibited by the Microlead I and XK-3, on the other
hand, has generally worse implications for similar reasons.
The L-shell instruments were negatively biased to a
substantial degree, with the possible exception of the XL, and
the X-MET 880 under certain conditions. Even at high lead
levels, the L-shell instruments in the full study often failed to
give readings greater than 1.0 mg/cm2.
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6.4.8 Details and Statistical Methodology
The purpose of this section is to provide details on the
data used in describing XRF instrument performance, and the
development of the XRF measurement model, which made provision
for the combined effect of spatial variation and laboratory error
in ICP measurements on the assessment of XRF instrument
performance.
6.4.8.1 Non-Lead Factors that Affect XRF Performance
The readings obtained from an XRF instrument may depend on
factors in addition to the level of lead present at the sample
locations. These non-lead factors include
• the substrate underlying the painted surface;
• pipes, ducts, wires, screening, and other materials
underlying the substrate;
• the operator of the instrument;
• the machine (usually distinguished by serial number);
• battery, source age, and source type;
• location or temporal effects that vary in an aggregate way,
and are associated with a unit or a city.
Describing how these non-lead factors affected XRF
performance in the full study is important for understanding how
an XRF instrument can be expected to perform in practice.
Because the study was not a factorial experiment with
respect to these and perhaps other factors that affect XRF
performance, it was not usually possible to discretely separate
each effect from the others. Moreover, they were confounded to
varying degrees with the lead levels at the sampled locations.
For example, two machines would be difficult to compare if one
were applied mainly to painted surfaces having low lead levels,
and the other to painted surfaces having high lead levels.
In spite of this, an attempt to control for factors that
affect XRF performance was made. Analyses are presented
separately by substrate for each instrument. Within each
substrate analyses are presented by machine, and at finer levels
of detail (operator within machine, city within operator within
machine, etc.) where possible.
City effects, when recognized, refer to factors associated
with the units that were sampled in the three cities. Age and
the mass of paint samples are examples of factors that may have
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affected XRF instrument performance, and that were known to vary
across field samples grouped by city. There were usually too few
data to meaningfully ascribe effects at this low level of detail
absent the confounding effects of other factors. City effects
may comprise a range of circumstances that are normally
encountered in practical testing, in which case combining data
across cities would give a useful indication of instrument
performance under varying conditions.
The opportunity for detailed analysis varied by the
instrument. For example, the X-MET 880 readings were all made on
the same machine, making inter-machine comparisons impossible.
While the MAP-3 readings were made on three different machines, a
different operator was used for each, making it impossible to
tell if observed differences were due to the operator, the
machine, or both. On some instruments a limited crossing of
operators with machines produced too few data to draw useful
inferences. The Microlead I readings, by contrast, gave insight
into operator within machine, machine within operator, and city
within operator within machine effects on several substrates.
Pooling data across factors is desirable for reaching
general conclusions about the performance of an instrument on a
substrate type, to account for varying practical conditions, and
to give sample size strength to estimates. Where pronounced
effects due to operator or machine were indicated, however, the
wisdom of such pooling is questionable, since the pooled results
may not reflect the performance of any one machine, operated by
any one person. Pooled estimates are reported, except where
doing so clearly would have failed to reflect how the instrument
performed in practice.
6.4.8.1.1. Paint Mass as an Explanatory Factor
It was found that the masses of paint samples affected the
performance of all L-shell instruments evaluated in the study.
On heavier paint samples, the L-shell instruments were
significantly less responsive to the lead level than on lighter
samples. When paint mass was included as an additional
explanatory variable in models fit to wood substrate data,
however, the L-shell instruments were still found to remain
highly under-responsive to lead. By contrast, paint mass did not
affect the performance of the K-shell instruments to an
appreciable degree.
Paint mass, which was considered as a surrogate for
thickness, was confounded with other factors, such as the city
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from which field samples were obtained. On wood substrates, for
example, the Philadelphia samples had a significantly higher
average paint mass than the Denver samples. This fact reinforces
the need for caution when attempting to ascribe apparent
differences to factors that were not controlled in the full
study.
An objective underlying the analyses presented in this
chapter was to explain how XRF instruments performed at fixed
lead levels, under practical conditions. Lead level was
distinguished from other factors, such as paint mass, machine and
operator, by its designation as the explanatory (or independent)
variable in the analyses. The other factors were regarded as
covariates, representing conditions under which the relationship
of XRF readings to the lead level may vary.
The inclusion of covariates in the analyses has the effect
of reducing the apparent variability of XRF readings. Whether
this reduction in variability is appropriate in describing the
performance of an XRF instrument depends on the appropriateness
of regarding the covariates as "fixed" under practical
conditions. Machines and operators were treated as covariates
where it was possible to do so, because the additional
variability in XRF measurements arising from the use of different
machines or operators in the study would not be realized in
situations where one operator used one machine. Paint mass, like
the level of paint itself, is not a controllable factor in
nondestructive testing. Thus, the variability that paint mass
imparted to XRF measurements in the study was considered an
aspect of the performance of an XRF instrument.
6.4.8.2 Statistical Description of XRF Performance
This section, which contains 8 parts, describes the
methodology and reasoning used to derive the XRF measurement
model, which takes into account the fact that the lead levels
were only approximately known in the form of laboratory ICP
measurements. At the beginning of section 6.4, it was explained
that ICP measurements were imperfect substitutes for the true
lead levels, because of spatial variation, and laboratory error.
A sharply defined relationship between a set of XRF readings and
true lead levels may appear less so when the true lead levels are
replaced by estimates. An objective in describing the
performance of an XRF instrument was to develop a statistical
methodology that provided reliable estimates with respect to true
lead levels, although the ICP measurements themselves were used.
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The development of a model that explains how XRF readings
were related to the true levels of lead in paint is presented in
three stages. First, a model is described which does not take
the imperfect substitution of ICP measurements for true lead
levels into account. Second, the impact of this imprecision on
assessing the performance of an XRF instrument is considered.
Third, and finally, a modification of the model that accounts for
this imprecision is presented.
6.4.8.2.1 A Model for the Relationship of XRF to ICP
Measurements
The discussion in section 6.4.2.1 suggests that, as an
approximation, a linear response model, with a standard deviation
(SD) that increases with the lead level, was a reasonable choice
for describing XRF readings as a function of the ICP level. The
SD should increase in such a way that it remains positive even in
the absence of lead, as measured by the ICP level. A simple
specification that incorporates these features has the following
form:
XRF = a + b-(ICP) + e + r- (ICP)
Var(e) = c, Var(r) = d,
where e and 7 represent independent normal random variables. The
mean response of XRF at a fixed ICP level is a linear function of
ICP given by the expression a + b- (ICP) . The variance of XRF at
a fixed ICP level is a linear function of ICP squared, given by
the expression c + d-(ICP)2, where c is the variance of e and d
is the variance of r. The SD, which is the square root of the
variance, approaches the form of a linear function of ICP as ICP
increases. For ICP = 0.0 mg/cm2, the SD of XRF readings is equal
to the square root of c, while at ICP = 2.0 mg/cm2, for instance,
the SD is given by the square root of c + 4-d.
6.4.8.2.2 Sources of XRF Variability
The terms e and r in the model allow for fluctuation of XRF
measurements around a "mean response" value for a fixed level of
lead, as represented by the ICP measurement. These fluctuations
occurred for a number of reasons, the most obvious of which was
instrumental error. Repeated XRF measurement under identical
conditions did not typically produce identical readings. This
was clearly seen in the control block data. Repeated measurement
on the field samples at different locations having approximately
the same lead levels exhibited not only instrumental error, but
fluctuations due to location-specific factors that are less well
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understood. A detailed discussion of this issue can be found in
section 6.4.5.3.
Combining data across machines, operators, or cities often
increased the SD estimates for an instrument. Variability due to
the pooling of nonhomogeneous data is not characteristic of
instrument readings obtained by a single human operator using a
single machine at a single place. This again highlights the fact
that care must be exercised in combining data across factors. To
some extent, however, such combination was unavoidable.
6.4.8.2.3 Nonparametric Estimation Based on Monotone
Regression
It was possible to derive nonparametric estimates of the
mean XRF response to the ICP level, and the standard deviation of
XRF readings as a function of the ICP level, without resorting to
a strictly specified model.
The following two assumptions formed the basis for the
derivation of nonparametric estimates: (1) On average, XRF
readings did not decrease as the lead level, as measured by ICP,
increased; (2) The SD of XRF readings also did not decrease as
the ICP level increased.
These assumptions also underlie the derivation of the
nonparametric standardized residuals, used both to identify XRF
outliers {section 3.2.5) and to calculate correlations between
XRF instrument readings (section 3.2.4.3). Monotone regression
was the technique used to derive nonparametric estimates that
were consistent with the assumptions. Like regular linear
regression, monotone regression sought to minimize the sum of
squared errors between the actual XRF readings and the estimated
mean XRF reading at the observed ICP measurements. But rather
than enforcing a constraint that the mean XRF reading be a linear
function of the ICP level, the only requirement was that larger
ICP measurements could not result in smaller estimates.
Monotone regression is the solution to a quadratic
programming problem, and is obtained with the "pool adjacent
violators" (PAY) algorithm. The solution takes the form of a
step function, formed by averaging data over subgroups in a way
that the averages do not decrease. Although a monotone
regression cannot be "smooth" in appearance, it will approximate
the true mean response if the sample is large, and if the true
mean response is itself a nondecreasing function. A full
treatment of monotone regression can be found in Barlow,
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Bartholomew, Bremner, Brunk [8] .
Nondecreasing (as a function of the TCP level) SD estimates
for XRF readings were also obtained using monotone regression.
First, the monotone regression estimates described above were
subtracted from the XRF readings, and the differences squared.
Then, monotone regression was applied to the squared differences.
The square root of the monotone regression using squared
differences was the nonparametric estimate.
The SD estimate, like the estimated mean response, becomes
unbiased as the sample size increases, provided that the two
assumptions stated above are valid.
6.4.8.2.4 The Effect of Substituting ICP Measurements for
the True Lead Levels
The XRF-ICP relationship was not the same as the
relationship between XRF measurements and the true levels of
lead. This is because the ICP measurements only estimated the
true level of lead in paint. Estimates of bias and variability
obtained from the observable XRF-ICP relationship give an
imperfect picture of how XRF measurements responded to the lead
level in the study.
Deriving estimates of bias and variability was difficult for
two reasons. The first reason is that the variability exhibited
by XRF instruments with respect to the lead level was
nonconstant. The second is that the combined spatial variation
and laboratory error in ICP measurements had approximately a log-
normal distribution, while XRF deviations from the mean response
appeared to be normal, or at least symmetric. Standard
techniques developed for the errors-in-variables problem in
regression are not applicable to phenomena of this kind. One
generalization that does appear to hold is that SD estimates
obtained from an XRF-ICP relationship overestimated the true
variability present in the corresponding XRF-true lead
relationship.
6.4.8.2.5 The Magnitude of Spatial Variation and
Laboratory Error in ICP Measurements
Estimates of the magnitude of laboratory error, expressed as
standard deviations of the natural logarithm of the ICP level,
are presented for ICP laboratory duplicates in section 4.3.1.
Estimates for field duplicates, presented in section 4.3.2,
reflect laboratory error and spatial variation combined.
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Estimates are produced separately by city, and by the six
different substrates encountered. The distance between field
duplicates was approximately 9 inches in Denver and Philadelphia,
and 2 inches in Louisville. For Denver and Philadelphia, field
duplicate standard deviations were larger than those for
laboratory duplicates.
The full study, however, maintained a distance averaging
about 4 inches between the locations of XRF measurement and ICP
paint sample removal. For Philadelphia and Denver, interpolation
was used to impute standard deviations at 4 inches. For
Louisville, where interpolation was not possible, the standard
deviation was extrapolated to a distance of 4 inches in a manner
similar to the change observed in Denver and Philadelphia. Using
the results presented in Tables 4-16 and 4-23, plausible SD
values on the logarithmic scale are approximately 0.3 in Denver,
and 0.2 in Philadelphia and Louisville.
6.4.8.2.6 The Impact of Substituting ICP Measurements for
True Lead Levels: Simulations
A simulation experiment was conducted to assess the
consequences of not accounting for imprecision caused by
substituting ICP measurements for the true lead levels. The
"true" model linking XRF to the lead level used the following
specification, which is described in section 6.4.8.2.1:
XRF = a + b- {Pb) + e + T (Pb)
Var(e) = c, Var(r) = d,
with a = 0, Jb = 1.2, c = 0.01, and d = 0.30. This model is based
on behavior exhibited by several of the K-shell instruments on
wood substrates. Nonconstant XRF variability is a notable
feature of the model, because d is large relative to c. Since Pb
(the true lead level) was not observable, a model component
linking ICP to Pb is also part of the simulation model. It takes
the form
logr(ICP) = log(Pb) + 6,
where log refers to the natural logarithm. The term 6 is a
normally distributed error having mean equal to 0.0 and SD taken
at the five values 0.1 through 0.5 in the experiment. Both
normal and uniform random variates were generated to simulate
log(Pb) , with mean equal to -2.16 and SD equal to 2.72, and a
sample size of N = 300. These values again were typical of wood
substrate analyses. Estimation of the model parameters was based
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on the 300 pairs of (ICP, XRF) measurements randomly generated
according to the model. The method of estimation was normal
maximum likelihood, which treated the ICP measurements as if they
were the true lead levels.
Table 6-157 gives the results of the simulation experiment,
based on 100 replications at each of five error SD levels. In
addition, 100 replications were conducted with no random error
relating ICP to Pb. This was done to determine the comparable
normal maximum likelihood estimates of the parameters for the
case where the ICP measurements are regarded as the true lead
levels.
As the error SD increased with both normal and uniform
distributions of log(Pb), bias increased in the estimated model
parameters Jb (the slope) , and to a greater extent in d (the
nonconstant variance component). The intercept term a and the
baseline variance c were, however, affected very little. The
bias tended to overstate the slope in the XRF-Pb relationship to
a small extent, but overstated the variability in a way that
became more severe as the lead level increased. Little
difference is seen between results obtained for the normal and
uniform cases.
Since error SD imputations were in the 0.2 to 0.3 range, the
results of this experiment suggest that a failure to account for
such error could make an XRF instrument appear to perform worse
than it does. With log-normally distributed lead levels for
instance, and an error SD of 0.2, the XRF SD at a lead level of
1.0 mg/cm2 should be close to the square root of 0.010 + 0.373 or
.619 mg/cm2, compared to a true SD of 0.557 mg/cm2 (the square
root of 0.01 + 0.30). With an error SD of 0.3, the XRF SD
diverged even more, centering near 0.7 mg/cm2.
In this experiment, the main consequence of failing to
account for the imprecise substitution of ICP measurements for
true lead levels was an overstatement of the SD of XRF
measurements, especially at higher lead levels, with bias in the
mean response a less prominent phenomenon. Bias in the slope
parameter b is a well-known consequence of regression with errors
in the independent variables, and there is an extensive
statistical literature that deals with this problem. Results
from the literature, however, assume that variability of the
dependent variable remains constant as a function of the
independent variable, which was not true in the example presented
above.
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Table 6-157.
Simulation Results (Based on 100 Replications), to Assess
the Effect of Spatial Variability and Laboratory Error in
ICP Measurements on Model Estimates.
losr(pb)
DISTRIBUTION
Normal
Uniform
TKUiS
VALUE
a=0.00
Jb=1.20
c=0 . 01
d=0.30
a=0.00
Jb=1.20
c=0.01
d=0.30
ERROR SD
0.0
-.0003
1.1948
.0097
.3034
-.0011
1.1992
.0099
.2978
0.1
-.0007
1.2046
.0097
.3197
-.0003
1.2044
.0100
.3163
0.2
-.0001
1.2060
.0100
.3772
.0006
1.2150
.0101
.3731
0.3
.0016
1.2194
.0103
.4702
.0012
1.2257
.0101
.4778
0.4
.0023
1.2374
.0102
.6288
.0033
1.2485
.0100
.6522
0.5
.0066
1.2412
.0104
.8179
.0021
1.2925
.0101
.8946
An objective of the study was to obtain accurate
descriptions of XRF instrument performance, with respect to fixed
levels of lead in painted surfaces. In order to meet this
objective, it was necessary to develop a methodology that
recognized both the imprecise substitution of ICP measurements
for true lead levels, and the nature of the relationship between
XRF measurements, ICP measurements, and the true levels of lead
in paint.
6.4.8.2.7 The XRF Measurement Model
The following model fully describes the XRF-true lead
relationship in the presence of spatial variation and laboratory
error in ICP measurements:
XRF = a + Jb- (Pb) + e + T (Pb)
logr(ICP) = logr(Pb) + 6,
Var(e) = c, Var(r) = d, Var(5) = a62.
The terms e, T and 6 are normally distributed random
variables having zero means and variances as indicated. The true
lead Pb is unobservable, and is assumed to have a log-normal
distribution with unknown mean and variance. Since ICP is
observable, the mean and variance of Pb is estimable, given
knowledge of o6.
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Estimates of the model parameters a, Jb, c and d based on XRF
and ICP can be derived using maximum likelihood. This requires
expression of the joint density of XRF and ICP, which is an
integral that does not have a closed form. To implement maximum
likelihood requires the use of numerical integration. It was
found that using Riemann sums with 200 equally spaced
subintervals achieved a reasonable compromise between accuracy
and computational speed to make maximum likelihood practicable.
Using 1000 subintervals increased numerical accuracy very little
but did increase the computational time substantially in a
limited number of cases where it was tried. Newton-Raphson
iteration normally provided convergence in less than ten
iterations depending on the starting values supplied. The
maximum likelihood estimates have approximately normal
distributions in large samples. The matrix of second derivatives
used in the Newton-Raphson iterations allows standard error
estimates of the model parameters to be derived.
A small simulation exercise was conducted to determine how
well maximum likelihood can estimate the model of the previous
section.
Ten simulations with log-normal Pb and ab = 0.2 produced
average estimates a = .006, Jb = 1.090, c = .010 and d = .278.
The slope Jb produced the greatest divergence between the
estimator and the true value of the parameter (here, equal to
1.2), but variation in the simulated estimates may explain the
divergence. The XRF variability parameter estimate d appears to
have overcome the effect of error caused by substituting ICP for
Pb, shown in Table 6-157.
Although the maximum likelihood method as developed is not
designed to work with uniformly distributed log(P~b) , ten
simulations show that it not only seems to work well but that it
might even work a little better than in the normal case. The
average estimates were a = -.003, b = 1.251, c = .010 and d =
.297. This result is noteworthy, because it indicates that
maximum likelihood is not highly sensitive to misspecification of
the log(Pb) distribution, which is important because departures
from normality can be expected.
6.4.8.2.8 Model Limitations
The purpose of the XRF measurement model was to describe, in
an approximate way, the behavior of XRF readings in the presence
of varying lead levels in paint. The eight instrument classes
did not all exhibit similar performance, and performance varied
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markedly with the substrate. The model did a good job describing
XRF behavior on certain substrates, but not on others. When a
poor model fit was obtained, it could have been for one of
several observable reasons:
1. A small group of data stood out as different from the
rest.
2. The XRF-true lead relationship either was not linear,
or was linear over a restricted range of lead levels.
This was usually true for the L-shell instruments,
especially on substrates where high ICP measurements
were present.
3. XRF readings were truncated, or constrained not to read
above or below certain values. Two of the instruments
evaluated in the full study produced truncated
readings. The XK-3 did not read above 10 mg/cm2. The
XL did not read below 0 mg/cm2 or above 5 mg/cm2.
Data anomalies, aside from outliers that were formally
identified and removed from the analyses, consisted of near
outliers, or isolated groups of data for which it was not
possible to tell if the data were unusual, or if the relationship
itself may have changed. In the former case, discretion was used
in deciding whether or not the anomalies should be removed. In
the latter case, and where the global validity of the model was
doubtful, analyses on restricted ICP ranges were conducted.
Truncation of XRF readings, especially at the upper end, can
make an otherwise linear XRF-true lead relationship take on a
nonlinear character. Upper end truncation of the XK-3 and XL
instruments was usually seen at ICP measurements much larger than
1.0 mg/cm2. A model that accounted both for truncation, and the
combined effect of spatial variation and laboratory error in ICP
measurements, would be complex, and reap very little benefit in
describing performance at lower lead levels where interest was
primarily focused. Instead, restriction of the data to an ICP
range where upper end truncation was infrequent was used to fit
the XRF measurement model. Truncation of the XL at 0.0 mg/cm2
appeared to have little effect on the linearity of the
relationship in the low ICP range, except on wood substrates,
where truncated zero readings predominated at ICP levels below
0 .1 mg/cm2.
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6.4.8.3 The Analysis of Field Classified Data
Two sets of readings, with different machines and operators,
were made at each sampled location with the MAP-3, Microlead I,
and XK-3. For these instruments it was possible to assign
machines and operators to two field classifications. Direct
comparisons between certain machines, operators, and cities were
made without the need for fitting models, or accounting for the
substitution of ICP measurements for true lead levels. On the
other hand, pooling data across field classifications needed to
take into account the fact that location-specific sources of
variability in XRF readings introduced dependence between the two
sets of measurements.
6.4.8.3.1 Analyses Based on Matched Pairs
If two machines of the same instrument model produce XRF
readings at the same location, there is a 50-50 chance that one
machine will read higher than the other if the machines are
indistinguishable in their performance. A simple technique for
testing this hypothesis is the sign test, which depends only on
the sign (positive or negative) of the difference in readings.
To illustrate, suppose that in 20 readings on common locations,
Machine 1 gave higher readings than Machine 2 on 19 occasions.
The p-value, or probability that one machine will produce a
higher reader than the other on at least 19 occasions assuming
that the 50-50 chance hypothesis is correct, is calculated to be
2- (19 + 1) • (0.5)20, which is less than 40 in one million. This
is not a very likely occurrence, suggesting that Machine 1
systematically produced higher readings than Machine 2.
For large sample sizes a normal approximation was used to
estimate the p-value. Tied readings (zero differences) were
handled with a conditional sign test, using the remaining cases.
Correlations of the differences between field classified readings
and ICP measurements were calculated to determine if the
performance of the two machines relative to each other changed
with the lead level.
Comparisons between machines, operators or cities that are
not directly matched were sometimes made using Fisher's exact
test for 2 by 2 contingency tables. This test required the use
of a third machine-operator as a point of common reference. This
can be useful for finding effects of one factor within another,
and is illustrated in the following example. Operator E of the
Microlead I used two different machines (21 and 22) in Denver,
matched against Operator G using a third machine (20). On metal
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substrates Machine 20 was matched against Machine 21 35 times, of
which 3 had a higher Machine 20 reading. Machine 20 was matched
against Machine 22 24 times (removing ties), and 18 had a higher
Machine 20 reading. These results can be presented in a 2 by 2
contingency table as follows:
Machines 20 vs 21
Machines 20 vs 22
Machine 20 smaller
32
6
Machine 20 larger
3
18
The resulting chi-square statistic for the 2 by 2 table is
27.4, which has a p-value of less than one in ten-thousand,
suggesting either that Machine 21 read systematically higher than
Machine 22, or that some other factor came into play. Since the
sample locations within Denver are non-overlapping in the two
comparisons described above, differences in paint samples between
units in Denver, for example, may be the reason for the
significant chi-square statistic.
6.4.8.3.2 Combining Across Field Classifications
When it is appropriate to do so, pooling data across
instruments, operators, and cities is desirable. Pooling within
field classifications, which avoids the combination of paired
measurements, is straightforward. But, combining paired
measurements across field classifications introduces the problem
of dependence. The effect of this is difficult to determine on
estimates obtained with the XRF measurement model, which assumes
that observations are independent.
The problem was avoided by first pooling within field
classifications, estimating model parameters, and then averaging
the estimates across field classifications. Conservative
standard error estimates were obtained using the "triangle
inequality", which states that the standard error of the sum of
two estimators is no greater than the sum of the individual
standard errors.
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6.5 Comparison of Different Types of XRF Measurements Using
Classification Results
This section compares classifications of XRF measurements to
classifications of the ICP measurements measured in mg/cm2 lead.
The purpose of this analysis is to examine the accuracy of XRF
instruments relative to the ICP measurement and to compare the
different types of XRF measurements and addresses the following
study objectives:
• to characterize the performance (precision and accuracy) or
portable XRF instruments under field conditions
• to evaluate the effect on XRF performance of interference
from material (the substrate) underlying the paint
• to evaluate field quality assurance and control methods.
Both the ICP measurement and the XRF measurement were
compared by classifying them against the 1.0 mg/cm2 lead federal
standard. Note that "XRF measurement" is a term used for general
discussion purposes. In each subsection where a specific
classification analysis is discussed, the XRF measurement will be
defined as either a single reading, a single reading corrected
for substrate bias, an average of three readings, or an average
of three readings corrected for substrate bias. Due to the large
number of tables presented in this section, tables showing
results are not intermingled with text, but instead, tables
referenced in a given subsection appear after the text for that
subsection.
The previous section of this chapter provided a detailed
model-based examination of XRF instrument behavior. Among its
findings were that 1) a single reading taken at a sampling
location provided almost as much information as an average of
three readings taken at that same location, 2) XRF instruments'
behavior is influenced by substrate, 3) substrate correction is
beneficial in selected cases, 4) the K-shell instruments behave
differently from the L-shell instruments, and, 5) XRF instruments
may be positively or negatively biased depending on the
substrate. The classification results presented in this section
provide empirical evidence in support of these findings.
However, these results apply only to the set of sampling
locations tested in this study. Another set of locations with
significantly different lead levels than the tested locations
might provide different results, even if the same instruments
were used. Other paint characteristics, such as thicker paint,
could also provide different results.
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Outliers were not omitted from this analysis.
6.5.1 XRF and ICP Measurement Classification Rules
Both the primary sample ICP measurement and the XRF
measurement were classified at each sampling location. For all
results provided here, the ICP measurements were always
classified using the 1.0 mg/cm2 lead federal standard. That is,
a ICP measurement was classified:
POSITIVE if the ICP measurement was 1.0 mg/cm2 lead or
greater;
NEGATIVE if the ICP measurement was less than 1.0 mg/cm2
lead.
For a given analysis, the XRF measurements were classified
using one of two methods. The first method classified an XRF
measurement either positive or negative and the second method
added an inconclusive classification. The first method
classified the XRF measurements the same way that the ICP
measurement was classified as shown above. That is, an XRF
measurement was classified using the following rules:
POSITIVE if the XRF measurement was 1.0 mg/cm2 lead or
greater;
NEGATIVE if the XRF measurement was less than 1.0 mg/cm2
lead.
The second method added an inconclusive range in the
classification. An XRF measurement could be classified
inconclusive if it fell within a range bounded above and below by
pre-specified values. A measurement above the upper bound was
classified positive, and one below the lower bound, negative.
For this analysis, two sets of bounds were applied. One set of
bounds had an upper bound equal to 1.6 mg/cm2 and a lower bound
equal to 0.4 mg/cm2. The other set had 1.3 mg/cm2 and 0.7 mg/cm2
as upper and lower bounds. Specifically, an XRF measurement was
classified negative, positive, or inconclusive using the
following rules:
POSITIVE if the XRF measurement was 1.6 (or 1.3) mg/cm2 or
greater,
NEGATIVE if the XRF measurement was 0.4 {or 0.7) mg/cm2 or
less, and
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INCONCLUSIVE if the XRF measurements were greater than 0.4 (or
0.7) mg/cm2 and less than 1.6 (or 1.3) mg/cm2.
Once the ICP and XRF measurements were classified at each
sampling location, the classifications were compared. Several
outcomes are possible. Three outcomes, the false negative, false
positive, and inconclusive outcomes are presented in detail in
this section to describe the behavior of the XRF instruments.
For this analysis, rates or percentages were computed for these
outcomes. A false negative for an XRF measurement is defined as
an XRF measurement classified negative that was taken from a
sampling location that had a corresponding ICP measurement
classified as positive. A false positive is, conversely, a
sampling location with an XRF measurement classified positive and
an ICP measurement classified as negative.
Other data presented in the tables in this section are the
XRF measurement sample sizes that were classified and compared to
the ICP measurement. The sample sizes depend on the number of
instruments collecting data, variations in the data collection
protocol, and missing data, all of which were described in
section 6.1. Three of the XRF instruments represented in this
study, the MAP-3, the Microlead I revision 4 (ML I), and the
XK-3, each had two different instruments operating at the same
time in Denver and Philadelphia. As a result, these three
instruments had two results for each sampling location in Denver
and Philadelphia. For this analysis, results were obtained for
these three XRF instruments by combining all measurements from
each pair of instruments prior to computing the misclassification
and inconclusive rates. The other XRF instruments were
represented in this study by a single instrument at a time, and
thus, only one measurement per sampling location was available.
The sample size for those instruments that had two different
instruments operating at the same time was approximately double
the sample size for the other instruments.
Sampling locations from the XRF instruments that had both
K-shell and L-shell measurements were further classified into a
K-shell and an L-shell instrument, for purposes of analysis.
Applying this methodology resulted in eight XRF categories, four
K-shell instruments and four L-shell instruments which are
presented in the tables in this section.
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6.5.2 Classification Results Without an Inconclusive
Range
6.5.2.1 Standard XRF Measurements
The first set of tables presented are results for the first
standard paint reading as defined in the first section of this
chapter. Table 6-158 shows the overall false positive and false
negative percentages for the eight XRF instruments based on the
first standard paint measurements. In Table 6-158, overall the
Lead Analyzer K-shell had the lowest misclassification rates.
Among all instruments, only the MAP-3 and Lead Analyzer had both
misclassification rates less than 10%, but both rates associated
with the Lead Analyzer were less than those associated with the
MAP-3. Also, among the K-shell instruments, the Lead Analyzer
had the lowest false positive rate. Two other K-shell
instruments, the Microlead I and the XK-3, have a lower false
negative rate, but the false positive rates for these two
instruments were 20.3% and 39.7%, respectively. Excluding the
Lead Analyzer and the MAP-3, the other XRF instruments had at
least one misclassif ication rate greater than 20%, ranging from
20.3% to 89.1%.
Tables 6-159 and 6-160 show the same information for four
categories of ICP measurements. These two tables indicate where
the misclassification errors are occurring relative to the ICP
measurement. For all sampling locations with ICP measurements
less than 0.1964 mg/cm2 (the median of the 1,290 ICP
measurements), Table 6-159 shows a difference between the L-shell
and K-shell instruments. Overall, the false positive rates for
the L-shell instruments range from 0.0% to 0.8% and the for the
K-shell instruments the false positive rates range from 1.0% to
64.2%. Comparisons between L-shell and K-shell instruments from
sampling locations with results in the median ICP measurement to
1.0 mg/cm2 range show greater differences. In this ICP
measurement range, the false positive rates for the L-shell
instruments range from 0.0% to 1.0% and the for the K-shell
instruments the false positive rates range from 6.6% to 64.2%.
In contrast, a different relationship between the L-shell
and K-shell instruments is shown in Table 6-160. For all
sampling locations with ICP measurements greater than or equal to
1.0 mg/cm2 lead but less than 0.24891 (the 90th percentile of the
1,290 ICP measurements), Table 6-160 shows that false negative
rates for the L-shell instruments range from 50.8% to 96.6% and
the for the K-shell instruments the false negative rates range
from 4.1% to 12.0%. From sampling locations with results greater
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than the 90th percentile, the table shows that false negative
rates for the L-shell instruments range from 31.4% to 82.2% and
the for the K-shell instruments the false negative rates range
from 0.0% to 4.0%. Thus, comparisons of these two tables
illustrates differences between the K-shell and L-shell
instruments. The higher misclassification errors for the K-shell
instruments occur at lower ICP measurements shown in Table 6-159.
This is in contrast to the L-shell instruments which have higher
misclassification errors from locations with higher ICP
measurements shown in Table 6-160.
The information in Tables 6-158 and 6-159 is presented
graphically in Figures 6-84 through 6-91, for each XRF instrument
classification. In these figures, each horizontal bar in the
graphs corresponds to one of the four ICP measurement categories
shown in Tables 6-159 and 6-160. The top bar, labeled "high
neg", represents XRF data collected at sampling locations with
corresponding ICP measurement less than the ICP measurement
median (0.1964 mg/cm2) . The next bar down ("low neg") represents
XRF data collected at sampling locations with corresponding ICP
measurement equal to or greater than the ICP measurement median
(0.1964 mg/cm2) but less than 1.0 mg/cm2 lead standard. The
third bar from the top ("low pos") represents XRF data from
sampling locations equal to or greater than 1.0 mg/cm2 lead but
less than the ICP measurement 90th percentile, 2.4891 mg/cm2.
Finally, the bottom bar ("high pos") represents XRF data from
sampling locations equal to and greater than the 90th percentile.
Overall frequency and percent of sampling locations by ICP
measurement category is given in the figures as "FREQ." and
"PCT.", respectively.
Each bar is divided into "AGREE" (no shading) categories and
"DISAGREE" (black shading) categories. A sampling location is
categorized as agree if the XRF measurement provides the same
classification of the sampling location relative to the 1.0
mg/cm2 lead standard as does the ICP measurement. In other
words, the classification provided when the XRF measurement and
ICP measurement agree. A sampling location is categorized as
disagree if the XRF measurement, or first standard paint reading
in this case, provides a different classification of the sampling
location relative to the 1.0 mg/cm2 lead standard than does the
classification provided by the ICP measurement. That is, a
sampling location is categorized as disagree if the XRF
measurement is greater than 1.0 mg/cm2 lead and the ICP
measurement is less than 1.0 mg/cm2 lead or vice versa.
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Figures 6-84 through 6-91 clearly illustrate the differences
between K-shell and L-shell instruments. Most of the time the
K-shell instruments' first standard paint readings where able to
correctly classify the high levels of lead whereas those from the
L-shell instruments had high false negative rates for high levels
of lead. This can be observed in Figures 6-84 through 6-91 by
comparing the disagree categories (black shading) that occurred
on the bottom two bars. The L-shell instruments show a greater
frequency of false negative results {a greater amount of black
shading) than do the K-shell instruments.
To further illustrate differences between K-shell and
L-shell instrument results, a nonparametric statistic was
computed to measure the amount of agreement between two XRF
instruments. First, the first standard paint readings were
classified negative or positive relative to the 1.0 mg/cm2 lead
standard as described above. Next, the results from one
instrument were cross-tabulated against the results of another
instrument and computed from each cross-tabulation result was an
agreement statistic, K [13] , which was used to compare the one
XRF instrument to another. The agreement statistic was computed
for all pairs of XRF instruments with first standard paint
readings from sampling locations with corresponding ICP
measurement greater or equal to its 90th percentile (2.4891
mg/cm2) and the results are given in Table 6-161. The Microlead
I did not have any negative classifications for its first
standard paint readings from sampling locations used in this
analysis.
Interpreting K depends on its sign and magnitude. The sign
measures agreement or disagreement. For example, a +1.0
indicates total agreement and a -0.17 indicates disagreement but
less than total disagreement. Herein lies the limitation of the
agreement statistic, K. The interpretation of K does not allow
quantitative measures of the relative amounts of agreement or
disagreement. However, differences can be observed by comparing
the K-shell instruments to L-shell instruments using the K
statistics provided in Table 6-161. The K statistics computed
between one K-shell instrument and another K-shell instrument
were an order of magnitude greater than the K statistics computed
from a K-shell and L-shell instrument pairing. Similar results
can be observed by comparing results from the pairing of two
L-shell instruments to the results from a K-shell and L-shell
instrument pairing. Therefore, Table 6-161 provides additional
evidence that the first standard paint readings were similar
among K-shell instruments and dissimilar from L-shell instruments
and vice versa. However, one K-shell instrument, the XK-3,
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showed differences from the other K-shell instruments. The XK-3
had negative agreement statistics computed for the other K-shell
instruments whereas all of the agreement statistics for the other
K-shell instruments among each other, except for the XK-3, were
positive.
Tables 6-162 through 6-169 provide the misclassification
rates for each XRF classification by substrate. Results were
fairly consistent across all substrates for the Lead Analyzer.
The results for the other instruments were more variable by
substrate.
6.5.2.2 First Standard Paint Reading Versus Average of
Three Readings
The averages of the three standard paint readings at a
sampling location were classified. Table 6-170 is analogous to
Table 6-158 except that it provides results for the average of
the three paint readings. Likewise, Tables 6-171 through 6-178
provide the same information for the eight XRF classifications by
substrate.
For the K-shell instruments the error percentages (false
positive and false negative) are the same in one case, slightly
larger for the average in one case, and slightly smaller for the
average in six cases. For the L-shell instruments the error
percentages are the same in three cases, while the average is
slightly superior in the remaining cases. In no case, either for
K- or L-shell instruments, does the average represent a
significant improvement over the first standard paint reading.
In particular, cases where the error rate was high, (the false
negative rates for the L-shell instruments and false positive
rates for the Microlead I and XK-3), the error rates were only
very minimally improved by use of the average of three readings.
Comparisons by substrate were made by comparing Tables 6-162
through 6-169 to Tables 6-171 through 6-178. For the four
K-shell instruments, there are a total of 44 error percentages
when broken down by substrate. In 26 cases, the error
percentages for the average are smaller, in seven cases they are
larger, and in 11 cases no change occurred between the average
and the error percentages for the first standard paint readings.
For the L-shell instruments, 32 cases are the same, 10 show the
average as better, and two show the first standard paint reading
as better. In no case was any improvement of the average over
the first standard paint reading significant. For example, there
are 31 error rates exceeding 10%; of these, only two were reduced
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below 10% by use of the average, and both improvements were small
(11.1 % versus 10.2% false negative rates for the Lead Analyzer
K-shell on concrete and 7.4% versus 6.8% false negative rates for
the Microlead I on plaster).
The conclusion from examining these classification results
is that, although use of the average of three 15-second readings
may result in more accurate classification of paint than the use
of only a single reading, the likelihood of improvement is small.
In any case, improvement was always too small to be of practical
significance. Thus, it appears that the additional effort
involved in taking three 15-second readings at a sampling
location versus only one is not justified by an increase in the
accuracy of classification of paint. Experience in the field in
this study suggests that approximately 50% of on-site time is
spent taking XRF readings. Thus, reducing the number of readings
from three to one would reduce inspection time in the field on
the order of 33%.
The conclusion that there is very little difference in the
accuracy of paint classification between a single reading and the
average of three readings is somewhat paradoxical. The
expectation that the average will perform much better than a
single reading is based on the statistical fact that the variance
of the average of three independent readings is one-third the
variance of a single reading, so that the average is much more
precise than a single reading. This expectation is not borne out
by the XRF data for two reasons. First, for most instruments,
successive readings taken at the same point are positively
correlated, so that the independence assumption is violated.
Thus, the gain in precision from taking repeated readings is
generally much less than if the readings were independent.
Second, taking repeated readings and averaging them reduces only
the component of variability due solely to the performance of the
instrument ("instrumental variability"). As shown in section
6.4, the study data demonstrates clearly that there are
additional sources of variability in XRF readings that are
generally at least as large as the instrumental component.
Taking repeated readings cannot reduce the impact of these
additional sources of variation. The additional variation is due
to location-specific factors such as paint and substrate
composition. Much greater detail on this issue can be found in
section 6.4 of this chapter. However, another discussion
comparing a single reading to an average of three readings with
the addition of the inconclusive range is found in section
6.5.3.3.
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6.5.2.3 Impact of Correcting for Substrate Bias
The tables given in the last two sections that break down
results by substrate (Tables 6-162 through 6-169 and 6-171
through 6-178) illustrate the effect that the underlying
substrate can have on classifying XRF measurments. The next set
of tables provide error percentages for XRF readings after they
have been corrected for substrate bias. A single XRF reading was
"corrected" by subtracting a known offset value. For this
analysis, the first standard paint reading at a sampling location
was corrected. There are three types of corrections as defined
in section 6.1:
• control correction
• full correction
• red NIST SRM average correction.
Discussions comparing a single reading to corrected readings
are found in this section. Discussions comparing a single
reading to corrected readings with the addition of the
inconclusive classification are found in section 6.5.3.3.
6.5.2.3.1 Impact of Control Correction
The first standard paint readings were "control corrected"
by subtracting the average of all the initial and end red NIST
SRM control block measurements in the dwelling, minus 1.02
mg/cm2. Table 6-179 shows the overall false positive and false
negative percentages for the eight XRF instruments based on the
first standard paint reading control corrected for all locations.
Tables 6-180 and 6-181 show the same information for four
categories of ICP measurements. Tables 6-182 through 6-189 break
down the results for the first standard paint measurement by
substrate.
Table 6-179 shows that for the L-shell instruments, control
correction is ineffective since false negative rates remained
high. For the Lead Analyzer K-shell, there was little impact;
the false positive rate decreased slightly and the false negative
rate increased slightly. Similarly for the MAP-3 K-shell; the
false positive rate increased slightly and the false negative
rate decreased slightly. However, a high false positive rate on
metal and high false negative rates on concrete and plaster were
all reduced by control correction as shown in Tables 6-164 and
6-184. For the Microlead I, control correction was ineffective;
the false negative rate increased five fold to 18.3% and the
false positive rate decreased to 12.5%. The increase in the
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false negative rate was due to the high false negative rates on
concrete, metal, and plaster shown in-Table 6-186. For the XK-3,
high false positive rates were reduced, but at the expense of a
substantial increases in the false negative rates for metal,
plaster, and wood as shown in Table 6-188.
The results shown in Tables 6-180 and 6-181 are analogous to
the results shown in Tables 6-159 and 6-160. Comparisons of
Table 6-159 to Table 6-180 show that the control correction
greatly improved the XK-3 performance in the ICP measurement
range 0.0 to 0.1964 mg/cm2 (the ICP measurement median) and
showed substantial improvement in the ICP measurement range
0.1964 to 1.0 mg/cm2 lead. The Microlead I showed some
improvement in the 0.0 to 0.1964 mg/cm2 range. However,
comparisons of the results in Table 6-160 with those in Table
6-181 show that the false negative rate for the Microlead I
increased for ICP measurements equal to or greater than 1.0
mg/cm2 lead.
6.5.2.3.2 Impact of Full Correction
The first standard paint reading was "fully corrected" by
subtracting the average of the three standard red NIST SRM
readings taken at the same location, minus 1.02 mg/cm2. Table
6-190 shows overall error rates by instrument for the first
standard paint reading fully corrected. Tables 6-191 through
6-198 break down the information by substrate.
For the L-shell instruments, full correction was ineffective
since false negative rates still remain high. Similarly, for the
Lead Analyzer K-shell, there was little impact; error rates were
low before correction and decrease slightly after correction.
For the MAP-3 K-shell, full correction was effective on some
substrates. High false negative rates on concrete and plaster
were not reduced by full correction but false positive rates on
metal and wood were substantially reduced as shown in Tables
6-164 and 6-193. For the XK-3, full correction was effective;
false positive rates were substantially reduced without an
unacceptable increase in false negative rates. It must, of
course, be remembered that full correction is never a practical
field procedure.
6.5.2.3.3 Impact of Red NIST SRM Average Correction
The first standard paint readings were corrected using red
NIST SRM average correction. This was done by subtracting from
the first standard paint reading, the corresponding substrate
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average of all red NIST SRM readings taken at the sample
locations in the dwelling, minus 1.02 rag/cm2. Table 6-199 shows
overall error rates by instrument for the first standard paint
reading red NIST SRM average corrected. Tables 6-200 through
6-207 break down the information by substrate. The impact was
very similar to full correction.
Table 6-158.
First Standard Paint Reading Without an Inconclusive Range.
XRF
Lead Analyzer
K-shell
Lead Analyzer
L- shell
MAP-3
K- shell
MAP-3
L- shell
Micro-lead I
K-shell
X-Met 880
L- shell
XK-3
K-shell
XL
L- shell
Sample
Size
1,190
1,190
2,367
2,367
2,475
1,174
2,478
1,189
% False
Positive
3.1
0.0
8.0
0.9
20.3
0.0
39.7
0.5
% False
Negative
5.9
89.1
8.3
69.7
3.8
87.1
3.6
41.8
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Table 6-159.
False Positive Results for First Standard Paint Readings
Without an Inconclusive Range, Categorized by Their
Corresponding ICP Measurement Above and Below the 0.1964
mg/cm2 Median of the 1,290 ICP Measurements.
XRF
Lead Analyzer
K- shell
Lead Analyzer
L-shell
MAP-3
K- shell
MAP-3
L-shell
Microlead I
K- shell
X-Met 880
L-shell
XK-3
K- shell
XL
L-shell
Sample
Size
608
362
608
362
1,209
723
1,209
723
1,252
754
596
361
1,251
754
607
362
ICP Measurement Range
(mg/cm2)
[0 - median)
[median - 1.0)
[0 - median)
[median - 1.0)
[0 - median)
[median - 1.0)
[0 - median)
[median - 1.0)
[0 - median)
[median - 1.0)
[0 - median)
[median - 1.0)
[0 - median)
[median - 1.0)
[0 - median)
[median - 1.0)
% False
Positive
1.0
6.6
0.0
0.0
4.6
13.6
0.8
1.0
15.8
27.7
0.0
0.0
24.9
64.2
0.2
1.1
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Table 6-160.
False Negative Results for First Standard Paint Readings
Without an Inconclusive Range Categorized by Their
Corresponding ICP Measurement Above and Below the 2.4891
mg/cm2 90th Percentile of the 1,290 ICP Measurements.
XRF
Lead Analyzer
K-shell
Lead Analyzer
L-shell
MAP-3
K-shell
MAP-3
L-shell
Microlead I
K-shell
X-Met 880
L-shell
XK-3
K-shell
XL
L-shell
Sample
Size
118
102
118
102
233
202
233
202
240
229
116
101
242
231
118
102
ICP Measurement Range
(mg/cm2)
[1.0 - 90th %tile)
[90th %tile - oo)
[1.0 - 90th %tile)
[90th %tile - oo)
[1.0 - 90th %tile)
[90th %tile - oo)
[1.0 - 90th %tile)
[90th %tile - oo)
[1.0 - 90th %tile)
[90th %tile - co)
[1.0 - 90th %tile)
[90th %tile - oo)
[1.0 - 90th %tile)
[90th %tile - oo)
[1.0 - 90th %tile)
[90th %tile - oo)
% False
Negative
9.3
2.0
96.6
80.4
12.0
4.0
77.7
60.4
7.5
0.0
91.4
82.2
4.1
3.0
50.8
31.4
6-347
-------
LEAD ANALYZER K-SHELL CLASSIFICATIONS
high neg
1ow neg
low pos
high pos
O
r— l - 1
11
1 - 1 - •
22
33
1 - 1 - 1
44
FREQ .
6O8
362
118
1O2
PCT .
51 .09
3O .42
9 . 92
8 .57
55
PERCENT
XRF
J Agree
Di sagr ee
high neg=CO , median}
low POS=C!.O mg/cm2, 9Oth SStile}
ICP Categories
low neg=Cmedi an , l.O mg/cnr
high pos = £9Oth £tile, °°^)
Figure 6-84. Bar chart of classifications by laboratory ICP categories for Lead
Analyzer K-shell, no inconclusive range.
6-348
-------
LEAD ANALYZER
L
-SHELL CLASSIFICATIONS
ICP
high neg
low neg
1ow pos
high pos
O
1 1
22 33
PERCENT
FREQ .
608
362
1 18
102
PCT .
51 .09
3O .42
9 . 92
8 . 57
44
55
XRF
Agree
ICP Categories
Di sagr ee
high neg=CO, median}
low pos = [l.O tng/cm2, 9Oth 9Stile)
low neg=nmedian, l.O ing/ ctn
high pos = [9Oth 96tile, «.}
Figure 6-85.
Bar chart of classifications by laboratory ICP categories for Lead
Analyzer L-shell, no inconclusive range.
6-349
-------
MAP-3 K-SHELL CLASSIFICATIONS
ICP
high neg
low neg
low pos
high pos
O
1—i—'
1 1
XRF
22 33
PERCENT
1 i '
44
FREQ .
12O9
723
233
2O2
PCT ,
51 , OS
3O . 54
9 . 84
8 .53
55
J Agree
Di sagree
ICP Categories
high neg=CO, median}
low pos = [l.O mg/cm2, 9Oth 961 i 1 e
low neg = t^medi an , 1 .O mg/ctn2}
high pos = [9Oth 9Stile, ~)
Figure 6-86. Bar chart of classifications by laboratory ICP categories for MAP-3 K-
shell, no inconclusive range.
6-350
-------
MAP-3 L-SHELL CLASSIFICATIONS
ICP
high nee
low neg
1ow pos
high pos
O
FREQ.
1209
723
233
2O2
PCT .
5 1 . OS
3O . 54
9 . 84
8 . 53
1 1
22 33
PERCENT
44
55
XRF
H Agree
Di sagree
IGP Categories
high neg = QO, median} low neg=Cmedian, i.o rug/cm2)
low pos=[l.O mg/cmz , 9Oth 96tile} high pos = [9Oth 96tile, «5
Figure 6-87. Bar chart of classifications by laboratory ICP categories for MAP-3 L-
shell, no inconclusive range.
6-351
-------
MICROLEAD I K-SHELL CLASSIFICATIONS
ICP
high neg
low neg
low pos
hi gh pos
o
I
FREQ .
1252
754
24O
229
PCT .
50 .59
3O .46
9 . 7O
9 .25
11
22 33
PERCENT
55
XRF
H Agree
ICP Categories
high neg = Q O, median^ low neg=Qmedian, l.O ing/ cm'
low pos = £l,O mg/crnz, 9Oth 96tile)
high
= [;9Oth %t i 1 e ,
Figure 6-88.
Bar chart of classifications by laboratory ICP categories for Microlead
I, no inconclusive range.
6-352
-------
X-MET 880 L-SHELL CLASSIFICATIONS
ICP
high neg
low neg
low pos
hi gh pos
O
1 1
22 33
PERCENT
44
XRF
Agree
Di sagree
FREQ .
596
361
1 16
101
PCT .
5O . 77
30 . 75
9 . 88
8 . 6O
55
high neg=[O, median}
low pos = [l,O mg/cm2 , 9Oth 9Stile)
ICP Categories
low neg=Cmedian, l.O mg/cm2}
high pos = C9Oth 961 i 1 e , ~}
Figure 6-89. Bar chart of classifications by laboratory ICP categories for X-MET 880,
no inconclusive range.
6-353
-------
XK-3 K-SHELL CLASSIFICATIONS
ICP
high neg
low neg
low pos
high pos
1—i—'
11
XRF
22 33
PERCENT
44
FREQ .
1251
754
242
231
PCT.
50 .48
3O .43
9 . 77
9 . 32
55
J Agree
Di sagree
ICP Categories
high neg = [|O, median}
low pos = [l.O mg/cmz , 9Oth 961 i 1 e
low neg=Cmedian, l.O rng/cm2}
high pos = [9Oth 961 i 1 e , <*O
Figure 6-90.
Bar chart of classifications by laboratory ICP categories for XK-3, no
inconclusive range.
6-354
-------
ICP
high neg
1ow neg
low pos
high pos
O
XL L-SHELL CLASSIFICATIONS
1—i—'
1 1
T
"T
22 33
PERCENT
XRF
J Agree
FREQ ,
607
362
1 18
1O2
PCT ,
51 . 05
3O .AS
9 . 92
8 .58
Di sagree
high neg = QO, median}
low pos=[l.O rag/cm2 , 9Oth 96tile)
ICP Categories
low neg=C medi an , l.O ing/cm2}
high pos = C9Oth 95tile, ~)
Figure 6-91. Bar chart of classifications by laboratory ICP categories for XL, no
inconclusive range.
6-355
-------
Table 6-161. Agreement Statistic, K, For All Pairs of XRF Readings Taken At Testing Locations From Which the ICP
Measurement in mg/cm2 Units Was Greater To or Equal to the 90th percentile of all 1,290 Testing Locations.
Lead Lead MAP-3 MAP-3 MAP-3 MAP-3 ML I*
Anal Anal (I) (II) (I) (n) (I)
K L K K L L
Lead Analyzer K 1.00 0.01 0.66 0.27 0.01 0.01
Lead Analyzer L 1.00 0.01 0.03 0.53 0.56
MAP-3 (I) K 1.00 0.48 0.03 0.03
MAP-3 (II) K 1.00 0.05 0.08
MAP-3 (I) L 1.00 0.92
MAP-3 (II) L 1.00
ML I (I)
ML I (II)
X-MET
ML I* X-MET
(II) 880
0.00
0.94
0.01
0.03
0.48
0.51
-
-
880 1.00
XK-3 (I)
XK-3
XK-3
(I)
-0
0
-0
0
-0
0
-
-
0
1
(II)
.03
.02
.03
.16
.01
.05
.02
.00
XK-3
(ID
-0
-0
-0
-0
-0
-0
-
-
-0
-0
1
.02
.06
.02
.04
.06
.06
.06
.03
.00
XL
* The Microlead I did not have any negative classifications for
analysis.
the sampling locations
used
XL
0
0
0
0
0
0
-
-
0
-0
-0
1
.02
.20
.08
. 06
.48
.45
.18
.02
.06
.00
in this
6-356
-------
Table 6-162.
Lead Analyzer K-shell by Substrate for the First Standard
Paint Reading Without an Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
189
222
355
1,190
% False
Positive
2.8
1.6
1.8
3.4
1.0
6.3
3.1
% False
Negative
0.0
11.1
naa
6.8
3.8
5.9
5.9
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-163.
Lead Analyzer L-shell by Substrate for the First Standard
Paint Reading Without an Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
189
222
355
1,190
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
90.5
96.3
naa
81.8
100.0
87.3
89.1
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
6-357
-------
Table 6-164.
MAP-3 K-shell by Substrate for the First standard Paint
Reading Without an Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
185
436
226
378
444
698
2,367
% False
Positive
4.2
5.8
3.5
19.3
2.3
10.6
8.0
% False
Negative
0.0
24.1
naa
1.1
21.2
5.5
8.3
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
Table 6-165.
MAP-3 L-shell by Substrate for the First Standard Paint
Reading Without an Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
185
436
226
378
444
698
2,367
% False
Positive
0.0
0.0
0.4
5.2
0.0
0.2
0.9
% False
Negative
28.6
85.2
naa
60.2
100.0
70.4
69.7
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
6-358
-------
Table 6-166.
Microlead I by Substrate for the First Standard Paint
Reading Without an Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
186
444
237
406
463
739
2,475
% False
Positive
22.2
25.5
17.9
18.8
9.7
26.2
20.3
% False
Negative
2.4
1.8
naa
2.2
10.2
3.6
3.8
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-167.
X-MET 880 by Substrate for the First Standard Paint Reading
Without an Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
175
222
353
1,174
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
85.7
96.3
naa
69.8
100.0
89.0
87.1
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
6-359
-------
Table 6-168.
XK-3 by Substrate for the First Standard Paint Reading
Without an Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
186
444
237
406
462
743
2,478
% False
Positive
52.8
66.2
5.1
57.3
45.9
16.5
39.7
% False
Negative
2.4
1.8
naa
5.4
1.7
4.0
3.6
* Not available since drywall ICP measurements were all less than l.O
mg/cm2 lead.
Table 6-169.
XL by Substrate for the First Standard Paint Reading Without
an Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
217
113
189
222
355
1,189
% False
Positive
0.0
0.5
0.9
0.7
0.0
0.8
0.5
% False
Negative
23.8
40.7
naa
29.6
57.7
47.1
41.8
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
6-360
-------
Table 6-170.
Standard Paint Average Without an Inconclusive Range.
XRF
Lead Analyzer
K- shell
Lead Analyzer
L-shell
MAP-3
K- shell
MAP-3
L-shell
Microlead I
K-shell
X-Met 880
L-shell
XK-3
K-shell
XL
L-shell
Sample
Size
1,190
1,190
2,367
2,367
2,475
1,174
2,478
1,189
% False
Positive
2.5
0.0
6.0
0.8
18.2
0.0
40.1
0.4
% False
Negative
5.9
89.1
7.4
68.7
2.3
86.6
3.0
43.2
6-361
-------
Table 6-171.
Lead Analyzer K-shell by Substrate for the Standard Paint
Average Without an Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
189
222
355
1,190
% False
Positive
1.4
1.6
1.8
2.1
1.0
5.1
2.5
% False
Negative
0.0
7.4
naa
6.8
7.7
5.9
5.9
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-172.
Lead Analyzer L-shell by Substrate for the Standard Paint
Average Without an Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
189
222
355
1,190
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
90.5
96.3
naa
81.8
100.0
87.3
89.1
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
6-362
-------
Table 6-173.
MAP-3 K-shell by Substrate for the Standard Paint Average
Without an Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
185
436
226
378
444
698
2,367
% False
Positive
2.8
1.8
3.1
13.8
1.5
10.2
6.0
% False
Negative
0.0
22.2
naa
1.1
26.9
2.5
7.4
a Not available since drywall TCP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-174.
MAP-3 L-shell by Substrate for the Standard Paint Average
Without an Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
185
436
226
378
444
698
2,367
% False
Positive
0.0
0.0
0.0
5.2
0.0
0.0
0.8
% False
Negative
26.2
83.3
naa
59.1
100.0
69.8
68.7
9 Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
6-363
-------
Table 6-175.
Microlead I by Substrate for the Standard Paint Average
Without an Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
186
444
237
406
463
739
2,475
% False
Positive
18.1
19.6
20.3
18.2
5.7
26.2
18.2
% False
Negative
0.0
1.8
naa
1.1
6.8
2.3
2.3
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
Table 6-176.
X-MET 880 by Substrate for the Standard Paint Average
Without an Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
175
222
353
1,174
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
85.7
96.3
naa
69.8
100.0
88.0
86.6
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
6-364
-------
Table 6-177.
XK-3 by Substrate for the Standard Paint Average Without an
Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
186
444
237
406
462
743
2,478
% False
Positive
53.5
69.6
4.2
57.0
48.6
13.9
40.1
% False
Negative
2.4
0.0
naa
4.3
3.4
3.1
3.0
a Not available since drywall ICP measurements were all less than 1 . 0
rag/cm2 lead.
Table 6-178.
XL by Substrate for the Standard Paint Average Without an
Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
217
113
189
222
355
1,189
% False
Positive
0.0
0.5
0.0
0.7
0.0
0.8
0.4
% False
Negative
23.8
59.3
naa
25.0
65.4
45.1
43.2
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
6-365
-------
Table 6-179.
First Standard Paint Reading Control Corrected Without an
Inconclusive Range.
XRF
Lead Analyzer
K- shell
Lead Analyzer
L- shell
MAP-3
K- shell
MAP-3
L- shell
Microlead I
K- shell
X-Met 880
L- shell
XK-3
K- shell
XL
L- shell
Sample
Size
1,190
1,190
2,367
2,367
2,475
1,174
2,478
1,189
% False
Positive
2.3
0.0
10.2
0.8
12.5
0.0
11.3
0.5
% False
Negative
7.3
90.0
5.7
73.8
18.3
88.5
10.6
45.5
6-366
-------
Table 6-180.
False Positive Results for First Standard Paint Readings
Control Corrected Without an Inconclusive Range, Categorized
by Their Corresponding ICP Measurement Above and Below the
0.1964 mg/cm2 Median of the 1,290 ICP Measurements.
XRF
Lead Analyzer
K- shell
Lead Analyzer
L-shell
MAP-3
K-shell
MAP-3
L-shell
Microlead I
K-shell
X-Met 880
L-shell
XK-3
K-shell
XL
L-shell
Sample
Size
608
362
608
362
1,209
723
1,209
723
1,252
754
596
361
1,251
754
607
362
ICP Measurement Range
(mg/cm2)
[0 - median)
[median - 1.0)
[0 - median)
[median - 1.0)
[0 - median)
[median - 1.0)
[0 - median)
[median - 1.0)
[0 - median)
[median - 1.0)
[0 - median)
[median - 1.0)
[0 - median)
[median - 1.0)
[0 - median)
[median - 1.0)
% False
Positive
0.5
5.2
0.0
0.0
6.2
17.0
0.7
0.8
9.5
17.4
0.0
0.0
5.1
21.5
0.2
1,1
6-367
-------
Table 6-181.
False Negative Results for First Standard Paint Readings
Control Corrected Without an Inconclusive Range Categorized
by Their Corresponding ICP Measurement Above and Below the
2.4891 mg/cm2 90th Percentile of the 1,290 ICP Measurements.
XRF
Lead Analyzer
K- shell
Lead Analyzer
L-shell
MAP-3
K- shell
MAP-3
L-shell
Microlead I
K- shell
X-Met 880
L-shell
XK-3
K-shell
XL
L-shell
Sample
Size
118
102
118
102
233
202
233
202
240
229
116
101
242
231
118
102
ICP Measurement Range
(mg/cms)
[1.0 - 90th %tile)
[90th %tile - oo)
[1.0 - 90th %tile)
[90th %tile - oo)
[1.0 - 90th %tile)
[90th %tile - oo)
[1.0 - 90th %tile)
[90th %tile - co)
[1.0 - 90th %tile)
[90th %tile - oo)
[1.0 - 90th %tile)
[90th %tile - oo)
[1.0 - 90th %tile)
[90th %tile - oo)
[1.0 - 90th %tile)
[90th %tile - oo)
% False
Negative
11.9
2.0
96.6
82.4
8.2
3.0
81.5
64.9
27.1
9.2
93.1
83.2
12.8
8.2
56.8
32.4
6-368
-------
Table 6-182.
Lead Analyzer K-shell by Substrate for the First Standard
Paint Reading Control Corrected Without an Inconclusive
Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
189
222
355
1,190
% False
Positive
1.4
1.6
1.8
2.1
0.5
4.7
2.3
% False
Negative
0.0
14 .8
naa
6.8
7.7
6.9
7.3
a Not available since drywall ICP measurements were all less than 1.0
rag/cm2 lead.
Table 6-183.
Lead Analyzer L-shell by Substrate for the First Standard
Paint Reading Control Corrected Without an Inconclusive
Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
189
222
355
1,190
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
90.5
96.3
naa
84.1
100.0
88.2
90.0
a Not available since drywall TCP measurements were all less than 1 . 0
mg/cm2 lead.
6-369
-------
Table G-184.
MAP-3 K-shell by Substrate for the First Standard Paint
Reading Control Corrected Without an Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
185
436
226
378
444
698
2,367
% False
Positive
7.7
9.7
3.1
12.1
12.2
12.0
10.2
% False
Negative
0.0
16.7
naa
1.1
11.5
4.5
5.7
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-185.
MAP-3 L-shell by Substrate for the First Standard Paint
Reading Control Corrected Without an Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
185
436
226
378
444
698
2,367
% False
Positive
0.0
0.0
0.0
5.2
0.0
0.0
0.8
% False
Negative
33.3
85.2
naa
62.5
100.0
77.4
73.8
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
6-370
-------
Table 6-186.
Microlead I by Substrate for the First Standard Paint
Reading Control Corrected Without an Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
186
444
237
406
463
739
2,475
% False
Positive
16.0
6.7
16.5
13.7
6.2
18.0
12.5
% False
Negative
2.4
28.6
naa
31.5
27.1
10.9
18.3
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
Table 6-187.
X-MET 880 by Substrate for the First Standard Paint Reading
Control Corrected Without an Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
175
222
353
1,174
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
90.5
96.3
naa
72.1
100.0
90.0
88.5
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
6-371
-------
Table 6-188.
XK-3 by Substrate for the First Standard Paint Reading
Control Corrected Without an Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
186
444
237
406
462
743
2,478
% False
Positive
9.0
24.2
0.8
9.2
13.9
6.2
11.3
% False
Negative
2.4
3.6
naa
20.7
13.6
8.9
10.6
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-189.
XL by Substrate for the First Standard Paint Reading Control
Corrected Without an Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
217
113
189
222
355
1,189
% False
Positive
0.0
0.5
0.9
0.7
0.0
0.8
0.5
% False
Negative
23.8
48.1
naa
31.8
69.2
49.0
45.5
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead .
6-372
-------
Table 6-190.
First Standard Paint Fully Corrected Reading Without an
Inconclusive Range.
XRF
Lead Analyzer
K- shell
Lead Analyzer
L-shell
MAP-3
K- shell
MAP-3
L-shell
Microlead I
K-shell
X-Met 880
L-shell
XK-3
K-shell
XL
L-shell
Sample
Size
1,190
1,190
2,366
2,366
2,475
1,174
2,478
1,187
% False
Positive
1.9
0.0
4.8
0.4
9.4
0.0
10.1
0.5
% False
Negative
6.8
86.8
10.8
78.4
10.0
88.9
9.9
43.4
6-373
-------
Table 6-191.
Lead Analyzer K-shell by Substrate for the First Standard
Paint Fully Corrected Reading Without an Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
189
222
355
1,190
% False
Positive
2.8
1.6
0.9
2.8
0.0
3.2
1.9
% False
Negative
0.0
7.4
naa
6.8
11.5
6.9
6.8
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
Table 6-192.
Lead Analyzer L-shell by Substrate for the First Standard
Paint Fully Corrected Reading Without an Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
189
222
355
1,190
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
85.7
96.3
naa
72.7
100.0
87.3
86.8
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead .
6-374
-------
Table 6-193.
MAP-3 K-shell by Substrate for the First Standard Paint
Fully Corrected Reading Without an Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
185
435
226
378
444
698
2,366
% False
Positive
2.8
8.4
1.3
5.5
4.1
4.2
4.8
% False
Negative
2.4
24.1
naa
2.3
23.1
9.5
10.8
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
Table 6-194.
MAP-3 L-shell by Substrate for the First Standard Paint
Fully Corrected Reading Without an Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
185
435
226
378
444
698
2,366
% False
Positive
0.0
0.5
0.0
1.0
0.5
0.2
0.4
% False
Negative
50.0
87.0
naa
64.8
100.0
'82.4
78.4
a Not available since drywall ICP. measurements were all less than 1.0
mg/cm2 lead.
6-375
-------
Table 6-195.
Microlead I by Substrate for the First Standard Paint Fully
Corrected Reading Without an Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
186
444
237
406
463
739
2,475
% False
Positive
11.8
15.2
1.7
10.5
8.9
7.7
9.4
% False
Negative
0.0
14.3
naa
8.7
8.5
11.8
10.0
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-196.
X-MET 880 by Substrate for the First Standard Paint Fully
Corrected Reading Without an Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
175
222
353
1,174
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
85.7
100.0
naa
76.7
100.0
89.0
88.9
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
6-376
-------
Table 6-197.
XK-3 by Substrate for the First Standard Paint Fully
Corrected Reading Without an Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
186
444
237
406
462
743
2,478
% False
Positive
10.4
16.2
2.1
11.1
12.4
6.6
10.1
% False
Negative
2.4
10.7
naa
16.3
8.5
8.9
9.9
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-198.
XL by Substrate for the First Standard Paint Fully Corrected
Reading Without an Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
216
113
188
222
355
1,187
% False
Positive
0.0
0.5
0.9
0.7
0.0
0.8
0.5
% False
Negative
23.8
51.9
naa
30.2
61.5
46.1
43 .4
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
6-377
-------
Table 6-199.
First Standard Paint Reading Red NIST Average Corrected
Without an Inconclusive Range.
XRF
Lead Analyzer
K- shell
' Lead Analyzer
L-shell
MAP-3
K- shell
MAP-3
L-shell
Microlead I
K-shell
X-Met 880
L-shell
XK-3
K-shell
XL
L-shell
Sample
Size
1,190
1,190
2,367
2,367
2,475
1,174
2,478
1,189
% False
Positive
1.9
0.0
4.6
0.3
9.1
0.0
10.6
0.5
% False
Negative
7.7
88.2
9.7
77.9
9.0
89.4
9.9
42.7
6-378
-------
Table 6-200.
Lead Analyzer K-shell by Substrate for the First Standard
Paint Reading Red NIST SRM Average Corrected Without an
Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
189
222
355
1,190
% False
Positive
2.8
1.0
1.8
1.4
0.5
3.6
1.9
% False
Negative
0.0
11.1
naa
9.1
3.8
8.8
7.7
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-201.
Lead Analyzer L-shell by Substrate for the First Standard
Paint Reading Red NIST SRM Average Corrected Without an
Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
189
222
355
1,190
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
85.7
96.3
naa
79.5
100.0
87.3
88.2
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
6-379
-------
Table 6-202.
MAP-3 K-shell by Substrate for the First Standard Paint
Reading Red NIST SRM Average Corrected Without an
Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
185
436
226
378
444
698
2,367
% False
Positive
2.1
6.5
2.2
4.8
3.1
6.0
4.6
% False
Negative
2.4
20.4
naa
1.1
21.2
9.0
9.7
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
Table 6-203.
MAP-3 L-shell by Substrate for the First Standard Paint
Reading Red NIST SRM Average Corrected Without an
Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
185
436
226
378
444
698
2,367
% False
Positive
0.0
0.0
0.0
2.1
0.0
0.0
0.3
% False
Negative
50.0
87.0
naa
63.6
100.0
81.9
77.9
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
6-380
-------
Table 6-204.
Microlead I by Substrate for the First Standard Paint
Reading Red NIST SRM Average Corrected Without an
Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
186
444
237
406
463
739
2,475
% False
Positive
12.5
12.1
2.5
8.9
8.7
9.2
9.1
% False
Negative
0.0
16.1
naa
5.4
8.5
10.5
9.0
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
Table 6-205.
X-MET 880 by Substrate for the First Standard Paint Reading
Red NIST SRM Average Corrected Without an Inconclusive
Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
175
222
353
1,174
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
85.7
96.3
naa
79.1
100.0
90.0
89.4
3 Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
6-381
-------
Table 6-206.
XK-3 by Substrate for the First Standard Paint Reading Red
NIST SRM Average Corrected Without an Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
186
444
237
406
462
743
2,478
% False
Positive
11.1
18.0
2.1
11.1
11.9
7.3
10.6
% False
Negative
2 .4
7.1
naa
18.5
13.6
7.6
9.9
• Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-207.
XL by Substrate for the First Standard Paint Reading Red
NIST SRM Average Corrected Without an Inconclusive Range.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
217
113
189
222
355
1,189
% False
Positive
0.0
0.5
0.9
0.7
0.0
0.8
0.5
% False
Negative
23.8
55.6
naa
27.3
69.2
43.1
42.7
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
6-382
-------
6.5.3 Impact of An Inconclusive Range With a 1.6 ma/cm2
Upper Bound and a 0.4 mg/cm2 Lower Bound
All of the error percentage tables given above were results
from classifying XRF measurements as negative or positive. This
section and the next section present results from classifying XRF
measurements as negative, positive, or inconclusive. In this
section, an XRF measurement was classified positive if the XRF
measurement was 1.6 mg/cm2 or greater, negative if the XRF
measurement was 0.4 mg/cm2 or less, and in the inconclusive range
if the XRF measurement was between 0 .4 and 1. 6 mg/cm2. As noted
above, an "XRF measurement" is a term used for general discussion
purposes. In each subsection below where a specific
classification analysis is discussed, the XRF measurement will be
defined as either a single reading, a single reading corrected
for substrate bias, an average of three readings, or an average
of three readings corrected for substrate bias.
€.5.3.1 First Standard Paint Readings With an (0.4 - 1.6
mg/cm2) Inconclusive Range
Table 6-208 shows overall error rates by instrument for the
first standard paint reading using the (0.4 - 1.6 mg/cm2)
inconclusive range. Tables 6-209 and 6-210 provide the same
information for four ICP measurement categories and Tables 6-211
through 6-218 provide the same information by substrate.
In Table 6-208, the Lead Analyzer K-shell had the lowest
false positive and false negative rates (0.5% and 1.4%,
respectively) for those instruments with both misclassification
rates (the false positive and false negative percentages) less
than 10%. The MAP-3 K-shell had both misclassification rates
under 4%. The Microlead I also had low misclassification rates
with a 7.5% false positive rate and a 1.1% false negative rate.
The XL had a somewhat higher false negative rate (11.4%) and a
very low false positive rate (0.1%). All other instruments had
at least one misclassification rate greater than 20% ranging from
the 21.8% false positive rate for the XK-3 to the 66.4% false
negative rate from the X-MET 880.
Comparisons of Table 6-208 to Table 6-158 shows that the
addition of the inconclusive range substantially reduces the
error percentages in all cases. However, the Lead Analyzer
L-shell, the MAP-3 L-shell, the X-MET 880, and the XK-3
instruments still had at least one error rate greater than 20%.
Two XRF instruments had inconclusive percentages less than 10%:
the Lead Analyzer L-shell and the X-MET 880, but, both of these
6-383
-------
instruments had false negative rates greater than 65%.
Furthermore, Table 6-217 shows that XK-3 instrument's results on
concrete, metal, and plaster substrates had false positive rates
greater than 26%.
Tables 6-209 and 6-210 show the same information as Table
6-208 but for four categories of ICP measurements and Figures
6-92 through 6-99 graphically illustrates the same information.
These two tables indicate where the misclassification errors are
occurring relative to the ICP measurement. Tables 6-209 and
6-210 are analogous to Tables 6-159 and 6-160 with the addition
of the inconclusive range. Tables 6-209 and 6-210 show
differences between K-shell instruments and L-shell instruments
by comparing the percent in the inconclusive range. In Table
6-209, the inconclusive percentages for the L-shell instruments
were all five percent or less except for the XL which had 10.5%
of its first standard paint readings in the higher ICP range
classified as inconclusive. This is in contrast to the K-shell
instruments that had inconclusive rates greater than 35% in the
ICP measurement category bounded by the ICP measurement median
and 1.0 mg/cm2 lead. Figures 6-92 through 6-99 clearly
illustrate this difference. For example, in the bottom two bars,
the L-shell instruments a greater percentage of inconclusive and
disagree results than did the K-shell instruments.
6.5.3.2 Average of Three Standard XRF Readings With an
(0.4 - 1.6 mg/cm2) Inconclusive Range
Table 6-219 shows overall error rates by instrument for the
average of three first standard paint readings using the {0.4 -
1.6 mg/cm2) inconclusive range. Comparisons of Table 6-219 and
Table 6-208 show that for the K-shell instruments the error
percentages (false positive and false negative) are the same in
two cases and slightly smaller for the average in six cases. The
error percentages for the L-shell instruments are the same in six
cases, while the average is slightly smaller the remaining two
cases. In no case, either for K- or L-shell instruments, does
the average represent a significant improvement over the first
standard paint reading. In particular, in cases where the error
rate was high, the false negative for the L-shell instruments and
false positive for the XK-3, only very minimal improvement
occurred by use of the average of three readings.
Tables 6-211 through 6-218 break down the results for the
first standard paint reading by substrate. Tables 6-220 through
6-227 are the companion tables for the average of three readings.
For the four K-shell instruments, there are a total of 44 error
6-384
-------
percentages when broken down by substrate. In 22 cases, the
error percentages for the average are smaller, in 20 cases there
is no difference between the average and the first standard paint
reading error percentages, and in two cases the error percentages
are higher for the average. For the L-shell instruments, 35
cases are the same, four cases show the average as lower, and
five cases show the average as higher. In no case was any
improvement of the average over the first standard paint reading
very great. For example, there are 24 error rates exceeding 10%;
of these, only four were reduced below 10% by use of the average,
and all of the improvements were small. For the MAP-3, 11.1 %
and 11.5% false negative rates on concrete and plaster for the
first standard paint reading were reduced to 9.3% and 9.6%. On
wood, an XL false negative rate of 13.7% was reduced to 7.8% and
a Microlead I false positive rate of 12.3 was reduced to 10.4%.
The conclusion from examining these classification results
is the same as given above. That is, although use of the average
of three 15-second readings may result in a more accurate
classification of paint than use of only a single reading, the
improvement is usually minimal and not of practical significance.
Thus, it appears that the additional effort involved in taking
three 15-second readings at a sampling location versus only one
is not justified by an increase the accuracy of classification of
paint.
6.5.3.3 Standard XRF Readings Control Corrected With an
(0.4 - 1.6 mg/cm2) Inconclusive Range
The first standard paint reading was "control corrected" by
subtracting the average of the initial and ending red NIST SRM
control block readings in the dwelling, minus 1.02 mg/cm2. Table
6-228 shows overall error rates by instrument for the first
standard paint control corrected readings using the (0.4 - 1.6
mg/cm2) inconclusive range. This table should be compared to
Table 6-208, which shows the same information for the first
standard paint [uncorrected] reading. For the MAP-3 K-shell and
the Lead Analyzer K-shell, both error rates were low before and
after correction, so the procedure again had little impact. For
the XK-3, control correction reduces the false positive rate from
21.8% to 3.5% with only a small increase in the false negative
rate, from 1.1% to 4.0%. For the Microlead I, the false positive
rate was decreased from 7.5% to 4.9%, but at the expense of an
increase in the false negative rate from 1.1% to 12.4%. The
performance of the XK-3 was improved by control correction, while
that of the Microlead I was worsened by control correction. The
L-shell instruments showed no improvement. Overall, then,
6-385
-------
control correction did not improve the performance of L-shell
instruments. Thus, the impact of control correction appears to
be instrument-specific, so that no general recommendation on its
use can be made.
Tables 6-229 and 6-230 provide the same information by ICP
measurement category. Tables 6-209 and 6-210 are the companion
tables for the first standard [uncorrected] reading with a (0.4 -
1.6 mg/cm2) inconclusive range.
Tables 6-231 through 6-238 break down the control corrected
error rates by substrate for the eight instruments, and are to be
compared to Tables 6-211 through 6-218 for the first standard
paint [uncorrected] reading. For the L-shell instruments, the
same picture emerges as from the overall data. False negative
rates by substrate remain high after correction. In the case of
the XL, correction has a substantial negative impact on concrete.
For the Lead Analyzer K-shell, error rates by substrate were low
without correction and remain so after correction, confirming
that the procedure has little impact. For the MAP-3 K-shell,
false positive rates by substrate were generally increased
slightly with a corresponding decrease in false negative rate.
However, the false negative rates for concrete and plaster shown
in Table 6-213 were above 10% before correction {11.1% and
11.5%), and were reduced by correction (to 7.4% and 5.8%) as
shown in Table 6-233. Thus, on an individual substrate basis,
control correction has merit for the MAP-3 K-shell. For the
XK-3, four of the substrates have high false positive rates which
were dramatically reduced by control correction. However, the
false negative rate on metal was increased sharply, from 0 to
15.2%. Thus, on a substrate-specific basis, control correction
usually improves accuracy for the XK-3, but not always. For the
Microlead I, metal and plaster have very high false negative
rates after control correction, which outweighs the modest
reductions in false positive rates. Thus, substrate-specific
analyses generally confirm the overall results, except that some
positive impact of control correction for the MAP-3 K-shell was
indicated, while the approach appears somewhat less effective for
the XK-3 than indicated by the overall data.
6.5.3.4 Standard XRF Readings Fully Corrected With an (0.4
- 1.6 mg/cm2) Inconclusive Range
For this analysis, the first standard paint reading was
"fully corrected" by subtracting the average of the three
standard red NIST SRM readings taken from the same sampling
location, minus 1.02 mg/cm2. Table 6-239 shows overall error
6-386
-------
rates by instrument for the first standard paint fully corrected
readings using the (0.4 - 1.6 mg/cm2) inconclusive range. This
table should be compared to Table 6-208, which shows the same
information for the first standard paint [uncorrected] reading.
Tables 6-240 through 6-247 provide the same information by
substrate category. Tables 6-211 through 6-218 are the companion
tables for the first standard [uncorrected] reading with a (0.4 -
1.6 mg/cm2) inconclusive range. Full correction was effective in
reducing error rates the Microlead I and the XK-3 and on wood and
metal substrates for the MAP-3«
6.5.3.5 Standard XRF Readings Red NIST SRM Average
Corrected With, an {0.4 - 1.6 mg/cm2) Inconclusive
Range
The first standard paint reading was "red NIST SRM average
corrected" by subtracting the corresponding substrate average of
all red NIST SRM reading taken at each sampling location in the
dwelling, minus 1.02 mg/cm2. Table 6-248 shows overall error
rates by instrument. Tables 6-249 through 6-256 break down the
information by substrate. This method of correction provided
results similar to full correction.
.2
6.5.4 Impact of An Inconclusive Range With a 1.3 mq/cm
Upper Bound and a 0.7 ma/cm2 Lower Bound
In this section, an alternative inconclusive range was used
to classify the XRF readings as negative, positive, or
inconclusive. The previous section defined the inconclusive
range as having a 1.6 mg/cm2 upper bound and a 0.4 mg/cm2 lower
bound. This section defines the inconclusive range as having a
1.3 mg/cm2 upper bound and a 0.7 mg/cm2 lower bound, and will be
referred to as the alternate inconclusive range. The impact of
the alternate inconclusive range can be assessed by comparing the
results in this section to the results presented in the previous
section.
6-387
-------
Table 6-208.
First Standard Paint Reading With an Inconclusive Range
Bounded by 0.4 mg/cm2 and 1.6 mg/cm2.
XRF
Lead Analyzer
K- shell
Lead Analyzer
L-shell
MAP-3
K- shell
MAP-3
L-shell
Microlead I
K-shell
X-Met 880
L-shell
XK-3
K-shell
XL
L-shell
Sample
Size
1,190
1,190
2,367
2,367
2,475
1,174
2,478
1,189
% False
Positive
0.5
0.0
2.3
0.0
7.5
0.0
21.8
0.1
% False
Negative
1.4
65.5
3.7
36.8
1.1
66.4
1.1
11.4
%
Inconc lus i ve
18.1
6.1
23.4
12.2
30.3
6.8
35.1
15.3
6-388
-------
Table 6-209.
False Positive Results for First Standard Paint Readings
With an Inconclusive Range Bounded by 0.4 mg/cm2 and 1.6
mg/cm2, Categorized by Their Corresponding ICP Measurement
Above and Below the 0.19S4 mg/cm2 Median of the 1,290 ICP
Measurements.
XRF
Lead Analyzer
K-shell
Lead Analyzer
L-shell
MAP-3
K-shell
MAP-3
L-shell
Microlead I
K-shell
X-Met 880
L-shell
XK-3
K-shell
XL
L-shell
Sample
Size
608
362
608
362
1,209
783
1,209
723
1,252
754
596
361
1,251
754
607
362
JCP Measurement Range
{mg/cm2)
[0 - median)
[median - 1.0)
[0 - median)
[median - 1.0)
[0 - median)
[median - 1.0)
[0 - median)
[median - 1.0)
[ 0 - median)
[median - 1.0)
[0 - median)
[median - 1.0)
[0 - median)
[median - 1.0)
[0 - median)
[median - 1.0)
% False
Positive
0.2
1.1
0.0
0.0
1.6
3.5
0.0
0.0
5.6
10.7
0.0
0.0
9.9
41.5
0.0
0.3
%
Inconclusive
4.6
40.3
0.3
1.4
19.3
37.1
4.1
4.4
28.4
45.0
1.5
3.0
39.9
42.7
3.0
10.5
6-389
-------
Table 6-210.
False Negative Results for First Standard Paint Readings
With an Inconclusive Range Bounded by 0.4 mg/cm2 and 1.6
mg/cm2 Categorized by Their Corresponding ICP Measurement
Above and Below the 2.4891 mg/cm2 90th Percentile of the
1,290 ICP Measurements.
XRF
Lead Analyzer
K- shell
Lead Analyzer
L- shell
MAP-3
K- shell
MAP-3
L- shell
Microlead I
K- shell
X-Met 880
L- shell
XK-3
K- shell
XL
L- shell
Sample
Size
118
102
118
102
233
202
233
202
240
229
116
101
242
231
118
102
ICP Measurement Range
(mg/cm2)
[1.0 - 90th %tile)
[90th %tile - »)
[1.0 - 90th %tile)
[90th %tile - oo)
[1.0 - 90th %tile)
[90th %tile - oo)
[1.0 - 90th %tile)
[90th fctile - o>)
[1.0 - 90th %tile)
[90th %tile - oo)
[1.0 - 90th %tile)
[90th %tile - oo)
[1.0 - 90th %tile)
[90th %tile - oo)
[1.0 - 90th %tile)
[90th %tile - oo)
% False
Negative
1,7
1.0
69.5
60.8
4.7
2.5
44 .6
27.7
2.1
0.0
68.1
64.4
2.1
0.0
13.6
8.8
%
Inconclusive
33.9
1.0
30.5
28.4
21.5
2.0
47.2
48. 5
22.1
1.3
31.0
23.8
13.6
6.9
69.5
43.1
6-390
-------
LEAD ANALYZER K-SHELL CLASSIFICATIONS
ICP
high neg
1ow neg
1ow pos
high pos
O
XRF
high
low
1 1
T 1—t 1 . 1 . , . 1 1 1 r
22 33
PERCENT
FREQ .
6O8
362
1 IS
1O2
PCT .
5 1 . O9
30 ,42
9 . 92
8 , 57
44
55
H Agree
Di sagree
ICP Categories
KXXXXXXX Inconclusive
= t;O, median}
= Cl,O mg/cm2
9Oth 95tile5
low neg = [ med i an , l.O mg/cm2}
high pos = [9Oth 96 1 ± 1 e , ~^
Figure 6-92. Bar chart of classifications by laboratory ICP categories for Lead
Analyzer K-shell, with an inconclusive range bounded by 0 . 4 mg/cm2 and 1.6
mg/cm2.
6-391
-------
LEAD ANALYZER L-SHELL CLASSIFICATIONS
TCP
high neg
low neg
low pos
high pos
O
XRF
11
1 i •
22
FREQ .
6O8
362
1 18
1O2
PCT .
5 1 . O9
30 .42
9 . 92
8 . 57
55
PERCENT
J Agree
Di sagree
ICP Categories
fcxxxxxxx Inconclusive
high neg=QO, median}
low
mg/ctn
9Oth
low neg=[median, 1.O mg/cm2)
high pos = [9Oth 96tile, <~}
Figure 6-93.
Bar chart of classifications by laboratory ICP categories for Lead
Analyzer L-shell, with an inconclusive range bounded by 0.4 mg/cm2 and 1.6
mg/cm2.
6-392
-------
ICP
high neg
low nee
1ow pos
high pos
O
XRF
MAP-3 K-SHELL CLASSIFICATIONS
T
T
FREQ .
12O9
723
233
2O2
PCT .
51 . OS
30 .54
9 . 84
8 .53
1 1
22 33
PERCENT
55
J Agree
Di sagree
KXXXXXXfl Inconclusive
ICP Categories
high neg=[0, median} low neg=[median, l.O rng/cm2}
low pos=[l.O mg/cmz, 9Oth 96tile} high pos = C9Oth 95tile, ~5
Figure 6-94. Bar chart of classifications by laboratory ICP categories for MAP-3 K-
shell, with an inconclusive range bounded by 0.4 mg/cm2 and 1.6 mg/cm2.
6-393
-------
ICP
high neg
low neg
low pos
high pos
O
XRF
MAP-3 L-SHELL CLASSIFICATIONS
FREQ.
12O9
723
233
202
PCT .
51 .08
30 .54
9 . 84
8 .53
1 1
22 33
PERCENT
44
55
J Agree
Di sagree
ICP Categories
Inconclusive
high neg=QO, median)
low pos=[l.O mg/cm2, 9Oth 9Stile)
low neg = (] medi an , 1 . O mg/cm2}
high pos = [9Oth 95tile, ~5
Figure 6-95. Bar chart of classifications by laboratory ICP categories for MAP-3
L-shell, with an inconclusive range bounded by 0.4 mg/cm2 and 1.6 mg/cm2.
6-394
-------
MIGROLEAD I K-SHELL CLASSIFICATIONS
ICP
high neg
1ow neg
low pos
high pos
O
XRF
T
T
1 1
22 33
PERCENT
1 i '
44
FREQ .
1252
754
24O
229
55
PCT .
5O ,59
3O . 46
9 . 7O
9 .25
II Agree
high neg=QO, median)
low pos=£l.O
ICP Categories
Inconclusive
low neg = Qniedian, l.O
high pos = [9Oth 96t i 1 e ,
Figure 6-96. Bar chart of classifications by laboratory ICP categories for Microlead
I, with an inconclusive range bounded by 0.4 mg/cm2 and 1.6 mg/cm2.
6-395
-------
X-MET 880 L-SHELL CLASSIFICATIONS
1CP
XRF
22 33
PERCENT
FREQ .
596
361
116
101
55
PCT .
50 . 77
3O . 75
9 . 88
8 . 6O
D Agree
Di sagree
ICP Categories
Inconclusive
high neg=EO, median)
low pos = [l.O mg/cm2 , 9Oth 961 i 1 e
low neg = Q medi an , l.O mg/cin2)
high pos = [9Oth 9Stile, o»)
Figure 6-97. Bar chart of classifications by laboratory ICP categories for X-MET 880,
with an inconclusive range bounded by 0.4 mg/cm2 and 1.6 mg/cm2.
6-396
-------
TCP
o
XRF
XK-3 K-SHELL CLASSIFICATIONS
~T
1 1
J Agree
FREQ .
PCT .
SO .48
3O .43
9.77
9 , 32
22 33
PERCENT
44
55
Di sagree
IGP Categories
high neg = r.O, median}
low pos = Cl.O mg/cffl2, 9Oth
i 1 e
low
high
KKXXXXXH Inconclusive
t]median, l.O mg/cin2}
95-tile, «>}
Figure 6-98. Bar chart of classifications by laboratory ICP categories for XK-3, with
an inconclusive range bounded by 0.4 mg/cm2 and 1.6 mg/cm2.
6-397
-------
IGP
high neg
low neg
low pos
high pos
O
XRF
XL L-SHELL CLASSIFICATIONS
1—I—>
11
~T
T
22 33
PERCENT
J Agree
high neg=QO, median)
low pos = Cl.O mg/cm2
Di sagree
ICP Categories
low
9Oth 95tile) high
FREQ .
6O7
362
1 18
1O2
PCT .
51 . OS
3O .45
9 . 92
8 . 58
44
55
KXXXXXXX Inconclusive
Qmedian, l.O ing/ cm
[I9Oth «tile, =0)
Figure 6-99. Bar chart of classifications by laboratory ICP categories for XL, with an
inconclusive range bounded by 0.4 mg/cm2 and 1.6 mg/cm2.
6-398
-------
Table 6-211.
Lead Analyzer K-shell by Substrate for the First Standard
Paint Reading With an Inconclusive Range Bounded by 0.4
mg/cm2 and 1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
189
222
355
1,190
% False
Positive
0.0
1.1
0.0
0.0
0.5
0.8
0.5
% False
Negative
0.0
0.0
naa
0.0
0.0
2.9
1.4
%
Inconclusive
16.1
17.4
9.8
25.4
14.4
20.0
18.1
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
Table 6-212.
Lead Analyzer L-shell by Substrate for the First Standard
Paint Reading With an Inconclusive Range Bounded by 0.4
mg/cm2 and 1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
189
222
355
1,190
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
38.1
88.9
naa
54.5
88.5
63.7
65.5
%
Inconclusive
11.8
1.4
0.0
10.1
1.4
10.1
6.1
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
6-399
-------
Table 6-213.
MAP-3 K-shell by Substrate for the First Standard Paint
Reading With an Inconclusive Range Bounded by 0.4 mg/cm2 and
1. 6 mg/cm2.
S libs tr ate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
185
436
226
378
444
698
2,367
% False
Positive
0.7
2.6
1.3
1.7
1.3
4.0
2.3
% False
Negative
0.0
11.1
naa
1.1
11.5
1.5
3.7
%
Inconclusive
14.6
15.1
21.7
48.4
14.2
23.9
23.4
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
Table 6-214.
MAP-3 L-shell by Substrate for the First Standard Paint
Reading With an Inconclusive Range Bounded by 0.4 mg/cm2 and
1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
185
436
226
378
444
698
2,367
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
19.0
38.9
naa
38.6
71.2
30.2
36.8
%
Inconclusive
16.8
6.4
1.8
21.4
3.6
18.5
12.2
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
6-400
-------
Table 6-215.
Microlead I by Substrate for the First Standard Paint
Reading With an Inconclusive Range Bounded by 0.4 mg/cm2 and
1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
186
444
237
406
463
739
2,475
% False
Positive
3.5
9.8
5.1
8.3
1.5
12.3
7.5
% False
Negative
0.0
1.8
naa
1.1
1.7
0.9
1.1
%
Inconclusive
32.3
38.7
32.5
25.9
30.7
26.4
30.3
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
Table 6-216.
X-Met 880 by Substrate for the First Standard Paint Reading
With an Inconclusive Range Bounded by 0.4 mg/cm2 and 1.6
mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
175
222
353
1,174
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
61.9
77.8
naa
55.8
92.3
62.0
66.4
%
Inconc lus i ve
8.6
2.8
0.0
15.4
0.9
10.5
6.8
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
6-401
-------
Table 6-217.
XK-3 by Substrate for the First Standard Paint Reading With
an Inconclusive Range Bounded by 0.4 mg/cm2 and 1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
186
444
237
406
462
743
2,478
% False
Positive
19.4
44.8
0.4
31.2
26.6
5.6
21.8
% False
Negative
2.4
0.0
naa
0.0
1.7
1.3
1.1
%
Inconclusive
49.5
38.7
18.6
44.8
40.0
26.2
35.1
a Not available since drywall ICP measurements were all less than l.O
mg/cm2 lead.
Table 6-218.
XL by Substrate for the First Standard Paint Reading With an
Inconclusive Range Bounded by 0.4 mg/cm2 and 1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
217
113
189
222
355
1,189
% False
Positive
0.0
0.0
0.0
0.7
0.0
0.0
0.1
% False
Negative
9.5
7.4
naa
9.1
11.5
13.7
11.4
%
Inconclusive
9.7
13.4
6.2
15.3
11.3
23.4
15.3
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
6-402
-------
Table 6-219.
Standard Paint Average With an Inconclusive Range Bounded by
0.4 mg/cm2 and 1.6 mg/cm2.
XRF
Lead Analyzer
K-shell
Lead Analyzer
L- shell
MAP-3
K-shell
MAP-3
L-shell
Microlead I
K-shell
X-Met 880
L-shell
XK-3
K-shell
XL
L-shell
Sample
Size
1,190
1,190
2,367
2,367
2,475
1,174
2,478
1,189
% False
Positive
0.5
0.0
1.5
0.0
6.2
0.0
21.1
0.1
% False
Negative
0.9
65.5
3.0
37.7
0.2
66.4
1.1
9.1
%
Inconclusive
19.2
6.2
20.0
12.0
36.0
6.6
37.4
16.6
6-403
-------
Table 6-220.
Lead Analyzer K-shell by Substrate for the Standard Paint
Average With an Inconclusive Range Bounded by 0.4 mg/cm2 and
1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
189
222
355
1,190
% False
Positive
0.0
1.0
0.0
0.0
0.5
0.8
0.5
% False
Negative
0.0
0.0
naa
0.0
0.0
2.0
0.9
%
Inconclusive
14.0
19.3
9.7
29.1
16.7
19.7
19.2
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-221.
Lead Analyzer L-shell by Substrate for the Standard Paint
Average With an Inconclusive Range Bounded by 0.4 mg/cm2 and
1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
189
222
355
1,190
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
38.1
85.2
naa
54.5
88.5
64.7
65.5
%
Inconclusive
11.8
1.8
0.0
10.1
1.8
10.1
6.2
* Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
6-404
-------
Table 6-222.
MAP-3 K-shell by Substrate for the Standard Paint Average
With an Inconclusive Range Bounded by 0.4 rag/cm2 and 1.6
ing/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
185
436
226
378
444
698
2,367
% False
Positive
0.7
1.1
0.9
1.4
0.5
3.2
1.5
% False
Negative
0.0
9.3
naa
1.1
9.6
1.0
3.0
%
Inconc lus i ve
7.6
9.4
15.9
52.9
11.0
19.1
20.0
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-223.
MAP-3 L-shell by Substrate for the Standard Paint Average
With an Inconclusive Range Bounded by 0.4 mg/cm2 and 1.6
mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
185
436
226
378
444
698
2,367
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
19.1
46.3
naa
38.6
73.1
29.7
37.7
%
Inconclusive
16.8
5.7
1.3
21.2
3.7
18.9
12.0
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
6-405
-------
Table 6-224.
Microlead I by Substrate for the Standard Paint Average With
an Inconclusive Range Bounded by 0.4 mg/cm2 and 1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
185
444
237
406
463
739
2,475
% False
Positive
3.5
5.7
6.8
6.7
1.5
10.4
6.2
% False
Negative
0.0
0.0
naa
0.0
0.0
0.5
0.2
%
Inconclusive
36.6
48.9
34.2
30.8
35.9
31.8
36.0
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-225.
X-Met 880 by Substrate for the Standard Paint Average With
an Inconclusive Range Bounded by 0.4 mg/cm2 and 1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
175
222
353
1,174
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
61.9
77.8
naa
55.8
92.3
62.0
66.4
%
Inconc lus i ve
8.6
2.8
0.0
14.9
0.9
9.9
6.6
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
6-406
-------
Table 6-226.
XK-3 by Substrate for the Standard Paint Average With an
Inconclusive Range Bounded by 0.4 mg/cm2 and 1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
186
444
237
406
462
745
2,478
% False
Positive
16.8
46.7
0.0
27.7
25.3
5.0
21.1
% False
Negative
2.4
0.0
naa
0.0
1.7
1.3
1.1
%
Inconclus i ve
57.0
41.2
17.7
47.5
44.2
26.9
37.4
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
Table 6-227.
XL by Substrate for the Standard Paint Average With an
Inconclusive Range Bounded by 0.4 mg/cm2 and 1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
217
113
189
222
355
1,189
% False
Positive
0.0
0.0
0.0
0.7
0.0
0.0
0.1
% False
Negative
4.8
7.4
naa
9.1
19.2
7.8
9.1
%
Inconclus i ve
14.0
12.4
6.2
18.0
10.4
26.2
16.6
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
6-407
-------
Table 6-228.
First Standard Paint Control Corrected With an Inconclusive
Range Bounded by 0.4 mg/cm2 and 1.6 mg/cm2.
XRF
Lead Analyzer
K- shell
Lead Analyzer
L- shell
MAP-3
K- shell
MAP-3
L- shell
Microlead I
K- shell
X-Met 880
L- shell
XK-3
K- shell
XL
L- shell
Sample
Size
1,190
1,190
2,367
2,367
2,475
1,174
2,478
1,189
% False
Positive
0.4
0.0
2.8
0.0
4.9
0.0
3.5
0.1
% False
Negative
1.8
68.6
2.3
45.5
12.4
71.4
4.0
11.8
%
Inconclusive
18.1
5.1
27.3
9.7
24.0
5.0
25.1
15.7
6-408
-------
Table 6-229.
False Positive Results for First Standard Paint Readings
Control Corrected With an Inconclusive Range Bounded by 0.4
rag/cm2 and 1.6 mg/cm2, Categorized by Their Corresponding
ICP Measurement Above and Below the 0.1964 mg/cm2 Median of
the 1,290 ICP Measurements.
XRF
Lead Analyzer
K-shell
Lead Analyzer
L- shell
MAP-3
K-shell
MAP-3
L-shell
Microlead I
K-shell
X-Met 880
L-shell
XK-3
K-shell
XL
L-shell
Sample
Size
608
362
608
362
1,209
723
1,209
723
1,252
753
596
361
1,253
754
608
362
ICP Measurement Range
(mg/cm2)
[0 - median)
[median - 1.0)
[0 - median)
[median - 1.0)
[0 - median)
[median - 1.0)
[0 - median)
[median - 1.0)
[0 - median)
[median - 1.0)
[0 - median)
[median - 1.0)
[0 - median)
[median - 1.0)
[0 - median)
[median - 1.0)
% False
Positive
0.0
1.1
0.0
0.0
2.1
4.1
0.0
0.0
3.8
6.8
0.0
0.0
1.6
6.8
0.0
0.3
%
Inconclusive
4.1
40.3
0.0
0.8
22.7
44.0
3.1
2.1
22.9
31.9
0.5
1.9
15.2
46.2
2.8
11.9
6-409
-------
Table 6-230.
False Negative Results for First Standard Paint Readings
Control Corrected With an Inconclusive Range Bounded by 0.4
mg/cm2 and 1.6 mg/cm2 Categorized by Their Corresponding ICP
Measurement Above and Below the 2.4891 mg/cra2 90th Percentile
of the 1,290 ICP Measurements.
XRF
Lead Analyzer
K-shell
Lead Analyzer
L- shell
MAP-3
K-shell
MAP-3
L-shell
Microlead I
K-shell
X-Met 880
L-shell
XK-3
K-shell
XL
L-shell
Sample
Size
118
102
118
102
233
202
233
202
240
229
116
101
242
231
118
102
ICP Measurement Range
(mg/cm2)
[1.0 - 90th %tile)
[90th %tile - oo)
[1.0 - 90th %tile)
[90th %tile - oo)
[1.0 - 90th %tile)
[90th %tile - oo)
[1.0 - 90th %tile)
[90th %tile - co)
[1.0 - 90th %tile)
[90th %tile - CD)
[1.0 - 90th %tile)
[90th %tile - oo)
[1.0 - 90th %tile)
[90th %tile - oo)
[1.0 - 90th %tile)
[90th %tile - oo)
% False
Negative
1.7
2.0
72.9
63.7
2.6
2.0
52.4
37.6
17.5
7.0
73.3
69.3
2.9
5.2
15.3
7.8
%
Inconclusive
36.4
1.0
27.1
25.5
20.6
3.0
41.2
40.1
25.4
3.1
25.9
18.8
31.8
3.5
69.5
44.1
6-410
-------
Table 6-231.
Lead Analyzer K-shell by Substrate for the First Standard
Paint Control Corrected Reading With an Inconclusive Range
Bounded by 0.4 mg/cm2 and 1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
189
222
355
1,190
% False
Positive
0.0
1.0
0.0
0.0
0.0
0.8
0.4
% False
Negative
0.0
3.7
naa
0.0
0.0
2.9
1.8
%
Inconclusive
5.4
18.8
8.0
27.0
17.6
19.7
18.1
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-232.
Lead Analyzer L-shell by Substrate for the First Standard
Paint Control Corrected Reading With an Inconclusive Range
Bounded by 0.4 mg/cm2 and 1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
189
222
355
1,190
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
33.3
88.9
naa
56.8
92.3
69.6
68.6
%
Inconclusive
12.9
1.4
0.0
9.0
0.9
7.6
5.1
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
6-411
-------
Table 6-233.
MAP-3 K-shell by Substrate for the First Standard Paint
Control Corrected Reading With an Inconclusive Range Bounded
by 0.4 mg/cm2 and 1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
185
436
226
378
444
698
2,367
% False
Positive
1.4
3.7
1.3
1.4
1.8
5.0
2.8
% False
Negative
0.0
7.4
naa
1.1
5.8
1.0
2.3
%
Xnconc lus i ve
18.4
21.1
20.4
40.5
27.3
28.8
27.3
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-234.
MAP-3 L-shell by Substrate for the First Standard Paint
Control Corrected Reading With an Inconclusive Range Bounded
by 0 .4 mg/cm2 and 1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
185
436
226
378
444
698
2,367
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
19.0
57.4
naa
40.9
96.2
36.7
45.5
%
Inconc lus i ve
14.1
4.4
0.4
19.3
0.5
15.6
9.7
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
6-412
-------
Table 6-235.
Microlead I by Substrate for the First Standard Paint
Control Corrected Reading With an Inconclusive Range Bounded
by 0.4 mg/cm2 and 1. 6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
186
444
237
406
463
739
2,475
% False
Positive
2.1
2.1
6.0
6.4
2.5
8.3
4.9
% False
Negative
0.0
8.9
naa
29.3
16.9
7.3
12.4
%
Inconclusive
27.4
17.1
43.0
27.1
18.4
23.1
24.0
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
Table 6-236.
X-Met 880 by Substrate for the First Standard Paint Control
Corrected Reading With an Inconclusive Range Bounded by 0.4
mg/cm2 and 1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
175
222
353
1,174
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
61.9
88.9
naa
55.8
96.2
69.0
71.4
%
Inconclusive
6.5
1.4
0.0
12.6
0.5
7.6
5.0
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
6-413
-------
Table 6-237.
XK-3 by Substrate for the First Standard Paint Control
Corrected Reading With an Inconclusive Range Bounded by 0.4
mg/cm2 and 1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
186
444
237
406
462
743
2,478
% False
Positive
1.4
9.0
0.0
3.2
3.5
1.9
3.5
% False
Negative
2.4
0.0
naa
15.2
1.7
1.3
4.0
%
Inconclusive
19.4
43.7
8.0
19.2
33.1
19.2
25.1
a Not available since drywall ICP measurements were all less than l . 0
mg/cm2 lead.
Table 6-238.
XL by Substrate for the First Standard Paint Control
Corrected Reading With an Inconclusive Range Bounded by 0.4
mg/cm2 and 1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
217
113
189
222
355
1,189
% False
Positive
0.0
0.0
0.0
0.7
0.0
0.0
0.1
% False
Negative
9.5
14.8
naa
9.1
11.5
12.7
11.8
%
Inconclusive
9.7
12.9
7.1
15.3
10.8
25.1
15.7
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
6-414
-------
Table 6-239.
First Standard Paint Fully Corrected With an Inconclusive
Range Bounded by 0.4 mg/cm2 and 1.6 mg/cm2.
XRF
Lead Analyzer
K- shell
Lead Analyzer
L-shell
MAP-3
K- shell
MAP-3
L-shell
Microlead I
K-shell
X-Met 880
L-shell
XK-3
K-shell
XL
L-shell
Sample
Size
1,190
1,190
2,366
2,366
2,475
1,174
2,478
1,187
% False
Positive
0.2
0.0
1.6
0.0
2.1
0.0
2.2
0.1
% False
Negative
2.3
61.4
4.6
54.0
1.9
71.9
4.7
10.0
%
Inconclusive
19.3
6.8
19.7
8.2
30.3
4.9
27.6
18.7
6-415
-------
Table 6-240.
Lead Analyzer K-shell by Substrate for First Standard Paint
Fully Corrected Reading With an Inconclusive Range Bounded
by 0.4 mg/cm2 and 1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
189
222
355
1,190
% False
Positive
0.0
1.0
0.0
0.0
0.0
0.0
0.2
% False
Negative
0.0
3.7
naa
4.5
0.0
2.0
2.3
%
Inconclusive
12.9
17.9
8.0
29.1
20.7
19.4
19.3
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-241.
Lead Analyzer L-shell by Substrate for First Standard Paint
Fully Corrected Reading With an Inconclusive Range Bounded
by 0.4 mg/cm2 and 1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
189
222
355
1,190
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
38.1
81.5
naa
40.9
88.5
62.8
61.4
%
Inconclusive
11.8
2.3
0.0
13.8
1.4
10.1
6.8
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
6-416
-------
Table 6-242.
MAP-3 K-shell by Substrate for First Standard Paint Fully
Corrected Reading With an Inconclusive Range Bounded by 0.4
mg/cm2 and 1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
185
435
226
378
444
698
2,366
% False
Positive
1.4
4.5
0.9
0.7
1.3
0.6
1.6
% False
Negative
0.0
13.0
naa
1.1
11.5
3.0
4.6
%
Inconclus ive
7.0
16.3
15.0
31.2
17.3
22.1
19.7
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-243.
MAP-3 L-shell by Substrate for First Standard Paint Fully
Corrected Reading With an Inconclusive Range Bounded by 0.4
mg/cm2 and 1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
185
435
226
378
444
698
2,366
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
28.8
63.0
naa
44.3
90.4
51.8
54.0
%
Inconclusive
13.0
4.6
0.0
17.2
1.8
11.0
8.2
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
6-417
-------
Table 6-244.
Microlead I by Substrate for First Standard Paint Fully
Corrected Reading With an Inconclusive Range Bounded by 0.4
mg/cm2 and 1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
186
444
237
406
463
739
2,475
% False
Positive
2.8
4.4
0.0
3.2
0.5
1.9
2.1
% False
Negative
0.0
1.8
naa
2.2
3.4
1.8
1.9
%
Inconc lus i ve
27.4
36.7
18.1
28.8
38.0
27.1
30.3
* Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead .
Table 6-245.
X-Met 880 by Substrate for First Standard Paint Fully
Corrected Reading With an Inconclusive Range Bounded by 0.4
mg/cm2 and 1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
175
222
353
1,174
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
61.9
85.2
naa
65.1
96.2
67.0
71.9
%
Inconc lus i ve
6.5
1.8
0.0
9.1
0.5
8.5
4.9
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
6-418
-------
Table 6-246.
XK-3 by Substrate for First Standard Paint Fully Corrected
Reading With an Inconclusive Range Bounded by 0.4 mg/cm2 and
1.6 rag/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
186
444
237
406
462
743
2,478
% False
Positive
1.4
3.9
0.0
2.5
2.5
1,8
2.2
% False
Negative
2.4
3.6
naa
13.0
3.4
2.2
4.7
%
Inconclusive
24.7
39.4
8.9
29.1
36.1
21.3
27.6
a Not available since drywall ICP measurements were all less than 1.0
ing/ cm2 lead.
Table 6-247.
XL by Substrate for First Standard Paint Fully Corrected
Reading With an Inconclusive Range Bounded by 0.4 mg/cm2 and
1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
216
113
188
222
355
1,187
% False
Positive
0.0
0.0
0.0
0.7
0.0
0.0
0.1
% False
Negative
0.0
7.4
naa
9.3
11.5
12.8
10.0
%
Inconclusive
11.8
14.1
15.9
16.0
15.3
27.9
18.7
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
6-419
-------
Table 6-248.
First Standard Paint Reading Red NIST SRM Average Corrected
With an Inconclusive Range Bounded by 0.4 and 1.6 mg/cm2.
XRF
Lead Analyzer
K-shell
Lead Analyzer
L-shell
MAP-3
K-shell
MAP-3
L-shell
Microlead I
K-shell
X-Met 880
L-shell
XK-3
K-shell
XL
L-shell
Sample
Size
1,190
1,190
2,367
2,367
2,475
1,174
2,478
1,189
% False
Positive
0.3
0.0
1.1
0.0
3.1
0.0
2.3
0.1
% False
Negative
3.2
62.7
3.9
51.3
2.1
71.4
4.2
10.5
%
Inconc lus i ve
18.5
6.5
17.8
8.3
26.9
5.0
25.4
17.5
6-420
-------
Table 6-249.
Lead Analyzer K-shell by Substrate for the First Standard
Paint Reading Red NIST SRM Average Corrected With an
Inconclusive Range Bounded by 0.4 and 1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
189
222
355
1,190
% False
Positive
0.0
1.0
0.0
0.0
0.0
0.4
0.3
% False
Negative
0.0
3.7
naa
6.8
0.0
2.9
3.2
%
Inconclusive
8.6
18.8
9.7
24.9
21.2
18.6
18.5
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-250.
Lead Analyzer L-shell by Substrate for the First Standard
Paint Reading Red NIST SRM Average Corrected With an
Inconclusive Range Bounded by 0.4 and 1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
189
222
355
1,190
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
23.8
88.9
naa
40.9
92.3
65.7
62.7
%
Inconclus i ve
15.1
1.4
0.0
13.2
0.9
9.3
6.5
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
6-421
-------
Table 6-251.
MAP-3 K-shell by Substrate for the First Standard Paint
Reading Red NIST SRM Average Corrected With an Inconclusive
Range Bounded by 0.4 and 1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
185
436
226
378
444
698
2,367
% False
Positive
1.4
1.8
0.9
0.0
1.0
1.4
1.1
% False
Negative
0.0
13.0
naa
1.1
9.6
2.0
3.9
%
Inconclusive
7.6
16.5
12.4
30.2
15.5
17.8
17.8
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
Table 6-252.
MAP-3 L-shell by Substrate for the First Standard Paint
Reading Red NIST SRM Average Corrected With an Inconclusive
Range Bounded by 0.4 and 1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
185
436
226
378
444
698
2,367
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
26.2
61.1
naa
46.6
92.3
45.2
51.3
%
Inconclusive
13.5
3.7
0.4
15.9
0.9
12.9
8.3
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
6-422
-------
Table 6-253.
Microlead I by Substrate for the First Standard Paint
Reading Red NIST SRM Average Corrected With an Inconclusive
Range Bounded by 0.4 and 1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
186
444
237
406
463
739
2,475
% False
Positive
2.8
2.8
1.3
4.5
1.5
4.6
3.1
% False
Negative
0.0
3.6
naa
1.1
3.4
2.3
2.1
%
Inconclusive
23.7
36.3
14.3
22.7
36.7
22.2
26.9
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
Table 6-254.
X-MET 880 by Substrate for the First Standard Paint Reading
Red NIST SRM Average Corrected With an Inconclusive Range
Bounded by 0.4 and 1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
175
222
353
1,174
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
61.9
85.2
naa
58.1
96.2
69.0
71.4
%
Inconclusive
6.5
1.8
0.0
10.9
0.5
8.2
5.0
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
6-423
-------
Table 6-255.
XK-3 by Substrate for the First Standard Paint Reading Red
NIST SRM Average Corrected With an Inconclusive Range
Bounded by 0.4 and 1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
186
444
237
406
462
743
2,478
% False
Positive
2.8
3.6
0.0
2.9
1.7
2.5
2.3
% False
Negative
2.4
3.6
naa
12.0
1.7
2.2
4.2
%
Inconc lus i ve
21.0
37.6
8.0
24.6
35.9
18.6
25.4
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-256.
XL by Substrate for the First Standard Paint Reading Red
NIST SRM Average Corrected With an Inconclusive Range
Bounded by 0.4 and 1.6 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
217
113
189
222
355
1,189
% False
Positive
0.0
0.0
0.0
0.7
0.0
0.0
0.1
% False
Negative
0.0
7.4
naa
9.1
11.5
13.7
10.5
%
Inconclusive
12.9
13.4
12.4
15.9
12.6
26.8
17.5
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
6-424
-------
6.5.4.1 First Standard XRF Readings With an Alternate (0.7
- 1.3 mg/cm2) Inconclusive Range
Table 6-257 shows overall error rates by instrument for the
first standard paint reading using the (0.7 - 1.3 mg/cm2)
inconclusive range. Comparisons to Table 6-208, which shows
overall error rates by instrument for the first standard paint
reading using the (0.4 - 1.6 mg/cm2) inconclusive range, were
made to examine differences between the two methods for
classifying results using two different inconclusive ranges.
All but two of the sixteen error percentages in Table 6-257
are larger than those in Table 6-208. The exceptions that
remained unchanged were the zero percent false positive results
for the Lead Analyzer L-shell and X-MET 880. All of the false
negative rate increases for the L-shell instruments were
substantial including an increase from 11.4% to 29.5% for the XL.
All inconclusive rates in Table 6-258 decreased from those
in Table 6-208. The largest of the inconclusive percentages for
the L-shell instruments was attributable to the XL which had 5.9%
of its results classified as inconclusive. For the K-shell
instruments, inconclusive percentages ranged from 6.0% for the
Lead Analyzer to 17.0% for the XK-3.
Similar comparative results are shown in Tables 6-258
through 6-265 which provide results for the first standard paint
reading by substrate. Tables 6-211 and 6-218 are the companion
tables for classifying the first standard paint reading with a
(0.4 - 1.6 mg/cm2) inconclusive range.
Table 6-158 is useful for making comparisons to Table 6-257.
Table 6-158 displays results for the first standard paint reading
without an inconclusive range. Comparing Table 6-257 to Table
6-158 shows that the results described for XRF classification
without an inconclusive range in Table 6-158 are reflected in
Table 6-257. That is, the false negative rates for the L-shell
instruments are high in both tables and the error percentages for
the K-shell instruments are similar in the two tables, although
lower in Table 6-257. Using the alternate inconclusive range,
Table 6-258 shows that the Lead Analyzer K-shell instrument has
all error rates below five percent and inconclusive rates ranging
from 3.5% on drywall to 9.6% on wood with an overall rate of
6.0%. Table 6-260 shows that the MAP-3 K-shell instrument has
all error rates below ten percent except for two false positive
rates: 13.0% on concrete and 15.4% on plaster. The inconclusive
percentages for the MAP-3 range from 6.0% on brick to 25.4% on
6-425
-------
metal with an overall inconclusive rate of 11.1%. Table 6-262
shows that all of the false negative rates for the Microlead I
were low but its false positive rates range from 3.0% on plaster
to 19.3% on wood and its inconclusive rates range from 10.8% on
wood to 19.4% on concrete. Similarly, the XK-3 has low false
negative rates on all substrates but its false positive and
inconclusive rates were high. Table 6-264 shows that the overall
false positive rate for the XK-3 was 29.4% and over the
individual substrates it ranged from 1.3% on drywall to 55.7% on
concrete. The inconclusive rates for the XK-3 range from 6.8% on
drywall to 25.4% on metal.
6.5.4.2 Average of Three Standard XRF Readings With an
Alternate (0.7 - 1.3 mg/cm2) Inconclusive Range
The average of the three standard paint readings at a
sampling location were classified using the (0.7 - 1.3 mg/cm2)
alternate inconclusive range. Table 6-266 shows overall error
rates by instrument. Comparisons to Table 6-219, which shows
overall error rates by instrument for the standard paint average
using the (0.4 - 1.6 mg/cm2) inconclusive range, were made to
examine differences between the two methods for classifying the
average of three readings using different inconclusive ranges.
All inconclusive rates shown in Table 6-266 decreased from
those shown in Table 6-219. The Lead Analyzer K-shell and the
MAP-3 K-shell instruments have all overall rates (error rates and
inconclusive rates) less than 10%. The other two K-shell
instruments, the Microlead I and XK-3, have 13.6 and 18.8%
inconclusive rates and 10.4% and 29.0% false positive rates,
respectively.
Similar comparative results are shown in Tables 6-267
through 6-274 which provide results by substrate. Tables 6-220
and 6-226 are the companion tables for the (0.4 - 1.6 mg/cm2)
inconclusive range.
6.5.4.3 Standard XRF Readings Control Corrected With an
Alternate (0.7- 1.3 mg/cm2) Inconclusive Range
The first standard paint reading was "control corrected" by
subtracting the average of all the initial and ending red NIST
SRM control block readings in the dwelling, minus 1.02 mg/cm2.
Table 6-275 shows overall error rates by instrument for the first
standard paint control corrected readings using the (0.7 - 1.3
mg/cm2) inconclusive range. This table should be compared to
Table 6-228, which shows the same information for the first
6-426
-------
standard paint control corrected reading using the (0.4 - 1.6
mg/cm2) inconclusive range.
All but two of the sixteen error percentages shown in Table
6-275 are larger than those in Table 6-228. The exceptions that
remained unchanged were the zero percent false positive results
for the Lead Analyzer L-shell and X-MET 880. Again, all of the
false negative rate increases for the L-shell instruments were
substantial including an increase from 11.8% to 28.6% for the XL.
The false positive rates show relatively small differences
between the two tables.
Tables 6-276 through 6-283 display the control corrected
error rates by substrate for the eight instruments, and are to be
compared to Tables 6-231 through 6-238 which applied the (0.4 -
1.6 mg/cm2) inconclusive range.
6.5.4.4 Standard XRF Readings Fully Corrected With an (0.7
- 1.3 mg/cm2) Inconclusive Range
Table 6-284 shows overall error rates by instrument for the
first standard paint fully corrected readings using the (0.7 -
1.3 mg/cm2) inconclusive range. This table should be compared to
Table 6-239, which shows the same information for the results
classified using the (0.4 - 1.6 mg/cm2) inconclusive range.
Tables 6-285 through 6-292 provide the results by substrate
categories for the (0.7 - 1.3 mg/cm2) inconclusive range and
Tables 6-240 through 6-247 are the companion tables for the (0.4
- 1.6 mg/cm2) inconclusive range.
Again, similarities and differences noted in the last two
sections apply here when comparing the results in Table 6-284 to
Table 6-239. However, the results in Table 6-284 show that
K-shell instruments have error rates less than ten percent for
either false positive or false negative while maintaining
inconclusive percentages near ten percent. The largest
inconclusive percentage was for the Microlead I which had 13.8%
of its results classified as inconclusive.
6.5.4.5 Standard XRF Readings Red NIST SRM Average
Corrected With an (0.7 - 1.3 mg/cm2) Inconclusive
Range
For this analysis, the first standard paint reading was "red
NIST SRM average corrected". Table 6-293 shows overall error
rates by instrument using the (0.7 - 1.3 mg/cm2) inconclusive
range. Tables 6-294 through 6-301 display the information by
6-427
-------
substrate. Table 6-248 provides similar information for results
classified using the (0.4 - 1.6 mg/cm2) inconclusive range and
the comparative tables by substrate are Tables 6-249 through
6-256.
All but three of the sixteen error percentages shown in
Table 6-293 are larger than those in Table 6-248. The exceptions
that remained unchanged were the zero percent false positive
results for the Lead Analyzer L-shell and X-MET 880 and the 0.1%
false positive rate for the XL. Again, all of the false negative
rate increases for the L-shell instruments were substantial
including an increase from 10.5% to 25.5% for the XL. Similarly,
the false positive rate increases were small.
The results in Table 6-293 show that K-shell instruments
have error rates less than ten percent while maintaining
inconclusive percentages near ten percent. The largest
inconclusive percentage was for the XK-3 which had 11.9% of its
results classified as inconclusive. The results shown in Table
6-293 show that, for the K-shell instruments, the inconclusive
rates decreased noticeably compared to those in Table 6-248 and
that there were relatively small increases in the error rates.
Tables 6-285, 6-287, 6-289, and 6-291 show results by
substrate for the K-shell instruments. Misclassification rates
for the K-shell instruments were relatively consistent across
substrates with three exceptions. The exceptions were the false
negative rates for the MAP-3 K-shell on concrete and plaster and
the false negative rate for the XK-3 on metal.
6-428
-------
Table 6-257.
First Standard Paint Reading With an Alternative
Inconclusive Range Between 0.7 and 1.3 mg/cm2.
XRF
Lead Analyzer
K-shell
Lead Analyzer
L-shell
MAP-3
K-shell
MAP-3
L-shell
Microlead I
K-shell
X-Met 880
L-shell
XK-3
K-shell
XL
L-shell
Sample
Size
1,190
1,190
2,367
2,367
2,475
1,174
2,478
1,189
% False
Positive
1.2
0.0
4.1
0.3
12.3
0.0
29.6
0.2
% False
Negative
2.7
83.6
4.6
58.6
2.1
82.5
1.7
29.5
%
Inconclusive
6.0
1.5
11.1
5.1
14.5
2.0
17.0
5.9
6-429
-------
Table 6-258.
Lead Analyzer K-shell by Substrate for the First Standard
Paint Reading With an Alternative Inconclusive Range Between
0.7 and 1.3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
189
222
355
1,190
% False
Positive
0.0
1.0
1.8
0.7
0.5
2.4
1.2
% False
Negative
0.0
3.7
naa
4.5
3.8
3.9
2.7
%
Inconc lus i ve
4.3
3.7
3.5
6.3
4.1
9.6
6.0
* Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-259.
Lead Analyzer L-shell by Substrate for the First Standard
Paint Reading With an Alternative Inconclusive Range Between
0.7 and 1.3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
189
222
355
1,190
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
85.7
92.6
naa
65.9
100.0
84.3
83.6
%
Inconclus ive
1.1
0.9
0.0
4.8
0.0
1.7
1.5
* Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
6-430
-------
Table 6-260.
MAP-3 K-shell by Substrate for the First Standard Paint
Reading With an Alternative Inconclusive Range Between 0.7
and 1.3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
185
436
226
378
444
698
2,367
% False
Positive
2.1
3.9
1.8
6.2
2.0
6.2
4.1
% False
Negative
0.0
13.0
naa
1.1
15.4
2.0
4.6
%
Inconclusive
6.0
8.0
8.8
25.4
6.5
10.3
11.1
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-261.
MAP-3 L-shell by Substrate for the First Standard Paint
Reading With an Alternative Inconclusive Range Between 0.7
and 1.3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
185
436
226
378
444
698
2,367
% False
Positive
0.0
0.0
0.0
1.7
0.0
0.0
0.3
% False
Negative
26.2
66.7
naa
53.4
98.1
55.3
58.6
%
Inconclus ive
4.9
2.5
0.4
9.5
0.2
8.9
5.1
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
6-431
-------
Table 6-262.
Microlead I by Substrate for the First Standard Paint
Reading With an Alternative Inconclusive Range Between 0.7
and 1.3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
186
444
237
406
463
739
2,475
% False
Positive
11.1
15.5
9.7
11.1
3.0
19.3
12.3
% False
Negative
0.0
1.8
naa
2.2
5.1
1.8
2.1
%
Inconc lus i ve
15.1
19.4
14.8
15.0
14.9
10.8
14.5
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-263.
X-MET 880 by Substrate for the First Standard Paint Reading
With an Alternative Inconclusive Range Between 0.7 and 1.3
mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
175
222
353
1,174
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
85.7
92.6
naa
65.1
100.0
82.0
82.5
%
Inconclusive
1.1
0.9
0.0
6.9
0.0
2.5
2.0
" Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead .
6-432
-------
Table 6-264.
XK-3 by Substrate for the First Standard Paint Reading With
an Alternative Inconclusive Range Between 0.7 and 1.3
mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
186
444
237
406
462
743
2,478
% False
Positive
32.6
55.7
1.3
41.4
35.2
10.6
29.6
% False
Negative
2.4
0.0
naa
2.2
1.7
1.8
1.7
%
Inconclus ive
24.7
20.7
6.8
25.4
19.9
9.8
17.0
a Not available since drywall TCP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-265.
XL by Substrate for the First Standard Paint Reading With an
Alternative Inconclusive Range Between 0.7 and 1.3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
217
113
189
222
355
1,189
% False
Positive
0.0
0.5
0.0
0.7
0.0
0.0
0.2
% False
Negative
23.8
25.9
naa
20.5
46.2
31.4
29.5
%
Inconclusive
1.1
6.0
2.7
4.2
4.1
10.1
5.9
* Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
6-433
-------
Table 6-266.
Standard Paint Average With an Alternative Inconclusive
Range Between 0.7 mg/cm2 and 1.3 mg/cm2.
XRF
Lead Analyzer
K- shell
Lead Analyzer
L- shell
MAP-3
K- shell
MAP-3
L-shell
Microlead I
K- shell
X-Met 880
L-shell
XK-3
K- shell
XL
L-shell
Sample
Size
1,190
1,190
2,367
2,367
2,475
1,174
2,478
1,189
% False
Positive
0.8
0.0
2.6
0.3
10.4
0.0
29.0
0.3
% False
Negative
3.2
83.6
3.7
57.9
1.1
82.5
1.7
26.4
%
Inconclusive
7.0
1.6
8.7
5.0
13.6
2.0
18.8
6.8
6-434
-------
Table 6-267.
Lead Analyzer K-shell by Substrate for the Standard Paint
Average With an Alternative Inconclusive Range Between 0.7
mg/cm2 and 1.3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
189
222
355
1,190
% False
Positive
0.0
1.1
0.0
0.0
0.5
2.0
0.8
% False
Negative
0.0
3.7
naa
2.3
3.9
3.9
3.2
%
Inconclusive
5.4
3.2
6.2
9.5
5.0
9.9
7.0
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
Table 6-268.
Lead Analyzer L-shell by Substrate for the Standard Paint
Average With an Alternative Inconclusive Range Between 0.7
mg/cm2 and 1. 3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
189
222
355
1,190
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
85.7
92.6
naa
65.9
100.0
84.3
83.6
%
Inconclusive
1.1
0.9
0.0
4.8
0.5
1.7
1.6
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
6-435
-------
Table 6-269.
MAP-3 K-shell by Substrate for the Standard Paint Average
With an Alternative Inconclusive Range Between 0.7 mg/cm2
and 1.3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
185
436
226
378
444
698
2,367
% False
Positive
1.4
1.3
0.9
3.8
0.8
5.6
2.6
% False
Negative
0.0
13.0
naa
1.1
11.5
1.0
3.7
%
Inconclus ive
3.8
3.4
3.5
24.6
5.0
8.6
8.7
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
Table 6-270.
MAP-3 L-shell by Substrate for the Standard Paint Average
With an Alternative Inconclusive Range Between 0.7 mg/cm2
and 1.3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
185
436
226
378
444
698
2,367
% False
Positive
0.0
0.0
0.0
2.1
0.0
0.0
0.3
% False
Negative
26.2
70.4
naa
53.4
94.2
53.8
57.9
%
Inconclusive
5.4
2.1
0.0
8.5
0.7
9.2
5.0
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
6-436
-------
Table 6-271.
Microlead I by Substrate for the Standard Paint Average With
an Alternative Inconclusive Range Between 0.7 tug/cm2 and 1.3
mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
186
444
237
406
463
739
2,475
% False
Positive
8.3
10.3
11.4
10.8
1.7
17.0
10.4
% False
Negative
0.0
0.0
naa
0.0
3.4
1.4
1.1
%
Inconc lus i ve
14.5
19.4
14.3
11.1
11.7
12.3
13 .6
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-272.
X-MET 880 by Substrate for the Standard Paint Average With
an Alternative Inconclusive Range Between 0.7 mg/cm2 and 1.3
mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
175
222
353
1, 174
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
85.7
92.6
naa
65.1
100.0
82.0
82.5
%
Inconclusive
l.l
0.9
0.0
6.9
0.0
2.5
2.0
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
6-437
-------
Table 6-273.
XK-3 by Substrate for the Standard Paint Average With an
Alternative Inconclusive Range Between 0.7 mg/cm2 and 1.3
mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
186
444
237
406
462
743
2,478
% False
Positive
33.3
57.0
0.9
40.4
34.2
8.9
29.0
% False
Negative
2.4
0.0
naa
2.2
1.7
1.8
1.7
%
Inconclus i ve
28.0
23.0
7.6
26.1
24.0
10.4
18.8
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-274.
XL by Substrate for the Standard Paint Average With an
Alternative Inconclusive Range Between 0.7 mg/cm2 and 1.3
mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
217
113
189
222
355
1,189
% False
Positive
0.0
0.5
0.0
0.7
0.0
0.4
0.3
% False
Negative
23.8
25.9
naa
18.2
34.6
28.4
26.4
%
Inconc lus i ve
0.0
6.0
2.7
5.3
5.4
12.1
6.8
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
6-438
-------
Table 6-275.
First Standard Paint Reading Control Corrected With an
Alternative Inconclusive Range Bounded by 0.7 mg/cm2 and 1.3
mg/cm2.
XRF
Lead Analyzer
K-shell
Lead Analyzer
L- shell
MAP-3
K-shell
MAP-3
L-shell
Microlead I
K-shell
X-Met 880
L-shell
XK-3
K-shell
XL
L-shell
Sample
Size
1,190
1,190
2,367
2,367
2,475
1,174
2,478
1,189
% False
Positive
0.9
0.0
5.2
0.2
8.4
0.0
6.5
0.2
% False
Negative
4.5
84.5
3.7
64.1
14.5
85.3
6.8
28.6
%
Inconc lus i ve
6.2
1.3
11.8
4.4
11.1
1.4
12.4
6.7
6-439
-------
Table 6-276.
Lead Analyzer K-shell by Substrate for the First Standard
Paint Reading Control Corrected With an Alternative
Inconclusive Range Bounded by 0. 7 mg/cm2 and 1.3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
189
222
355
1,190
% False
Positive
0.0
1.0
0.9
0.7
0.5
1.6
0.9
% False
Negative
0.0
7.4
naa
6.8
3.8
3.9
4.5
%
Inconclusive
3.2
2.8
2.7
6.9
5.4
10.4
6.2
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
Table 6-277.
Lead Analyzer L-shell by Substrate for the First Standard
Paint Reading Control Corrected With an Alternative
Inconclusive Range Bounded by 0.7 mg/cm2 and 1.3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
189
222
355
1,190
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
85.7
92.6
naa
65.9
100.0
86.3
84.5
%
Inconclusive
1.1
0.9
0.0
4.8
0.0
1.1
1.3
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
6-440
-------
Table 6-278.
MAP-3 K-shell by Substrate for the First Standard Paint
Reading Control Corrected With an Alternative Inconclusive
Range Bounded by 0.7 tng/cm2 and 1.3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
185
436
226
378
444
698
2,367
% False
Positive
5.6
6.0
1.3
3.8
4.1
8.0
5.2
% False
Negative
0.0
13.0
naa
1.1
7.7
2.0
3.7
%
Inconclusive
7.6
8.5
8.0
18.8
14.9
10.5
11.8
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-279.
MAP-3 L-shell by Substrate for the First Standard Paint
Reading Control Corrected With an Alternative Inconclusive
Range Bounded by 0.7 mg/cm2 and 1.3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
185
436
226
378
444
698
2,367
% False
Positive
0.0
0.0
0.0
1.0
0.0
0.0
0.2
% False
Negative
26.2
83.3
naa
52.3
100.0
62.8
64.1
%
Inconclusive
8.1
0.7
0.4
10.1
0.0
6.9
4.4
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
6-441
-------
Table 6-280.
Microlead I by Substrate for the First Standard Paint
Reading Control Corrected With an Alternative Inconclusive
Range Bounded by 0.7 mg/cm2 and 1.3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
186
444
237
406
463
739
2,475
% False
Positive
9.7
4.4
9.3
7.6
4.7
13.9
8.4
% False
Negative
0.0
17.9
naa
30.4
23.7
7.3
14.5
%
Inconclus i ve
11.8
8.3
21.5
13.1
7.6
10.3
11.1
a Not available since drywall ICP measurements were all less than 1 . 0
rag/cm2 lead.
Table 6-281.
X-MET 880 by Substrate for the First Standard Paint Reading
Control Corrected With an Alternative Inconclusive Range
Bounded by 0.7 mg/cm2 and 1.3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
175
222
353
1,174
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
85.7
92.6
naa
67.4
100.0
87.0
85.3
%
Inconc lus ive
1.1
0.9
0.0
5.1
0.0
1.1
1.4
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
6-442
-------
Table 6-282.
XK-3 by Substrate for the First Standard Paint Reading
Control Corrected With an Alternative Inconclusive Range
Bounded by 0.7 mg/cm2 and 1.3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
186
444
237
406
462
743
2,478
% False
Positive
4.9
15.7
0.0
5.4
7.4
2.9
6.5
% False
Negative
2.4
3.6
naa
17.4
10.2
3.1
6.8
%
Inconclusive
9.7
20.0
4.2
9.9
15.2
10.8
12.4
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-283.
XL by Substrate for the First Standard Paint Reading Control
Corrected With an Alternative Inconclusive Range Bounded by
0.7 mg/cm2 and 1.3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
217
113
189
222
355
1,189
% False
Positive
0.0
0.5
0.0
0.7
0.0
0.0
0.2
% False
Negative
23.8
25.9
naa
20.5
50.0
28.4
28.6
%
Inconclusive
1.1
6.5
3.5
4.2
4.1
12.4
6.7
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
6-443
-------
Table 6-284.
First Standard Paint Reading Fully Corrected With an
Alternative Inconclusive Range Bounded by 0.7 mg/cm2 and 1.3
mg/cm2.
XRF
Lead Analyzer
K- shell
Lead Analyzer
L-shell
MAP-3
K- shell
MAP-3
L-shell
Microlead I
K-shell
X-Met 880
L-shell
XK-3
K-shell
XL
L-shell
Sample
Size
1,190
1,190
2,366
2,366
2,475
1,174
2,478
1,187
% False
Positive
0.5
0.0
2.5
0.1
4.2
0.0
5.0
0.1
% False
Negative
3.6
82.3
7.8
67.6
4.7
85.7
6.3
26.0
%
Inconc lus i ve
6.2
1.8
8.2
3.9
13.8
1.3
12.3
7.2
6-444
-------
Table 6-285.
Lead Analyzer K-shell by Substrate for the First Standard
Paint Reading Fully Corrected With an Alternative
Inconclusive Range Bounded by 0.7 mg/cm2 and 1.3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
189
222
355
1,190
% False
Positive
0.0
1.0
0.0
0.0
0.0
1.2
0.5
% False
Negative
0.0
3.7
naa
6.8
3.8
2.9
3.6
%
Inconclusive
4.3
5.0
2.7
6.3
5.9
8.7
6.2
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
Table 6-286.
Lead Analyzer L-shell by Substrate for the First Standard
Paint Reading Fully Corrected With an Alternative
Inconclusive Range Bounded by 0.7 mg/cm2 and 1.3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
189
222
355
1,190
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
76.2
92.6
naa
61.4
100.0
85.3
82.3
%
Inconclusive
3.2
0.9
0.0
6.3
0.0
1.4
1.8
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
6-445
-------
Table 6-287.
MAP-3 K-shell by Substrate for the First Standard Paint
Reading Fully Corrected With an Alternative Inconclusive
Range Bounded by 0.7 mg/cm2 and 1.3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
185
435
226
378
444
698
2,366
% False
Positive
2.1
5.2
0.9
1.7
2.0
2.0
2.5
% False
Negative
2.4
20.4
naa
l.l
19.2
5.5
7.8
%
Inconclusive
1.6
9.2
3.1
13.5
6.8
9.2
8.2
' Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-288.
MAP-3 L-shell by Substrate for the First Standard Paint
Reading Fully Corrected With an Alternative Inconclusive
Range Bounded by 0.7 mg/cm2 and 1.3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
185
435
226
378
444
698
2,366
% False
Positive
0.0
0.0
0.0
0.0
0.3
0.0
0.1
% False
Negative
31.0
85.2
naa
53.4
98.1
68.8
67.6
%
Inconc lus i ve
9.2
0.9
0.0
8.2
0.5
5.6
3.9
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
6-446
-------
Table 6-289.
Microlead I by Substrate for the First Standard Paint
Reading Fully Corrected With an Alternative Inconclusive
Range Bounded by 0. 7 mg/cm2 and 1.3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
186
444
237
406
463
739
2,475
% False
Positive
4.9
8.8
0.8
4.8
2.2
3.5
4.2
% False
Negative
0.0
3.6
naa
4.3
3.4
6.4
4.7
%
Inconclusive
16.1
17.3
6.8
12.8
17.9
11.2
13.8
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-290.
X-MET 880 by Substrate for the First Standard Paint Reading
Fully Corrected With an Alternative Inconclusive Range
Bounded by 0.7 mg/cm2 and 1.3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
175
222
353
1,174
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
85.7
92.6
naa
69.8
100.0
87.0
85.7
%
Inconclusive
1.1
0.9
0.0
5.1
0.0
0.8
1.3
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
6-447
-------
Table 6-291.
XK-3 by Substrate for the First Standard Paint Reading Fully
Corrected With an Alternative Inconclusive Range Bounded by
0 .7 mg/cm2 and 1.3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
186
444
237
406
462
743
2,478
% False
Positive
6.3
8.5
0.0
5.4
5.5
3.9
5.0
% False
Negative
2.4
5.4
naa
14.1
5.1
4.5
6.3
%
Inconclusive
9.7
19.1
3.8
11.8
17.1
9.0
12.3
* Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-292.
XL by Substrate for the First Standard Paint Reading Fully
Corrected With an Alternative Inconclusive Range Bounded by
0.7 mg/cm2 and 1.3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
216
113
188
222
355
1,187
% False
Positive
0.0
0.0
0.0
0.7
0.0
0.0
0.1
% False
Negative
19.0
33.3
naa
18.6
42.3
24.5
26.0
%
Inconclusive
1.1
6.5
3.5
6.4
5.4
11.8
7.2
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
6-448
-------
Table 6-293.
First Standard Paint Red NIST SRM Average Corrected Reading
With an Alternative Inconclusive Range Bounded by 0.7 mg/cm2
and 1.3 mg/cm2.
XRF
Lead Analyzer
K- shell
Lead Analyzer
L-shell
MAP-3
K- shell
MAP-3
L-shell
Microlead I
K- shell
X-Met 880
L-shell
XK-3
K- shell
XL
L-shell
Sample
Size
1,190
1,190
2,367
2,367
2,475
1,174
2,478
1,189
% False
Positive
0.7
0.0
2.6
0.1
4.9
0.0
5,5
0.1
% False
Negative
4.1
82.3
7.4
66.0
5.3
84.8
6.6
25.5
%
Inconclusive
5.7
1.7
6.8
4.2
11.7
1.5
11.9
7.4
6-449
-------
Table 6-294.
Lead Analyzer K-shell by Substrate for the First Standard
Paint Reading Red NIST SRM Average Corrected With an
Alternative Inconclusive Range Bounded by 0.7 mg/cm2 and 1.3
mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
189
222
355
1,190
% False
Positive
0.0
1.0
0.0
0.7
0.5
1.2
0.7
% False
Negative
0.0
3.7
naa
6.8
3.8
3.9
4.1
%
Inconclusive
3.2
4.1
3.5
5.8
4.5
8.7
5.7
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-295.
Lead Analyzer L-shell by Substrate for the First Standard
Paint Reading Red NIST SRM Average Corrected With an
Alternative Inconclusive Range Bounded by 0.7 mg/cm2 and 1.3
mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
189
222
355
1,190
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
85.7
92.6
naa
61.4
100.0
83.3
82.3
%
Inconclusive
1.1
0.9
0.0
5.3
0.0
2.0
1.7
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
6-450
-------
Table 6-296.
MAP-3 K-shell by Substrate for the First Standard Paint
Reading Red NIST SRM Average Corrected With an Alternative
Inconclusive Range Bounded by 0.7 mg/cm2 and 1.3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
185
436
226
378
444
698
2,367
% False
Positive
1.4
3.9
1.8
1.7
2.0
3.2
2.6
% False
Negative
0.0
18.5
naa
1.1
19.2
5.5
7.4
%
Inconclus ive
3.2
7.1
2.7
11.6
6.1
6.6
6.8
a Not available since drywall ICP measurements were all less than 1 . 0
mg/cm2 lead.
Table 6-297.
MAP-3 L-shell by Substrate for the First Standard Paint
Reading Red NIST SRM Average Corrected With an Alternative
Inconclusive Range Bounded by 0.7 mg/cm2 and 1.3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
185
436
226
378
444
698
2,367
% False
Positive
0.0
0.0
0.0
0.3
0.0
0.0
0.1
% False
Negative
28.6
83.3
naa
53.4
98.1
66.3
66.0
%
Inconc lus ive
9.7
0.7
0.4
9.0
0.2
6.2
4.2
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
6-451
-------
Table 6-298.
Microlead I by Substrate for the First Standard Paint
Reading Red NIST SRM Average Corrected With an Alternative
Inconclusive Range Bounded by 0.7 mg/cm2 and 1.3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
186
444
237
406
463
739
2,475
% False
Positive
4.2
5.2
1.3
5.7
3.7
6.9
4.9
% False
Negative
0.0
10.7
naa
l.l
5.1
6.8
5.3
%
Inconclus ive
14.0
16.0
5.5
9.4
16.0
9.1
11.7
* Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
Table 6-299.
X-MET 880 by Substrate for the First Standard Paint Reading
Red NIST SRM Average Corrected With an Alternative
Inconclusive Range Bounded by 0.7 mg/cm2 and 1.3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
218
113
175
222
353
1,174
% False
Positive
0.0
0.0
0.0
0.0
0.0
0.0
0.0
% False
Negative
85.7
92.6
naa
67.4
100.0
86.0
84.8
%
Inconclusive
1.1
0.9
0.0
5.7
0.0
1.4
1.5
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
6-452
-------
Table 6-300.
XK-3 by Substrate for the First Standard Paint Reading Red
NIST SRM Average Corrected With an Alternative Inconclusive
Range Bounded by 0.7 mg/cm2 and 1.3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
186
444
237
406
462
743
2,478
% False
Positive
6.3
10.1
0.0
5.1
5.5
4.8
5.5
% False
Negative
2.4
3.6
naa
15.2
6.8
4.5
6.6
%
Inconclus i ve
8.6
16.9
4.6
11.8
18.0
8.2
11.9
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
Table 6-301.
XL by Substrate for the First Standard Paint Reading Red
NIST SRM Average Corrected With an Alternative Inconclusive
Range Bounded by 0.7 mg/cm2 and 1.3 mg/cm2.
Substrate
Brick
Concrete
Drywall
Metal
Plaster
Wood
Overall
Sample
Size
93
217
113
189
222
355
1,189
% False
Positive
0.0
0.0
0.0
0.7
0.0
0.0
0.1
% False
Negative
23.8
33.3
naa
18.2
46.2
21.6
25.5
%
Inconclusive
1.1
6.5
3.5
6.9
4.5
13.0
7.4
a Not available since drywall ICP measurements were all less than 1.0
mg/cm2 lead.
6-453
-------
6.5.5 The Effect of Spatial Variation and Laboratory
Error in ICP Measurements on XRF Classification
Rates
The false positive and false negative rates presented in
Tables 6-158 through 6-301 did not account for the fact that ICP
measurement was not a perfect substitute for the true lead level.
At the beginning of section 6.4, it was explained that the
substitution was subject to both spatial variation and laboratory-
error. Chapter 4 elaborates more fully on both types of
imprecision.
A simulation experiment was conducted to assess the effect
that the substitution might have had on the reported
classification rates. For each of the 48 combinations of XRF
instrument type with substrate, random errors were introduced to
the ICP measurements obtained in the study. This created sets of
"new" ICP measurements, treating the original ICP measurements as
if they were true lead levels. A new ICP measurement was
generated by adding a normally distributed random error with mean
zero and SD = 0.3 to the logarithm of an original ICP
measurement, and exponentiating. The choice of 0.3 for the SD
reasonably reflects the size of the combined effect of spatial
variation and laboratory error in ICP measurements, as
demonstrated in section 6.4.8.2.5. A total of 1000 new ICP
measurements for each instrument-substrate combination were
generated in this manner. False positive and false negative
rates for each of these samples were computed, based on the first
uncorrected nominal 15-second XRF readings observed in the study.
This experiment was similar to one conducted for classifications
using lead test kit data, reported in section 5.1.1.
Table 6-302 summarizes the results of the experiment. The
sample false positive (FP) and false negative rates (FN), the
means of the 1000 simulated values, and ranges consisting of the
2.5th and 97.5th percentiles of the simulated values are
presented. It is apparent that the introduction of random errors
did not markedly affect the classification rates. False negative
rates exhibited greater variability than did false positive
rates, which was due at least in part to the fact that the sample
sizes for ICP measurements greater than 1.0 mg/cm2 lead were much
smaller than for ICP measurements below this value. In no case
would a substantially different conclusion about the
classification ability of an XRF instrument be reached based on
the simulation results. A similar conclusion may be reached
concerning the use of the FP and FN rates reported in Tables
6-211 through 6-301 as substitutes for rates based on the
unobservable true lead levels.
6-454
-------
Table 6-302. Simulation Study Percentage Results of the Effect of Spatial Variation
and Laboratory Error in ICP Measurements on Reported False Positive and
False Negative Rates for XRF Instruments.
XRF
INSTRUMENT
Lead Analyzer
K-shell
Lead Analyzer
L-shell
MAP-3
K-shell
MAP-3
L-shell
SUBSTRATE
Brick
Concrete
Drywall
Metal
Plaster
Wood
Brick
Concrete
Drywall
Metal
Plaster
Wood
Brick
Concrete
Drywall
Metal
Plaster
Wood
Brick
Concrete
Drywall
Metal
Plaster
Wood
FALSE POSITIVE RESULTS
FP%"
3
2
2
3
1
6
0
0
0
0
0
0
4
6
4
19
2
11
0
0
0
5
0
0
MEAN%b
3
1
2
4
2
8
0
0
0
0
0
0
4
6
3
19
3
12
0
0
0
5
0
1
95%
INTERVALC
1.4, 4.1
0.5, 2.6
0.9, 1.8
2.1, 5.4
1.0, 3.0
6.3, 10.3
0.0, 0.0
0.0, 0.0
0.0, 0.0
0.0, 0.0
0.0, 0.0
0.0, 0.0
3.5, 5.5
5.0, 6.5
2.7, 3.6
17.1, 20.8
2.3, 3.8
10.6, 14.3
0.0, 1.4
0.0, 0.0
0.4, 0.5
3.8, 5.9
0.0, 0.0
0.2, 1.2
FALSE NEGATIVE RESULTS
FN%d
0
11
naf
7
4
6
91
96
na£
82
100
87
0
24
na£
1
21
6
29
85
na£
60
100
70
MEAN%*
1
15
na£
12
6
8
91
97
na£
83
100
87
2
27
na£
4
22
7
30
86
na£
61
100
70
95%
INTERVAL1
0.0, 4.8
7.7, 21.9
na£
6.7, 18.0
0.0, 13.8
4.4, 10.7
90.0, 91.3
96.2, 96.9
na£
81.0, 84.3
100, 100
85.9, 87.5
0.0, 8.7
21.2, 33.3
na£
1.1, 8.3
15.2, 29.3
4.7, 9.9
28.6, 34.8
84.6, 87.5
na£
57.3, 64.3
100, 100
67.9, 72.0
1 Rounded false positive percent reported in Tables 6-162 through 6-165.
b Simulation false positive percent.
c Simulation 95% coverage interval.
d Rounded false negative percent reported in Tables 6-162 through 6-165.
e Simulation false negative percent.
£ Not available since drywall ICP measurements were all less than 1.0 mg/cm lead.
6-455
-------
Table 6-302 (cent). Simulation Study Percentage Results of the Effect of Spatial
Variation and Laboratory Error in ICP Measurements on Reported
False Positive and False Negative Rates for XRF Instruments.
XRF
INSTRUMENT
Microlead I
X-MET 880
XK-3
XL
SUBSTRATE
Brick
Concrete
Drywall
Metal
Plaster
Wood
Brick
Concrete
Drywall
Metal
Plaster
Wood
Brick
Concrete
Drywall
Metal
Plaster
Wood
Brick
Concrete
Drywall
Metal
Plaster
Wood
FALSE POSITIVE RESULTS
FP%"
22
26
18
19
10
26
0
0
0
0
0
0
53
66
5
57
46
17
0
1
1
1
0
1
MEAN%b
22
25
18
19
10
28
0
0
0
0
0
0
53
66
5
57
46
18
0 .
1
1
1
0
2
95%
INTERVAL'
21.1, 22.9
24.3, 26.3
17.2, 18.0
17.3, 20.3
9.5, 11.3
26.0, 29.1
0.0, 1.4
0.0, 0.0
0.0, 0.0
0.0, 1.5
0.0, 0.0
0.0, 0.0
51.4, 52.9
65.3, 66.6
3.5, 5.1
55.9, 57.8
45.8, 47.1
16.6, 19.9
0.0, 1.4
0.0, 1.6
0.9, 0.9
0.0, 2.1
0.0, 1.0
0.4, 2.7
FALSE NEGATIVE RESULTS
FN%a
2
2
na£
2
10
4
86
96
na£
70
100
89
2
2
na£
5
2
4
24
41
na£
30
58
47
MEANV
4
4
naf
6
11
5
86
97
na£
72
100
89
2
2
na£
6
3
5
26
46
na£
34
58
47
95%
INTERVAL0
0.0, 10.4
0.0, 8.3
na£
2.3, 10.8
5.7, 16.9
2.8, 6.5
85.7, 90.0
96.2, 97.0
na£
69.0, 75.0
100, 100
87.8, 89.3
0.0, 6.5
1.5, 4.8
na£
4.3, 8.2
0.0, 7.3
3.3, 7.3
23.8, 30.4
40.0, 51.7
na£
27.9, 38.3
52.2, 63.0
43.5, 50.5
• Rounded false positive percent reported in Tables 6-166 through 6-169.
b Simulation false positive percent.
c Simulation 95% coverage interval .
d Rounded false negative percent reported in Tables 6-166 through 6-169.
e Simulation false negative percent,
f Not available since drywall ICP measurements were all less than 1.0 mg/cm2 lead.
6-456
-------
6.5.6 Summary of Classification Results
Presented in this section were classification results for
the set of sampling locations tested in this study. Another set
of locations with significantly different lead levels than the
tested locations might provide different results, even if the
same instruments were used. The classification results provided
empirical evidence that classifying the K-shell XRF instrument
results against the federal standard of 1.0 mg/cm2 lead without
an inconclusive range, and with substrate correction if needed,
produced low classification error rates, no greater than 11%
overall, that is, averaged for all substrates. However, error
rates on particular substrates could be substantially higher than
the overall rates. These results provided further evidence of
differences between the K- and L-shell instruments. All L-shell
instruments had high false negative rates and low false positive
rates when classifying against the 1.0 mg/cm2 lead standard
without an inconclusive range. The overall false negative rate
for the XL was 41.8%, and the other L-shell instruments had
higher false negative rates. The XL had a low false positive
rate of 0.5%, which was typical for an L-shell instrument.
Substrate correction did not significantly improve these results
for the L-shell instruments.
The Lead Analyzer and MAP-3 had overall misclassification
rates less than 10% compared to the 1.0 mg/cm2 lead federal
standard without substrate correction. For some K-shell
instruments, error rates were reduced when readings were
corrected for substrate bias. For the Microlead I and XK-3,
overall classification error rates were reduced to 10% or less by
full and red NIST SRM average correction methods. Control
correction produced mixed results: for the XK-3, overall error
rates were about 11% or less, but, the false positive rate on
concrete was greater than 24% and the false negative rate on
metal was greater than 20%. Control correction did not improve
the error rates for the Microlead I. The MAP-3 K-shell had its
high false positive rate on metal and high false negative rates
on concrete and plaster reduced by control correction.
The classification results showed that using an inconclusive
range provided satisfactory results for K-shell instruments, but,
false negative rates remained high for the L-shell instruments.
Results showed that the K-shell XRF instruments provided
satisfactory classification results using an inconclusive range
between 0.4 and 1.6 mg/cm2 and correcting for substrate biases in
XRF readings if needed. With the exception of the XK-3 false
positive rates, all error rates for the K-shell XRF instruments
6-457
-------
were below 10%. On individual substrates, most error rates were
still below 10%. The exceptions were: false negative rates for
the MAP-3 on concrete and plaster; the Microlead I false positive
rate on wood; and, false positive rates for the XK-3 on brick,
concrete, metal, and plaster. These false positive rates for the
XK-3 were dramatically reduced by substrate correction.
When the inconclusive range was narrowed to 0.7 to 1.3
mg/cm2, percentages in the inconclusive range were reduced by at
least 50% for all instruments compared to the 0.4 - 1.6 mg/cm2
inconclusive range. Observed changes in the error rates coupled
with this dramatic decrease in percentages in the inconclusive
range indicates that a balance needs to be struck between error
rates and the inconclusive range, which determines the number of
paint-chip samples requiring laboratory confirmation.
The K-shell instruments continued to provide error rates
near ten percent using the 0.7 - 1.3 mg/cm2 range. The Microlead
I and the XK-3 both needed substrate correction to achieve false
positive rates near ten percent. On individual substrates, error
rates were generally below 10%. The exceptions were the false
negative rate for the MAP-3 on concrete; and the false negative
rate for the XK-3 on metal. The results for the Microlead I were
substantially improved by full correction.
With the exception of the XL, classifying L-shell instrument
results using either inconclusive range provided very high false
negative rates, reflecting the large negative biases exhibited by
these instruments. False positive rates were very low for all
L-shell instruments. Using the 0.4 to 1.6 mg/cm2 inconclusive
range, the XL had a false negative rate of approximately 11% and
a false positive rate of 0.1%. However, the instrument still
provided readings below 0.4 mg/cm2 on a number of samples with
lead levels in excess of 10.0 mg/cm2, which were classified as
false negative. With the narrower inconclusive range of 0.7 to
1.3 mg/cm2, the XL had an overall false negative rate of 28.6%
and a 0.2% false positive rate.
Classification results in this section show that a single
XRF reading at a point provided almost as much information as an
average of three XRF readings at the same point. When paint
samples were classified with or without the use of an
inconclusive range, there was very little difference in the error
rates (false positive and false negative) for the average of
three 15-second readings versus a single 15-second reading. For
example, when classifying results using the 0.4 to 1.6 mg/cm2
inconclusive range, the overall error percentages for the K-shell
6-458
-------
XRF instruments were the same in two cases and slightly lower for
the average in six cases. For L-shell instruments, the error
percentages were the same in six cases and slightly lower for the
average in two cases. Thus, the small improvement in
classification accuracy did not justify the additional time and
expense of taking three repeat readings at the same point. This
remained true when substrate corrected readings and different
inconclusive ranges were considered.
6-459
-------
6.6 EFFECTS RELATED TO CHANGING FROM ONE SUBSTRATE TO
ANOTHER
It has been hypothesized that an XRF device may operate
erratically when a change has been made from one substrate to
another. To study the effect of changing from one substrate to
another, the laboratory ICP results measured in mg/cm2 were
paired with the standard first paint readings made on each sample
location over the painted surface. This analysis addresses the
following study objectives:
• to characterize the performance (precision and accuracy) or
portable XRF instruments under field conditions
• to evaluate the effect on XRF performance of interference
from material (the substrate) underlying the paint
• to investigate XRF measurements that were very different
than their corresponding laboratory results.
Differences between the XRF reading on paint and the
laboratory ICP result (measured in mg/cm2) were computed for each
sample location. These differences were used to examine the
hypothesis that the XRF instruments behaved erratically after
changing from one substrate to another. A description of the
analysis and results follows.
If the XRF instruments behaved erratically when changing
substrate, one would expect differences (that is, XRF reading
minus ICP result differences) computed from the first sampling
location on the new substrate to differ systematically from the
subsequent differences on the same substrate. Erratic behavior
would be detected if the observed incidence of extreme
differences (maxima or minima) on the first reading of a new
substrate were higher than the expected incidence of extremes.
Section 6.1 and Tables 6-5 and 6-6 describe the substrates for
each dwelling and the order in which testing on substrates was
done. In Tables 6-5 and 6-6, the "Number of Substrate Changes"
values are the number of opportunities from which extremes per
substrate per dwelling were tabulated.
Tables 6-303 through 6-308 provide a count of the number of
maxima and minima per dwelling that occurred on the first
standard paint reading on a substrate. Also found in the tables
are the number of days an XRF instrument tested in Denver,
Philadelphia, and Louisville, and the total number of daily
extreme values that occurred for the first regular paint reading
minus laboratory ICP differences. Standard data as defined in
section 6.1 were used for this analysis.
6-460
-------
Table 6-303.
Counts of the Number of Dwellings an XRF Instrument Tested
on BRICK, the Number of Dwelling Maximum and Minimum Values,
and the Total Number of Extreme Values that Occurred for the
First Paint Reading Minus Laboratory ICP Differences.
XRF INSTRUMENT
Lead Analyzer
K-shell
Lead Analyzer
L- shell
MAP-3
K-shell
MAP-3
K-shell
MAP-3
L-shell
MAP-3
L-shell
Microlead I
K-shell
Microlead I
K-shell
X-MET 880
L-shell
XK-3
K-shell
XK-3
K-shell
XL
L-shell
FIELD
CODE
NO.
na
na
I
II
I
II
I
II
na
I
II
na
THREE
CITIES?
no
no
no
no
no
no
yes
no
no
yes
no
no
NO. OF
DWELLINGS
11
11
11
11
11
11
11
11
11
11
11
11
NO. OF
MINIMUM
VALUES
1
0
0
1
1
0
0
1
0
2
0
0
NO. OF
MAXIMUM
VALUES
0
1
1
0
0
0
0
0
0
0
0
0
TOTAL
NO.
EXTREME
1
1
1
1
1
0
0
1
0
2
0
0
The total number of daily extreme values observed for each
instrument and substrate in these tables was evaluated using a
statistical model. The field classification of the XRF
instruments was used to insure independence of readings between
sampling locations. Assume that the number of testing locations
for a substrate in a housing unit is Nj. If extreme values are
equally likely to occur at every location, the probability that
an extreme (maximum or minimum) occurs on the first reading is
2/N.j. The expected number of extreme values, M, for an
instrument on a substrate is then found by summing the quantities
2/N.j over all units tested by the instrument. Further, under the
independence assumption, the variance of the number of extremes
is found by summing the quantity (2/Nj)*(l - 2/N.j) over all units
tested. The square root of this quantity, S, is the standard
6-461
-------
Table 6-304.
Counts of the Number of Dwellings an XRF Instrument Tested
on CONCRETE, the Number of Dwelling Maximum and Minimum
Values, and the Total Number of Extreme Values that Occurred
for the First Paint Reading Minus Laboratory ICP
Differences.
XRF INSTRUMENT
Lead Analyzer
K- shell
Lead Analyzer
L-shell
MAP-3
K-shell
MAP-3
K-shell
MAP-3
L-shell
MAP-3
L-shell
Microlead I
K-shell
Microlead I
K-shell
X-MET 880
L-shell
XK-3
K-shell
XK-3
K-shell
XL
L-shell
FIELD
CODE
NO.
na
na
I
II
I
II
I
II
na
I
II
na
THREE
CITIES?
no
no
no
no
no
no
yes
no
no
yes
no
no
NO. OF
DWELLINGS
17
17
17
17
17
17
19
17
17
19
17
17
NO. OF
MINIMUM
VALUES
1
2
2
2
2
2
0
2
2
2
1
1
NO. OF
MAXIMUM
VALUES
1
3
1
2
2
2
2
1
4
2
1
1
TOTAL
NO.
EXTREME
2
5
3
4
4
4
2
3
6
4
2
2
deviation of the number of extremes.
Approximate statistical tests of significance for the
observed number of extremes can be constructed using the
quantities M and S. For example, under the asymptotic normality
assumption, the 95th percentile of the number of extremes is
given by M + 1.645*3. If the observed number of extremes exceeds
this, then there is significant evidence, at the 0.05 level, that
the number of extremes for the first reading is elevated above
what would be expected by chance. There are 72 combinations of
instrument and substrate represented in Tables 6-303 through
6-308. Thus, to achieve an overall significance level of 0.05, a
significance level of 0.05 -=- 72 = 0.0007 should be used for each
6-462
-------
Table 6-305.
Counts of the Number of Dwellings an XRF Instrument Tested
on DRYWALL, the Number of Dwelling Maximum and Minimum
Values, and the Total Number of Extreme Values that Occurred
for the First Paint Reading Minus Laboratory ICP
Differences.
XRF INSTRUMENT
Lead Analyzer
K- shell
Lead Analyzer
L- shell
MAP- 3
K- shell
MAP- 3
K- shell
MAP- 3
L- shell
MAP-3
L-shell
Microlead I
K- shell
Microlead I
K- shell
X-MET 880
L-shell
XK-3
K- shell
XK-3
K- shell
XL
L-shell
FIELD
CODE
NO.
na
na
I
II
I
II
I
IX
na
I
II
na
THREE
CITIES?
no
no
no
no
no
no
yes
no
no
yes
no
no
NO. OF
DWELLINGS
11
11
11
11
11
11
13
11
11
13
11
11
NO. OF
MINIMUM
VALUES
0
0
1
0
0
0
2
0
0
1
0
0
NO. OF
MAXIMUM
VALUES
1
0
0
1
2
1
1
1
2
2
1
1
TOTAL
NO.
EXTREME
1
0
1
1
2
1
3
1
2
3
1
1
individual instrument and substrate combination. The calculated
limit for the number of extremes is then M + 3.2*S. Table 6-309
shows the critical limits for obtaining an overall significance
level of 0.05 for two cases. The first is for XRF instruments
which tested in all three cities; the second is for Denver and
Philadelphia combined, that is, excluding Louisville. Note that
in the tables, the XRF instruments are classified according to
the field classification. This classification was necessary in
order to maintain the assumption that extreme values are equally
likely to occur on any reading within a group of readings. If we
had used the classifications of eight XRF instruments defined
previously in this report, this assumption would have been
violated.
6-463
-------
Table 6-306.
Counts of the Number of Dwellings an XRF Instrument Tested
on METAL, the Number of Dwelling Maximum and Minimum Values,
and the Total Number of Extreme Values that Occurred for the
First Paint Reading Minus Laboratory ICP Differences.
XRF INSTRUMENT
Lead Analyzer
K- shell
Lead Analyzer
L- shell
MAP-3
K- shell
MAP-3
K- shell
MAP-3
L-shell
MAP-3
L-shell
Microlead I
K- shell
Microlead I
K- shell
X-MET 880
L-shell
XK-3
K- shell
XK-3
K- shell
XL
L-shell
FIELD
CODE
NO.
na
na
I
II
I
II
I
II
na
I
II
na
THREE
CITIES?
no
no
no
no
no
no
yes
no
no
yes
no
no
NO. OF
DWELLINGS
18
18
18
18
18
18
20
18
18
20
18
18
NO. OF
MINIMUM
VALUES
2
4
3
3
4
4
3
2
3
3
3
2
NO. OF
MAXIMUM
VALUES
2
2
3
4
3
2
3
2
1
2
4
3
TOTAL
NO.
EXTREME
4
6
6
7
7
6
6
4
4
5
7
5
The total number of extreme values from all three cities for
the Microlead I revision 4 and XK-3 instruments was compared to
the three city critical limits provided in Table 6-309. As
described in section 6.1, the Microlead I and XK-3 were used in
all three cities. These instruments were given the field
designation "I" and are so designated in the tables in this
section. Extreme values for all other XRF instruments were
compared to the two city (Denver and Philadelphia) critical
limits provided in Table 6-309. Comparisons of Tables 6-303
through 6-308 to Table 6-309 shows that none of the total number
of extreme values exceeded the critical limits. Hence, since
there is no statistically significant evidence, at the overall
0.05 level, the incidence of extreme values recorded on the first
reading of a substrate is not unusually high. Thus, there is no
6-464
-------
Table 6-307.
Counts of the Number of Dwellings an XRF Instrument Tested
on PLASTER, the Number of Dwelling Maximum and Minimum
Values, and the Total Number of Extreme Values that Occurred
for the First Paint Reading Minus Laboratory ICP
Differences.
XRF INSTRUMENT
Lead Analyzer
K- shell
Lead Analyzer
L-shell
MAP-3
K- shell
MAP-3
K- shell
MAP-3
L-shell
MAP-3
L-shell
Microlead I
K-shell
Microlead I
K-shell
X-MET 880
L-shell
XK-3
K-shell
XK-3
K-shell
XL
L-shell
FIELD
CODE
NO.
na
na
I
II
I
II
I
II
na
I
II
na
THREE
CITIES?
no
no
no
no
no
no
yes
no
no
yes
no
no
NO. OF
DWELLINGS
14
14
14
14
14
14
16
14
14
16
14
14
NO. OF
MINIMUM
VALUES
2
3
2
1
1
2
1
2
3
2
1
1
NO. OF
MAXIMUM
VALUES
0
1
1
1
0
0
1
0
0
1
1
3
TOTAL
NO.
EXTREME
2
4
3
2
1
2
2
2
3
3
2
4
statistically significant evidence of erratic behavior of the
first reading on a substrate.
However, observations of Tables 6-303 through 6-308 indicate that
a higher incidence of extremes occurred more often on metal and
wood substrates. Although this suggests the possibility of
increased erratic behavior on the first reading for metal and
wood, the evidence is weak. First, as previously explained, the
results are not significant using an overall significance level
of 0.05. Second, the statistical model is approximate, in that
it assumes that extremes are equally likely to occur on any
reading. The testing order could invalidate this assumption in
some cases. For example, if the higher lead levels were tested
6-465
-------
Table 6-308.
Counts of the Number of Dwellings an XRF Instrument Tested
on WOOD, the Number of Dwelling Maximum and Minimum Values,
and the Total Number of Extreme Values that Occurred for the
First Paint Reading Minus Laboratory ICP Differences.
XRF INSTRUMENT
Lead Analyzer
K- shell
Lead Analyzer
L-shell
MAP-3
K- shell
MAP-3
K- shell
MAP-3
L-shell
MAP-3
L-shell
Microlead I
K- shell
Microlead I
K- shell
X-MET 880
L-shell
XK-3
K- shell
XK-3
K- shell
XL
L-shell
FIELD
CODE
HO.
na
na
I
II
I
II
I
II
na
I
II
na
THREE
CITIES?
no
no
no
no
no
no
yes
no
no
yes
no
no
NO. OF
DWELLINGS
17
17
17
17
17
17
19
17
17
19
17
17
NO. OF
MINIMUM
VALUES
3
4
0
2
2
2
2
0
3
0
1
3
NO. OF
MAXIMUM
VALUES
4
1
4
4
1
0
5
5
1
4
5
1
TOTAL
NO.
EXTREME
7
5
4
6
3
2
7
5
4
4
6
4
Table 6-309.
Critical Values for the Observed Number of Extreme Absolute
XRF minus ICP Differences for XRF Readings Taken at the
First Sampling Location Tested for a Given Substrate.
OVERALL 0.05
SIGNIFICANCE
LEVEL
Three Cities
Denver &
Philadelphia
SUBSTRATE
Brick
3.5
3.5
Concrete
8.3
6.7
Drywall
5.9
4.4
Metal
9.3
8.7
Plaster
6.7
5.9
Wood
8.8
8.3
earlier, then extreme differences between XRF and ICP would be
more likely early in the testing.
6-466
-------
6.7 DESCRIPTIVE STATISTICS FOR "SPECIAL" AND NON-STANDARD
DATA
The first section of this chapter described XRF data and
categorized the data as standard, control, special, and non-
standard data. This section provides summary statistics for
"special" and non-standard data that include the number of
readings, mean, median, maximum, minimum, 25th percentile, and
75th percentile and addresses the following study objectives:
• to characterize the performance (precision and accuracy) or
portable XRF instruments under field conditions
• to evaluate the effect on XRF performance of interference
from material (the substrate) underlying the paint
• to investigate XRF measurements that were very different
than their corresponding laboratory results
• to evaluate field quality assurance and control methods.
Due to the large number of tables presented in this section,
the organization of this section is a departure from normal. For
this section only, most tables are not intermingled with text,
but instead, all tables referenced in a given subsection that
provide summary statistics were placed after the text for that
subsection.
For this analysis, eight distinct XRF classifications were
analyzed as if they were a separate XRF instrument:
• Lead Analyzer K-shell
• Lead Analyzer L-shell
• MAP-3 K-shell
• MAP-3 L-shell
• Microlead I (K-shell)
• X-MET 880 (L-shell)
• XK-3 (K-shell)
• XL (L-Shell)
6.7.1 Summary Statistics for "Special" Data
This section provides summary statistics for the "special"
data for the eight classifications of XRF instruments. For an
in-depth discussion of "special" data refer to section 6.1.
There are two types of "special" data: "special" readings and
"special-special" readings. "Special-special" locations were
used in Denver and Philadelphia by the MAP-3 instruments only.
The data collection protocol at "special" locations depended upon
the XRF instrument type and whether data were being collected for
6-467
-------
the pilot study or the full study and affected the number of
readings and nominal reading times. These differences provide a
method for examining instrument readings relative to the number
of readings and nominal reading times. The information to make
these comparisons is provided in the tables below.
The next seven tables contain summary statistics for
"special" data in the full study and standard data collected at
"special" locations in the full study. Tables 6-310 through
6-313 provide summary statistics for the "special" readings taken
in Denver and Philadelphia. Tables 6-310, 6-311, and 6-612
provide results for all instruments except the MAP-3. The
"special" data results for the MAP-3 are provided separately from
the other XRF results in Table 6-313 since the "special" data
collection protocol used by the MAP-3 was unique. Tables 6-314,
6-315, and 6-316 are for making comparisons to the tables of
"special" data and show results of standard data that was
collected only at "special" locations. Table 6-314 provides
summary statistics for the MAP-3 of standard data collected at
"special" and "special-special" locations and will be useful for
making comparisons to Table 6-313. Table 6-315 provides summary
statistics for the first red NIST SRM reading taken from
"special" locations in the full study minus 1.02 mg/cm2. Table
6-316 provides summary statistics for the first standard paint
fully corrected reading at "special" locations in the full study.
Tables 6-315 and 6-316 will be useful for making comparisons to
Tables 6-310, 6-311, and 6-312.
Comparisons of Table 6-313 to 6-314 show that the extended
nominal reading times did not greatly affect the result as shown
by comparing the "PAINT" or "NIST" between the two tables or by
comparing the "Bare" results in Table 6-313 to "Paint-ICP" or
"NIST-1.02" results in Table 6-314. Further evidence is given by
the results of paired Student's t tests which were performed to
determine if the longer nominal reading times significantly
affected the outcome. The "special" data were paired with
nominal 15-second readings and also nominal 60-second readings
were paired with nominal 240-second readings. Twenty-four t
statistics were computed for each instrument by shell
classification for all possible pairs. Using an overall
significance level of 0.002 (0.05 -=- 24 = 0.002), no statistically
significant results were found for readings made on paint or for
readings made on paint compared to readings made on the bare
substrate. Similar results were found comparing the readings
made on the bare substrate to those made on the bare substrates
covered with the red (1.02 mg/cm2) NIST SRM minus 1.02 mg/cm2 and
for comparing the "special" readings taken on the bare substrates
6-468
-------
covered with the red (1.02 mg/cm2) NIST SRM to the (standard)
readings taken on the bare substrates covered with the red (1.02
mg/cm2) NIST SRM at "special" locations. Therefore, the longer
60-second and 240-second nominal reading times made by the MAP-3
at "special" locations appeared to have little effect on the
outcome compared to the nominal 15-second reading.
The bare substrate "special" readings in Tables 6-310 to
6-312 were consistent with the bare results given in Table 6-315.
However, results in Tables 6-310 to 6-312 were not as consistent
as the results shown in Table 6-316, which are the results for
the first standard paint readings minus the appropriate ICP
measurement in mg/cm2 taken from "special" locations. This could
be due in part to the lead levels found in the paint.
The next five tables provide summary statistics for
"special" data collected in Louisville. Tables 6-317 through
6-321 provide summary statistics for the "special" readings taken
in Louisville by the MAP-3 K-shell, MAP-3 L-shell, Microlead I,
X-MET 880, and XK-3, respectively. The results given in these
tables are very similar to readings taken at "special" locations
using a different data collection protocol. That is, the
non-special means were not significantly different from the
"special" means computed for readings taken at the same
locations. This was observed in Tables 6-322 and 6-323. These
tables provide results for the (pilot) standard data for the
first paint reading and the first red NIST SRM reading for all
instruments.
6-469
-------
Table 6-310.
Summary Statistics of Lead Measured in mg/cm3 Units of the First Bare Substrate Reading
("Special" Data) For All XRF Instrument Types Except the MAP-3.
XRF TYPE
Lead Analyzer K- shell
Lead Analyzer L-shell
Microlead I
X-MET 880
XK-3
XL
NUMBER OF
READINGS
299
299
601a
255b
596
301
ARITHMETIC
MEAN
0.073
0.013
0.395
0.048
0.636
0.101
MAXIMUM
1.700
0.970
4.500
1.444
4.000
1.200
MINIMUM
-0.300
-0.051
-1.600
0.022
-1.000
0.000
25th
PERCENTILE
-0.020
-o.ooe
-0.200
0.028
0.200
0.000
MEDIAN
0.030
0.000
0.200
0.033
0.500
0.000
75TH
PERCENTILE
0.100
0.016
0.700
0.039
1.000
0.100
* One Microlead I reading was omitted from this analysis due to known instrument problems and two
additional readings were made.
b Forty seven sampling locations composed of metal substrates are missing.
6-470
-------
Table 6-311.
Summary Statistics of Lead Measured in mg/cm2 Units of the Second Bare Substrate Reading
("Special" Data) For All XRF Instrument Types Except the MAP-3.
XRF TYPE
Lead Analyzer K- shell
Lead Analyzer L- shell
Microlead I
X-MET 880
XK-3
XL
NUMBER OF
READINGS
299
299
600a
255b
596
301
ARITHMETIC
MEAN
0.066
0.013
0.413
0.047
0.653
0.108
MAXIMUM
2.100
0.970
4.600
1.355
3 .400
1.600
MINIMUM
-0.300
-0.053
-2.300
0.022
-1.200
0.000
25th
PERCENTILE
-0.030
-0.009
-0.100
0.028
0.100
0.000
MEDIAN
0.020
0.000
0.200
0.033
0.500
0.000
75TH
PERCENTILE
0.090
0.016
0.700
0.039
1.100
0.100
a One Microlead I reading was omitted from this analysis due to known instrument
problems and one additional reading was made.
b Forty seven sampling locations composed of metal substrates are missing.
6-471
-------
Table 6-312.
Summary Statistics of Lead Measured in trig/cm2 Units of the Third Bare Substrate Reading
("Special" Data) For All XRF Instrument Types Except the MAP-3.
XRF TYPE
Lead Analyzer K- shell
Lead Analyzer L-shell
Microlead I
X-MET 880
XK-3
XL
NUMBER OF
READINGS
299
299
599*
255"
596
301
ARITHMETIC
MEAN
0.067
0.013
0.402
0.046
0.628
0.113
MAXIMUM
2.500
0.970
4.600
1.092
3.600
1.300
MINIMUM
-0.300
-0.055
-2.800
0.022
-1.000
0.000
25th
PERCENTILE
-0.030
-0.008
-0.300
0.028
0.100
0.000
MEDIAN
0.020
0.000
0.200
0.033
0.500
0.100
75TH
PERCENTILE
0.090
0.016
0.900
0.039
1.000
0.100
a One Microlead I reading was omitted from this analysis due to known instrument problems.
b Forty seven sampling locations composed of metal substrates are missing.
6-472
-------
Table 6-313.
Summary Statistics of Lead Measured in rag/cm2 Units of the "Special" Readings for the MAP-3 for the
Full Study on the Painted Surface, the Bare Substrates Covered With the Red (1.02 mg/cm2) NIST SRM
Film, and the Bare Substrates.
SHELL
K-shell
L-shell
TYPE OF
SPECIAL*
Special
(60-sec. )
"Special-
special"
{240-sec. )
Special
(60-sec. }
"Special-
special "
(240-sec.)
READING
SURFACE
Paint
NIST
Bare
Paint
NIST
Bare
Paint
NIST
Bare
Paint
NIST
Bare
NUMBER OF
READINGS
601b
601b
600
162
162
0
601b
601b
600
162
162
0
ARITHMETIC
MEAN
0.843
1.128
-0.448
0.691
1.151
na
0.139
1.207
-0.031
0.081
1.201
na
MAXIMUM
23.760
4.041
2.950
14.222
2,911
na
5.098
1.776
2.414
2.445
1.691
na
MINIMUM
-2.929
-0.381
-2.834
-2.601
0.193
na
-1.129
-0.401
-1.234
-0.265
0.391
na
25th
PERCENTILE
-0.486
0.849
-1.129
-0.640
0.910
na
-0.135
1.149
-0.175
-0.138
1.149
na
MEDIAN
0.008
1.112
-0.295
-0.042
1.095
na
-0.060
1.207
-0.138
-0.080
1.205
na
75TH
PERCENTILE
0.840
1.347
0.187
0.804
1.312
na
0.132
1.271
-0.085
0.089
1.263
na
a Nominal reading times are shown in parenthesis.
b One additional reading was taken at a "special" location.
6-473
-------
Table 6-314.
Summary Statistics of Lead Measured in mg/cm2 Units For Standard Readings for the MAP-3 at the
"Special" and "Special-Special" Full Study Locations Taken on the Painted Surface, the Bare Substrates
Covered With the Red {1.02 mg/cm2) NIST SRM Film, the Painted Surface Minus Its Corresponding
Laboratory Result in mg/cm2 From Each Sampling Location, and the Red NIST SRM Film Minus 1.02 mg/cm
For Nominal 15-Second Readings.
SHELL
K
L
TYPE OF
LOCATION
Special
"Special
-special"
Special
"Special
-special"
READING
Paint
NIST
Paint- ICP
NIST-1.02
Paint
NIST
Paint-ICP
NIST-1.02
Paint
NIST
Paint-ICP
NIST-1.02
Paint
NIST
Paint-ICP
NIST-1.02
NUMBER OF
READINGS
600
600
600
600
162
162
162
162
600
600
600
600
162
162
162
162
ARITHMETIC
MEAN
0.8997
1.223
-0.214
0.203
0.660
1.283
-0.232
0.263
0.138
1.189
-0.973
0.169
0.076
1.189
-0.816
0.169
MAXIMUM
25.369
3.983
12.371
2.963
12.884
3.695
2.641
2.675
5.129
1.694
1.523
0.674
2.534
1.694
0.746
0.674
MINIMUM
-4.439
-0.855
-13.231
-1.875
-4.439
-0.292
-4.453
-1.312
-1.275
-0.983
-26.257
-2.003
-1.109
-0.404
-13.870
-1.424
25th
PERCENTILE
-0.385
0.858
-0.702
-0.163
-0.612
0.989
-0.816
-0.031 j
-0.127
1.126
-0.527
0.106
-0.132
1.113
-0.492
0.093
MEDIAN
0.107
1.160
-0.163
0.140
0. 019
1.299
-0.166
0.279
-0.050
1.207
-0.232
0.187
-0.058
1.201
-0.226
0.181
75TH
PERCENTILE
0.888
1.559
0.338
0.539
0.830
1.614
0.401
0.594
-0.150
1.300
-0.130
0.279
0.107
1.299
-0.130
0.279
6-474
-------
Table 6-315.
Summary Statistics of Lead Measured in mg/cm2 Units for First Standard Red NIST SRM Reading Minus 1.02
mg/cm2 for All XRF Instrument Types Except the MAP-3 at Full Study "Special" and "Special-special"
Locations Only.
XRF TYPE
Lead Analyzer K- shell
Lead Analyzer L-shell
Microlead I
X-MET 880
XK-3
XL
NUMBER OF
READINGS
302
302
601
301
602
301
ARITHMETIC
MEAN
0.077
-0.026
0.427
0.076
0.699
-0.001
MAXIMUM
2.280
0.270
26.480
0.460
3.280
0.780
MINIMUM
-1.020
-1.010
-1.620
-0.073
-1.020
-0.420
25th
PERCENTILE
-0.120
-0.040
-0.220
0.029
0.180
-0.120
MEDIAN
0.080
-0.005
0.280
0.071
0.580
-0.020
75TH
PERCENTILE
0.180
0.030
0.680
0.109
1.080
0.080
6-475
-------
Table 6-316.
Summary Statistics of Lead Measured in mg/cm2 Units for First Standard Paint Reading Minus the
Laboratory Result in mg/cm2 For All XRF Instrument Types Except the MAP-3 at Full Study "Special" and
Special-Special Locations Only.
XRF TYPE
Lead Analyzer K- shell
Lead Analyzer L- shell
Microlead I
X-MET 880
XK-3
XL
NUMBER OF
READINGS
302
302
601
295
602
301
ARITHMETIC
MEAN
-0.127
-0.999
0.206
-0.966
0.512
-0.711
MAXIMUM
5.002
0.176
7.858
0.579
7.928
2.040
MINIMUM
-15.783
-28.353
-12.383
-27.577
-20.583
-25.583
25th
PERCENTILE
-0.093
-0.470
-0.218
-0.403
0.098
-0.271
MEDIAN
-0.003
-0.142
0.174
-0.101
0.598
-0.038
75TH
PERCENTILE
0.089
-0.019
0.727
0.024
1.258
0.019
6-476
-------
Table 6-317.
Summary Statistics of Lead Measured in mg/cm2 Units of the Paint and Red (1.02 mg/cm2) NIST SRM
Readings ("Special" Data) For MAP-3 K-shell in Louisville Only.
READING
First Paint
Second Paint
Third Paint
First Red NIST SRM
Second Red NIST SRM
Third Red NIST SRM
NUMBER OF
READINGS
26
26
26
26
26
26
ARITHMETIC
MEAN
1.865
2.096
1.713
1.504
1.592
1.661
MAXIMUM
5.873
8.515
6.455
3.210
2.777
5.784
MINIMUM
0.000
0.000
0.000
0.434
0.000
0.258
25th
PERCENTILE
0.441
0.308
0.000
0.904
1.349
1.065
MEDIAN
1.468
1.357
1.009
1.481
1.680
1.449
75TH
PERCENTILE
2.935
3.407
2.704
1.946
1.982
1.954
Table 6-318.
Summary Statistics of Lead Measured in mg/cm2 Units of the Paint and Red (1.02 mg/cm2} NIST SRM
Readings ("Special" Data) For MAP-3 L-shell in Louisville Only.
READING
First Paint
Second Paint
Third Paint
First Red NIST SRM
Second Red NIST SRM
Third Red NIST SRM
NUMBER OF
READINGS
26
26
26
26
26
26
ARITHMETIC
MEAN
0.384
0.417
0.409
1.366
1.360
1.296
MAXIMUM
2.977
3.210
3 .072
2.026
2.012
1.870
MINIMUM
0.000
0.000
0.000
0.892
0.804
0.576
25th
PERCENTILE
0.000
0.000
0.000
1.156
1.165
1.108
MEDIAN
0.000
0.000
0.000
1.380
1.354
1.328
75TH
PERCENTILE
0.189
0.286
0.225
1.522
1.608
1.461
6-477
-------
Table 6-319.
Summary Statistics of Lead Measured in mg/cm2 Units of the Paint and Red (1.02 mg/cm2) NIST SRM
Readings ("Special" Data) For Microlead I in Louisville Only.
READING
First Paint
Second Paint
Third Paint
Fourth Paint
First Red NIST SRM
Second Red NIST SRM
Third Red NIST SRM
Fourth Red NIST SRM
NUMBER OF
READINGS
26
26
26
26
26
26
26
26
ARITHMETIC
MEAN
1.608
1.654
1.654
1.700
1.361
1.335
1.438
1.554
MAXIMUM
5.600
6.000
5.500
5.700
3.100
3.100
3.100
3.500
MINIMUM
-0.600
-0.600
-0.600
-1.000
0.100
0.300
0.400
0.700
25th
PERCENTILE
0.000
0.100
0.000
0.000
0.700
0.800
0.900
1.000
MEDIAN
0.900
1.050
1.000
1.100
1.400
1.200
1.300
1.450
75TH
PERCENTILE
3.500
3.600
3.600
3.900
1.700
1.800
2.000
1.900
Table 6-320.
Summary Statistics of Lead Measured in mg/cm2 Units of the Paint and Red (1.02 mg/cm2) NIST SRM
Readings ("Special" Data) For X-MET 880 in Louisville Only.
READING
First Paint
Second Paint
Third Paint
Fourth Paint
First Red NIST SRM
Second Red NIST SRM
Third Red NIST SRM
NUMBER OF
READINGS
26
0
0
0
26
0
0
0
ARITHMETIC
MEAN
0.995
na
na
na
1.143
na
na
na
MAXIMUM
4.973
na
na
na
2.478
na
na
na
MINIMUM
0.000
na
na
na
0.130
na
na
na
25th
PERCENTILE
0.143
na
na
na
1.084
na
na
na
MEDIAN
0.337
na
na
na
1.124
na
na
na
75TH
PERCENTILE
1.286
na
na
na
1.171
na
na
na
6-478
-------
Table 6-321.
Summary Statistics of Lead Measured in mg/cm2 Units of the Paint and Red (1.02 mg/cm2) NIST SRM
Readings ("Special" Data) For XK-3 in Louisville Only.
READING
First Paint
Second Paint
Third Paint
Fourth Paint
First Red NIST SRM
Second Red NIST SRM
Third Red NIST SRM
Fourth Red NIST SRM
NUMBER OF
READINGS
26
26
26
26
26
26
26
26
ARITHMETIC
MEAN
1.738
1.754
1.677
1.573
1.427
1.438
1.346
1.435
MAXIMUM
6.000
6.000
5.800
5.600
3.700
3.700
3.100
3.200
MINIMUM
-0.300
-0.600
-0.600
-0.500
0.400
0.400
0.400
0.400
25th
PERCENTILE
0.200
0.300
0.300
0.100
0.900
1.000
0.800
0.900
MEDIAN
0.850
1.000
0.950
0.750
1.300
1.350
1.350
1.400
75TH
PERCENTILE
3.000
2.500
2.400
2.900
1.800
1.900
1.700
1.700
6-479
-------
Table 6-322.
Summary Statistics of Lead Measured in mg/cm2 Units For First Paint Reading (Standard) data for All
XRF Instrument Types at Pilot Study "Special" Locations Only.
XRP TYPE
MAP-3 K-shell
MAP-3 L-shell
Microlead I
X-MET 880
XK-3
NUMBER OF
READINGS
26
26
26
26
26
ARITHMETIC
MEAN
1.842
0.411
1.619
0.966
1.692
MAXIMUM
6.571
3.109
5.500
4.947
6.500
MINIMUM
0.000
0.000
-0.400
0.000
-0.200
25th
PERCENTILE
0.015
0.000
0.300
0.113
0.200
MEDIAN
1.146
0.000
0.850
0.280
0.950
75TH
PERCENTILE
3.629
0.303
3.400
1.248
2.500
Table 6-323.
Summary Statistics of Lead Measured in mg/cm2 Units For First Red NIST SRM Reading (Standard) data for
All XRF Instrument Types at Pilot Study "Special" Locations Only.
XRF TYPE
MAP-3 K- shell
MAP-3 L-shell
Microlead I
X-MET 880
XK-3
NUMBER OF
READINGS
26
26
26
26
26
ARITHMETIC
MEAN
1.452
1.298
1.438
1.130
1.458
MAXIMUM
3.001
1.910
3.500
2.548
3.800
MINIMUM
0.824
0.000
0.100
0.879
0.400
25th
PERCENTILE
1.184
1.109
1.000
0.997
1.100
MEDIAN
1.250
1.345
1.400
1.072
1.400
75TH
PERCENTILE
1.647
1.485
1.800
1.127
1.600
6-480
-------
6.7.2 Summary Statistics for Non-Standard Data
This section provides summary statistics for the non-
standard data that were collected by the eight classifications of
XRF instruments. For an in depth discussion of non-standard data
refer to section 6.1. Non-standard data are XRF readings that
were taken for the pilot study that are not directly comparable
with data collected in the full study and are composed of too few
data to make parameter estimations using model based procedures.
However, comparisons based on summary statistics can be made.
Non-standard data are:
• XRF readings made by the MAP-3 in Louisville.
• XRF readings made by the X-MET 880 in Louisville.
• Variability XRF readings taken on the sampling
locations that followed a change in substrate in
Louisville. (See chapter 3, section 5.2.4 for a
detailed explanation of variability XRF readings).
• XRF readings taken on the bare concrete substrates
covered by the yellow (3.53 mg/cm2) NIST SRM film in
Louisville.
The summary statistics shown in Tables 6-324 and 6-325 are
for XRF readings taken by the MAP-3 and X-MET 880 in Louisville,
respectively. These data were collected during the pilot study.
The data obtained by the X-MET 880 in the pilot study consisted
of only 100 sampling locations. Sufficient data, however, was
collected from locations composed of metal and wood by the X-MET
880 in Louisville to allow limited analyses to be performed.
These data were analyzed separately from the Denver and
Philadelphia data and are presented in section 6.4.
The next six tables, 6-326 through 6-331, provide summary
statistics of the variability readings. In Louisville,
variability readings were taken on the first sampling location
after a change in substrate had occurred. These reading were
taken to examine if the XRF instruments behaved erratically when
changing from one substrate to another. Variability readings
were an additional five repetitions of readings using the same
data collection protocol as was used when the readings were first
taken at that same sampling location. Thus, at each sampling
location after a change in substrate had occurred, a total of six
repetitions of readings were taken using the same data collection
protocol. The latter five were designated as variability
readings.
6-481
-------
All four participating XRF instruments were used to take the
five repetitions of variability readings. Since, in Louisville,
a change in substrate occurred eight times, there were forty
(eight sampling locations times five repetitions) applications of
variability readings taken per XRF instrument. However, the
Microlead I only took variability readings at seven of the
sampling locations after a change in substrate had occurred.
Tables 6-326 through 6-328 show the results for all variability
readings taken on the painted surface of the sampling location.
Tables 6-329 through 6-331 show the results for all variability
readings taken on the red NIST SRM film that had been placed on
the bare substrate area of the sampling location.
To make comparisons, results from standard readings taken at
variability locations in the full study are shown in the next two
tables. Tables 6-332 and 6-333 provide summary statistics for
the first standard paint and the first standard red NIST SRM
readings taken at variability locations, respectively.
The summary statistics for all XRF instrument types show
that the standard paint readings taken prior to the variability
readings at the same locations were very consistent with the mean
of the five variability (first-paint) readings shown in Table
6-326. Similarly, the same is true for the readings taken on the
bare substrate covered with the red NIST SRM film. The Microlead
I, the X-MET 880, and the XK-3 instruments also show very
consistent results when comparing the second and third paint
readings to the variability reading means. (The MAP-3 made only
one paint reading per sampling location except for "special"
readings.) Specifically, the results shown in Table 6-332 are
very consistent with results shown in Tables 6-326, 6-327, and
6-328 as are the results shown in Table 6-333 compared to Tables
6-329, 6-330, and 6-331. This implies that the instruments
remained in control after a change of substrate occurred and that
significant variability did not occur, at least when testing was
performed on like substrate components grouped together as was
done in this study.
Table 6-334 provides results from collecting readings on
concrete substrate in Louisville. According to the data
collection protocol used in Louisville, several additional
readings were made if the substrate was concrete. These
additional readings were made on yellow (3.53 mg/cm2) NIST SRM
film over bare concrete substrate. Table 6-334 provides summary
statistics for each type of reading minus 3.53 mg/cm2. For the
MAP-3 K-shell, the "special" results are consistently greater
than the 60-second or variability results. This same
6-482
-------
relationship was not present for the MAP-3 L-shell. The results
for the Microlead I and X-MET 880 were consistent across data
types. The XK-3 displayed differences across data types.
To make comparisons to standard data results, results from
standard readings taken at locations composed of concrete in
Louisville are shown in the next four tables. Tables 6-335 and
6-336 provide summary statistics for the first paint and red NIST
SRM reading taken at concrete locations in Louisville,
respectively. Tables 6-337 provides summary statistics for the
first standard paint reading minus the corresponding laboratory
result in mg/cm2 at concrete substrate locations in Louisville.
Table 6-338 provides summary statistics for the first red NIST
SRM reading taken from "special" locations in the pilot study
minus 1.02 mg/cm2. Of these four tables, the first standard red
NIST SRM results in Table 6-338 provide the most informative
comparison with the results for readings taken using the yellow
NIST SRM in Table 6-334.
6-483
-------
Table 6-324.
Summary Statistics of Lead Measured in mg/cm2 Units of the MAP-3 Paint and Red (1.02
mg/cm2) NIST SRM Readings (Non-standard) in Louisville Only.
DATA
SOURCE
K-shell
L-shell
Laboratory
READING
Paint
NIST
Paint
NIST
Paint
NUMBER OF
READINGS
100
100
100
100
100
ARITHMETIC
MEAN
2.728
1.560
0.744
1.3679
1.9324
MAXIMUM
21.277
3.958
6.204
2.508
14.047
MINIMUM
0.000
0.200
0.000
0.000
0.0001
25th
PERCENTILE
0.019
1.182
0.000
1.134
0.128
MEDIAN
0.872
1.500
0.000
1.402
0.388
75TH
PERCENTILE
3.598
1.836
0.685
1.563
2.555
Table 6-325.
Summary Statistics of Lead Measured in mg/cm2 Units of the X-MET 880 Non-Standard
Readings, Louisville Only.
READING
First Paint
Second Paint
Third Paint
First NIST SRM
Second NIST SRM
Third NIST SRM
Laboratory
NUMBER OF
READINGS
100
100
100
100
100
100
100
ARITHMETIC
MEAN
1.303
1.299
1.292
1.213
1.196
1.184
1.9324
MAXIMUM
8.065
8.177
8.200
3.093
2.758
2.651
14.047
MINIMUM
0.000
0.000
0.000
0.879
0.902
0.800
0.0001
25th
PERCENTILE
0.095
0.121
0.096
1.045
1.036
1. 047
0.128
MEDIAN
0.301
0.306
0.275
1.134
1.112
1. 130
0.388
75TH
PERCENTILE
2.035
2.003
2.097
1.228
1.202
1.203
2.555
6-484
-------
Table 6-326.
Summary Statistics of Lead Measured in mg/cm2 Units of the First Variability Paint Reading
(Non-Standard Data) For All XRF Instrument Types.
XRF TYPE
MAP-3 K-shell
MAP-3 L-shell
Microlead I
X-MET 880
XK-3
NUMBER OF
READINGS
40
40
35
40
40
ARITHMETIC
MEAN
1.685
0.209
1.683
0.687
1.220
MAXIMUM
5.933
0.944
5.900
2.636
4.900
MINIMUM
0.000
0.000
-0.700
0.000
-0.700
25th
PERCENTILE
0.000
0.000
0.200
0.036
0.000
MEDIAN
0.622
0.000
0.700
0.210
0.400
75TH
PERCENTILE
3.134
0.372
4.200
1.226
2.350
Table 6-327.
Summary Statistics of Lead Measured in mg/cm2 Units of the Second Variability Paint
Reading (Non-Standard Data) For All XRF Instrument Types.
XRF TYPE
MAP-3 K-shell
MAP-3 L-shell
Microlead I
X-MET 880
XK-3
NUMBER OF
READINGS
0
0
35
40
40
ARITHMETIC
MEAN
na
na
1.654
0.682
1.330
MAXIMUM
na
na
5.600
2.522
4.700
MINIMUM
na
na
-0.500
0.000
-0.800
25th
PERCENTILE
na
na
0.000
0.024
0.100
MEDIAN
na
na
0.600
0.171
0.550
75TH
PERCENTILE
na
na
4.700
1.268
2.650
6-485
-------
Table 6-328.
Summary Statistics of Lead Measured in mg/cm2 Units of the Third Variability Paint Reading
{Non-Standard Data) For All XRF Instrument Types.
XRF TYPE
MAP-3 K-shell
MAP-3 L-shell
Microlead I
X-MET 880
XK-3
NUMBER OF
READINGS
0
0
35
40
40
ARITHMETIC
MEAN
na
na
1.737
0.684
1.268
MAXIMUM
na
na
5.600
2.444
4.600
MINIMUM
na
na
-0.800
0.000
-0.400
25th
PERCENTILE
na
na
0.200
0.042
0.100
MEDIAN
na
na
0.900
0.223
0.450
75TH
PERCENTILE
na
na
4.800
1.269
2.700
Table 6-329.
Summary Statistics of Lead Measured in mg/cm2 Units of the First Variability Red (1.02
mg/cm3} NIST SRM Reading (Non-Standard) For All XRF Instrument Types.
XRF TYPE
MAP-3 K-shell
MAP-3 L-shell
Microlead I
X-MET 880
XK-3
NUMBER OF
READINGS
40
40
35
40
40
ARITHMETIC
MEAN
1.320
1.332
1.289
1.132
1.283
MAXIMUM
2.326
1.687
1.900
1.392
3.800
MINIMUM
0.301
1.055
0.400
0.909
0.600
25th
PERCENTILE
0.959
1.213
1.000
1.058
1.000
MEDIAN
1.217
1.342
1.300
1.145
1.200
75TH
PERCENTILE
1.715
1.429
1.600
1.213
1.450
6-486
-------
Table 6-330.
Summary Statistics of Lead Measured in mg/cm2 Units of the Second Variability Red (1.02
mg/cm2) NIST SRM Reading (Non-Standard) For All XRF Instrument Types.
XRF TYPE
MAP-3 K-shell
MAP-3 L-shell
Microlead I
Microlead I
XK-3
NUMBER OF
READINGS
0
0
35
40
40
ARITHMETIC
MEAN
na
na
1.180
1.122
1.243
MAXIMUM
na
na
2.300
1.466
2.000
MINIMUM
na
na
0.000
0.915
0.200
25th
PERCENTILE
na
na
0.900
1.025
0.900
MEDIAN
na
na
1.200
1.136
1.200
75TH
PERCENTILE
na
na
1.500
1.194
1.650
Table 6-331.
Summary Statistics of Lead Measured in mg/cm2 Units of the Third Variability Red (1.02
mg/cm2) NIST SRM Reading (Non-Standard) For All XRF Instrument Types.
XRF TYPE
MAP-3 K-shell
MAP-3 L-shell
Microlead I
X-MET 880
XK-3
NUMBER OF
READINGS
0
0
35
40
40
ARITHMETIC
MEAN
na
na
1.140
1.145
1.143
MAXIMUM
na
na
2.200
1.342
2.200
MINIMUM
na
na
-0.400
0.819
0.400
25th
PERCENTILE
na
na
0.600
1.063
0.900
MEDIAN
na
na
1.200
1.156
1.000
75TH
PERCENTILE
na
na
1.500
1.216
1.300
6-487
-------
Table 6-332.
Summary Statistics of Lead Measured in mg/cm2 Units of the First Standard Paint Reading at
Variability Locations For All XRF Instrument Types.
XRP TYPE
MAP-3 K-shell
MAP-3 L-shell
Microlead I
X-MET 880
XK-3
NUMBER OF
READINGS
8
8
7
8
8
ARITHMETIC
MEAN
1.653
0.208
1.786
0.678
1.300
MAXIMUM
5.369
0.861
5.600
2.457
4.500
MINIMUM
0.000
0.000
-0.400
0.000
-0.100
25TH
PERCENTILE
0.010
0.000
0.100
0.022
0.150
MEDIAN
0.386
0.003
0.700
0.188
0.550
75TH
PERCENTILE
3.532
0.400
5.100
1.276
2.300
Table 6-333.
Summary Statistics of Lead Measured in mg/cm2 Units of the First Standard Red NIST SRM
Reading at Variability Locations For All XRF Instrument Types.
XRF TYPE
MAP-3 K-shell
MAP-3 L-shell
Microlead I
X-MET 880
XK-3
NUMBER OF
READINGS
8
8
7
8
8
ARITHMETIC
MEAN
1.411
1.340
1.400
1.112
1.288
MAXIMUM
2.345
1.594
2.400
1.247
1.900
MINIMUM
0.824
1.121
0.700
0.943
0.800
25TH
PERCENTILE
1.018
1.296
0.900
1.051
1.000
MEDIAN
1.185
1.316
1.500
1.133
1.200
75TH
PERCENTILE
1.856
1.392
1.800
1.168
1.600
6-488
-------
Table 6-334.
Summary Statistics of Lead Measured in mg/cm2 Units of the Yellow (3.53 mg/cm2) NIST SRM Readings
minus 3.53 mg/cm2 (Non-Standard) on Concrete in Louisville Only.
XRF TYPE
MAP- 3 K-shell
MAP-3 L-shell
Microlead I
X-MET 880
XK-3
DATA TYPE
60-seconda
Specialb
Variability*
60 -second*
Special"
Variability"
15 -second0
Special"
Variability"
15-second
Special"
Variability8
15 -second0
Special"
Variability"
NUMBER OF
MEASUREMENTS
8
6
10
8
6
10
24
8
30
24
2
30
24
8
30
ARITHMETIC
MEAN
0.066
0.578
0.165
-0.101
0.189
0.346
-0.167
-0.030
-0.150
0.483
0.565
0.580
-0.730
-0.292
-0.403
MAXIMUM
0.639
1.100
0.739
0.544
0.665
0.985
0.570
0.370
0.570
1.035
0.575
0.904
0.070
0.170
0.470
MINIMUM
-2.017
0.132
-0.498
-2.254
-0.069
-0.158
-1.030
-0.830
-1.130
0.077
0.555
0.220
-1.230
-0.730
-1.230
25th
PERCENTILE
-0.002
0.163
0.086
-0.351
0.007
-0.072
-0.430
-0.230
-0.430
0.357
0.555
0.423
-1.030
-0.630
-0.630
MEDIAN
0.191
0.545
0.151
0.354
0.069
0.248
-0.130
0.120
-0.030
0.443
0.565
0.583
-0.730
-0.180
-0.430
75TH
PERCENTILE
0.541
0.982
0.372
0.450
0.396
0.777
0.170
0.220
0.170
0.658
0.575
0.692
-0.430
-0.080
-0.130
a One 60 -second reading.
b Average of three 15-second readings.
c One 15-second reading.
d Average of four 15-second readings.
6-489
-------
Table 6-335.
Summary Statistics of Lead Measured in mg/cm2 Units For First Paint Reading (Standard) Data for All
XRF Instrument Types at Pilot Study Concrete Locations Only.
XRP TYPE
MAP-3 K-shell
MAP-3 L-shell
Microlead I
X-MET 880
XK-3
NUMBER OF
READINGS
8
8
8
8
8
ARITHMETIC
MEAN
0.754
0.540
1.188
0.542
0.563
MAXIMUM
3.480
3.915
4.000
2.027
2.500
MINIMUM
0.000
0.000
0.000
0.079
-0.700
25th
PERCENTILE
0.000
0.000
0.500
0.111
0.100
MEDIAN
0.025
0.005
0.700
0.289
0.300
75TH
PERCENTILE
1.252
0.196
1.500
0.715
0.950
Table 6-336.
Summary Statistics of Lead Measured in mg/cm2 Units For First Red (1.02 mg/cm2) NIST SRM Reading
(Standard) Data For All XRF Instrument Types at Pilot Study Concrete Locations Only.
XRP TYPE
MAP-3 K-shell
MAP-3 L-shell
Microlead I
X-MET 880
XK-3
NUMBER OF
READINGS
8
8
8
8
8
ARITHMETIC
MEAN
1.583
1.242
1.525
1.092
0.988
MAXIMUM
3.958
1.578
2.100
1.224
1.600
MINIMUM
0.554
0.686
0.900
0.971
0.700
25th
PERCENTILE
0.953
1.146
1.200
1.047
0.700
MEDIAN
1.370
1.301
1.600
1.072
0.950
75TH
PERCENTILE
1.754
1.390
1.800
1.153
1.150
6-490
-------
Table 6-337.
Summary Statistics of Lead Measured in mg/cm2 Units For First Paint Reading (Standard) Data Corrected
by ICP For All XRF Instrument Types at Pilot Study Concrete Locations Only.
XRF TYPE
MAP-3 K-shell
MAP-3 L-shell
Microlead I
X-MET 880
XK-3
NUMBER OF
READINGS
8
8
8
8
8
ARITHMETIC
MEAN
-0.164
-0.378
0.270
-0.376
-0.355
MAXIMUM
-0.036
0.371
0.764
0.094
0.143
MINIMUM
-0.433
-2.324
-0.334
-1.589
-1.044
25th
PERCENTILE
-0.222
-0.251
-0.082
-0.804
-0.835
MEDIAN
-0.138
-0.239
0.397
0.001
-0.192
75TH
PERCENTILE
-0.061
-0.047
0.550
0.047
0.057
Table 6-338.
Summary Statistics of Lead Measured in mg/cm2 Units For First Red NIST SRM Reading (Standard) Data
Minus 1.02 mg/cm2 For All XRF Instrument Types at Pilot Study Concrete Locations Only.
XRF TYPE
MAP-3 K-shell
MAP-3 L-shell
Microlead I
X-MET 880
XK-3
NUMBER OF
READINGS
8
8
8
8
8
ARITHMETIC
MEAN
0.563
0.222
0.505
0.072
-0.033
MAXIMUM
2.938
0.558
1.080
0.204
0.580
MINIMUM
-0.466
-0.334
-0.120
-0.049
-0.320
25th
PERCENTILE
-0.067
0.126
0.180
0.027
-0.320
MEDIAN
0.350
0.281
0.580
0.052
-0.070
75TH
PERCENTILE
0.734
0.370
0.780
0.133
0.130
6-491
-------
Chapter 7 Summary; Data Quality Assurance and Quality Control
• Four types of errors were investigated.
Monitor/Operator errors,
Data Entry errors,
Programming errors, and
"Other" errors.
Several quality control methods and systems were
employed to assure the quality of the field data.
These were:
Data Entry Systems,
Exploratory Data Analysis,
Captured Data Comparisons,
Double Data Entry, and
100 Percent Verification.
Three error rates were computed. The first is the
error rate found through the compare procedure using
captured data, the second is the error rate found
through double data entry, and the third is the
residual error rate remaining in the data sets after
double data entry and captured data comparison
procedures were completed, that is, after completion
of all QC steps.
The overall compare procedure error rate is:
XRF Standard and Non-Standard data: 1.96%,
XRF Control data: 2.00%.
The overall double data entry error rate is:
All XRF data: 0.41%.
The overall residual data entry error rate is:
Sample definition data: 0.07%,
Test kit data: 0.10%,
XRF Standard and Non-Standard data: 0.04%,
XRF Control data: 0.011%.
Laboratory system audits, performance audits, and data
audits were performed by the Senior Quality Assurance
Officer (QAO) for the program who is independent from
the laboratory operation with respect to line
management of the laboratory. An additional
evaluation of the analytical activity was performed
separately by EPA.
-------
7 DATA QUALITY ASSURANCE AND QUALITY CONTROL
7.1 QUALITY ASSURANCE AND QUALITY CONTROL PROCEDURES
Quality control (QC) procedures were employed throughout the
data management process to assure the quality of the field data.
Five data sets were created. The common variable shared by all
five data sets and used to map data between data sets is the
sample identification number. Ideally, each analysis data set
contains at least one record for each sample identification
number. The names of the analysis data sets that were created, a
brief description of each, and the numbers of records and
variables per record included in them are given in Table 7-1.
7.2 ERROR IDENTIFICATION
Although many measures were taken during field work and data
management to minimize the occurrence of errors in the study
data, it is impossible to completely eliminate all errors.
Several types of errors were possible. These error types are
identified below.
Monitor/Operator errors: These are errors that occurred
during the actual testing process when incorrect data was
recorded. For QC discussions, an operator either performs
test kit testing or operates an XRF. A monitor is the XRF
monitor. Examples are: transposition of numbers by operator
or monitor, adding extra decimal places to the reading of a
single decimal place XRF, failure to record data, or reversal
of the XRF reading sign. These errors occur in the Test Kit,
XRF, and XRF Control data sets.
Data Entry errors: These are errors made by the data entry
personnel when entering the data. Examples include number
transposition, entering the wrong data point, misplacement of
the decimal point, and failure to enter data which results in
missing data. Such errors occur more often in the XRF and XRF
Control data sets due to the more complicated data (i.e.,
multiple decimal XRF readings) and larger amounts of data.
Programming errors: These are errors which occur during or
are the direct result of errors in data transfer or analysis.
Examples may be XRF or test kit record mis-identification.
7-1
-------
Table 7-1.
Data Set Descriptions.
DATA SET
SAMPLE
DEFINITION
TEST KIT
XRF
XRF
CONTROL
LABORATORY
CONTENTS
Sample location and substrate
information
Test kit data
Standard and "special" XRF data
excluding control data
Initial, continuing, and ending XRF
control data
Laboratory ICP paint chip analysis
results
NUMBER OF:
RECORDS
1,314
7,185
15,836
5,594
1,314
VARIABLES
PER RECORD
13
7
21
18
18
"Other" errors: "Other" errors are errors that cannot be
attributed to a specific cause. An example of this type of
error would be if a device reacted to the heat of direct
sunlight and recorded extreme measurements. This error is
only present in the XRF and XRF Control data sets.
7.3
QUALITY CONTROL METHODS AND SYSTEMS
7.3.1 Data Entry Systems
Quality control began with data entry. The data entry
personnel used a menu-driven data entry software that provides
the ability to develop specific data entry regimes. Screens
resembling the data forms were designed to facilitate the data
entry process and reduce errors. The data entry software also
performs simple data entry error checks, such as limiting numeric
variables to an assigned range, thus identifying data entry
errors before the information is written to a data file. The
user can sort and list records to identify inconsistent data, and
has easy access to individual records for updating or editing in
the event that an error is identified. Output from this data
entry software were flat files storing data from Philadelphia,
Denver, and Louisville separately.
Output from data entry along with the disk files provided by
the laboratory were input into statistical analysis software
programs that created the analysis data sets.
7-2
-------
7.3.2 Exploratory Data Analysis
Exploratory data analysis methods, derived from the pilot
study, were applied to the Sample Definition, Test Kit, XRF, and
XRF Control data sets. These techniques were used to identify
data errors of large magnitude within these four data sets. Data
errors of smaller magnitude were identified through other means
discussed later in this chapter. Data errors found included data
entry errors, monitor errors, operator errors, programming
errors, and "other" errors. The techniques applied included
data sorts and tabulations, frequency tables, and outlier
analysis using summary statistics and graphics.
Data sorts and tabulations help to point out possible data
entry, operator/monitor, and "other" errors. Data sorts were
performed on the data sets before any other QC was performed.
Data sorts rearrange the observations according to the values of
a specific variable. After the sort, observations out of order
or which exceeded specified ranges were flagged as possible data
errors. For example, a sort of the difference between the test
kit start time and end time was used to identify errors present
in the start and end times. Sorts were performed on the
following variables:
• Time (both start and end times)
• Testing date
• The difference between test kit start time and end
time
• Test kit sampler or XRF operator
• Test kit identification codes
• XRF device identification codes.
Frequency tables were a useful means for providing counts of
categorized data and were applied to the data sets. Also,
frequency counts by values of a variable show error. Count
discrepancies indicated that the type of error could be an
operator/monitor errors or data entry errors. For example, the
number of results categorized by substrate should be equal for
all test kits. Other examples of frequency counts performed for
test kit categorizations and, in similar fashion, for the XRF
results are listed below.
Substrates by test kit
Identification number by unit
Substrate by address
XRF device by operator
Test kit by tester
XRF readings per device
7-3
-------
Once frequency counts were completed and verified, outlier
data point identification was performed on the Test Kit and XRF
data sets. A description of the methodology follows. Specific
groups of XRF and test kit data were created. The arithmetic
means and sample standard deviations were computed for each
grouping. Next, any data point greater than three standard
deviations from its corresponding group mean was flagged as a
possible error. These data points were then verified against
copies of the original data sheets for accuracy. This
methodology was applied to variables stored in the Test Kit, XRF
and XRF Control data sets and was especially useful in
identifying monitor/operator and "other" errors. Most of the
errors identified at this stage were large in magnitude. Smaller
errors were identified through other means, discussed later in
this chapter.
Graphical analyses provided a visual method for detecting data
errors. Scatter plots applied summary statistics and were
designed to detect large errors by comparing XRF readings taken
at the same sampling location. These plots were created for
specific groups of XRF readings from both the XRF and XRF Control
data sets. For each city by XRF device by operator combination,
scatter plots were generated which compared readings performed at
common sampling locations. At each sampling location, several
XRF readings were made. Typically, three readings were performed
on the painted surface (designated here as paint 1, paint 2, and
paint 3, respectively). Likewise, three XRF readings taken on
the red NIST standard and on the bare substrate are designated
red 1, red 2, red 3, bare 1, bare 2, and bare 3, respectively.
Each axis on the scatter plots measures a reading taken at a
sampling location. Scatter plots were created by matching pairs
of readings. For example, the vertical axis measured the paint 1
readings and the horizontal axis measured the paint 2 readings.
The regression of the two variables where the vertical axis
measures the dependent variable was drawn with the 99% confidence
limits on the individual predicted values. Any data point
outside of the 99% confidence limit was researched. Scatter
plots were created for each city by XRF by operator combination
for the pairs of readings given below.
paint 1 vs paint 2
paint 1 vs paint 3
red 1 vs red 2
red 1 vs red 3
bare 1 vs bare 2
bare 1 vs bare 3
7-4
-------
Scatter plots of the average initial control readings versus
the average end control readings were developed using the same
city by XRF device by operator combinations as described above.
When researching data flagged as possible errors, all data was
compared to copies of the original data sheets and information
provided by the operators. Corrections were made where needed.
7.3.3 Captured Data Comparisons
Once the aforementioned exploratory data analysis had been
completed, comparisons of the already entered data versus the
captured data files provided by the XRF operators were performed
using programs written in statistical analysis software.
Comparisons were performed using XRF and XRF Control data sets.
Captured data comparisons are a unique method for identifying and
obtaining missing data and identifying data entry errors, monitor
errors, and operator errors. In a few instances, the captured
data gave indication that a machine error had occurred. All
types of discrepancies found during captured data comparison are
discussed in the Error Rates section. The captured data
comparison methodology is described below.
Data disks storing Denver and Philadelphia data were received
from operators of the two MAP-3 instruments (MAP-3 (I) and MAP-3
(II)), the X-MET 880, and the Lead Analyzer. No data disk were
available from any of the Louisville XRF operators. Complete
data were present from Philadelphia. However, several of the XRF
operators did not provide data for all of the addresses in
Denver. The X-MET 880 data logger was inoperative during testing
of buildings B, I, J, and portions of building H. Also, the
second MAP-3 operator did not provide data from all of buildings
C and D, and portions of building B data. Some data was also
missing because the MAP-3 devices in Denver stored all negative
readings as 0.000 mg/cm2 rather than the actual negative value as
displayed to the operator. This problem did not occur during
testing in Philadelphia because both MAP-3 devices had been
modified to store negative values, however, many negative
readings were incorrectly stored as 0.000 mg/cm2 in the Denver
captured data files. The number of Denver readings incorrectly
stored as a result of this phenomenon is shown in Table 7-2.
Since each XRF device has its own method for data storage, a
more detailed description is given below.
• The MAP-3 devices stored the data in the form of a tabular
listing which included ID number, component structure,
sample number (1-3 for the three paint readings, 4-6 for
the three red NIST readings), K-shell reading, L-shell
reading, soil reading, reading length in seconds, and date
(Figure 7-1).
7-5
-------
Table 7-2. Number of Negative Readings Incorrectly Stored in the MAP-3
Denver Captured Data Files.
DEVICE
MAP-3 (I) K-shell
MAP-3 (I) L-shell
MAP-3 (II) K-shell
MAP-3 (II) L-shell
DATA TYPE
Standard and Special
1167
1531
710
847
Control
751
969
541
619
• The Lead Analyzer stored data in the form of text. The
captured data files included the date, time of reading,
operator entered substrate sequence number, L-shell
reading, and K-shell reading. Figure 7-2 provides an
example. The substrate sequence number denotes the
sample's placement within the current substrate. For
example, the first wood sample within a house would be
labeled 1W. Each wood sample after that would be
sequentially labeled 2W, 3W, etc. If the next substrate"
present in that house was drywall, the first drywall sample
would be labeled ID, with the next samples sequentially
labeled 2D, 3D, etc. The substrate sequence number was
used in place of the identification number.
• The X-MET 880 also stored the data in the form of text,
similar to the Lead Analyzer. The captured data from the
Denver X-MET 880 included the sampling location
identification number, operator input substrate mode, date,
time of reading, length of reading, and reading result
measured in mg/cm2. The operator entered one of four
substrate modes depending upon the underlying substrate of
the sample. Figure 7-3 provides an example. The captured
data collected in Philadelphia contained the same
information, but without an identification number.
To complete the comparison procedure, the captured data files
passed through three stages of processing. Because of the
differing storage formats of the files, the files were modified
from their original form. This is the first stage of captured
data processing. This was done by modifying the captured data
files with a FORTRAN program that would arrange the data into one
common file format.
Output from the FORTRAN program consisted of eight files, one
for each instrument by Denver and Philadelphia combination.
These files entered the second processing stage. The purpose of
the second stage is to properly order records in the captured
data files so that the individual data items can be compared to
7-6
-------
Application:Pb-IN-PAINT Q015 4-JULY-1993
Meas Time: 12-OCT-1993 14:17:38
ID: <43M>
( ) ( )
Value Std. dev.
PbL 0.580052 0.0146903 mg/cm^2
PbK 2.24696 0.257504 mg/cm*2
Application:Pb-IN-PAINT Q015 4-JULY-1993
Meas Time: 12-OCT-1993 14:18:32
ID: <44M>
( ) ( )
Value Std. dev.
PbL 1.01137 0.0191814 mg/cm^2
PbK 1.45181 0.214201 mg/cm*2
Application:Pb-IN-PAINT Q015 4-JULY-1993
Meas Time: 12-OCT-1993 14:19:13
ID: <45M>
( ) ( )
Value Std. dev.
PbL 1.01945 0.0192311 mg/cmA2
PbK 0.568510 0.174674 mg/cm*2
Application:Pb-IN-PAINT Q015 4-JULY-1993
Meas Time: 12-OCT-1993 14:19:50
ID: <46M>
( ) ( )
Value Std. dev.
PbL 1.02456 0.0192766 mg/cm"2
PbK 0.790094 0.188462 mg/cm^2
Application:Pb-IN-PAINT Q015 4-JULY-1993
Meas Time: 12-OCT-1993 14:20:55
ID: <47M>
( ) ( )
Value Std. dev.
PbL 0.119683 0.00678722 mg/cm*2
PbK 2.83148 0.288397 mg/cmA2
Figure 7-2. Example of the Lead Analyzer data storage method.
those of the data set during stage three. A description of the
second processing stage follows.
Along with the expected information, the captured data files
also contained extra data such as additional readings, incorrect
readings (for example, taken with the wrong NIST standard, taken
on the wrong surface, etc.), and the operator's calibration
readings. In a very few cases, unexplained text appeared in
place of readings. Before the captured data and the previously
entered data could be compared, it was necessary to manually edit
and remove extra data from each of the eight files. To
accomplish this, each file was compared with the data set. After
each pass of the comparison procedure, records were identified
7-7
-------
MODEL 3 ?
MODEL 3 ? 2
OLD ASSAY MODEL PBDRYPLAST
MEASURING TIME 15 ? 16
> 41
WHAT?
(MODEL 2: PBDRYPLAST) DATE: 05.08.93 TIME: 10-05-10
MEASURING: PROBE 6 TYPE DOPS (A)
16 SECONDS
ASSAYS :PB 3.694
(MODEL 2: PBDRYPLAST) DATE: 05.08.93 TIME: 10-05-38
MEASURING: PROBE 6 TYPE DOPS (A)
16 SECONDS
ASSAYS :PB 3.766
(MODEL 2: PBDRYPLAST) DATE: 05.08.93 TIME: 10-06-06
MEASURING: PROBE 6 TYPE DOPS (A)
16 SECONDS
ASSAYS :PB 3.712
Figure 7-3. Example of the X-MET 880 data storage method.
for output. These records were output because they belonged to a
group of mismatched records. Records became mismatched when, for
example, missing or extra data was present in the captured data
files. Those records output were visually compared with the
project data sheets and adjustments made where necessary. In
most cases, the reason for the mismatch was that an extra reading
had been performed (for example, one or two additional readings
per identification number) or readings were not saved to the
captured data file. Frequently there were comments from the
operator on the field data sheet explaining the presence of extra
readings. Additional readings were only used when operator
comments indicated the original reading was incorrectly tested.
For each mismatch, the problem was corrected so that the order of
records would be properly matched.
Next, the captured data files entered the third and final
stage of processing. In this stage, the comparison procedure was
again performed, but instead of comparing the order in which
readings occur, individual data items were compared. A
description of the final processing stage follows.
For each XRF device, XRF readings were compared for
observations with matching identification data (eg. ,
identification number, sample number, etc.), and to be considered
7-8
-------
ID#
355
355
355
355
355
355
356
356
356
356
356
356
357
357
357
357
357
357
358
358
358
358
358
358
359
359
359
359
359
359
359
Comp Sample*
Struct
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
7
K-Shell L-Shell
mg/cm"^ mg/cmA2
0.
0.
0.
1.
1.
0.
0.
0.
0.
0.
1.
0.
0.
0.
0.
0.
1.
0.
0.
0.
0.
0.
1.
0.
0.
1.
0.
0.
0.
0.
1.
000
000
000
129
642
891
000
000
000
959
065
982
170
000
000
158
221
873
000
000
000
822
364
814
000
006
000
368
384
633
216
0.
0.
0.
1.
1.
1.
0.
0.
0.
1.
1.
1.
0.
0.
0.
1.
1.
1.
0.
0.
0.
1.
1.
1.
0.
0.
0.
0.
1.
1.
1.
000
003
000
224
354
306
050
000
025
286
281
207
000
000
000
215
331
221
040
000
000
189
373
219
450
397
400
367
401
454
351
Pb-Soil Time Date
ppm seconds
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
16
16
16
16
16
16
16
16
16
16
16
16
16
16
16
16
16
16
16
16
16
16
16
16
16
16
16
16
16
16
16
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Figure 7-1. Example of the MAP-3 data storage method.
a match the data set had to exactly match the captured data. Any
readings which did not match the captured data were researched
against copies of the original field data sheets, documented and
corrected if needed. However, it was found that in most
instances the Lead Analyzer captured data and both Denver MAP-3
captured data files did not exactly match the data set.
As a result of their storage of negative values as 0.000
mg/cm2, no negative MAP-3 data set readings from Denver matched
their captured data counterparts. To contend with this, the
compare code converted all negative data_set readings to 0.000
mg/cm2, eliminating the mismatch during the compare procedure,
but not guaranteeing error free data. For example: if a
negative reading was incorrectly recorded or entered as another
negative reading, it would still exactly match the captured data
reading because they would both be compared as 0.000 mg/cm2.
Only if the negative reading was incorrectly recorded as a
positive reading, or incorrectly entered as a positive reading
would it be identified as an error through the compare procedure.
Again, data from the MAP-3 devices used in Philadelphia did not
present this problem.
7-9
-------
In addition to the MAP-3 data storage problem, the Lead
Analyzer also presented a data storage problem. In many cases
throughout Denver and Philadelphia testing, the Lead Analyzer had
rounded the actual value of the reading when it was displayed to
the operator, but stored the complete reading in the captured
data. As a result, the compare procedure identified a majority
of readings as mismatched data. To prevent this, the comparison
procedure for the Lead Analyzer was changed so that the data set
value had to be at least ± 0.05 mg/cm2 different from the
captured data value to be considered a mismatch. This method was
useful for identifying significant discrepancies between the
captured data and data sets, however, small discrepancies of
magnitude less than 0.05 mg/cm2 were not identified through this
process.
All types of discrepancies found during captured data
comparison are discussed in the Error Rates section.
7.3.4 Double Data Entry
Double data entry comparisons were performed on the XRF data
set for the XL, XK-3, and Microlead I XRF devices, because
captured data were not available for comparison. Double data
entry comparisons were also performed on the XRF data from those
buildings missing data in the MAP-3 and X-MET 880 captured data
files from Denver.
Double data entry was performed at the same time, but
independent of the captured data comparison process. Data entry
personnel entered the XRF instrument, sample identification
number, and XRF readings into a data base. The resulting file
was input into a statistical analysis software program and
compared with the original XRF data set. Discrepancies between
the two data sets were researched. Data entry errors were the
only discrepancy types identifiable through double data entry
comparisons. All types of discrepancies found during double data
entry comparison are discussed in the Error Rates section.
7.3.5 100 Percent Verification
For some study data, every item of every record was compared
to copies of the original data sheets. This procedure will be
referred to as 100% verification and was performed for the
following:
• Sample Definition data set
• Louisville test kit and XRF data
• XRF Control data set
100% verification was done for the Sample Definition data set,
XRF Control data set, and Louisville test kit and XRF data
because it reduced data errors while remaining time efficient due
7-10
-------
to the size of these data sets. 100% verification can identify
only data entry errors.
7.4 ERROR RATES
Three different error rates were computed. The first is the
error rate found through the compare procedure using the captured
data. The second is the error rate found through double data
entry. The third is the residual error rate remaining in the
data sets even after double data entry and captured data
comparison procedures were completed, that is, after completion
of all QC steps. Whenever possible, error rates have been broken
down to individual test kits or XRF instruments. These three
error rates are summarized below.
It is important to note that all data error rates were
computed on the basis of data items, not records. By
convenience, all samples were randomly selected using records as
the sampling unit. However, each record contains between 8 and
21 data items, depending upon the data set from which it was
retrieved. The formula for computing the error rate is the
number of data item errors divided by the number of data items in
the sample. Data items were used instead of records as the basis
for computing error rates because an error rate computed in this
manner is more indicative of the true error rate than an error
rate computed on the basis of records. This is supported by the
random occurrence of the errors by item and that multiple errors
in a single record are rare. For example, one datum in error on
a record does not cause the remaining record data items to be in
error.
7.4.1 Comparison Discrepancies
After comparisons had been completed using captured data and
double data entry, there were three types of discrepancies
identified. All of the identified discrepancies described below
were corrected.
1) Monitor/Operator errors: These are errors that occur
during the actual testing process. Such errors encompass
transposition of numbers by operator or monitor, adding extra
decimal places to the reading of a single decimal place XRF,
failure to record the necessary data, etc.
2) Data Entry errors: These are errors made by the data
entry personnel when entering the data. They include number
transposition, entering the wrong data point, misplacement of
the decimal point, etc. Data entry errors are the only
discrepancy type identified by double data entry comparisons.
3) Undetermined Discrepancies: Some discrepancies which were
identified by the captured data comparison could not be
7-11
-------
attributed to a specific cause. The cause of the discrepancy
cannot be determined but it is known that they are not data
entry errors. The cause could be an "other" error, or a
monitor/operator error. Due to the nature of this
discrepancy, it was not possible to determine whether the
captured data was correct or whether the field data sheet was
correct. In the event of a undetermined discrepancy, the
value on the field data sheet was not changed.
Error rates for data within the XRF data set {standard and
"special" XRF measurements) determined through the captured data
compare process are shown in Table 7-3. The error rates are
.categorized by discrepancy type for each XRF. Table 7-4 contains
error rates computed through captured data comparisons for data
from the XRF control data set. Data entry error rates for data
from the XRF data set from those devices without captured data
were determined through the double data entry process and are
shown in Table 7-5. Note that the data entry error rates are
much lower than the monitor/operator error rates computed from
captured data comparisons. Total error rates for the XRF data
set are displayed in Table 7-6 and are categorized by discrepancy
type. Table 7-7 contains the error rates categorized by
discrepancy type for the XRF control data set.
The magnitude of the three types of errors/discrepancies
identified by comparing the captured data files to the data sets
is given in Tables 7-8 through 7-10. Computed for each
identified error/discrepancy was the difference and absolute
difference between the value found in the data set and the value
found in the captured data file. Table 7-8 provides the sample
size, arithmetic mean, sample standard deviation, minimum, 25th
percentile, median, 75th percentile and maximum of XRF standard
and "special" measurements for each type of discrepancy. Tables
7-9 and 7-10 display the same summary statistics as Table 7-8,
but for the XRF control data set and the two data sets combined,
respectively. A frequency plot of the absolute difference
categorized by magnitude of the difference is provided in Figure
7-4. Each category represents the number of discrepancies with
absolute differences within a 0.2 mg/cm2 range. In Figure 7-4,
the categories are labeled by their corresponding range midpoint
except for the category labeled "2.0+". The range for this
category are all absolute differences greater than 1.8 mg/cm2.
The range for the smallest category includes all values less than
0.2 mg/cm2.
7.4.2 Residual Error Rates
After data entry, exploratory data analysis, captured data
comparisons, double data entry comparisons, and 100% verification
were completed, random samples of each analysis data set were
selected for visual verification against copies of the field data
sheets. A stratified sampling scheme was used to randomly select
7-12
-------
Table 7-3. Error Rates from Denver and Philadelphia Captured Data
Comparison Procedure of XRF Standard and "Special" Readings.
Errors are Listed for each Discrepancy Type.
DEVICE
Lead Analyzer
K- she 11
Lead Analyzer
L-shell
MAP- 3 (I) K- shell
MAP-3 (I) L-shell
MAP-3 (II) K-shell
MAP-3 (II) L-shell
X-Met 880
TOTAL
SAMPLE
SIZE
7,986
7,986
8,038
8,043
6,363
6,363
6,163
50, 942
DISCREPANCY TYPE
Mon . /Oper Error
Data Entry Error
Undetermined Discrepancy
Mon . /Oper . Error
Data Entry Error
Undetermined Discrepancy
Mon . /Oper . Error
Data Entry Error
Undetermined Discrepancy
Mon . /Oper . Error
Data Entry Error
Undetermined Discrepancy
Mon . /Oper . Error
Data Entry Error
Undetermined Discrepancy
Mon . /Oper . Error
Data Entry Error
Undetermined Discrepancy
Mon. /Oper. Error
Data Entry Error
Undetermined Discrepancy
NO. OF
ERRORS
35
45
20
22
15
3
66
66
16
72
38
36
155
20
71
213
14
33
35
43
1
1,019
% ERROR
RATE
0.44
0.56
0.25
0.28
0.19
0.04
0.82
0.82
0.20
0.90
0.47
0.45
2.44
0.31
1.12
3.35
0.22
0.52
0.57
0.70
0.02
2.00
10% of the total number of records from each data set. The data
were stratified by city and XRF device or test kit. This process
resulted in samples that will be referred to as the 10% random
sample. Code was written in statistical analysis software to
perform the random selection process. Estimates of the residual
data entry error rates were made from the 10% random sample.
Only the residual data entry error rate can be estimated.
However, we would expect that monitor/operator errors in the
7-13
-------
Table 7-4. Error Rates from Denver and Philadelphia Captured Data
Comparison Procedure of XRF Control Readings. Error Rates are
Listed for each Discrepancy Type.
DEVICE
Lead Analyzer
K- shell
Lead Analyzer
L- shell
MAP- 3 (I) K- shell
MAP-3 (I) L-shell
MAP-3 (II) K-shell
MAP-3 (II) L-shell
X-MET 880
TOTAL
SAMPLE
SIZE
3,807
3,807
5,037
5,032
3,881
3,881
2,590
28,035
DISCREPANCY TYPE
Mon . Oper . Error
Data Entry Error
Undetermined Discrepancy
Mon . /Oper . Error
Data Entry Error
Undetermined Discrepancy
Mon . /Oper . Error
Data Entry Error
Undetermined Discrepancy
Mon. /Oper. Error
Data Entry Error
Undetermined Discrepancy
Mon . /Oper . Error
Data Entry Error
Undetermined Discrepancy
Mon . /Oper . Error
Data Entry Error
Undetermined Discrepancy
Mon. /Oper. Error
Data Entry Error
Undetermined Discrepancy
NO. OF
ERRORS
22
4
35
4
0
5
30
13
7
36
11
24
107
20
38
141
14
28
6
4
0
549
% ERROR
RATE
0.58
0.11
0.92
0.11
0.00
0.13
0.60
0.26
0.14
0.72
0.22
0.48
2.76
0.52
0.98
3.63
0.36
0.72
0.23
0.15
0.00
1.96
instruments without captured data (XL, X-MET 880, and Microlead
I) to occur less frequently than those instruments with captured
data. This is due to the fact that the captured data instruments
have multiple decimal place readings while those instruments
without captured data have single decimal place readings. Of the
monitor/operator errors identified through captured data
comparisons, 50.53 percent occurred in the decimal numbers to
the right of the first decimal place. Also, five of the seven
errors found through 10% random verification occurred in the
7-14
-------
Table 7-5. Data Entry Error Rates from Denver and Philadelphia Double Data
Entry Comparison Procedure Categorized by Device.
DEVICE
MAP-3 (II) K-shell
MAP-3 (II) L-shell
Microlead I (I)
Microlead I (II)
X-MET 880
XK-3 (I)
XK-3 (II)
XL
TOTAL
SAMPLE SIZE
1,547
1,547
9,252
9,266
9,273
9,239
9,266
9,273
51,684
NO. OF ERRORS
9
13
44
24
25
52
39
25
212
% ERROR RATE
0.58
0.84
0.48
0.26
0.27
0.56
0.42
0.27
0.41
Table 7-6. Error Rates from Denver and Philadelphia Captured Data
Comparison Procedure for 50,942 XRF Standard and "Special1
Readings Listed by Discrepancy Type.
DISCREPANCY TYPE
Mon . /Oper . Error
Data Entry Error
Undetermined Discrepancy
All Types Combined
CAPTURED DATA
NO. OF ERRORS
598
241
180
1,019
% ERROR RATE
1.17
0.47
0.35
2.00
Table 7-7. Error Rates from Denver and Philadelphia Captured Data
Comparison Procedure for 28,035 XRF Control Readings Listed by
Discrepancy Type.
DISCREPANCY TYPE
Mon. /Oper. Error
Data Entry Error
Undetermined Discrepancy
All Types Combined
CAPTURED DATA
NO. OF ERRORS
346
66
137
549
% ERROR RATE
1.23
0.24
0.49
1.96
7-15
-------
Table 7-8. Summary Statistics from Denver and Philadelphia Captured Data
Comparison Procedure of XRF Standard and "Special" Measurements
Listed by Discrepancy Type.
STATISTIC
Difference
mg/cm2
Absolute
Difference
mg/cm2
Sample Size
Mean
STD Deviation
Minimum
25th Percentile
Median
75th Percentile
Maximum
Sample Size
Mean
STD Deviation
Minimum
25th Percentile
Median
75th Percentile
Maximum
MON./OPER.
ERROR
598
0.026
0.773
-3.796
-0.072
0.001
0.133
6.108
598
0.381
0.673
0.001
0.008
0.100
0.500
6.108
DATA ENTRY
ERROR
226
-0.004
0.605
-3.000
-0.104
-0.005
0.089
3.322
226
0.322
0.512
0.000
0.029
0.090
0.375
3.322
UNDETERMINED
DISCREPANCY
180
0.307
0.866
-3.374
0.020
0.133
0.866
2.622
180
0.615
0.682
0.001
0.098
0.344
1.076
3.374
readings of XRFs with multiple decimal numbers. The other two
errors occurred in data fields other than XRF reading results. No
errors were found in readings from 10% random samples of XRF
instruments that output only a single decimal number.
7.4.2.1 Residual Data Entry Error Rates
The residual data entry error rates for the four data sets
{Laboratory data set QC is discussed in section 7.5) are
summarized below.
• One error was found out of 1,424 data items in the 10%
random sample of the Sample Definition data set equalling a
data entry error rate of 0.07 percent.
• The data entry error rate computed from the 10% sample of
the Test kit data set is five errors in 5,020 data items
equaling 0.10 percent.
7-16
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Table 7-9. Summary Statistics from Denver and Philadelphia Captured Data
Comparison Procedure of XRF Control Readings Listed by
Discrepancy Type.
STATISTIC
Difference
ing /cm2
Absolute
Difference
mg/cm2
Sample Size
Mean
STD Deviation
Minimum
25th Percentile
Median
75th Percentile
Maximum
Sample Size
Mean
STD Deviation
Minimum
25th Percentile
Median
75th Percentile
Maximum
MON./OPER.
ERROR
346
0.021
0.897
-3.000
-0.100
0.001
0.180
5.984
34S
0.457
0.773
0.000
0.009
0.153
0.600
5.984
DATA ENTRY
ERROR
66
-0.038
0.881
-6.174
-0.050
0.000
0.060
1.412
66
0.348
0.809
0.000
0.020
0.052
0.481
6.174
UNDETERMINED
DISCREPANCY
137
-0.499
7.655
-73.664
-0.041
0.100
0.642
3.409
137
1.481
7.526
0.001
0.100
0.241
0.918
73.664
Data entry error rates for the XRF data set are shown in
Table 7-11. In this sample, 75 records from Denver and 44
records from Philadelphia were randomly selected
independently for each XRF device. Note that the third and
fourth columns of Table 7-11 describe errors concerning the
actual reading values, whereas the fifth and sixth columns
comprise errors in other variables such as date, time,
operator, etc. The percent error rates for each error type
were computed using that portion of the 'Total Number of
Items' composed only of data items from the variables
associated with that error type. The '% Overall Rate' is
computed using the 'No. of XRF Errors' over the 'Total
Number of Items'. Notice that four out of five of the XRF
reading errors occur in the Lead Analyzer readings. These
four were not observed during the captured data comparison
process because they fell within the ± 0.05 mg/cm2
allowance for rounding.
7-17
-------
Table 7-10.
Summary Statistics from Denver and Philadelphia Captured Data
Comparison Procedure of XRF Standard, "Special" and Control
Readings Listed by Discrepancy Type.
STATISTIC
Difference
mg/cm2
Absolute
Difference
mg/cm2
Sample Size
Mean
STD Deviation
Minimum
25th Percentile
Median
75th Percentile
Maximum
Sample Size
Mean
STD Deviation
Minimum
25th Percentile
Median
75th Percentile
Maximum
MON./OPER.
ERROR
944
0.024
0.820
-3.796
-0.080
0.001
0.151
6.108
944
0.409
0.712
0.000
0.008
0.100
0.529
6.108
DATA ENTRY
ERROR
292
-0.011
0.676
-6.174
-0.081
-0.005
0.081
3.322
292
0.328
0.591
0.000
0.027
0.081
0.400
6.174
UNDETERMINED
DISCREPANCY
317
-0. 041
5.080
-73.664
-0.005
0.105
0.690
3.409
317
0.989
4.982
0.001
0.100
0.271
1.000
73.664
• Even though the XRF Control data set had 100% verification
performed, a 10% random sample was still selected for
residual error rate determination. One error was found in
the XRF Control data set. With 9,443 items in the sample
the resulting error rate was 0.011% for the XRF Control
data set.
7.5 RESULTS OF LABORATORY AUDITS
An evaluation of the laboratory analysis activity was
performed by the Senior Quality Assurance Officer (QAO) for the
program who is independent from the laboratory operation with
respect to line management of the laboratory. The evaluation
procedures and results, including system audits, performance
audits, and data audits are discussed in sections 7.5.1, 7.5.2,
and 7.5.3. An audit is a systematic evaluation to determine the
quality of the operational function.
7-18
-------
NUMBER OF DISCREPANCIES
Horizontal axis measures the magnitude of the discrepancy
Number
900
800 -
700 -
600 -
500 -
400 -
300 -
200 -
100 -
\
C
±
TYPE
000011111
357913579
Absolute Difference Midpoints
Monitor/Operator
Data Entry
Unknown
2
:
Figure 7-4. Frequency plot of the absolute differences of the
errors found through the Denver and Philadelphia
captured data comparison process.
7-19
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Table 7-H. Residual Data Entry Error Rates and Counts in the XRF NORM Data Set.
DEVICE
Lead Analyzer
K-shell
Lead Analyzer
L-shell
MAP-3 K-shell
(I)
MAP-3 L-shell
(I)
MAP-3 K-shell
(II)
MAP-3 L-shell
(ID
Microlead (I)
Microlead (II)
X-MET 880
XK-3 (I)
XK-3 (II)
XL
TOTAL
TOTAL
NUMBER OF
ITEMS
1,613
1,616
1,547
1,541
1,536
1,540
1,644
1,681
1,613
1,628
1,634
1,646
19,239
No. XRF
ERRORS
1
3
1
0
0
0
0
0
0
0
0
0
5
% XRF
ERROR
RATE
0.13
0.38
0.14
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.05
No. OTHER
ERRORS
0
0
0
0
0
0
0
0
0
0
1
1
2
% OTHER
ERROR
RATE
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.12
0.12
0.02
TOTAL NO.
ERRORS
1
3
1
0
0
0
0
0
0
0
1
1
7
% OVERALL
RATE
0.06
0.19
0.06
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.06
0.06
0.04
7-20
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An additional evaluation of the analytical activity was
performed separately by EPA. Results of these audits are
presented in section 7.5.4.
7.5.1 System Audit
The system audit for this work was a qualitative examination
of the facility and the conduct of the analytical task which is
all the work required to analyze samples. Requirements for the
facility and the conduct of the analytical task are different and
therefore, a separate inspection was performed for each. The
results of the system audits are given below.
7.5.1.1 Facility Inspection
Facility inspections at the laboratory are performed on a
quarterly basis. The items covered in the facility inspection
were the equipment, sample and standards storage, and documen-
tation. The facility was found to be adequately maintained. The
equipment necessary for the operation of the facility was
available and in operational condition. Calibration and
maintenance of the equipment were documented in instrumental log
books and were found to be current. No systematic problems were
seen with the facility or with the equipment and the associated
documentation for the equipment.
7.5.1.2 Analytical Task
The system audit of the analytical task was conducted in
August, 1993. The areas inspected during the audit were
personnel qualifications, sample control, sample preparation
techniques (on samples similar to those to be analyzed for this
work), and Standard Operating Procedures. A detailed listing of
items checked during a system audit is presented in Table 7-12.
A separate inspection of the homogenization technique used for
the paint chips was conducted during the initial testing in April
1993. No systematic problems were observed during this audit.
7.5.2 Performance Audit
Three Performance Evaluation Samples (PESs) were prepared for
each sample preparation batch. The PESs were prepared by the
project sample custodian using a National Institute of Standards
and Technology (NIST) Standard Reference Material (SRM) and two
American Industrial Hygiene Association (AIHA) materials as
discussed in section 3.2.2. The lead levels were determined
through round robin testing performed under the Environmental
7-21
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Table 7-12. Table of Items Checked During the Laboratory System Audit.
Category
Items Checked
Personnel
Qualifications
Safety—Chemical Hygiene Plan
Training
Facilities
Adequacy
Housekeeping
Maintenance
Safety
Security
Equipment
Adequacy
Maintenance
Safety
Security
Standard Operating Procedures
Sample Control
Personnel
Equipment
Facilities
Standard Operating Procedures
Sample Preparation
Personnel
Equipment
Facilities
Standard Operating Procedures
Instrumental Measurement
Personnel
Equipment
Facilities
Standard Operating Procedures
Data Collection—Validation and
Verification
Personnel
Equipment
Facilities
Standard Operating Procedures
Standard Operating Procedures
Corporate
Department
Section
Project Specific
Documentation
Personnel—Qualifications and
Training
Facilities SOPs
Equipment SOPs
Data—Samples, Standards, and
Quality Control Collection
Validation and Verification
Archival
Sample Handling as Defined by
the Quality Assurance Project
and Work Plans
Collection
Preparation
Analysis
Storage
Disposal
7-22
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Lead Proficiency Analytical Testing (ELPAT) Program. The NIST
SRM No. 1579a containing 11.995% lead was used as a high, lead-
level reference material. The same ELPAT material was used for
the two PESs in each batch. Four different ELPAT lead
concentrations used during the study were 0.2007%, 0.3809%,
3.218%, and 9.5536%.
The results of the blind samples are reported in
section 4.4.2.2 Figures 4-30, 4-31, and 4-32. Results, in terms
of the data quality objectives, are discussed in section 2.2.4.
One control situation with the NIST SRM, which did not meet the
accuracy objectives at the start of the Philadelphia sample
analyses, was found during a data audit and is discussed in
section 7.5.3.
7.5.3 Data Audit
The data audit is a qualitative and a quantitative evaluation
of the documentation and procedures associated with the
measurements to verify that the resulting data are of known and
acceptable quality. The analytical data were audited using the
criteria given in Table 2-18 for the instrumental quality control
and Table 2-16 for the method performance. Both tables can be
found in the design elaboration section of the report, section
3.3.2. Selected data in 100% of the instrumental measurement
batches were audited. The instrumental measurement batches
consisted of one or more sample preparation batches. Analyses
within each instrumental measurement batch were randomly selected
following the American National Standard Sampling Procedures by
Attributes, MIL-STD-105-D. These sampling procedures specify the
number of analyses in each instrumental measurement batch that
must be sampled to guarantee that the fraction of unacceptable
analyses in the batch is less than 5% at the 95% confidence
level. Acceptability of an analysis is defined as per data and
measurement quality objectives defined in the study plans.
Randomly selected analytical results from each instrumental
measurement batch were followed through the analytical process to
evaluate the data generation and reporting system for systematic
problems and to follow the audit trail. This procedure starts
with the reported data and back calculates this number to the
original raw data output (instrument response). Then the sample
is tracked through each step of the analytical process, as
documented in the notebook and other analytical records, to the
instrumental measurement. The raw data and documentation for the
analysis process includes but is not limited to the weighing
records, the laboratory notebook entries, instrumental output,
and summary tables containing final calculated data.
7-23
-------
Of the 3,765 ICP measurements in this study, approximately 18%
of the analytical results in 26 instrumental measurement batches
were audited. The audits found that the data folder format
provided a systematic means for ensuring a complete audit trail.
The audit of the analytical results found no systematic problems
in sample preparation, instrumental measurement, or generation of
the analytical data.
The data audit for the full study data included a 100% check
of data for 270 randomly selected paint sample results from the
full study. From this check, a total of 9 random errors were
detected and corrected prior to releasing the data for further
statistical analysis testing.
Only one systematic error was found during the data auditing
process, as noted in section 7.5.2, where the low recoveries
resulted in a control situation in specific sample preparation
batches for the NIST blind PESs that indicated a systemic
problem. The change in control posture for these sample
preparation batches was investigated, resulting in no
explanation. To evaluate if the low recoveries had an effect on
the field sample results in these sample preparation batches,
experiments were performed as discussed in sections 4.4.2.2.1 and
4.4.2.2.2. The statistical evaluation of the results from these
experiments indicated that the results from the questionable
sample preparation batches are consistent with those of
acceptable sample preparation batches, therefore, a systematic
problem is unlikely.
7.5.4 Results of EPA Audits
Several audits were conducted on study activities both in the
field and the laboratory by the EPA work assignment manager.
These audits included the evaluation of the field training
conducted for the test kit operators and the performance of field
test kit supervisors overseeing the operators. A system audit on
laboratory operations was conducted during the initial analysis
of sample preparation and instrumental measurement batches
associated with the full study. Data audits conducted included
the evaluation of laboratory data values associated with 75 final
sample results. These audits included the review of over 700
values tracing the raw sample data and the associated quality
control sample values affiliated with the final results through
the system to the final reported data. No errors were revealed
in the data audits.
7-24
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8. BIBLIOGRAPHY
[1] Title X--Residential Lead-Based Paint Hazard Reduction Act of
1992, Public Law 102-550.
[2] United States Department of Housing and Urban Develpment
(1990), "Lead-Based Paint: Interim Guidelines for Hazard
Identification and Abatement in Public and Indian Housing",
Office of Public and Indian Housing, Washington DC 20410.
[3] Williams, E.E., Binstock, D.A., O'Rourke, J.A., Grohse, P.M,
and Gutknecht, W.F., (Draft 1992, revised September 1994),
"Evaluation of Procedures for Measuring Lead in Paint, Soil
and Dust Utilizing Hot Plate and Microwave-Based Acid
Extractions and Atomic Absorption and by Inductively Coupled
Plasma Emission Spectrometry", RTI/RTP, North Carolina, EPA
Contract No. 68-02-4550, EPA No. 600/R-94/147.
[4] Lide, David R. , Editor-in-Chief, CRC Handbook of Chemistry and
Physics, 74th Edition, 1993-94.
[5] United States Department of Housing and Urban Develpment
(1992), "Lead-Based Paint: Interim Guidelines for Hazard
Identification and Abatement in Public and Indian Housing",
unpublished revision of chapter 4.
[6] Pella, P.A., McKnight, M., Murphy, K.E., Vocke, R.D., Byrd,
E., DeVoe, J.R., Kane, J.S., Lagergren, E.S., Schiller, S.B.,
and Marlow, A.F., "NIST SRM 2579 Lead Paint Films for Portable
X-Ray Fluorescence Analyzers", Lead Poisoning: Exposure,
Abatement, Regulation, Breen, J.J., and Stroup, C.R., Editors,
CRC Press, 1995.
[7] Chatterjee, S., and Price, B. (1977), Regression Analysis by
Example, New York: John Wiley.
[8] Barlow, R.E., Bartholomew, D.J., Bremner, J.M., and Brunk,
H.D. (1972), Statistical Inference under Order Restrictions,
New York: John Wiley.
[9] Stefanski, L.A. and Carroll, R.L. (1990) , "Structural Logistic
Regression Measurement Error Models," Contemporary
Mathematics, 112, 115-127.
[10] Whittemore, A.S. and Keller, J.B. (1988), "Approximations for
Regression with Covariate Measurement Error," Journal of the
American Statistical Association, 83, 1057-1066.
[11] Stefanski, L.A. (1989) , "Correcting Data for Measurement Error
in Generalized Linear Models," Communications in Statistics,
Part A--Theory and Methods, 5, 1715-1733.
8-1
-------
[12] Warrington Inc., "Microlead I Revision 4 Instruction Guide",
2113 Wells Branch Parkway, Suite 6700, Austin, Texas 78728.
[13] Bishop, Y.M.M., Fienberg, S.E., and Holland, P.W. (1975),
Discrete Multivariate Analysis: Theory and Practice,
Cambridge: MIT Press.
8-2
-------
9.
GLOSSARY
The terms presented in this glossary are defined specifically for
this report and are not intended as universal definitions for
these terms across other projects or work. Defined terms that
appear within definitions for other terms are presented in
italics.
area units
Expression of the lead level as the mass of
lead in the specimen divided by the area of
the specimen. The units were reported in
milligrams per centimeter squared (mg/cm2) .
bare substrate
A building component targeted for testing that
had been scraped clean of paint.
baseline
probability
(rate) of
positives,
negatives
For a lead testing method, the baseline
probability (rate) of positives is the
probability of a positive result in the
absence of lead in paint. The
.baseline probability (rate) of negatives is
the probability of a negative result in the
presence of maximal lead content.
batching
See sample batching.
beginning
control block
reading
A quality control XRF reading performed on a
control JblocJc at the beginning of a testing
day.
bias
The systematic tendency of a measurement
process to either underestimate or
overestimate the quantity of interest. Bias
and variability together describe the accuracy
and precision of the process, respectively.
bias
correction
A method for removing the bias present in an
XRF measurement. The three methods considered
in the study were control correction, full
correction, and red NIST SRM averaged
correction.
9-1
-------
blind
reference
material
A paint sample originating from the National
Institute of Standards and Technology (NIST)
that has a precisely known level of lead.
These samples were submitted for analysis
along with other field samples in a manner
blind to the laboratory personnel performing
the analysis.
blind
performance
material
A paint sample originating from the American
Industrial Hygiene Association (AIHA) that has
a level of lead determined from round robin
analysis. These samples were submitted for
analysis along with other field samples in a
manner blind to the laboratory personnel
performing the analysis.
bootstrap
A statistical technique for estimating the
Mas, standard error, or other attributes of
an estimator, which entails randomly recycling
the sample data through computer simulation.
classification
Designation of a specimen as having a high or
low lead level relative to a fixed criterion,
such as the 1.0 mg/cm2 federal standard; or,
in the case of test Jtits, the visual
observation of a colored chemical reaction
indicating the presence of lead. The
classification is negative (positive) if a low
(high) lead level is indicated.
chemical test
kit
see test kit
clock time
The total time that elapsed during the
observation of a single XRF reading.
confidence
interval
An estimated range of values in which the
quantity of interest lies. A 95% confidence
interval covers the quantity of interest 95
percent of the time.
continuing
control block
readings
A quality control XRF reading made on a
control block covered by a NIST SRM film
during the testing day whenever a substrate
change occurred.
9-2
-------
control block
readings
Any of the quality control XRF readings made
on a control bloefc either covered or not
covered by NIST SRM films. Readings may be
taken 1) at the beginning of the day, 2) at
the end of the day, or 3) whenever a substrate
change occurred.
control
average
reading
The average of a set of control block
readings, made by a specific XRF instrument on
a specific substrate type within a dwelling-.
control block
A sample designed for the purpose of XRF
quality control, constructed from one of the
following commonly encountered substrate
materials: brick, concrete, drywall, metal,
plaster, and wood.
control
correction
Bias correction of an XRF measurement,
obtained by subtracting from it the control
average reading computed for its common
substrate and dwelling minus the lead level of
the red NIST SRM film (1.02 mg/cm2) .
control XRF
data
XRF readings made on control blocks for the
purpose of quality control.
dead time
The time that elapsed in making a single XRF
reading when the detector was not actively
accumulating X-rays for producing a lead
result.
detection
limit
A modification of the instrumental detection
limit (IDL), specific to a paint-chip sample,
that accounts for sample preparation
parameters involving dilution, mass, and
collected sample area.
digestion
See hot-plate digestion.
digestion
blank
See method blank.
9-3
-------
DL
See detection limit.
dwelling
A unit or pair of units targeted for testing.
ending control
block reading
A quality control XRF reading performed on a
control JblocJfc at the end of a testing day.
endpoint
effect
In nonparametric estimation of a response
function, the phenomenon whereby the function
exhibits greater variability and/or Mas near
an upper or lower endpoint of its domain.
enhanced
logistic
regression
model
The model that was used to estimate the
operating characteristic (OC) curves of the
test Jfcits.
false negative
An erroneous negative classification obtained
by a lead testing method such as a test Jcit or
an XRF instrument; i.e., for which a positive
classification is indicated by the true lead
level.
false positive
An erroneous positive classification obtained
by a lead testing method such as a test kit or
an XRF instrument; i.e., for which a negative
classification is indicated by the true lead
level.
field blank
A paint collection container that was taken to
the field, not used to hold a paint sample,
but designated to be analyzed for lead as an
assessment of potential lead contamination
resulting from field collection and sample
transport activities.
field
classification
One of two designations made for measurements
made with three of the XRF instruments
evaluated in the full study (MAP-3, Microlead
1, and XK-3), where two machines made readings
at each sampling location. The two field
classifications were denoted I and II, and
were used for scheduling and data
identification purposes.
9-4
-------
field
duplicate
A second paint-chip sample taken at a sampling
location within the same proximity as the
primary sample.
field sample
A paint-chip sample collected in the field.
Also used as a synonym for sampling location.
fifty percent
point
For a lead testing method, the level of lead
at which there is a 50% probability that a
positive result is obtained.
first paint
reading
The first of a possible series of paint
readings comprising an XRF measurement at a
standard location.
full study
The portion of the activity described in this
report that took place from July through
October 1993 in Denver and Philadelphia.
full
correction
Bias correction of an XRF measurement,
obtained by subtracting from it the red NIST
SRM average reading at the same sampling
location minus the lead level of the red NIST
SRM film (1.02 mg/cm2) .
homogenization
See sample homogenization.
hot-plate
digestion
A sample preparation method for paint-chip
samples that used heat from hot-plates to
facilitate dissolution of the sample. The
batch size varied from one to approximately 40
paint-chip samples.
ICP or ICP-AES
A laboratory instrument, inductively coupled
plasma atomic emission spectrometer, used to
make lead measurements on prepared samples.
ICP
instrumental
error
Error in measuring the true lead level of a
specimen that is attributable to the ICP
instrument used for that purpose.
IDL
See instrumental detection limit.
9-5
-------
instrumental
analysis QC
sample
A laboratory quality control sample that
contains known levels of lead and other
analytes. These samples were processed during
the same time period as the prepared field
samples for the purpose of evaluating adequate
laboratory instrument operation.
instrumental
detection
limit
Three (3) times the standard deviation of a
minimum of 5 replicate TCP measurements
obtained from a 0.1 /zg/mL lead standard
measured during the processing of a given
instrumental analysis batch. All TCP results
below this limit were identified as non-
detectable .
instrumental
analysis batch
A group of digested paint-chip samples that
were analyzed together in a sequential manner
following calibration of the JCP instrument.
The batch size varied from one to
approximately 200 digested paint-chip samples
K-shell
reading
An XRF reading that originates from emission
lines that correspond to the X-ray
fluorescence transitions from the K electron
orbital of the lead atom.
L-shell
reading
An XRF reading that originates from emission
lines that correspond to the X-ray
fluorescence transitions from the L electron
orbital of the lead atom.
laboratory
duplicate
A second portion of a single field sample
prepared and analyzed for lead.
laboratory
error
A source of measurement error in ICP analysis,
arising from preparation of a sample in the
laboratory prior to lead measurement by an ICP
instrument or by the ICP instrument itself.
Possible sources of laboratory error include
variation in subsampling, incomplete
nomogenization, incomplete digestion, handling
of the digestate prior to ICP analysis, and
instrumental measurement.
9-6
-------
laboratory QC
sample
See instrumental analysis QC sample.
LBP
Lead-based paint or leaded paint.
live time
The time that elapsed in making a single XRF
reading while the detector was actively
accumulating X-rays for producing a lead
result.
measurement
error
For an instrument, laboratory or other
procedure, measurement error is the
measurement obtained minus the true value of
the quantity of interest. An unbiased
procedure is considered more accurate
(precise) than another if its measurement
errors have a smaller standard deviation (SD).
method blank
A sample preparation guality control sample
that is processed in the same manner as field
sample except that no sample is placed into
the digestion vessel. These samples were
placed into hatches of field samples at the
beginning of the sample preparation process to
determine the extent of the potential lead
contamination originating from laboratory
handling processes.
microwave
digestion
A sample preparation method for paint-chip
samples that uses microwave energy to
facilitate dissolution of the sample.
model
A mathematical (functional) relationship that
relates a response to a measurable independent
variable or set of variables.
model fit
model
parameters
Refers to the ability of a model to correctly
predict a response from a known independent
variable or set of variables.
Mathematical elements which together comprise
a model.
9-7
-------
monotone
regression
A nonparametric method for estimating the
response function of one variable with respect
to another, that minimizes the sum of squared
errors under the constraint that the estimated
response be a non-decz-easingr function.
negative
classification
(result)
See classification.
NIST SRM film
One of the paint film samples, SRM 2579 lead-
based paint films, originating from the
National Institute of Standards and Technology
(NIST) that have precisely known levels of
lead. The films are layers of paint with
known lead content sandwiched between two
layers of plastic. Two of the five films
within SRM 2579 were used in the study. This
included the red NIST SRM film containing lead
at 1.02 mg/cm2 and the yellow NIST SRM film
containing lead at 3.53 mg/cm2.
nominal
reading time
An XRF instrument surface exposure and x-ray
data collection time that is based on a new,
non-decayed, radiation source.
non-decreasing
function
In mathematics, a function of one variable
that has the property that larger values of
the variable do not result in smaller values
of the function.
non-detectable
Refers to a lead level, as measured by TCP,
that is below the instrumental detection limit
(IDL).
non-standard
XRF data
XRF data that were collected using measurement
protocols, or under conditions, that differed
from those typically used.
nonparametric
Refers to statistical procedures that do not
depend on the formulation of a model, and that
have validity over a wide range of conditions.
9-8
-------
nonparametrie
response
The monotone regression of a set of XRF
readings with respect to ICP measurements,
used as an approximation to the mean XRF
readings expressed as a function of the true
lead level.
nonparametrie
SD
The square root of the monotone regression,
with respect to ICP measurements, of the
squared differences between a set of XRF
readings and the nonparametrie response, used
as an approximation to the standard deviation
(SD) of XRF readings expressed as a function
of the true lead level.
nonparametrie
atandardi zed
residuals
A set of XRF readings minus the estimated
nonparametrie response, divided by the
nonparametrie SJD . These " transformed" XRF
readings exhibit little or no dependence on
the lead level.
operating
characteristic
(OC) curve
The probability of an event (e.g., a positive
result with a test kit) expressed as a
function of the lead level.
outlier
A data value that is unusual with respect to
other data observed under apparently similar
conditions. An outlier may represent
erroneous data, or measurement conditions that
are actually dissimilar.
outlier
criterion
A mathematical rule or procedure that is used
to identify outliers.
over-
responsive
See responsive.
paint average
reading
The average of three paint readings comprising
an XRF measurement at a standard sampling
location.
paint reading
Any of the XRF readings taken on the painted
surface during an XRF measurement at a
standard location.
9-9
-------
percent by
weight units
Expression of the lead level as the ratio of
the mass of lead in the specimen (grams) to
the total mass of the specimen (grams),
reported as a percentage.
pilot study
The portion of the activity described in this
report that took place in Louisville, Kentucky
in March and April 1990.
positive
classification
(result)
See classification.
primary sample
The first paint-chip sample collected from a
sampling location.
QC
An abbreviation for quality control.
reading time
A single open-shutter XRF instrument event,
including exposure of the painted surface with
energy from the XRF instrument radiation
source; emission of X-rays from fluorescence
transitions within lead atoms residing in the
painted surface; counting of the X-rays
received at the detector,- electronic
processing of the detector signals; and
displaying a lead-area value result in mg/cm2.
One lead result was produced from each XRF
reading.
real time
The total time that elapsed in making a single
XRF reading. Synonymous with clock time.
red NIST SRM
One of the NIST SRM 2579 lead-based paint
films that contains 1.02 mg/cm2 of lead. See
NIST SRM film.
9-10
-------
red NIST SRM
average
reading
The average of the bare substrate red NIST SRM
film covered XRF readings taken during an XRF
measurement at a specific standard location.
Consists of the average of the first, second,
and third bare substrate red NIST SRM film
covered XRF readings for a specific XRF
instrument.
red NIST SRM
averaged
correction
Bias correction of an XRF measurement,
obtained by subtracting from it the average of
red NIST SRM average readings obtained at
sampling locations in the same unit and of the
same substrate type, minus the lead level of
the x-ed NIST SRM film (1.02 mg/cm2) .
response,
response
function
The average (mean) XRF reading expressed as a
function of the lead level.
responsive
An XRF instrument is responsive if a unit
change in the lead level results in a unit
change in the average XRF reading. It is
under-responsive if less, and over-responsive
if more than a unit change in average XRF
reading results.
running mean
An estimate of the relationship between two
variables, obtained by averaging the values of
one variable corresponding to the other
variable taking on nearly constant values.
SD
See standard deviation.
SE
See standard error.
SRM
sample
batching
An abbreviation for standard reference
material. See NIST SRM film.
The grouping of paint-chip samples for
simultaneous processing in a laboratory
procedure.
9-11
-------
sample
homogenization
The act of grinding samples into a powder-like
form to permit subsampling in a uniform and
representative manner.
sample
preparation QC
sample
A quality control sample placed into a batch
of samples at the beginning of the sample
preparation process.
sampling
location
A specific location on a painted substrate
within a unit where lead testing was
performed. The sampling location covered the
entire template.
sign test
A statistical test based on the number of
times an event was observed in a sample, under
the hypothesis that the event occurred with a
50 percent probability each time. Observing
the event many more, or many fewer times than
one-half the sample size constitutes evidence
against the hypothesis.
spatial
variation
The difference in true lead levels between
painted areas within the same template: (1)
for field duplicates, the difference is
between the two paint-chip samples; (2) for
test Jkit and XRF instrument analyses, the
difference is between the primary sample and
where measurements were made on the painted
surface.
special data
XRF data that were collected using special
readings.
special
measurement
A specified set of special readings taken at a
special sampling location.
special
reading
An XRF reading taken with a MAP-3 XRF
instrument using a nominal reading time of 60
seconds at a special sampling location.
special
sampling
location
A sampling location that was specifically
designated to receive additional XRF
measurements with a nominal reading time of 60
seconds.
9-12
-------
special-
special data
XRF data that were collected using special-
special readings.
special-
special
measurement
A specified set of special-special readings
taken at a special-special sampling location
special-
special
reading
An XRF reading taken with a MAP-3 XRF
instrument using a nominal reading time of 240
seconds at a special-special sampling
location.
special-
special
sampling
location
A sampling- location that was specifically
designated to receive additional XRF
measurements with a nominal reading time of
240 seconds.
standard data
XRF data that were collected using standard
readings.
standard
deviation
(SD), of a
population
A measure of variability in a population (or
process) from which data are obtained,
quantified by the square root of the expected
squared difference between the the value
obtained from the population and the
population mean. An SD is equal to zero if
and only if the population (or process)
generates the same value every time, i.e., if
it does not vary.
standard
deviation
(SD), of a
sample
A measure of variability in a sample of data,
quantified by the square root of the average
squared difference between the sample values
and the sample mean. A sample SD is equal to
zero if and only if all sample data have the
same value. If the sample was obtained in a
manner that is representative of a population
or process, the sample SD can serve as an
estimator of the population SD.
standard error
(SE)
A measure of variability applied to an
estimator, which is the analog of the standard
deviation (SD; applied to a population.
9-13
-------
standard
measurement
A specified set of standard readings taken at
a standard sampling location.
standard
reading
An XRF reading taken with a nominal reading
time of 15 seconds at a standard sampling
location.
standard
sampling
location
A sampling location that was designated to
receive XRF measurements with a nominal
reading time of 15-seconds.
subsampling
That portion of a homogenized sample that is
used in the laboratory procedure for analysis
with an TCP instrument.
substrate
The building material that lies under the
paint.
substrate type
The type of building material that lies under
the paint. All substrate types in the study
were classified as one of the following:
brick, concrete, drywall, metal, plaster, or
wood.
template
A marking design used to physically mark the
sampling locations within each dwelling.
test kit
A set of chemicals and other supplies that are
packaged together with instructions for use in
making lead measurements on painted surfaces.
testing
location
A specific location on a painted substrate
within a unit where lead testing is performed.
The testing location covers the entire
template. Synonymous with sampling location.
threshold
probability
The probability of a positive result when the
true lead level in paint is 1.0 mg/cm2.
true lead
level
The actual lead level in a paint specimem or
sample.
9-14
-------
under-
responsive
See responsive.
unit
An unoccupied structure that is used to house
a person or family. May be all or a portion
of a single structure.
variability
Fluctuation in data generated under similar
conditions. Bias and variability together
describe the accuracy and precision of a
measurement process, respectively. A commonly
used measure of variability is the standard
deviation (3D).
variability
location
Louisville sampling locations which were
selected to take additional XRF readings.
Variability locations occurred immediately
following a substrate change.
variance
Of a random variable or a collection of data,
the standard deviation squared. Of an
estimator, the standard error squared.
XRF
X-ray fluoresence
XRF instrument
A portable lead detection instrument that
detects fluoresced x-rays from lead. These
instruments contain a radioactive source to
induce lead to emit x-rays for detection.
XRF
measurement
A specified set of XRF readings taken at a
sampling location.
XRF
measurement
model
The model that was used to describe the
relationship between XRF readings and the true
lead level in paint. Estimation was performed
using the observable TCP measurements, taking
into account the combined effect of spatial
variation and laboratory error.
XRF reading
A lead measurement collected from a surface
using an XRF instrument operating under a
specified nominal reading time.
9-15
-------
yellow NIST One of the NIST SRM 2579 lead-based paint
SRM films that contains 3.53 mg/cm2 of lead. See
NIST SRM film.
9-16
-------
TABLE OF CONTENTS FOR APPENDICES
INTRODUCTION AND CLARIFICATIONS ii
SUMMARY OF PROTOCOL DIFFERENCES BETWEEN THE PILOT AND FULL
STUDIES iv
Appendix A Selection of measurement and sampling
location A-l
Appendix B Measurement protocols for XRF testing . . . . B-l
Appendix Bm Modifications to measurement protocols
for XRF testing Bm-1
Appendix C Measurement protocols for spot test kits . . . C-l
Appendix Cm Modifications to measurement protocols
for spot test kits Cm-1
Appendix D Collection of paint chip samples D-l
Appendix Dm Modifications to collection of paint
chip samples Dm-1
Appendix E Generation of total field sample weights and
homogenization of paint chip samples E-l
Appendix F Preparation of paint chip samples for
subsequent atomic spectrometry Lead
analysis F-l
Appendix G Standard test protocol for the analysis of
digested samples for Lead by inductively
coupled plasma-atomic emission spectroscopy
(ICP-AES), flame atomic absorption (FAAS) ,
or graphite furnace atomic absorption (GFAAS)
techniques G-l
Appendix H Protocol for packaging and shipping of
samples from the field H-l
Appendix I Glassware/plasticware cleaning procedure . . . 1-1
Appendix J Acid bath cleaning procedures J-l
Appendix AA Selection of measurement and sampling
location AA-1
Appendix BB Measurement protocols for XRF testing . . . BB-1
Appendix CC Measurement protocols for spot test kits . . CC-1
Appendix DD Collection of paint chip samples DD-1
Appendix EE Weighing, homogenization and digestion of
homogenized paint chip samples for subsequent
atomic spectrometry Lead analysis EE-1
Appendix FF Standard test protocol for the analysis of
digested samples for Lead by inductively
coupled plasma-atomic emission spectroscopy
(ICP-AES) , flame atomic absorption (FAAS) ,
or graphite furnace atomic absorption (GFAAS)
techniques FF-l
Appendix GG Protocol for packaging and shipping of
samples from the field GG-1
Appendix HH Glassware/plasticware cleaning procedure . . HH-1
Appendix II Acid bath cleaning procedures II-1
Appendix AAA Laboratory Sample Preparation Experiments . AAA-1
-------
INTRODUCTION AND CLARIFICATIONS
The appendices presented in this volume contain the following
three types of information:
• Protocols and procedures used for the performance of
the full study, represented using single letter
designations A through J.
• Protocols and procedures used for the performance of
the pilot study, represented using double letter
designations AA through II.
• Laboratory sample preparation experiments represented
using the triple letter designation of AAA.
Some modifications to planned protocols were made during the
performance of the studies. Modifications to the full study
affected three appendices: Appendix B, Appendix C, and Appendix
D. Modifications to full study protocols are presented
immediately following each of these corresponding Appendices and
are further identified by addition of an "m" to the appropriate
Appendix letter designations. Modifications to pilot study
protocols have been incorporated into the pilot study appendices
and are differentiated from planned protocols through the use of
footnotes.
The term "dried paint sample" has been converted to "paint chip
sample" throughout these appendices. These two terms are
synonymous and were interspersed throughout the original planned
protocols used for these studies. The conversion of the two
terms to a single term has been made to improve the readability
of this document.
Portions of the protocols or entire protocols have not been
reproduced in these Appendices because copyright and proprietary
information considerations. Protocols not present in these
Appendices are summarized Table A-l below.
-------
Table A-l. Summary of Appendix Protocol Information not
present
INFORMATION NOT PRESENT
Appendix C and Appendix
CC: Manufacturer printed
test procedures only
Appendix I and Appendix HH
Appendix J and Appendix II
REASON FOR DELETION
Copyright considerations
Proprietary information
Proprietary information
111
-------
SUMMARY OF PROTOCOL DIFFERENCES BETWEEN THE PILOT AND FULL
STUDIES
Some protocol changes were made between the pilot and full
studies. These changes are discussed in detail in the design
section of Volume II. A summary of these changes are presented
in Table A-2 below.
TABLE A-2. SUMMARY OF DIFFERENCES BETWEEN PROTOCOLS FOR PILOT AND FULL
STUDIES.
PROTOCOL
APPENDIX
LETTER
FULL
STUDY
PILOT
STUDY
DESCRIPTION OF PRIMARY DIFFERENCES
Selection
of
Sampling
Locations
AA
• Some changes in the format of the sampling
template were made between the full and pilot
studies. See Figures 1-1 and 1-2 in Volume II
of this report.
• For the full study, the substrate order for
XRF testing was metal, wood, brick, drywall,
concrete, and plaster. For the pilot, the
substrate order for XRF testing was wood,
drywall, plaster, concrete, and metal.
• For the full study, the starting substrate
during XRF testing was varied among units and
fixed for a specific unit for all instruments.
For the pilot, the starting substrate during
XRF testing was the same among all units and
for all instruments.
• For the full study, relative positions on a
given sampling location tested by a given test
kit operator was randomized by assignment of
specific test kit to specific positions. For
the pilot, relative testing positions were
indirectly determined by staggering the
starting sequence.
• For full study, prefix "S" barcode labels
were used to identify field duplicate samples.
For the pilot, a "DUP" suffix was added to the
sample ID to identify field duplicate samples.
• For full study, a "Sample Locations Data
Form" was used to identify testing areas. For
the pilot, a marked up drawing of a floor-plan
was used to identify testing areas.
IV
-------
TABLE A-2. SUMMARY OF DIFFERENCES BETWEEN PROTOCOLS FOR PILOT AND FULL
STUDIES.
PROTOCOL
APPENDIX
LETTER
FULL
STUDY
PILOT
STUDY
DESCRIPTION OF PRIMARY DIFFERENCES
XRF
Testing
B
BB
• Some changes in reading times and replicates were
made between the full and pilot studies. See
Tables 4-5 and 4-6 in Volume II of this report.
• For full study, control block measurements were
made using both the red (3.53 mg/cm2) and yellow
(1.02 mg/cm2) NIST standard films. For the pilot,
only the concrete control block was measured using
both red and yellow NIST standard films.
• For full study, NIST standard film covered
substrate measurements were made at all sampling
locations using the yellow (1.02 mg/cm2) film. For
the pilot, additional NIST standard film covered
substrate measurements were made at the concrete
sampling locations using the red (3.53 mg/cm2)
film.
• For the full study, measurements at special
sample locations and on control blocks included
bare substrate testing (no NIST films). For the
pilot, bare substrate testing was not performed.
• For the full study, QC variability checks were
not performed. For the pilot, these checks were
performed.
• For the full study, special measurements were
performed on days separate from standard
measurements. For the pilot, special measurements
were performed during standard measurement days.
• For the full study using the ML-1, performance of
replicate measurements using a single trigger pull
was formalized into the protocol. For the pilot,
the same procedure for the ML-1 was used. However,
it was not formalized within the written protocols.
• For the full study, "coverage" and "density"
values were collected for the XL and ML-1
instruments respectively as presented in Note 2.
For the pilot, specific instructions for collection
of this information was not provided. However,
some density values were collected for the ML-Is.
• Field data recording forms were changed to
reflect changes in protocols between the full and
pilot studies. ^^^^^^^
v
-------
TABLE A-2. SUMMARY OF DIFFERENCES BETWEEN PROTOCOLS FOR PILOT AND FULL
STUDIES.
PROTOCOL
SUMMARY
APPENDIX
LETTER
FULL
STUDY
PILOT
STUDY
DESCRIPTION OF PRIMARY DIFFERENCES
Test Kits
Testing
CC
• For the full study using the Lead Detective kit,
a cotton swab was used to deliver reagent to the
testing surface. For the pilot, a plastic stirring
rod or toothpick was used for delivery of reagent
to the testing surface.
• For the full study using the Lead Detective kit,
the paint chip removed during notching of the test
surface was retained an used for further testing
if testing results were negative or doubtful. For
the pilot, this procedure was not included in the
protocols.
• For the full study using the Lead Alert kit
(labeled "F"), paint was exposed using a sanding
method and testing was performed on the resulting
dust. For the pilot, paint was exposed using a
notch method and testing was performed on the
exposed paint layers.
• For the full study using the Lead Alert kit
(labeled "F") and the Lead Alert All-in-One kit
(labeled "B"), the indicator mixing time was
reduced from that used in the pilot to reflect
changes in kit instruction sets supplied from the
manufacturer.
• For the full study using the Lead Alert kit
(labeled "F") and the Lead Alert All-in-One kit
(labeled "B") , one drop of each reagent was used
during QC checks during the full study. For the
pilot two drops of each reagent were used during
QC checks.
• For the full study using the Lead Alert All-in-
One kit (labeled "B"), the importance of cleaning
the coring tool between samples was formalized
into the protocols. For the pilot, importance of
cleaning the coring tool was emphasized during
training.
• Field data recording forms were changed between
the full and pilot studies. Full study forms were
simplified by removing information blocks that
were not needed. In addition, shaded blocks were
added to full study forms for use in reporting
shading from gray to black for kits that used
sodium sulfide.
VI
-------
TABLE A-2. SUMMARY OF DIFFERENCES BETWEEN PROTOCOLS FOR PILOT AND FULL
STUDIES .
PROTOCOL
SUMMARY
Collection of
Paint Chip
Samples
Weighing,
Homogenization
and
Preparation of
Paint Chip
Samples
ICP-AES
Analysis of
Prepared Paint
Chip Samples
Packaging and
Shipping of
Paint Chip
Samples
Glassware
Cleaning
Acid Bath
Cleaning
APPENDIX
LETTER
FULL
STUDY
D
E
F
G
H
I
PILOT
STUDY
DD
EE
and
FF
GG
HH
II
JJ
DESCRIPTION OF PRIMARY DIFFERENCES
• Full study protocols contained more
detailed descriptions on paint removal
methods than that contained in the pilot
protocols .
• Field data recording forms were changed
between the full and pilot studies. Full
study forms were simplified by removing
information blocks that were not needed.
• For full study, determination of total
collected sample weight preceded sample
homogenization. For the pilot, sample
homogenization preceded determination of
total collected sample weight.
• There were no differences between full and
pilot studies.
• There were no differences between full and
pilot studies .
• There were no differences between full and
pilot studies.
• There were no differences between full and
pilot studies.
VI1
-------
APPENDIX A
FULL STUDY PROTOCOLS:
SELECTION OF MEASUREMENT AND SAMPLING LOCATIONS
A-l
-------
SELECTION OF MEASUREMENT AND SAMPLING LOCATIONS
1. 0 SUMMARY
Selection of interior and exterior sampling sites will be made
from as many painted substrate types as can be found in the test
structure (metal, wood, brick, drywall, concrete, and plaster).
The Field Team Leader (field statistician, provided by David C.
Cox & Associates) will be responsible for all selection and
marking of measurement and sampling locations. The DCC&A Field
Team Leader will also assist the MRI supervisor during the course
of the field sampling efforts.
The Field Team Leader will be responsible for attaching the
correct bar-code sets to each location. The bar codes will be
removed by the various samplers and applied to the individual's
test results data form at the time the test is performed.
The Team Leader will numerically order the sampling locations so
that all locations with the same substrate material will be
tested sequentially by the XRF instruments. The order in which
the substrates are tested will be: metal, wood, brick, drywall,
concrete, and plaster. This ensures the maximum number of
transitions between light and dense materials in order to best
simulate transitions that are likely to be encountered under
testing more commonly to be encountered during routine LBP
investigations. For each unit, the starting substrate for XRF
testing will be fixed. This starting point will be determined on
a random or judgmental basis. The order of XRF testing for
beginning and end-of-day control block measurements will be the
same for all units (metal, wood, brick, drywall, concrete, and
plaster).
Test kit operators will not follow the same testing order as the
XRFs and will be instructed to test all locations within a room.
The relative position on a given location tested by a given test
kit operator will be randomized by assignment of specific test
kits to specific positions.
2.0 DETAILED MARKING PROCEDURE
1. Obtain or create a rough floor plan of the targeted
structure.
2 . Perform a review of available Lead testing data and
summarize to .aid in selection of sampling locations.
A-3
-------
This is anticipated to be performed prior to on-site
selection and marking activities.
3. Perform a walk through of each unit as an aid to
selecting locations. Make notes on a copy of the floor
plan as needed for later marking of locations.
4. Perform location selections. For each location
selected, mark the sampling locations using an
indelible marking pen and attach bar code labels as
follows:
a. Draw an outline of the testing location, which
includes separate boxes for XRF testing, paint
chip sample collection, and test kit measurements.
A typical testing location will be a rectangle
approximately 4 in high by 14 in long. The
rectangle will include two squares approximately
4 in by 4 in the left and center portions of the
rectangle, and six smaller rectangles 4 in high by
1 in wide in the right portion of the rectangle.
In addition, for those locations targeted for a
side-by-side samples, an approximately 2 in x 2 in
square will be drawn at one end of the rectangle.
For components where a 4 in x 14 in rectangle
cannot be obtained, the field statistician will
exercise judgment in defining a comparable
sampling area. There will be six smaller
rectangles for test kits and five test kits in the
study. The sixth rectangle will be used for
contingencies.
b. Divide the middle large squares into four
individual 2 in x 2 in squares using the marking
pen. Indicate with an arrow pointing to one of
the small squares that portion to be sampled by
the paint chip collectors for a regular paint chip
sample. For those locations targeted for a side-
by-side sample, the independent approximately 2 in
x 2 in square drawn at one end of the rectangle
will be used for collection of this extra paint
chip sample.
c. Mark the six rectangles approximately 4 in high by
1 in wide with the codes A-E to designate test kit
position assignments (the supervisor will assign
each test kit with a letter to follow for
determining testing position).
A-4
-------
d. Attach a resealable plastic bag containing a
minimum of 30 bar code labels matching the
location ID number in the vicinity of the marked
area. Use duct tape and a staple gun (if needed)
to properly secure the bag. If the location is an
exterior location, then attach the bag to inside
the nearest inside area and write a note
describing the placement of the bag next to the
marked testing location.
For locations that are targeted for side-by-side
paint samples, attach a second resealable plastic
bag containing a minimum of 12 bar code labels
matching the location ID number combined with a
preceding "S" in the vicinity of the marked area.
Attach these in the vicinity of the first bag of
bar code labels containing location ID numbers.
e. Mark, in large print, the location number in two
places around the location area.
f. Mark the location with any other needed indicator,
such as "SPECIAL," "SPECIAL-SPECIAL," or "ARCHIVE"
to indicate additional testing requirements to
this location.
g. On the floor plan, indicate the position of the
sampling location (and its number).
5. After completing the location marking activity, review
each location and compile a comprehensive list of all
locations within the unit.
6. Make copies of floor plans with identified locations
and the comprehensive listing for all supervisors and
testers.
3.0 NUMBERING SYSTEM
Two sets of bar-code numbers will be used. The first type is for
use on XRF data forms, test kit data forms, and regular paint
chip sample containers and data forms. The second type is for
use on side-by-side paint chip sample containers and data forms.
Both sets will contain the same five digit numbers starting with
80001. The second set will differ from the first by inclusion of
a preceding "S." Each unit will be assigned a range of 100
numbers for marking locations.
A-5
-------
Bar code labels with identical ID numbers will be pre-loaded into
plastic bags and sorted into folders prior to shipment to the
field. Sorting bar codes into separate folders and placing them
in consecutive order will ease marking activities.
A-6
-------
Date
Substrate Code: M=Metal, V
Sampl(
Testing Sit
V=Wood, B=B
3 Locations Data Form
e
paae of
rick, D=Drywall, C=Concrete, P=Plaster
Use for Testing Complete Column i
Tester or XRF Monitor (Printed Nam
Circle Test Performed:
Test Kit Code: A, B, C, D, E Paint Collect
e)
on XRFs: Scitec, PGT, Warrington, TN, Niton, Outokumpu
:• Sample ID (Bar code)
Room
Substrate
Code
Description
Testing
Complete?
93-38 SEV dewaltfrmG 070683
-------
APPENDIX B
FULL STUDY PROTOCOLS:
MEASUREMENT PROTOCOLS FOR XRF TESTING
B-l
-------
MEASUREMENT PROTOCOLS FOR XRF TESTING
1.0 SUMMARY
NOTE; READ ENTIRE APPENDIX B BEFORE DOING ANY WORK!!
This document describes the standard protocol for collecting XRF
measurement data on painted surfaces and corresponding substrate
surfaces. This document also includes instructions for recording
the measurements and making QC checks for XRF instruments
participating in this study.
In general, XRF operators will be requested to make measurements
according to their manufacturers' general operating procedures.
In situations where this study protocol (contained in this
Appendix) differs dramatically from the manufacturers' protocol,
or when this study protocol cannot be followed because of
operational limitations, the XRF operator is required to discuss
the situation with the acting MRI field supervisor to resolve the
problems. It is the responsibility of the XRF monitor to record
as much information as possible about the operation of a given
XRF instrument during this full field study.
Any deviations from this protocol must be agreed to by the acting
MRI field supervisor and fully documented before implementing the
deviation. In any case, each XRF must be operated in a
consistent manner throughout this study.
2.0 MATERIALS AND EQUIPMENT
• Portable field XRF instrument with any extra required
supporting equipment. (To be provided by XRF
contractor.)
• One set of NIST paint films for each XRF instrument
(SRM 2579); contains five films of different Lead
levels. (To be provided by XRF contractor.)
• Dosimeter badges; one for each XRF operator and one for
each individual working within the same unit where XRF
testing takes place. (Operator badges will be provided
by XRF contractor, badges for monitors and supervisors
hired by DCC&A will be provided by DCC&A, and badges
for MRI personnel will be provided by MRI) .
B-3
-------
Reporting forms; see exemplars in this protocol (to be
provided by MRI.)
Adhesive labels or bar-code labels for identifying
samples. (To be provided by MRI; will be available at
each sampling location.)
Waterproof (indelible) permanent marking pen. (To be
provided by MRI; will be available at site.)
Watch, clock, or other equivalent timepiece. (Each
team member in the field will be required to have a
timepiece for reporting the sampling times on the data
forms.)
Device(s) to measure temperature and relative humidity.
(To be provided by MRI; will be available at site and
operated by the acting MRI field supervisor or designee
at a frequency deemed necessary to gather supplemental
information during testing activities).
Pre-moistened wipes for cleaning of tools, hands, etc.
(To be provided by MRI; will be available at site.)
QC test blocks, each approximately 4 in x 4 in. The
thicknesses given are approximate: 3A in. wood (pine),
2 in concrete (with aggregate), 1/2 in sheet rock, 20 to
25 gauge metal, and 1 in plaster. A full set of
labelled QC test blocks will be prepared by MRI and
placed in unit.
One 12-in thick Styrofoam block for supporting QC test
blocks under measurement. (To be provided and labelled
by MRI; will be available at site.)
3 . 0 MEASUREMENT PROCEDURES
AN ORDERED LIST OF MEASUREMENTS SPECIFIC FOR EACH UNIT WILL
BE PROVIDED BY THE SUPERVISOR FOR EACH UNIT. TESTERS MUST
FOLLOW THAT ORDER EXACTLY.
The starting point for each unit will be based on a specific
substrate type (metal, wood, brick, sheetrock, concrete, or
plaster). Units will be assigned different substrates for
initiation of testing, but testing will always follow the same
substrate order. The substrate starting point will be fixed for
B-4
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a given unit and will be indicated on the testing order
instructions provided by the supervisor.
The general order of testing is metal -=» wood -» brick -> sheetrock
-» concrete -» plaster. An example of the general work plan,
testing order, and measurements for a unit targeted to beginning
with brick is given below:
1. Receive beginning-of-day instructions from MRI field
supervisor
2. Perform initial manufacturer's calibration checks
3. Perform additional manufacturer's calibration checks at
intervals as required by the manufacturer's specifications
4. Perform beginning-of-day control block measurements (all six
blocks).
5a. Perform continuing drift check on brick control block.
5b. Perform measurements on all brick substrates, including
standard measurements and any required special location
measurements.
5c. Perform continuing drift check on brick control block.
6a. Perform continuing drift check on sheetrock control block.
6b. Perform measurements on all sheetrock substrates, including
standard measurements and any required special location
measurements.
6c. Perform continuing drift check on sheetrock control block.
7a. Perform continuing drift check on concrete control block.
7b. Perform measurements on all concrete substrates, including
standard measurements and any required special location
measurements.
7c. Perform continuing drift check on concrete control block.
8a. Perform continuing drift check on plaster control block.
8b. Perform measurements on all plaster substrates, including
standard measurements and any required special location
measurements.
B-5
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8c. Perform continuing drift check on plaster control block.
9a. Perform continuing drift check on metal control block.
9b. Perform measurements on all metal substrates, including
standard measurements and any required special location
measurements.
9c. Perform continuing drift check on metal control block.
lOa. Perform continuing drift check on wood control block.
lOb. Perform measurements on all wood substrates, including
standard measurements and any required special location
measurements.
lOc. Perform continuing drift check on wood control block.
11. Perform end-of-day control block measurements (all six
blocks).
12. Review data forms for completeness and transfer all data
forms to the MRI field supervisor. Receive end-of-day
instructions from MRI field supervisor.
3.1 BEGINNING OF ALL XRF TESTING AT A SITE PROCEDURE
XRF operators and data monitors will receive detailed overview
instructions from the acting MRI field supervisor on the first
XRF testing day that will include the following topics:
• General safety instructions
• Definitions: housing units, testing locations, measurements,
sampling time
• Specific site issues and description of marked locations and
what markings signify
• Use of testing location listings and order of performing
measurements
• Use of each data form and placement of bar codes and other
data on forms
• Responsibilities of XRF operators to call out all readings
real-time
B-6
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Responsibilities of monitors to record all data real-time
and use verbal feedback to verify data value. (No reading
is to be discarded; however more data can be taken if
insisted on by the XRF operator.)
Completion of the "XRF Instrument Information" form (See
exemplar p. B-13)
Responsibilities of monitors to periodically observe the
actual instrument readout (particularly for recording both K
and L shell data).
Definition of 15-sec reading: 15 sec is based on a new
radiation source. XRF operators will be instructed to
compensate for source age as needed to give radiation flux
equivalent to a 15-sec exposure with a new source.
3.2 BEGINNING OF EACH DAY ON-SITE PROCEDURES
The XRF operator and data monitor will receive initial
instructions from the acting MRI field supervisor at the
beginning of each testing day. Items will generally include a
brief overview of those listed under Section 3.1. plus any
additional items that are dictated by variable field conditions.
Two types of XRF testing days will be performed: a "standard"
measurement day and a "special" measurement day. All XRF
instruments will perform the "standard" measurements day of
testing. Only the Scitec instruments will perform the "special"
measurements day (in addition to the "standard" measurements
day) .
At the beginning of each type of measurements day at a given
unit, the XRF operator will perform tests and instrument checks
that are required by the manufacturer of the XRF to prepare the
instrument for taking Lead measurements. The XRF operator must
inform the data monitor that a manufacturer-recommended procedure
is being performed, and the name and nature of the procedure.
The data monitor will record the time and nature of all such
manufacturer-recommended procedures in the "Comments" column of
the "Control Blocks" form.
The XRF operator will perform XRF "standard" measurements as
follows:
• BEGINNING-OF-DAY control block measurements, as described in
Section 3.3.
B-7
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• STANDARD location measurements in the order listed on unit
list received from acting MRI supervisor. STANDARD
measurements are described in Section 3.4.
• CONTINUING DRIFT CHECK substrate transition measurements
each time the substrate changes, as described in
Section 3.6.
• END-OF-DAY control block measurements as described in
Section 3.3.
The Scitec XRF operators will perform XRF "special" measurements
as follows:
• BEGINNING-OF-DAY control block measurements as described in
Section 3.3.
• SPECIAL location measurements in the order listed on unit
list received from the acting MRI supervisor. SPECIAL
measurements are described in Section 3.5.
• END-OF-DAY control block measurements as described in
Section 3.3.
NOTE: No continuing drift checks are preformed during
"special" day testing.
3.3 CONTROL BLOCK MEASUREMENTS-BEGINNING- AND END-OF-DAY
At the beginning and end of each day, each XRF operator will
perform a set of measurements on six control blocks with two of
the NIST SRM 2579 standards (red, 1.02 mg/cm2; and yellow,
3.53 mg/cm2) and with no NIST standard. These calibration checks
will be carried out for the XRF instruments using sets of six
substrate blocks (metal, wood, brick, drywall, concrete, and
plaster) . One set of these blocks will be placed in each unit
for use by the testers making measurements in that unit. Before
the start of testing in each unit, one measurement will be taken
on each block with each of the three NIST films designated above.
Data from these beginning and end drift check measurements will
be recorded on the "XRF QC DATA: CONTROL BLOCKS" form. A step-
by-step description is provided below:
At the beginning of each testing day, before starting testing in
any unit perform the following procedures:
B-8
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1. For each new "XRF QC DATA: CONTROL BLOCKS" form needed,
complete the header of the form (see exemplar p. B-14).
2. Fill in the columns for each control block measurement taken
and "time of measurement," "test block type," and "NIST std
film used."
3. Perform whatever normal instrument checks are required by
the XRF manufacturer to prepare the instrument for taking
Lead measurements. Inform the data monitor what the
procedure is and why it is being done. The data monitor
will write this information in the "Comments" column on the
"XRF QC DATA: CONTROL BLOCKS" form.
4. Perform NIST/test block measurements for two NIST films and
the base control block. Place the test blocks, one at a
time, in the center of the Styrofoam support block. For the
two measurements requiring the NIST standard films, center
the appropriate NIST film on the test block and place the
XRF probe to take readings through the NIST film into the
center of the control block. Perform the measurements in
the following order.
a. Metal—Center the metal test block on the Styrofoam
support. Center the yellow NIST film on the metal test
block and perform one measurement (three nominal 15-sec
read cycles). Then perform one measurement using the
red NIST film, followed by the bare control block.
Call out the value after each reading. The monitor
will write each read cycle value on the "XRF QC DATA-
CONTROL BLOCKS" form, verbally verifying the value
written. The monitor will record other information in
the "Comments" column.
b. Wood—Center the wood test block on the Styrofoam
support. Center the yellow NIST film on the wood test
block and perform one measurement (three nominal 15-sec
read cycles). Then perform one measurement using the
red NIST film, followed by the bare control block.
Call out the value after each reading. The monitor
will write each read cycle value on the "XRF QC DATA-
CONTROL BLOCKS" form, verbally verifying the value
written. The monitor will record other information in
the "Comment s" column.
c. Brick—Center the brick test block on the Styrofoam
support. Center the yellow NIST film on the brick test
block and perform one measurement (three nominal 15-sec
B-9
-------
read cycles). Then perform one measurement using the
red NIST film, followed by the bare control block.
Call out the value after each reading. The monitor
will write each read cycle value on the "XRF QC DATA-
CONTROL BLOCKS" form, verbally verifying the value
written. The monitor will record other information in
the "Comments" column.
d. Sheetrock—Center the sheetrock test block on the
Styrofoam support. Center the yellow NIST film on the
sheetrock test block and perform one measurement (three
nominal 15-sec read cycles). Then perform one
measurement using the red NIST film, followed by the
bare control block. Call out the value after each
reading. The monitor will write each read cycle value
on the "XRF QC DATA-CONTROL BLOCKS" form, verbally
verifying the value written. The monitor will record
other information in the "Comments" column.
e. Concrete—Center the concrete test block on the
Styrofoam support. Center the yellow NIST film on the
concrete test block and perform one measurement (three
nominal 15-sec read cycles). Then perform one
measurement using the red NIST film, followed by the
bare control block. Call out the value after each
reading. The monitor will write each read cycle value
on the "XRF QC DATA - CONTROL BLOCKS" form, verbally
verifying the value written. The monitor will record
other information in the "Comments" column.
f. Plaster—Center the plaster test block on the Styrofoam
support. Center the yellow NIST film on the plaster
test block and perform one measurement (three nominal
15-sec read cycles). Then perform one measurement
using the red NIST film, followed by the bare control
block. Call out the value after each reading. The
monitor will write each read cycle value on the "XRF QC
DATA-CONTROL BLOCKS" form, verbally verifying the
value written. The monitor will record other
information in the "Comments" column.
At the end of the testing day (regardless of whether all
locations in a given unit were completed) perform all of the
above control block measurements exactly as they were performed
at the beginning of the day.
B-10
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3.4 PROCEDURE FOR STANDARD MEASUREMENTS AT EACH SAMPLING
LOCATION
For each instrument, one standard measurement will consist
of three consecutive nominal 15 -sec readings on the paint
followed by three consecutive nominal 15 -sec readings on the bare
substrate covered with the red NIST standard (1.02 mg/cm2) . At
each sampling location perform the following steps:
1. For each new "XRF TEST DATA - STANDARD MEASUREMENTS" form
needed, complete the header of the form (see exemplar p.
B-15) .
2. Affix the sampling location/identification bar code in the
correct box on the "XRF TEST DATA - STANDARD MEASUREMENTS . "
These bar code labels should be present in close proximity
to the sampling location marked by the field team leader
(see Note 1) . If a bar code label is not available, write
in the sampling location number written at the location.
NOTE 1: The sampling location will be marked in advance by
the field team leader using a dark colored marking
pen. The marking will be in the form of squares
and rectangles with letters. The painted surface
location to be used for XRF measurements will be
the largest painted square, approximately 4 in x
4 in. The exposed substrate surface location to
be used for XRF measurements will be the largest
exposed area present at the sampling location.
3 . Perform the normal instrument checks required by the
manufacturer of the XRF to prepare the instrument for taking
Lead measurements. Inform the data monitor what the
procedure is and why it is being done . The data monitor
will write this information in the "Comments" column.
4 . Perform measurements on the painted and exposed surfaces as
follows (See Note 2) :
a. Perform a "measurement" (three nominal 15 -sec readings)
on the painted surface at the sampling location. Call
out the value after each reading. The monitor will
write each read cycle value on the "XRF TEST DATA -
STANDARD MEASUREMENTS," verbally verifying the value
written. The monitor will record other information in
the "Comments" column.
b. Perform a "measurement" (three nominal 15 -sec ^
cycles) on the exposed substrate surface covered with
B-ll
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the 1.02 mg/cm2 NIST standard film (red) at the
sampling location (see Note 3).
c. If the location is market as a "special" location, then
perform a "measurement" (three nominal 15-sec read
cycles) on the exposed substrate surface (bare, with NO
NIST film). Call out the value after each reading.
The monitor will write each read cycle value on the
"XRF TEST DATA - STANDARD MEASUREMENTS," verbally
verifying the value written. The monitor will record
other information in the "Comments" column. DO NOT DO
THIS STEP FOR THE Scitec.
NOTE 2: For the ML-1, the three readings will be obtained
with a single pull of the instrument's trigger.
The readout corresponding to each "beep" of the
instrument will be recorded. For other XRF
instruments that can take multiple read cycles
using a single trigger pull event, perform
replicate read cycles in this manner recording
each transient read cycle value. In addition, any
special operations performed during measurement
(such as use of a reset button for PGT) must be
noted in the "Comments" column of data forms. For
the NITON XRF, record the "coverage" value in the
"Comments" column. The "density" value for the
ML-1 will be recorded in the "Comments" column.
NOTE 3: If difficulties are encountered holding the NIST
film against the substrate surface, try using a
small piece of masking tape to hold it in place.
Be sure the tape is placed such that it adheres
only to areas outside the marked location.
3.5 PROCEDURE FOR SPECIAL MEASUREMENTS
Two additional sets of measurements, called "Special" and
"Special-Special" measurements, will be carried out at selected
sampling locations for each substrate. The special measurements
will be used to test alternative protocols for the instruments on
a case-by-case basis. "Special" measurements are in addition to
standard measurements and are only being performed by the Scitec
XRF instruments on a separate testing day.
Procedure for performing a "Special" measurement is as
follows:
B-12
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1. For each new "XRF TEST DATA - SPECIAL MEASUREMENTS" form
needed, complete the header of the form. (See exemplar p.
B-16)
2. Affix the sampling location/identification bar code in the
correct box on the "XRF TEST DATA - SPECIAL MEASUREMENTS."
These bar code labels should be present in close proximity
to the sampling location marked by the field team leader
(see Note 1). If a bar code label is not available, write
in the sampling location number written at the location.
NOTE 1: The "SPECIAL" AND "SPECIAL-SPECIAL" sampling
location will be marked in advance by the field
team leader using a dark colored marking pen. The
words "SPECIAL" AND "SPECIAL-SPECIAL" will be
marked on these locations to signify the testing
required.
3. Perform the normal instrument checks required by the
manufacturer of the XRF to prepare the instrument for taking
Lead measurements. Inform the data monitor what the
procedure is and why it is being done. The data monitor
will write this information in the "Comments" column of the
form.
4. Perform SPECIAL measurements on the painted and exposed
surfaces as follows (See Note 2):
a. The Scitec MAP will perform one nominal 60-sec reading
(Test Mode) on the painted surface (this corresponds to
the TEST mode of the Scitec}. Call out the value after
reading. The monitor will write the read cycle value
on the "XRF SPECIAL LOCATIONS DATA FORM," verbally
verifying the value written. The monitor will record
other information in the "Comments" column. The XRF
Monitor will record the nominal time of 60 sec in the
"Approx. Sampling Time (Sec.)" column.
b. Perform the same measurement as described in the
previous step (a) except on the bare substrate covered
by the red NIST film (1.02 mg/cm2) as opposed to the
painted surface (see Note 3).
c. Perform the same measurement as described in the
previous step (a) except on the bare substrate (with NO
NIST film) as opposed to the painted surface.
B-13
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IF the location is marked as a "SPECIAL-SPECIAL" location, first
perform the "SPECIAL" measurement (described above) . Then
perform the "SPECIAL-SPECIAL" measurements listed below,
recording the results of the "SPECIAL-SPECIAL" readings using a
new row of the same "XRF TEST DATA - SPECIAL MEASUREMENTS" form.
Procedure for performing a "Special-Special" measurement is as
follows:
1. For each new "XRF TEST DATA - SPECIAL MEASUREMENTS" form
needed, complete the header of the form (see exemplar p.
B-16) .
2. Affix the sampling location/identification bar code in the
correct box on the "XRF TEST DATA - SPECIAL MEASUREMENTS."
These bar code labels should be present in close proximity
to the sampling location marked by the field team leader
(see Note 1) . If a bar code label is not available, write
in the sampling location number written at the location.
3. Perform whatever normal instrument checks are required by
the manufacturer of the XRF to prepare the instrument for
taking Lead measurements. Inform the data monitor what the
procedure is and why it is being done. The data monitor
will write this information in the "Comments" column of the
form.
4 . Perform SPECIAL-SPECIAL measurements on the painted and
exposed surfaces as follows (See Notes 2 and 4) :
a. The Scitec MAP will perform one nominal 240-second
reading (confirm mode) on the painted surface (this
corresponds to the CONFIRM mode of the Scitec) . Call
out the value after readings. The monitor will write
the read cycle value on the "XRF SPECIAL LOCATIONS DATA
FORM," verbally verifying the value written. The
monitor will record other information in the "Comments"
column. The XRF Monitor will record the nominal time
of 240 sec. in the "Approx. Sampling Time (Sec.)"
column.
b. Perform the same measurement as described in the
previous step (a) except on the bare substrate covered
by the red NIST film (1.02 mg/cm2) as opposed to the
painted surface (see Note 3) .
B-14
-------
NOTE 4: No measurements using the nominal 240-sec reading
(CONFIRM mode) will be taken on the bare
substrate.
3.5 PROCEDURES FOR CONTINUING DRIFT CHECKS
Continuing drift checks are performed when the location substrate
changes from one type to another. The first metal-continuing
drift check measurement is performed immediately following the
beginning-of-day control block measurements and before the first
painted metal location is measured. NO continuing drift checks
are to be performed on the "special" measurement day by the
Scitec instruments.
If the surface substrate is of a different type than the previous
location.
then perform the following measurements:
1. For each new "XRF TEST DATA - CONTINUING DRIFT CHECKS" form
needed, complete the header of the form (see exemplar, p.
B-17)
2. Perform two measurements each using two NIST standard films
and one measurement on the bare control block (three nominal
15-sec readings with the yellow NIST film, red NIST, and no
NIST film in that order) on the test block corresponding to
the substrate just completed. Call out the value after
reading. The monitor will write the read cycle value on the
"XRF TEST DATA-CONTINUING DRIFT CHECKS" form, verbally
verifying the value written. The monitor will record other
information in the "Comments" column.
3. Perform two measurements each using two NIST standard films
and one measurement on the bare control block (three nominal
15-sec readings with the yellow NIST film, red NIST, and no
NIST film in that order) on the test block corresponding to
the NEXT substrate to be tested. Call out the value after
reading. The monitor will write the read cycle value on the
"XRF DATA - CONTINUING DRIFT CHECKS" form, verbally
verifying the value written. The monitor will record other
information in the "Comments" column.
For example, after completing the beginning-of-day test
block readings, perform the continuing drift check
measurements on the metal test block, then proceed to test
all metal substrates in the unit as listed. After
completion of all painted metal substrate locations, repeat
B-15
-------
the continuing drift check measurements on the metal test
block, then perform the continuing drift check measurements
on the wood test block. Next, repeat for all wood
locations, etc. Consult the test-order list received from
the supervisor AND FOLLOW THAT ORDER EXACTLY.
3.6 END-OF-DAY ACTIVITIES
XRF operator and monitor will ascertain that all form headers are
completed, including the appropriate pagination. Paginate the
forms of the same type in chronological order for that day of
testing only starting with page 1. XRF operator and monitor will
verify that all required locations and required measurements at
each location have been made. Verification will be performed by
reviewing the data forms and adding a check mark to each location
on the test-order list provided by the supervisor for each data
entry found on the data forms. Transfer of XRF data forms to the
acting MRI field supervisor will be made at the end of each day.
The acting MRI field supervisor will check the data forms for
completeness and conduct other end-of-day activities before
releasing workers for the day.
B-16
-------
XRF Instrument Information
Date
Testing Site
Testing Dates
Contractor
Manufacturer
Model No.
XRF Operator (Printed Name)
XRF Operator (Signature)
Serial No.
Source Material
Source Age or Date
Detector Type
Approximate Open Shutter Sampling Time Used (Sec.)
Comments:
63-17 SEV dcwdt frm C 060BB3
-------
XRF Test Data - Standard Measurements Page of
Date Manufacturer
XRF Operator (Printed name)
Location ID
(Bar code)
XRF Field Monitor (Printed name)
Time of
Measurement
XRF Shell
(Korl)
Paint Surface
• Reading*
Substrate + NIST Red,
1, 02 mg/cm* Readings
Substrate Only Readings
(Special Locations Only)
.Comments
-------
Date
XRF Test Data — Special Measurements for Scltechi
Manufacturer
XRF Operator (Printed name)
Location ID
(Bar code)
Page „ ot
XRF Field Monitor (Printed name)
Time of
Measurement
Approx. Sampling
Time (Sec.)
XRF Shell
(KorL)
Paint Surface .
Reading*
Substrate + MIST Red,
1, 02 mg/cm2 Readings
Substrate Only
Readings
Comments
93-38 SEV dewaltlrmE 070193
-------
XRF QC Data: Control Blocks
Date Manufacturer
XRF Operator (Printed name) XRF Field Monitor (Printed name)
Test Block Type: M=Metal, W=Wood, B=Brick, D=Drywall, C=Concrete, P=Plaster
Test Block
Type
Time of
Measurement
XRF Shell
(KorL)
Readings
Yellow, 3.53 mg/cm2
Bed, 1.02 mg/cm»
NoNISTStd,
Comments
93-38 SEV dowaltttrnF 070193
-------
XRF Test Data - Continuing Drift Checks
Date Manufacturer
Paqe of
XRF Operator (Printed name) XRF Field Monitor (Printed name)
Test Block Type: M=Metal, W=Wood, B=Brick, D=Drywall, C=Concrete, P= Plaster
Test Block
Type
Time of
Measurement
XRF Shell
(KorL)
Readings
Yellow, 3.53 mg/cml
RedJ.tttmg/em1
No NIST Std.
Comments
93-38 SEV dewaltlrmA 070103
-------
APPENDIX Bm
MODIFICATIONS TO FULL STUDY PROTOCOLS:
MEASUREMENT PROTOCOLS FOR XRF TESTING
Bm-1
-------
Bm-2
-------
MODIFICATION SUMMARY
Appendix no.
Modification
no.
Effective
date
Modification
type
Portion of
work
affected
Description
B
1 of 4
August 2, 1993
Addition to appendix
Denver and Philadelphia
A summary of XRF testing was generated by EPA
for both Denver and Philadelphia immediately
preceding initiation of XRF testing in Denver.
The summary was used as a tool to aid in
training of field personnel for XRF
measurements .
XRF SUMMARY
On "regular sampling" days, all instruments will be operated
so that a measurement is defined as the average of three
readings of approximately 15 sec with the shutter open with
a fresh source. -One slight exception to this is the
Warrington ML-1 instrument, which will be operated so that a
single trigger pull will result in three beeps, signifying
that three readings have been taken. All instruments
except type TN Lead Analyzer and the Outokumpu X-MET 880 can
automatically adjust for source age. The TN Lead Analyzer
and the Outokumpu X-MET 880 will be adjusted for source age
by setting the time the shutter is open to somewhat more
than 15 sec.
On regular sampling days, all instruments will perform the
beginning and end of day drift checks, the continuing drift
checks, and measurements on all the sampling areas. At the
sampling areas not marked SPECIAL or SPECIAL-SPECIAL,
measurements will be taken on the painted area designated
for XRF and the scraped area covered by the NIST 1.02
standard. For all instruments except the MAP-3s, at the
SPECIAL and SPECIAL-SPECIAL locations, measurements will be
taken on the painted area designated for the XRF, the
scraped area covered by the NIST 1.02 standard, and the
Bm-3
-------
scraped area without any standard. For the MAP-3s, at the
SPECIAL and SPECIAL-SPECIAL locations, measurements will be
taken on the painted area designated for the XRF and the
scraped area covered by the NIST 1.02 standard. The order
of measurements at the sample locations will be: painted
area, NIST standard over painted area, and (if applicable) ,
bare substrate.
3. The MAP-3S (and only the MAP-3S) have been designated for
"special" sampling days. On special sampling days,
measurements will be taken for the beginning and end of day
drift checks using three SCREEN mode readings to define a
measurement, measurements will be taken at the SPECIAL and
SPECIAL-SPECIAL locations using the TEST mode of the MAP-3,
and measurements will be taken at SPECIAL-SPECIAL locations
with THE CONFIRM mode of the MAP-3. At the SPECIAL and
SPECIAL-SPECIAL locations, measurements will be made with
the TEST mode on the painted area, the scraped area covered
by the NIST 1.02 standards, and the scraped substrate area
without any standard, in that order. At the SPECIAL-SPECIAL
locations, measurements in the CONFIRM mode will be made on
the painted area and the scraped substrate area covered by
the NIST 1.02 standard, in that order. At SPECIAL-SPECIAL
locations, TEST measurements will be done before CONFIRM
measurements.
4. For each house, a starting substrate will be selected. An
order of substrates will be designated for the study, and
sampling at that house will follow the order established by
the starting substrate and the study order of substrates.
5. The beginning and end of day drift checks will follow the
order of substrates designated for the study. This will be
a constant that does not change from house to house. Within
each substrate, the order of standards will be: 3.52, 1.02,
bare.
6. For continuing drift checks, the order of standards will be
3.52, 1.02, bare.
Bm-4
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MODIFICATION SUMMARY
Appendix no.
B
Modification
no.
2 of 4
Effective
date
August 2, 1993
Modification
type
Addition and changes to Appendix
Portion of
work
affected
Denver and Philadelphia
Description
Note 4 added to appendix to clarify performance
control block measurements during special
testing days. All other following note
references changed as a result of addition of
note 4 as shown below:
• Add "(See note 4} " after "separate testing
day." located at the end of the first paragraph
under subsection 3.5, page B-12:
• Insert the following after the above addition
located at the end of the first paragraph under
subsection 3.5, page B-12:
NOTE 4: Perform control block measurements in
the same manner as that described in
Section 3.3 (i.e., use 3 nominal 15-s
read cycles, not the 60-s or 240-s
read cycles).
• Change " (see Note 1) " to " (see Note 5) "
located under item 2 on page B-12.
• Change "NOTE 1:" to "NOTE 5:" located under
item 2 on page B-12.
• Change "(See Notes 2 and 4)" to "(see Notes 5
and 6)" located under item 4 on page B-13.
• Change "NOTE 4:" to "NOTE 6:" located under
item 4 on page B-14.
Bm-5
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MODIFICATION SUMMARY
Appendix no.
B
Modification
no.
3 of 4
Effective
date
September 1, 1993
Modification
type
Replacement of pages in Appendix
Portion of
work
affected
Philadelphia only
Description
Replacement 3 of the original XRF data forms
with 4 forms as follows:
• Original:"XRF Instrument Information" form.
Replace with 2 forms:"Initial—XRF Instrument
Information" form and "Daily—XRF Instrument
Information" form as attached
• Original:"XRF QC Data: Control Blocks" form.
Replace with:"XRF QC Data: Control Blocks" form
as attached
• Original:"XRF Test Data: Continuing Drift
Checks" form. Replace with:"XRF Test Data:
Continuing Drift Checks" form as attached
Bm-6
-------
Initial - XRF Instrument Information
Date
Testing Site
Testing Dates
Contractor
Manufacturer
Model No.
XRF Operator (Printed Name)
XRF Operator (Signature)
Serial No.
Source Material
Source Age or Date
Detector Type
Approximate Open Shutter Sampling Time Used (Sec.)
Comments:
tl-37 DEOHO dtord 1 0*0793
-------
Daily-XRF Instrument Information
Date
Contractor
Manufacturer
Model No.
Serial No.
XRF Operator (Printed Name)
XRF Operator (Signature)
Approximate Open Shutter Sampling Time Used (Sec.)
Comments:
t3-37 DEOBO fcort
-------
XRF Test Data — Continuing Drift Checks
Date Manufacturer House ID
Paqe of
XRF Operator (Printed name) XRF Field Monitor (Printed name)
Test Block Type: M=Metal, W=Wood, B=Brick, D=Drywall, C=Concrete, P=Plaster
Test Block
Typo
Time of
Measurement
XRF Shell
(KorL)
Readings
Yellow, 3.53 mg/cm*
Red, 1,02 tng/tm1
NoNISTStd.
Comments
03-37 DEBORD debord 3 090793
-------
1 ______ __ -"
XRF QC Data: Control Blocks
Date Manufacturer House ID
Rape of
XRF Operator (Printed name) XRF Field Monitor (Printed name)
Test Block Type: M=Metal, W=Wood, B=Brick, D=Drywall, C=Concrete, P=Plaster
Test Block
Tyf»
Time of
Measurement
XRF Shell
(KorL)
Readings
Yellow, 3.53 mg/cm1
Red, 1.02 mg/cm1
No NIST Std.
Comments
03-37 DEBORD debold 4 090793
-------
MODIFICATION SUMMARY
Appendix no .
Modification
no.
Effective
date
Modification
type
Portion of
work
affected
Description
B
4 of 4
October 1, 1993
Addition to Appendix
Philadelphia only
A XRF testing handout was generated for field
testing in Denver and Philadelphia. This
handout consisted of a testing schedule and
selected pages from the QAPjP (Chapters 9, 10,
and Appendix B) . For Philadelphia, an
additional summary of Appendix B titled "XRF
TESTING REMINDERS" was generated and
incorporated into the handout . The 1 page
summary is attached and is hereby presented as
an addition to Appendix B.
Bm-11
-------
XRF TESTING REMINDERS
Measure and record in the Daily Information Data form Daily
the actual reading cycle times for each XRF instrument.
Check the reading time against that expected for a source
age. If the readings are other than expected contact the
general supervisor for a decision on corrective action.
FOR THE WARRINGTON: Record the density data in the comments
column of the data forms. It is desirable to record this
for all locations during the painted surface only readings.
However, at a minimum, record the coverage index data for
all the substrate transition points (i.e., record the
density value for the last and first location of a given
substrate).
FOR THE NITON: Record the coverage index data in the
comments column of the data forms. It is desirable to
record this for all locations during the painted surface
only readings. However, at a minimum, record the coverage
index data for all the substrate transition points (i.e.,
record the density value for the last and first location of
a given substrate).
For SPECIAL measurements (Scitec only):
Note that all modes of the Scitec are used during the
SPECIAL measurement days (Screen, Test, and Confirm) .
Perform Control Block Measurements using 3 nominal 15-
sec read cycles.
Perform Control Block Measurements only at the
beginning and end of day regardless of whether than
more than one unit is tested in that day (Philadelphia
only).
Be sure to perform End-of-Day (EOD) measurements on the
same control blocks as those used for Beginning-of-Day
(BOD) measurements (i.e., go back to the BOD control
blocks to perform the EOD measurements) . Do not move
the control blocks from the unit and general location
established for control block testing.
Bm-12
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APPENDIX C
FULL STUDY PROTOCOLS:
MEASUREMENT PROTOCOLS FOR SPOT TEST KITS
C-l
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C-2
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MEASUREMENT PROTOCOLS FOR SPOT TEST KITS
1.0 SUMMARY
This appendix describes the field protocols for using commercial
test kits for testing in situ painted surfaces for Lead content.
The chemistry and instructions vary from kit to kit but basic
steps common to all kits are:
• Select the area or item to be tested;
• Prepare the test kit reagents;
• Perform the quality control test included in the package;
• Clean the surface to be tested;
• Expose all layers of the paint by sanding or cutting; and
• Test the paint.
The actual test methods involve reaction of Lead in the paint
with the active reagent(s) in the test kit to produce a color
change, a precipitate, or both. Methods of reacting the Lead
with the reagents vary and include:
• Swabbing in situ with a reagent-soaked applicator;
• Pressing a reagent-soaked pad to the in situ surface for a
specified length of time;
• Adding drops of one or more solutions to the in situ paint;
• Removal of a paint chip or dust to a vial to which reagents
are added to produce the precipitate or color change; and
• Removal of a paint chip and applying test reagents to all
surfaces and edges of the paint chip.
2.0 MATERIALS AND EQUIPMENT
Materials and equipment needs vary from kit-to-kit. Equipment
and supplies are listed under the individual kit protocols.
C-3
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3.0 TEST KITS SELECTED FOR THE STUDY
The four commercially available Lead test kits selected for
inclusion in this study are listed in Table C-l. In addition to
the kits listed in Table C-l, a licensed Lead inspector will be
contracted to perform Lead testing with the Massachusetts state-
approved sulfide reagents and procedures. The protocol for the
Lead inspector will be the state-approved protocol included in
this Appendix, Section 4.5.
Table C-l. LEAD TEST KITS TARGETED FOR USE IN THE FULL STUDY
MANUFACTURER
ENZONE
Frandon/Pace
Innovative
Synthesis
HybriVet Systems
MA State Protocol
KIT NAME
Lead Zone
Lead Alert
(All-in-One)
Lead
Detective
Lead Check
NA
CODE
LETTER
A
B
C
D
E
TEST
Proprietary
Rhodi z ona t e
Sodium
Sulfide
Rhodizonate
Sodium
Sulfide
KIT METHOD
CHOSEN
Reagent -
impregnated pad
Core sample
paint chip
Apply reagent
to notch or
paint chip
Reagent -
impregnated
swabs
Apply reagent
to notch or
paint chip
4.0 TESTING PAINTED SURFACES FOR LEAD
In order to provide a reasonably uniform comparison of methods
for this study, differences among the kit instructions preclude
use of only the package-insert instructions for training and
testing. For purposes of this study, instructions supplied by
the manufacturers were edited to conform to the six steps listed
above in the Appendix C Summary (Section 1.0).
NOTE FOR ALL TEST KITS: If a new test kit is opened
for use, properly discard any chemicals or reagents
from previously used test kits and make fresh from the
new kit.
C-4
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4.1 ENZONE "Lead Zone" (PROPRIETARY CHEMICAL COMPOSITION)
This kit is designated with the code letter A.
4.1.1 List of Supplies Needed for Testing One Housing Unit
Containing up to 75 Locations
1 Plastic tote to carry supplies
1 Clipboard
1 Map of dwelling and/or instructions from supervisor
1 "Completed Testing" Checklist for the unit being tested
1 "Lead Zone" WA57 field testing protocol
1 pad Test Kit Results Recording Form (will be several pages)
2 Ball point pens
2 boxes Baby wipes
1 bag Disposable plastic gloves (100 pr per bag)
1 Flashlight
1 50-mL dropping bottle full of ASTM Type I water
1 pair Scissors
1 box Resealable plastic bags, 1 gt. (20/box)
2 Trash bags
1 roll Duct tape
17 kits "Lead Zone" test kits—enough to perform 100 tests
1 Stopwatch
1 Watch or other time piece
4.1.2 Performing the Lead Zone Tests
Perform Lead testing in a safe manner as instructed in the
training class.
1. Obtain the "Lead Zone" test kits, data recording forms, and
other supplies in the above list from the field supervisor.
2. Obtain instructions (starting point, other) from the field
supervisor.
3. Fill out the header information on the test form.
4. Find the location to be tested according to instructions
received from the field supervisor. The location map will
be provided by the supervisor, or alternately, may be posted
in the dwelling.
5. Remove one bar code label corresponding to the sampling
location from the strips held inside the plastic bag
C-5
-------
attached to the test location and affix it in the bar code
column on the results recording form.
6. Open one Lead Zone Kit and prepare the test kit pads. Be
careful not to contaminate the test pads or painted surfaces
with Lead from the test spots on the verification card
enclosed in the package. Open additional kits as needed.
a. Use scissors to cut each of the two Lead Zone Test Pads
into three equal sized pieces, creating six smaller
Lead Zone test pads.
b. Store the cut test pad pieces in a resealable plastic
bag. Remove one at a time as needed.
7. Perform the quality control (QC) test before the first
location is tested and after each negative result to verify
that the test reagents are working as listed below:
a. Remove one test pad piece from the resealable plastic
bag.
b. Moisten the test pad with a few drops of ASTM Type I
water {an orange color may develop when the pad is
moistened. The orange color is due to the reagents and
is not a positive test for Lead).
c. Press the moistened pad against one of the test dots on
the verification card. Hold the pad against the
surface for up to 2 min.
d. If a pink to purple color develops on the test dot or
pad (or both), the reagents are working correctly. If
no color develops on the test dot within the 2 min,
consult the supervisor.
e. Dispose of the used pad in the trash bag.
8. Clean the surface to be tested by wiping with a baby wipe.
9. Expose all layers of the paint by cutting through all paint
layers down to the substrate. Use the bevelled V-cut (as
taught in the training class.) Do not cut into the
substrates. If the substrate is cut, then make a new V-
notch for testing. (Be sure to make the V-notch such that
the paint layers are highly exposed. Use of a shallow V is
preferable to a deep V.)
C-6
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10. Test the exposed paint layers as listed below:
a. Remove one cut test pad piece from the plastic bag.
b. Moisten the test pad with a few drops of ASTM Type I
water.
c. Press the moistened pad against the exposed paint
layers. Hold for up to 2 min.
d. If a pink to purple color develops in any of the paint
layers or on the test pad within the 2 min, the test is
positive for Lead.
e. Dispose of the used test pad in the trash bag.
11. Record the test results as positive or negative on the
data form—a positive result is an observed change in
color on pad, or on any of the exposed paint layers
from the original color to a pink or purple color. Use
a flashlight if needed for observation. Record any
comments on the test form in the appropriate columns.
12. Cover the tested spot with a small piece of duct tape
to conceal the results from the next tester.
13 . Test the remaining locations in the structure as
instructed by the supervisor. Follow steps 5 through
13 until all locations in the structure have been
tested. Six tests may be performed with each Lead Zone
kit. Use the verification cards prior to the first
test in the structure and after any negative tests to
verify that the moistened pad is working correctly. As
long as positive tests are being obtained, it is not
necessary to use the verification card for each kit
opened. If a moistened pad does not produce a pink
color on the test dot, consult the supervisor.
14. At the end of the testing day, perform the following:
a. Check all test results recording forms for
completeness.
b. Use the "Completed Testing" Checklist to verify testing
of all locations within the housing unit. If one is
found to be missing, return and perform testing on it.
C-7
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c. Return the completed checklist, data forms, all
supplies, and remaining test kits to the supervisor.
A photocopy of the Lead Zone Lead Test Kit instructions provided
with the test kit is shown in Figure C-l.
C-8
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Lead Zone Test Kit-package insert copy removed because
of copyright considerations.
Figure C-l was presented on 1 page.
(Insert from packages obtained in June 1993 from Enzone
Corporation, College Point, NY 11356)
Figure C-l. Photocopy of Lead Zone Test Kit instructions,
C-9
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4.2 FRANDON/PACE LEAD ALERT ALL-IN-ONE (RHODIZONATE)
This kit is designated with the code letter B.
4.2.1 List of Supplies Needed for Testing One Housing Unit
Containing up to 75 Locations
1 Plastic tote to carry supplies
1 Clipboard
1 Map of dwelling and/or instructions from supervisor
1 "Completed Testing" Checklist for the unit being tested
1 "Lead-Alert" All-in-One WA57 field testing protocol
1 pad Test Kit Results Recording Form (will be several pages)
2 Ball point pens
2 boxes Baby wipes
1 bag Disposable plastic gloves (100 pr per bag)
1 Flashlight
1 50-mL dropping bottle full of ASTM Type I water
1 pair Scissors
1 box Resealable plastic bags, 1 qt. (20/box)
2 Trash bags
1 roll Duct tape
1 kit "Lead-Alert" All-In-One test kits—enough to perform 100
tests
1 Circular boring tool and cleaning brush
1 Stopwatch
1 Watch or other time piece
2 boxes Kimwipes
4.2.2 Performing the "Lead-Alert" All-in-One Test
The Frandon Lead Alert All-in-One kit offers the user three
different methods of sampling for Lead, two of which are also
offered in the "Homeowners" kit. For purposes of this study, we
are only interested in total Lead content of a given sample.
Therefore, only one of the three—removal of a paint sample using
the "coring technique"—will be used.
1. Obtain the "Lead-Alert" All-in-One test kits, data recording
forms, and other supplies listed above from the field
supervisor.
2. Obtain instructions (starting point, other) from the field
supervisor.
3. Prepare a new batch of indicating solution at the beginning
of each day of testing as listed below:
C-10
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a. Remove red cap and clear dropper insert from the bottle
labelled "Indicating Solution." Be careful not to
spill the contents.
b. Take the tablet from the foil wrapper and drop it into
the indicating solution bottle. Replace dropper
insert .•
c. Shake the bottle for 60 to 70 sec. Allow to stand for
an additional minute. Shake again for 30 sec. Reagent
is ready for use. When testing has been interrupted
for 15 min, shake the indicating solution bottle
vigorously for 5 to 10 sec before resuming testing
(shaking the solution bottle should be performed
periodically during the testing day) .
4. Perform a Quality Control (QC) Test on the freshly made
indicating solution as listed below:
a. Remove the QC test sheet from its bag and apply 1 drop
of Leaching Solution to the center of an unused test
circle. Let it sit for 10 sec.
b. Add one drop of Indicating Solution to the same circle
(do not touch the dropper to any surface).
c. A pink to rose/red color is a positive test, indicating
that the reagents are performing correctly. Record the
QC test results in the "Comments" column of data form
for the first sample location to be tested for the day.
If the test is negative, replace cap on red top bottle
and shake for an additional 60 sec. Repeat the QC
test. If test is still negative, mark the reagent
bottles as bad with a marking pen and consult the
supervisor. Under these conditions, the supervisor
will generally request that you go back to step 3 using
a new reagent from a new test kit and test kit.
5. Fill out the header information on the data recording form.
6. Find the first location to be tested according to
instructions received from the field supervisor. The
location map will be provided by the supervisor, or
alternately, may be posted in the dwelling.
7. Remove one bar code label corresponding to the sampling
location from the strips held inside the plastic bag
C-ll
-------
attached to the test location and affix it in the bar code
column on the results recording form.
8. Clean the test area with a pre-moistened wipe.
9. Perform the Coring Test for Total Lead.
a. Remove one of the adhesive-backed collection papers and
fold it in half. Apply the paper directly underneath
the area to be tested as shown in the package
instructions.
b. Using the circular coring tool, cut down into the
surface (use a drilling type motion to aid in cutting
through all layers of paint). Scrape the paint inside
the circle onto the paper. Be sure to remove all
layers of paint. Do not cut into the substrate. If
the substrate is cut, start over.
c. Transfer the paint from the paper to a plastic vial.
Grind up the paint for about 10 sec using a new plastic
rod for each sample (Lead paint grinds easily whereas
Latex-based paint will be harder to grind).
d. Add three drops of Leaching Solution to the vial (do
not touch the dropper to the vial or contents) and
grind the contents for another 10 sec. Let the vial
sit for 20 sec.
e. Add three drops of Indicating Solution to the tip of a
fresh applicator (always use a fresh applicator tip for
each sample and do not touch the applicator or any
other surface with the dropper) , then touch the surface
of the liquid in the plastic vial with the tip of the
applicator.
f. Observe for color changes on the applicator. A pink to
rose/red color indicates a positive test.
10. Record the results on the data recording form and enter
any comments in the appropriate columns.
11. Cover the completed test with duct tape to conceal the
results from the next tester.
12. Clean the coring tool with a dry paper tissue followed
by the brush before proceeding to the next location.
EXTREMELY IMPORTANT: THE CORING TOOL MUST BE CLEANED
C-12
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AFTER COLLECTING EACH SAMPLE. If the coring tool
becomes dull, see the supervisor to have it sharpened.
13 . Test the remaining locations in the structure as
instructed by the supervisor. Follow steps 5 through
12 until all locations in the structure have been
tested.
14. At the end of the testing day, perform the following:
a. Check all test results recording forms for
completeness.
b. Use the "Completed Testing" Checklist to verify testing
of all locations within the housing unit. If one is
found to be missing, return and perform testing on it.
c. Return the completed checklist, data forms, all
supplies, and remaining test kits to the supervisor.
A photocopy of the package instructions is shown in Figure C-2.
C-13
-------
Frandon Lead Alert All In One Kit—test kit package
insert copy removed because of copyright
considerations.
Figure C-2 was presented on 4 pages.
(Insert from packages obtained in June 1993 from Pace
Environs, 207 Rutherglen Drive, Gary, NC 27511)
Figure C-2. Photocopy of Frandon Lead-Alert Kit instructions.
C-14
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4.3 LEAD DETECTIVE (Sodium Sulfide)
This kit is designated with the code letter C.
4.3.1 List of Supplies Needed for Testing One Housing Unit
Containing up to 75 Locations
1 Plastic tote to carry supplies
1 Clipboard
1 Map of dwelling and/or instructions from supervisor
1 "Completed Testing" Checklist for the unit being tested
1 "Lead Detective" WA57 field testing protocol
1 pad Test Kit Results Recording Form (several pages)
2 Ball point pens
2 boxes Baby wipes
1 bag Disposable plastic gloves (100 pr per bag)
1 Flashlight
1 50-mL dropping bottle full of ASTM Type I water
1 pair Scissors
1 box Resealable plastic bags, 1 qt. (20/box)
2 Trash bags
1 roll Duct tape
1 kit "Lead-Detective" test kit-approximately 100 tests
1 Magnifying glass
1 roll Waxed paper
1 Stopwatch
1 Watch or other time piece
1 box round toothpicks
4.3.2 Performing the Lead Detective Tests
The "Lead Detective" kit detects Lead (and other heavy metals) by
reacting with the Lead to form a black insoluble precipitate of
Lead sulfide. Perform Lead testing in a safe manner as
instructed in the training class including wearing of safety
glasses at all times and wearing of leather gloves during cutting
or scraping activities. Wear disposable gloves when using this
and any other sodium sulfide test kit. The package instructions
included with the Lead Detective are contained in a 33-page
instruction booklet. A photocopy of this booklet is included in
this Appendix C as an attachment.
1. Obtain the "Lead Detective" test kits, data recording forms,
and supplies from the field supervisor.
2. Obtain sample location instructions (starting point, other)
from the field supervisor.
C-15
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3. Fill out the header information on the data recording form.
4. Prepare a new batch of reagents at the beginning of each day
of testing as listed below:
a. Carefully add the contents of the kit water bottle to
the bottle containing the sodium sulfide crystals.
b. Screw on the dropper cap and shake vigorously for 5 min
or until the crystals are dissolved. Do not use the
reagent until the crystals are totally dissolved.
5. Perform the quality control check on the freshly prepared
sodium sulfide solution.
a. Remove a quality control strip (or the paint chip) from
the plastic bag.
b. While holding the strip in the forceps, add a drop of
the sodium sulfide solution to the strip.
d. If black coloring appears, the QC test is positive,
indicating the reagents are working. Record the
results in the "Comments" column of the data recording
form. If a black color does not appear, mark the
reagent bottles as bad with a marking pen and consult
the supervisor. Under these conditions, the supervisor
will generally request that you go back to step 4 using
a new reagent from a new test kit and repeat the test.
6. Find the location to be tested according to instructions
received from the field supervisor. The location map will
be provided by the supervisor, or alternately, may be posted
in the dwelling.
7. Remove one bar code label corresponding to the sampling
location from the strips held inside the plastic bag
attached to the test location and affix it in the bar code
column on the results recording form.
8. Clean the surface of the test location with a pre-moistened
wipe.
9. Cut through all layers of the paint down to the substrate
with a bevelled V-notch. Save the paint chip removed from
the notch on a clean, waxed paper square.
C-16
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10. Add a drop of the sodium sulfide solution to the notch,
being careful not to drip the reagent on the surfaces
below or adjacent to the test notch. Use a toothpick
as needed to direct the solution into the notch. Use a
flashlight and/ or magnifying glass if needed to
observe the paint for changes in color. A black or
gray color is a positive test for Lead. Circle the box
in the Comments column that comes closest to matching
the color observed.
11. If the test is negative or doubtful, apply a drop of
the test reagent to the front, back, and edges of the
retained paint chip from the notch. Use a flashlight
if needed to observe the paint for changes in color. A
black or gray color is a positive test for Lead.
Circle the box in the Comments column that comes
closest to matching the color observed. Indicate use
of the retained chip by writing "chip" in the Comments
column.
12. Record the results on the data form and any comments in
the appropriate columns. Be sure to designate whether
the recorded results are for the notched surface or the
removed paint chip.
13. Cover the completed test spot with a small piece of
duct tape to conceal the results from the next tester.
14. Test the remaining locations in the structure as
instructed by the supervisor. Follow steps 6 through
14 until all locations in the structure have been
tested.
15. At the end of the testing day, perform the following:
a. Check all test results recording forms for
completeness.
b. Use the "Completed Testing" Checklist to verify testing
of all locations within the housing unit. If one is
found to be missing, return and perform testing on it.
c. Return the completed checklist, data forms, all
supplies, and remaining test kits to the supervisor.
The "Lead Detective" instructions in the kit consists of a 33-
page booklet. A photocopy of the test kit operating instructions
portion of this booklet is shown in Figure C-3.
C-17
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Lead Detective Lead Paint Detection Kit—package insert
copy removed because of copyright considerations.
Figure C-3 was presented on 7 pages.
(Insert from packages obtained in June 1993 from
Innovative Synthesis Corporation, 1425 Beacon Street,
Newton, MA 02168)
Figure C-3. Photocopy of "Lead Detective" instructions
C-18
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4.4 LEAD CHECK SWABS
4.4.1
1
1
1
1
1
1
This kit is designated with the code letter D.
List of Supplies Needed for Testing One Housing Unit
Containing up to 75 Locations
Plastic tote to carry supplies
Clipboard
Map of dwelling and/or instructions from supervisor
"Completed Testing" Checklist for the unit being tested
"Lead Check Swabs" WA57 field testing protocol
pad Test Kit Results Recording Form (several pages)
2 Ball point pens
2 boxes Baby wipes
1 bag Disposable plastic gloves (100 pr per bag)
1 Flashlight
2 Trash bags
1 roll Duct tape
100 "Lead Check" swabs and several control cards
100 Disposable 10-mL beakers
1 Pliers
1 Stopwatch
1 Watch or other time piece
1 Razor knife holder
75-100 Disposable razor blades
75-100 Cotton-tipped swabs
1 bottl Vinegar
4.4.2 Performing the Lead Check Test
The "Lead Check" swabs contain rhodizonate, which reacts with
Lead to form a pink to red color. Perform Lead testing in a safe
manner as instructed in the training class.
1. Obtain the "Lead Check" rhodizonate test swabs, data
recording forms, and supplies from the field supervisor.
2. Obtain instructions (starting point, other) from the field
supervisor.
3. Fill out the header information on the data recording form.
Measure and record temperature, relative humidity, and other
required information.
4. Find the location to be tested according to instructions
received from the field supervisor. The location map will
C-19
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be provided by the supervisor, or alternately, may be posted
in the dwelling.
5. Remove one bar code label corresponding to the sampling
location from the strips held inside the plastic bag
attached to the test location and affix it in the bar code
column on the results recording form.
6. Clean the test surface with a pre-moistened wipe.
7. Cut a beveled V notch through all paint layers down to the
substrate.
8. Check for leachable pink or red paint. Moisten a clean,
unused cotton-tipped swab with vinegar and rub the swab in
the notch. If the tip turns pink or red from vinegar only,
make a comment in the Comments column and continue on with
test.
9. Remove one "Lead Check" swab and reseal the package.
10. With the swab pointing up, squeeze points A and B to
crush the internal glass ampules (use pliers to perform
this task if needed).
11. With the swab pointing down, shake the swab twice, then
gently squeeze it until the yellow liquid appears on
the swab tip.
12. While gently squeezing, rub the swab tip on the test
area for 30 sec.
13. Observe swab tip for coloration. Use a flashlight to
read the results. Pink to red indicates positive test
for Lead. Orange plus pink is also positive for Lead.
IF a positive result is obtained, THEN
a. Tape a plastic disposable beaker, using duct tape, over
the tested notch.
b. Record the results in the appropriate box on the form.
IF no color change is observed within 2 min, THEN
a. Touch the swab to one of the dots on the Lead
confirmation card.
C-20
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If no color develops on the QC dot, discard the swab and
retest the paint layers with a new swab (steps 8 through
12) .
If color develops on the QC dot, tape a plastic disposable
beaker, using duct tape, over the tested notch and proceed
to the next spot. Record the time and return to re-observe
this spot in 30 min. If no color change has occurred, cover
and return to check the paint after another 30 min. If,
after 1 hr, no color has developed, the spot tested negative
for Lead. Record all observations, subsequent examinations,
and other comments on the data form. Pink to red is
positive for Lead. If an orange color develops, orange is
positive for barium, not positive for Lead.
14 . Test the remaining locations in the structure as
instructed by the supervisor. Follow steps 4 through
13 until all locations in the structure have been
tested. Do not reuse any of the swabs, even if no
color change was observed. As long as positive tests
are being obtained on the painted surfaces and
underlying layers, there is no need to perform the Lead
confirmation test on the test confirmation card.
15. At the end of the testing day, perform the following:
a. Check all test results recording forms for
completeness.
b. Use the "Completed Testing" Checklist to verify testing
of all locations within the housing unit. If one is
found to be missing, return and perform testing on it.
c. Return the completed checklist, data forms, all
supplies, and remaining test kits to the supervisor.
A photocopy of the "Lead Check" Swabs Test Kit package
instructions is shown in Figure C-4.
C-21
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Lead Check Swabs—test kit package insert copy removed
because of copyright considerations.
Figure C-4 was presented on 2 pages.
(Insert from packages obtained in June 1993 from
Hybrivet Systems, Inc., P.O. Box 1210, Framingham, MA
01701)
Figure C-4. Photocopy of Lead Check Swabs Test Kit instructions.
C-22
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4.5 MASSACHUSETTS SODIUM SULFIDE TEST
This test is designated with the code letter E.
A licensed lead inspector, qualified by the state of
Massachusetts, will perform this test according to the protocols
in Attachment 2 of this Appendix. The Massachusetts professional
will provide all of their supplies and equipment with the
exception of the data recording forms and masking tape, according
to the following protocol:
Perform Lead testing in a safe manner as instructed in the
training class, including wearing safety glasses at all
times and wearing leather gloves and respirator during
cutting or scraping activities. Wear disposable gloves when
using this and any other sodium sulfide test kit.
1. Obtain the data recording forms, masking tape, pre-moistened
wipes, and other supplies from the field supervisor.
2. Obtain instructions (starting point, other) from the field
supervisor.
3. Fill out the header information on the data recording form.
4. Find the location to be tested according to instructions
received from the field supervisor. The location map will
be provided by the supervisor, or alternately, may be posted
in the dwelling.
5. Remove one bar code label corresponding to the sampling
location from the strips held inside the plastic bag
attached to the test location and affix it in the bar code
column on the results recording form.
6. Clean the test surface with a pre-moistened wipe.
7. Perform the test according to the Massachusetts protocol.
8. Record the results in the appropriate box on the data
recording form. Record all observations, subsequent
examinations, and other comments in the data form.
9. Cover the completed test with a small piece of duct tape to
conceal the results from the next tester.
C-23
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10. Test the remaining locations in the structure as
instructed by the supervisor. Follow steps 4 through 9
until all locations in the structure have been tested.
11. At the end of the testing day perform the following:
a. Check all test results recording forms for
completeness.
b. Use the "Completed Testing" Checklist to verify testing
of all locations within the housing unit. If one is
found to be missing, return and perform testing on it.
c. Return the completed checklist, data forms, all
supplies, and remaining test kits to the supervisor.
A photocopy of the general Massachusetts protocol is shown
in Figure C-5.
C-24
-------
General Massachusetts Protocol removed because of
copyright considerations.
Figure C-5 was presented on 5 pages.
(Obtained in March 1993 from the State of
Massachusetts.)
Figure C-5. Photocopy of the General Massachusetts Protocol
C-25
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C-26
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APPENDIX Cm
MODIFICATIONS TO FULL STUDY PROTOCOLS:
MEASUREMENT PROTOCOLS FOR SPOT TEST KITS
Cm-1
-------
Cm-2
-------
MODIFICATION SUMMARY
Appendix no .
Modification
no.
Effective
date
Modification
type
Portion of
work
affected
Description
C
l of 2
July 14, 1993
Addition to Appendix
Denver and Philadelphia
Addition of protocols for performance
kit assigned to the letter "F". This
is shown on pages Cm-4 through Cm-9.
of a test
addition
Cm-3
-------
The Lead Alert "Homeowner" Kit (Product 1040) will be included in
the study. The sanding technique described in the kit's
instructions will be used to test layers of paint until either
(1) a positive result is obtained, or (2) the bottom layer of
paint is tested. This test kit will be assigned letter "F" for
identification purposes in the study. A detailed protocol
following the instructions in the kit follows.
Each location marked off for sampling will include 6 4-in. by 1-
in. rectangles for test kit applications. A letter representing
each test kit will be randomly assigned to each of the 6
rectangles at each location. Rectangles marked with letter F
will be designated for testing by the Lead Alert Homeowner Kit
(Product 1040).
Testing with the Lead Alert Homeowner Kit using the sanding
technique is expected to take approximately four times longer
than the other kits. Therefore, for each house, the test kit
operator assigned to the Lead Alert sanding technique for that
house will be asked to apply the kit only at the locations marked
"Special." (One-fourth of the locations in each house will be
marked "Special.") It is expected that the operator of the Lead
Alert Homeowner Kit will be able to complete testing at the
"Special" locations in the day and one-half allocated for testing
at each house.
If the test kit operator for the Lead Alert Homeowner Kit is able
to complete the "Special" locations ahead of schedule, the
operator will alternate between the substrates in the house as
follows: (1) first regular location for each of metal, wood,
brick, drywall, concrete, and plaster; (2) second regular
location for each of metal, wood, brick, drywall, concrete, and
plaster; (3) third regular location for each substrate, and so on
until available time for the unit is exhausted or until all
regular substrates are tested. The starting substrate for the
regular locations will change for each unit. The supervisor will
issue instructions for each unit to the tester applying the Lead
Alert sanding technique test.
Because the Lead Alert Homeowner Kit will be used with the
sanding technique, contamination avoidance is especially
important. Contamination avoidance techniques will include the
following:
1. During the marking phase, attempts will be made to avoid
placing one location directly over another.
Cm-4
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2. Operators of the Lead Alert Homeowner Kit will attempt to
sand so as to minimize the spreading of paint dust. Where
possible, paper or collection receptacles will be used to catch
the dust.
3. Where possible, operators of the Lead Alert Homeowner Kit
will apply the kit within the bottom most 2-in. of the rectangle
assigned to the kit (on a horizontal template) and all other
operators will use the top most 2-in. On vertical templates, the
Lead Alert operator will use the left most 2-in. and all other
operators will use the right most 2-in. On unusual locations
which do not fit a standard template, the immediate supervisor
for the house will give directions to the operators.
4. All operators will be told of the importance of wiping
rectangles before applying the kits. Wipes should be firm enough
to remove surface dust, but not so firm as to remove paint.
5. Operators of the Lead Alert Homeowner Kit will be instructed
to dispose of all sand paper properly and to clean their hands
(preferably with soap and water, but baby-wipes may be used if
running water and soap are not available) before applying the
test at the next location.
6. Paint chip collectors will wipe the area for paint chip
collection before collecting paint chip samples. Paint chip
collectors will wipe the area for XRF testing before moving to
the next location.
7. To the extent possible, the Lead Check tester and the Lead
Alert Sanding Technique tester will be on different teams.
List of Supplies Needed for Testing One Housing Unit Containing
up to 75 Locations (one-fourth designated as "Special.")
1 Plastic tote to carry supplies
1 Clipboard
1 Map of dwelling and/or instructions from
1 supervisor
1 "Completed Testing" Checklist for the unit being
1 pad tested
2 Lead Alert (Product 1040) WA57 field testing
2 boxes protocol
1 bag Test Kit Results Recording Form (will be several
1 pages)
1 pair Ball point pens
1 box Baby wipes
2 Disposable plastic gloves (100 pr per bag)
Cm-5
-------
1 roll Flashlight
1 kit Scissors
1 box Resealable plastic bags, 1 qt. (20/box)
Trash bags
1 box Duct tape
"Lead Alert" test kit (Product 1040) and extra
sandpaper
Kimwipes
Performing the "Lead Alert" Sanding Technique
1. Obtain the Lead Alert Product 1040 test kit, data recording
forms, and other supplies listed above from the field supervisor,
2. Obtain instructions (starting point, check list of
locations, other) from the field supervisor.
3. Prepare a new batch of indicating solution at the beginning
of each day of testing as instructed in the package instructions
a. Remove red cap and clear dropper insert from the bottle
labelled "Indicating Solution." Be careful not to spill the
contents.
b. Take the tablet from the foil wrapper and drop it into
the indicating solution bottle. Replace the dropper insert.
c. Shake the bottle for 60 to 70 sec. Allow to stand for
an additional minute. Shake again for 30 sec. Reagent is ready
for use. When testing has been interrupted for 15 min, shake the
indicating solution bottle vigorously for 5 to 10 sec before
resuming testing (shaking the solution bottle should be performed
periodically during the testing day).
4. Perform a Quality Control (QC) Test on the freshly made
indicating solution as listed below:
a. Remove the QC test sheet from its bag and apply 1 drop
of Leaching solution to the center of an unused test circle. Let
it sit for 10 sec.
b. Add one drop of Indicating Solution to the same circle
(do not touch the dropper to any surface).
Cm-6
-------
c. A pink to rose/red color is a positive test, indicating
that the reagents are performing correctly. Record the QC test
results in the "Comments" column of the data form for the first
location to be tested for the day. If the test is negative,
replace cap on red top bottle and shake for an additional 60 sec.
Repeat the AC test. If test is still negative, mark the reagent
bottles as bad with a marking pen and consult the supervisor.
Under these conditions, the supervisor will generally request
that you go back to.step 3 using a new reagent from a new test
kit.
5. Fill out the header information on the data recording form.
6. Find the first location to be tested according to
instructions received from the field supervisor. The location
map will be provided by the supervisor, or alternately, may be
posted in the dwelling.
7. Remove one bar code label corresponding to the sampling
location from the strips held inside the plastic bag attached to
the test location and affix it in the bar code column on the
results recording form.
8. Clean the test area with a pre-moistened wipe.
9. Perform the sanding test according to the following
instructions:
10. Take a clean paper square and tape it to the wall directly
underneath the test rectangle. This paper will catch the paint
particles loosened by the sand paper.
11. Proceed with testing, following instructions given below:
"Underlying layers of paint: If the surface layer of paint is
not positive for lead then all other layers should be tested
until either a positive is obtained for the underlying surface
(substrate) which has been painted (wood, brick, etc.) is
reached. Layers of paint may be tested individually or several
at a time. After sanding, follow specific instructions as listed
under Particles of paint, metal, dust, etc. below.
NOTE: Sulfates present in plaster, dust, or stucco may
interfere with the color development in test
procedures. Care should be taken not to sand through
into these substrates during testing. Drywall contains
gypsum. Care should be taken not to penetrate the
fiber layer (paper) of drywall. If, however, plaster;
Cm-7
-------
gypsum; or stucco is exposed during testing and that
test is positive, it is a valid test. Lead in paint
for residential use was banned in the USA in 1978. If
the test result is negative and your home was built
prior to 1978-80 we recommend that a sample of all
layers of paint from that test site be taken and sent
to a qualified laboratory for further analysis.
Particles of paint, metal, dust, etc.:
a. Apply two drops of leaching solution to applicator tip.
b. Pick up a very small amount of fine particles of the
material to be tested (such as sanded paint, ground paint chips,
paint dust, house dust, or dust from vacuum cleaner bag) on the
moistened applicator tip.
c. Apply one more drop of leaching solution over the
particles on the applicator tip. Wait 30 seconds.
d. Apply two drops of indicating solution to the applicator
tip and watch for color change. Interpret the results as
follows:
(1) Positive result - The appearance of a pinkish to
rose/red color. Leachable lead has been detected.
(2) Negative result - The appearance of a yellow stain
that fades away within a few minutes. No leachable lead has been
detected.
NOTE: The appearance of an orange color that doesn't turn
pinkish, or a yellow color that does not fade after a
few minutes may indicate the presence of barium that is
often used as an extender in paint. This is also to be
interpreted as a negative for lead."
12. Interpret the results. A pink to rose/red color is positive
for lead. A yellow stain is negative for lead.
13. Record the results on the test kit results form. Some
locations will have sufficient layers of paint to require the
sanding test to be performed in several steps; other locations
can be completed in only one or two sanding steps.
i. If the test was positive, STOP testing at this location,
and proceed to the next location.
Ctn-8
-------
ii. If the test was negative, proceed with the sanding
technique. Continue testing until a positive test is obtained,
or until the bottom most layer of paint has been tested.
Remember that some locations will have sufficient layers of paint
to require the sanding test to be performed in several steps;
other locations can be completed in only one or two sanding
steps.
NOTE: Whenever a pink or red paint color is encountered, look
at the applicator tip after rubbing the paint with
leaching solution but before adding the indicating
solution. The leaching solution may leach the natural
pink or red color from some paints thus leading to a
false positive for lead. If the leaching solution
leaches pink or red from the paint, record this
information in the "Comments" column for that location,
and consult the supervisor.
14. Cover the completed test with duct tape to conceal the
results from the next tester.
15. Test the remaining locations in the structure as instructed
by the supervisor. Follow steps 6 through 14 until all locations
have been tested.
16. At the end of the testing day, perform the following:
a. Check all test results recording forms for completeness.
b. Use the "Completed Testing" Checklist to verify testing
of all locations within the housing unit. If any are found to be
missing, return and perform testing.
c. Return the completed checklist, data forms, all
supplies, and remaining test kits to the supervisor.
Cm-9
-------
MODIFICATION SUMMARY
Appendix no.
Modification
no.
2 of 2
Effective
date
July 14, 1993
Modification
type
Change to Appendix
Portion of
work
affected
Denver and Philadelphia
Description
Change of a step to include use of cotton swab
for delivering sodium sulfide reagent to test
surface when using the Lead Detective Test Kit.
• Replace step 10 located on page B-15 with the
following:
10. Add a drop or two of the sodium sulfide
solution to a cotton swab, being careful
not to touch the swab to the reagent
container. Rub the swab tip on the test
area for 30 sec. Observe test surface for
coloration. Use a flashlight and/ or
magnifying glass if needed to observe the
paint for changes in color. A black or
gray color is a positive test for Lead.
Circle the box in the Comments column that
comes closest to matching the color
observed.
Cm-10
-------
APPENDIX D
FULL STUDY PROTOCOLS
COLLECTION OF PAINT CHIP SAMPLES IN AND AROUND
BUILDINGS AND RELATED STRUCTURES
D-l
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D-2
-------
COLLECTION OF PAINT CHIP SAMPLES IN AND AROUND
BUILDINGS AND RELATED STRUCTURES
SUMMARY
This document describes the standard protocol for obtaining a
single paint chip sample from a painted substrate. This standard
also includes instructions for sample storage and transport
requirements.
MATERIALS AND EQUIPMENT
ITEM
No. per pair of
collectors
Safety goggles
Leather gloves
Disposable gloves
Respirator with
organic vapor
filters
Razor blade holder
Razor blades
Wood chisel
Hammer
White paper, 8.5 x
11
Masking tape
Duct tape
Marking pens
Clip board with
timepiece
"Paint Chip
Collection" data
forms
Sample containers
(plastic centrifuge
tubes, plastic
resealable bags)
Resealable plastic
bags
2 + 1 extra
2 pair
1 bag 100 pair
2 - one fitted to
each collector
2+1 extra
25
2
1
300 sheets
20 rolls, 1-inch
8 rolls, 2-inch
6
2+1 extra
Enough for 300
samples
a minimum of 300
tubes
a minimum of 300 1
qt bags
D-3
-------
ITEM
No. per pair of
collectors
Extra shipping
container for paint
chip samples
Trouble lights and
spare bulbs or
equivalent lighting
Extension cords
Power generator
Pocket knife
Metal marking
template
Heat gun
Replacement heat gun
element
Tool pouch with belt
Fire extinguisher
Note:
Other items
200 ft.
1 at site
2+1 extra
2
2
2
1 per tester
2 at site, (1 for
each team, in each
unit during paint
chip collection)
as needed.
COLLECTION PROCEDURE
At each sampling location, perform the following steps (See
Note 1):
NOTE 1: A regular sample will be collected at all locations.
Some locations will require collection of an additional
sample called a side-by-side sample. Locations that require
a side-by-side sample are identified by the presence of an
individual 2 in x 2 in square placed at one end of the
marked location. For locations having a side-by-side
sample, follow steps 1 through 9 below for collection of the
regular sample first. After completing this sample
collection, collect the side-by-side sample using the same
procedure using different bar code number as described in
step 2.
1. For each new "Paint Chip Collection Reporting" form needed
(see attached), complete the header of the form.
D-4
-------
2. Record the sampling location/identification (ID) on an open
line of the " Paint Chip Collection Reporting" data form as
follows:
FOR REGULAR SAMPLES: Use the bar code labels that correspond
to the specific sampling location (NO PRECEDING LETTERS).
Collection of regular samples is done from inside the
middle, large square that is divided into four individual
2 in x 2 in squares. The sample to be collected is
indicated by the arrow to a specific 2 in x 2 in square.
The bar code labels should be present in close proximity to
the sampling location marked by the field team leader.
FOR SIDE-BY-SIDE SAMPLES: Use the bar code labels that
correspond to the specific sampling location preceded by an
"S." Collection of side-by-side samples is done from the
individual 2 in x 2 in square placed at one end of the
marked location. The bar code labels should be present in
close proximity to the sampling location marked by the field
team leader.
3. Affix an ID label to the outside of the container into which
the sample is to be placed, and ensure that the label
adheres well. Place 11 extra identical labels into a l-qt
resealable plastic bag which will hold the paint collection
container when sampling is complete.
4. Place the 5 cm x 5 cm template over the sampling site and
hold firmly; tape can be used to hold template in position.
Using a cutting tool and the template as a guide, score the
perimeter of the area to be removed. If it is impractical
to use the template, the score can be made using the outside
edge of the template as a guide. The area scored using the
alternative method should be approximately equivalent to the
area scored when using the inside of the template. Avoid
using pencil or pen to mark the sample outline.
5. Affix a closed bottom paper funnel (or other appropriate
collection shape) made from a clean white sheet of paper or
equivalent collection device directly below the sampling
location. The collection device should be located as close
as possible to the sampling site but should not interfere
with the removal procedure.
6. PRIMARY PAINT REMOVAL METHOD: Using a heat gun, heat the
sample area. Extreme caution should be exercised when using
the heat gun. Be sure to have a fire extinguisher nearby
during heat gun use. Do not overheat the sample area, heat
D-5
-------
only until the paint becomes soft and supple. If working in
teams of two persons, have one collector heat the area while
the other removes the sample with a paint scrapper. Remove
all paint down to the bare substrate. If the paint does not
become soft and supple in a minute or two, discontinue the
use of heat and try the alternative paint removal method.
If the paint is accidentally burned by the heat gun, then
contact the supervisor for selection of a new sample to
collect.
Avoid the inclusion of the substrate in the collection
device. If substrate does fall into the collection device,
remove only that substrate which can be easily removed
without losing any of the paint sample. Do not remove any
substrate which cannot be separated from the paint sample.
The laboratory will remove extraneous substrate if possible,
under laboratory conditions.
ALTERNATIVE PAINT REMOVAL METHOD: Using the appropriate
cutting tool for a particular substrate or condition of the
sample site, begin removing the paint from the substrate.
If possible peel the paint off of the substrate by sliding
the blade along the score and underneath the paint. Remove
all paint down to the bare substrate.
In areas where extreme difficulty is experienced in removing
the paint sample, consult with the field supervisor for
advice.
7. Transfer the collected paint sample to the sample container
and seal. Exercise care to ensure that all paint taken from
the recorded area is placed into the sample container. Use
the Styrofoam holder that comes with the sample containers
to aid in holding the container during transfer.
8. Carefully and accurately measure the sampling area
dimensions. Do not attempt to calculate areas in the field.
Record the data and dimensions including units used (e.g.,
5.1 cm x 5.0 cm) on the "Paint Chip Collection Reporting"
data form using a permanent marker. Try to use only
centimeters for recording data. Avoid making measurement
in inches. Any irregularities or problems which arise in
the process, should be noted in the Comments column of the
form.
9. Seal the container and place it into the plastic bag
containing the 11 extra bar code labels identical to the one
on the paint collection container. Store the samples in a
D-6
-------
safe place during sampling until shipment can be made back
to the laboratory. Return all completed "Paint Chip
Collection Reporting" forms and samples by the end of each
sampling day to the field supervisor.
SUBSTRATE CLEARING PROCEDURE
At each sampling location, after collection of all paint chip
samples, clear an area down to the substrate for later XRF
testing as follows:
Enlarge the exposed substrate area made during paint chip
collection of regular samples to a minimum of 4 in x 4 in
using the same general cutting and scraping methods followed
for paint chip collection (See Note 2). Avoid pitting or
significantly damaging the substrate surface. This area
will be used by XRF testers for taking substrate
measurements.
NOTE 2: For some locations, a full 4 in x 4 in area may not
be possible. For these locations, make the largest exposed
area possible up to the desired 4 in x 4 in exposed surface.
D-7
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Paint Chip Collection Reporting Form
page of
Date
Field Sampler (Printed name)
Sample ID (Bar code)
Dimensions of Area
Sampled (cm x cm)
Comments
93-38 SEV (XwalMrmG 070193
-------
APPENDIX Dm
MODIFICATIONS TO FULL STUDY PROTOCOLS:
COLLECTION OF PAINT CHIP SAMPLES IN AND AROUND
BUILDINGS AND RELATED STRUCTURES
Dm-1
-------
Dm-2
-------
MODIFICATION SUMMARY
Appendix no.
Modification
no.
Effective
date
Modification
type
Portion of
work
affected
Description
D
1 of 2
September 18, 1993
Addition to Appendix
Philadelphia
A Paint Collection handout was generated for
both Denver and Philadelphia field work to aid
in training of field personnel. This handout
consisted of a testing schedule and selected
pages from the QAPjP (Chapters 9, 10, and
Appendix D) . For Philadelphia, an additional
summary of Appendix D titled "PAINT COLLECTION
REMINDERS" was generated and incorporated into
the handout . The 1 page summary is attached
and is hereby presented as an addition to
Appendix D.
Dm-3
-------
PAINT COLLECTION REMINDERS
• BE AWARE OF THE FIRE EXTINGUISHER LOCATION AT ALL TIMES.
• BE SURE TO COLLECT FIELD BLANKS (ONE PER UNIT):
1) Pull one empty centrifuge tube from a package of tubes
being used for each unit sampled.
2) Label the empty centrifuge tube using a permanent
marking pen as follows:
For RUBY TERRACE building use
RUBY BLK # where # is equal to the unit number
(1A, IB, 3A, or 3B).
For 54TH DRIVE building use
54TH BLK # where # is equal to the unit number
(1A, IB, 3A, or 3B).
3) Fill in a line on the data form that corresponds to
taking the field blank.
4) Package and ship along with other paint samples.
• BE SURE TO MEASURE AND RECORD THE AREA SAMPLED IMMEDIATELY
AFTER COLLECTING EACH SAMPLE.
• ON WOOD SUBSTRATES, SCRAPE WITH GRAIN NOT ACROSS GRAIN.
• STRESS THE USE OF LESS STRENGTH AND MORE CAREFUL PAINT
COLLECTION TO AVOID SUBSTRATE INCLUSION AND PRODUCTION OF
SMOOTH SCRAPED SURFACES.
• BE SURE TO SCRAPE THE ENLARGED EXPOSED SUBSTRATE AREAS TO
THE SAME DEGREE AS THE AREA WHERE PAINT COLLECTION WAS
PERFORMED (DON'T LEAVE THE LOCATION UNTIL THE AREA SCRAPED
FOR LATER XRF MEASUREMENTS LOOKS THE SAME AS THE PAINT
SAMPLED AREA.)
Dm-4
-------
MODIFICATION SUMMARY
Appendix no.
D
Modification
no.
2 of 2
Effective
date
September 20, 1993
Modification
type
Change to previous modification to Appendix
Portion of
work
affected
Philadelphia
Description
Labeling of field blanks was changed.
• Replace step 2, under the second bullet of
the "PAINT COLLECTION REMINDERS" with the
following:
2) Label the empty centrifuge tube using a
permanent marking pen as a field blank and
place the marked tube along with others
collected from the unit undergoing active
sampling. The sample receiving personnel
at the laboratory will assign a unique
barcode number to field blank samples for
laboratory processing. The sample
receiving personnel at the laboratory will
also document ID assignments used for the
field blanks for tracking and reporting
purposes.
Dm-5
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APPENDIX E
FULL STUDY PROTOCOLS:
GENERATION OF TOTAL FIELD SAMPLE WEIGHTS
AND HOMOGENIZATION OF PAINT CHIP SAMPLES
E-l
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E-2
-------
GENERATION OF TOTAL FIELD SAMPLE WEIGHTS
AND HOMOGENIZATION OF PAINT CHIP SAMPLES
1.0 SUMMARY
Paint chip samples (chips, powder, etc.) are weighed and
homogenized to prepare them for digestion using a subsample of
the original collected sample. The total weight data is used to
determine the correction factors needed to convert a lead result
obtained from a homogenized subsample to the lead result of the
entire sample collected in the field. This permits calculation
and reporting of lead data on a rag/cm2 basis under conditions
when the entire sample collected in the field is not digested for
analysis.
2.0 APPARATUS
2.1 Instrumentation
• Analytical balance; suitable for weighing samples to
±0.0001 grams.
2.2 Glassware, and Supplies
• Resealable plastic centrifuge tubes, 50-mL
• Plastic rods with flat or round faces for breaking up paint
chip samples
• Dry ice
2.3 Reagents
• ASTM Type I water (D 1193)
3.1 WEIGHING PROCEDURE
1. Don a new, clean pair of vinyl gloves.
2. Label a new, clean centrifuge tube with lid with the sample
ID number.
3. Label the lid of the original sample container with the
sample ID number using an indelible marking pen. Allow the
ink to dry.
E-3
-------
4. Wipe off the outside of the paint sample container with a
clean laboratory paper wipe to remove any foreign material
or oils. Using an analytical balance shown to be operating
within normal calibration specifications, weigh the sample
container with lid containing the entire paint sample.
Record the total paint sample plus container weight (and if
provided, the area sampled) in a laboratory data form,
notebook, or equivalent recording device.
5. Transfer the remaining paint sample into a new, clean,
labeled centrifuge tube by carefully pouring the contents of
the original sample container into the new tube. Use a
clean glass rod to assist in the transfer as needed. Seal
the new tube and store for archival use.
6. Remove any remaining sample powder from the original sample
container and lid (received from the field) by rinsing with
ASTM Type I water. Set the container aside and allow it to
dry at room temperature.
7. After the original sample container has completely dried,
reweigh the container with lid and record the empty
container weight.
8. Determine the total field sample weight by subtracting the
empty container weight from the total paint sample plus
container weight generated in step 3.
3.2 HOMOGENIZATION PROCEDURE
1. Don a new, clean pair of vinyl gloves to perform sample
handling.
2. Remove any large amounts of substrate that may be present in
the sample. Exercise care when removing substrate to avoid
any paint losses. Leaving substrate in the sample is
preferred over paint chip loss. If required, use a clean
safety razor blade or equivalent tool to aid in substrate
removal.
3. Immerse the bottom portion of sample container into a
container containing dry ice. The depth of the container
should be sufficient to cover all paint present within the
sample container.
E-4
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4. Allow the paint chip sample to freeze for a minimum of
10 min. Add more dry ice as needed to freeze the paint chip
sample.
5. Using a clean plastic rod or other appropriate clean tool,
breakup the frozen paint chip sample inside the sample
container into a fine powder. Samples or sample portions
that resist homogenization should be noted in laboratory
records.
6. After completing breakup of the sample, tap off any powder
remaining on the tool used for breaking up the paint chips
back into the sample container.
7. Seal the container and roll for about a minute or two to mix
the samples. Rolling can be done by hand or by using
automated equipment.
E-5
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E-6
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APPENDIX F
FULL STUDY PROTOCOLS:
PREPARATION OF PAINT CHIP SAMPLES FOR SUBSEQUENT
ATOMIC SPECTROMETRY LEAD ANALYSIS
F-l
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F-2
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PREPARATION OF PAINT CHIP SAMPLES FOR SUBSEQUENT
ATOMIC SPECTROMETRY LEAD ANALYSIS
1.0 SUMMARY
Lead in paint chip samples (chips, powder, etc.) is solubilized
by extraction with nitric acid and hydrogen peroxide facilitated
by heat after sample homogenization. The lead content of the
digested sample is then in a form ready for measurement by Atomic
Spectrometry. This procedure is similar to NIOSH Method 7082.
Modifications have been made to convert this air particulate
method to a method appropriate for processing paint chip samples.
2.0 APPARATUS
2.1 Instrumentation
• Electric hot plate; suitable for operation at temperatures
up to at least 100°C as measured by a thermometer inside a
solution-filled container placed on the surface of the hot
plate.
2.2 Glassware and Supplies
• 150-mL or 250-mL beakers (borosilicate glass) equipped with
watch glass covers
Class A borosilicate 250-mL volumetric flasks
Class A borosilicate volumetric pipets; volume as needed
50-mL or 100-mL linear polyethylene tubes or bottles with
caps
Borosilicate or plastic funnels
Glass rods and appropriate devices for breaking up paint
chip samples
2.3 Reagents
• Concentrated nitric acid (16.0 M HN03) ; spectrographic grade
or equivalent
• Nitric acid, 10% (v/v): Add 100-mL concentrated HN03 to
500 mL ASTM Type I water and dilute to 1 L
• Hydrogen peroxide, 30% H202 (w/w); ACS reagent grade
• ASTM Type I water (D 1193)
F-3
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3.0 PROCEDURE
3 .1 WEIGHING OF SUBSAMPLES
For each homogenized sample, weigh into beakers for sample
digestion as described below:
1. Weigh a sub-sample of homogenized paint from the contents of
the sample container into a tared beaker labeled with the
sample ID. Weigh approximately 0.5 grams to 0.0001 grams.
2. Record the sub-sample weight (and if provided, the area
sampled) in a laboratory data form, notebook, or equivalent
recording device.
3.2 SAMPLE DIGESTION
For each sample weighed into beakers, plus any QC samples,
perform digestion as described below:
1. Wet the sample with about 2 to 3 mL of water from a squirt
bottle filled with ASTM Type I water.
2. Add 7.5 mL of concentrated HN03 and 2.5 mL 30% H2O2, and
cover with a watch glass.
3. Gently reflux on a hot plate for about 15 min (See Note 1) .
4. Remove the watch glass and evaporate gently on a hot plate
until the sample volume is reduced to about 1 to 2 mL (See
Note 2) .
5. Replace the watch glass and remove the beaker containing
sample from the hot plate and allow it to cool (See Note 3)
NOTE 1: The original NIOSH method called for temperatures
of 140°C as based on the use of digitally
programmable hot-plates, which measure the
temperature on the inside of the hot plate head.
Temperature drops of 40° to 50°C are not unusual
between the inside of the hot plate head and the
temperature actually experienced by the sample
solution. The temperatures of sample solution
should be between 85° to 100°C to prevent
spattering of the solution. Monitor solution
temperature on the hot plate by placing a
F-4
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NOTE 2:
NOTE 3:
thermometer in a flask or beaker filled with water
during digestion activities.
The original NIOSH method calls for evaporation
until most of the acid has been evaporated.
However, in order to avoid potential losses caused
by sample splattering at low volumes, the method
has been modified to specifically leave some
solution remaining in the digestion vessels.
Reduction volumes given are approximate and can be
dependent on the sample size and beaker size used
for preparation. Volumes should be reduced to as
low a level as comfortably possible without
causing sampling splattering or complete drying
out of the sample.
Cooling the sample is performed to avoid potential
splattering losses and resulting safety hazards
caused by addition of reagents to a partially
digested hot sample during subsequent processing
steps. Samples do not have to be cooled
completely to room temperature for safe further
processing of paint chip samples. However, the
operator must be aware that the potential for
splattering losses and resulting safety hazards
increases with increasing temperature of the
sample digest.
6.
7.
8.
9.
10.
11.
12.
Add 5 mL of concentrated HNO3
cover with a watch glass.
and 2.5 mL 30% H2O2/ and re-
Gent ly reflux on a hot plate for about 15 min (see Note 1).
Remove the watch glass and evaporate gently on a hot plate
until the sample volume is reduced to about 1 to 2 mL (see
Note 2) .
Replace the watch glass and remove the beaker containing
sample from the hot plate and allow it to cool (see Note 3).
Add 5 mL of concentrated HNO3 and 2.5 mL 30% H202, and re-
cover with a watch glass.
Gently reflux on a hot plate for about 15 min (see Note 1).
Remove the watch glass and evaporate gently on a hot plate
until the sample volume is reduced to about 1 to 2 mL (see
Note 2) .
F-5
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13. Replace the watch glass and remove the beaker containing
sample from the hot plate and allow it to cool (see Note 3) .
14. Rinse the watch glass and beaker walls with 3 to 5 mL of 10%
HNO3 into the beaker.
15. Remove the watch glass and evaporate gently on a hot plate
until the sample volume is reduced to about 1 to 2 mL (see
Note 2).
16. Replace the watch glass and cool to room temperature.
17. Add 1 mL concentrate HN03 to the residue; swirl to dissolve
soluble species.
18. Use a wash bottle filled with ASTM Type I water, rinse the
beaker walls and underside of the watch glass with Type I
water into the beaker.
19. Quantitatively transfer the digested sample into a 250-mL
volumetric flask using several rinses with ASTM Type I water
(see Note 4) . A plastic or glass funnel should be used to
avoid spillage during transfer from the beaker to the
volumetric flask.
20. Dilute to volume with ASTM Type I water and mix thoroughly.
The sample digest contains approximately 1% (v/v) HNO3.
21. Portions used for analysis must be filtered or centrifuged
prior to instrumental measurement to remove undissolved
material. Instrumental measurement should be performed
using calibration standards that are matched to the same
approximate acid levels as those in sample digest aliquot
analyzed for analyte content.
NOTE 4: Due to potential losses during filtration, it is
recommended to filter samples after dilution to
final volume. Additional volume consumed by
undissolved material will not cause any
significant bias.
F-6
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APPENDIX G
FULL STUDY PROTOCOLS:
STANDARD TEST PROTOCOL FOR THE ANALYSIS OF
DIGESTED SAMPLES FOR LEAD BY
INDUCTIVELY COUPLED PLASMA-ATOMIC EMISSION
SPECTROSCOPY (ICP-AES),
FLAME ATOMIC ABSORPTION (FAAS), OR
GRAPHITE FURNACE ATOMIC ABSORPTION (GFAAS) TECHNIQUES
G-l
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G-2
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STANDARD TEST PROTOCOL FOR THE ANALYSIS
OF DIGESTED SAMPLES
FOR LEAD BY
INDUCTIVELY COUPLED PLASMA-ATOMIC EMISSION
SPECTROSCOPY (ICP-AES),
FLAME ATOMIC ABSORPTION (FAAS), OR
GRAPHITE FURNACE ATOMIC ABSORPTION (GFAAS) TECHNIQUES
1.0 SUMMARY
A sample digestate is analyzed for Lead content using ICP-AES,
Flame-AAS, or Graphite Furnace-AAS techniques. Instrumental
Quality Control samples are analyzed along with sample digestates
to assure adequate instrumental performance. This procedure is
similar to SW-846 Method 6010. It is equivalent to the draft
procedure currently under consideration in ASTM Subcommittee
E06.23.
2 .0 DEFINITIONS
2.1 Digestion - The sample preparation process which will
solubilize targeted analytes present in the sample and
results in an acidified aqueous solution called the
digestate.
2.2 Digestate - An acidified aqueous solution which results
from performing sample preparation (digestion)
activities. Lead measurements are made using this
solution.
2.3 Batch - A group of field with QC samples which are
processed together using the same reagents and
equipment.
2.4 Serial Dilution - A method of producing a less
concentrated solution through one or more consecutive
dilution steps. Dilution step for a standard or sample
is performed by volumetrically placing a small aliquot
of a higher concentrated solution into a volumetric
flask and diluting to volume with water containing the
same acid levels as found in original sample
digestates.
2.5 Method Blank - A digestate which reflects the maximum
treatment given any one sample within a sample batch
except that it has no sample initially placed into the
G-3
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digestion vessel (the same reagents and processing
conditions which are applied to field samples within a
batch are also applied to the method blank). Analysis
results from method blanks provide information on the
level of potential contamination experienced by samples
processed within the batch.
2.6 No-Spiked Sample - A portion of a homogenized sample
which was targeted for addition of analyte but which is
not fortified with all the target analytes before
sample preparation. A method blank serves as a
no-spike sample in cases where samples cannot be
uniformly split as described in Section 2.7. Analysis
results for this sample is used to correct for native
analyte levels in the spiked and spiked duplicate
samples.
2.7 Spiked Sample and Spiked Duplicate Sample - Two
portions of a homogenized sample which were targeted
for addition of analyte and are fortified with all the
target analytes before preparation. In cases where
samples cannot be uniformly split (such as paint chip
samples taken for Lead per area determinations, a
method blank can be used in place of the homogenized
sample split. Use of a method blank for a spiked
sample should be referred to as a "spiked method blank"
or "spiked method blank duplicate." Analysis results
for these samples are used to provide information on
accuracy and precision of the overall analysis process.
2.8 Analysis Run - A period of measurement time on a given
instrument during which data is calculated from a
single calibration curve (or single set of curves).
Re-calibration of a given instrument produces a new
analysis run.
2.9 Instrumental QC Standards - Solutions analyzed during
an instrumental analysis run which provide information
on measurement performance during the instrumental
analysis portion of the overall Lead measurement
process.
2.10 Semi-quantitative Screen - An analysis run which is
performed on highly diluted sample digestates for the
purpose of determining the approximate analyte level in
the digest. This analysis run is generally performed
without inserting Instrumental QC standards except for
calibration standards. Data from this run are used for
G-4
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determining serial dilution requirements for sample
digestates to keep them within the linear range of the
instrument .
2.11 Quantitative Analysis - An analysis run on sample
digestates (or serial dilutions of sample digestates)
which includes Instrumental QC standards. Data from
this run are used to calculate and report final Lead
analysis results.
2.12 Initial Calibration Blank (ICB) - A standard solution
which contains no analyte and is used for initial
calibration and zeroing instrument response. The ICB
must be matrix matched to acid content present in
sample digestates . The ICB must be measured during
calibration and after calibration. The measured value
is to be less than five times the instrumental
detection limit.
2.13 Calibration Standards - Standard solutions used to
calibrate instrument. Calibration Standards must be
matrix matched to acid content present in sample
digestates and must be measured prior to measuring any
sample digestates .
2.14 Initial Calibration Verification (ICV) - A standard
solution (or set of solutions) used to verify
calibration standard levels. Concentration of analyte
to be near mid-range of linear curve, which is made
from a stock solution having a different manufacturer
or manufacturer lot identification than the calibration
standards. The ICV must be matrix matched to acid
content present in sample digestates. The ICV must be
measured after calibration and before measuring any
sample digestates . The measured value to fall within
of known value.
2.15 Interference Check Standard (ICS) - A standard solution
(or set of solutions) used for ICP-AES to verify
accurate analyte response in the presence of possible
spectral interferences from other analytes present in
samples. The concentration of analyte to be less than
25% of the highest calibration standard, concentrations
of interferant will be 200 ^g/Ml of Al , Ca, Fe, and Mg.
The ICS must be matrix matched to acid content present
in sample digestates. The ICS must be analyzed at
least twice, once before, and once after all sample
G-5
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digestates. The measured analyte value is expected to
be within ±20% of known value.
2.16 Continuing Calibration Verification (CCV) - A standard
solution (or set of solutions) used to verify freedom
from excessive instrumental drift. The concentration
to be near mid-range of linear curve. The CCV must be
matrix matched to acid content present in sample
digestates. The CCV must be analyzed before and after
all sample digestates and at a frequency not less than
every ten sample digestates. The measured value to
fall within ±10% of known value for ICP-AES or FAAS
(±20% for GFAA), run once for every 10 samples.
2.17 Continuing Calibration Blank (CCB) - A standard
solution which has no analyte and is used to verify
blank response and freedom from carryover. The CCB
must be analyzed after the CCV and after the ICS. The
measured value is to be less than five times the
instrumental detection limit.
3.0 APPARATUS AND MATERIALS
3.1 Analytical Instrumentation
3.1.1 Inductively Coupled Plasma-Atomic Emission
Spectrometer (ICP-AES) - Either sequential or simultaneous,
capable of measuring at least one of the primary ICP Lead
emission lines. Emission line used must be demonstrated to have
freedom from common major interferants such as Al, Ca, Fe, and Mg
or the ability to correct for these interferants.
3.1.2 Flame Atomic Absorption Spectrometer (FAAS) -
Equipped with an air-acetylene burner head, Lead hollow cathode
lamp or equivalent, and capable of making Lead absorption
measurements at the 283.3-nm absorption line.
NOTE: The 283.3-nm line is preferred over the 217-nm
line because of the increased noise levels commonly
observed at the 217-nm line for FAAS and GFAAS.
3.1.3 Graphite Furnace Atomic Absorption Spectrometer
(GFAAS) - Equipped with background correction, Lead hollow
cathode lamp or equivalent and capable of making Lead absorption
measurements at the 283.3-nm absorption line.
G-6
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3.2 Gases
Grades specified by manufacturer of the instrument employed.
3.2.1 Compressed air and acetylene for FAAS.
3.2.2 Compressed or liquid argon for ICP-AES and GFAAS.
3.2.3 Minimum of two-stage regulation of all gases.
3.3 Glassware and Miscellaneous Supplies
3.3.1 Vinyl gloves, powderless.
3.3.2 Micro-pipettors with disposable plastic tips, sizes
needed to make reagent additions, and spiking standards. In
general, the following sizes should be readily available: 1- to
5-mL adjustable, 1,000 fj.li, 500 /zL, 250 /zL, and 100 ^L.
3.3.3 Volumetric flasks, sizes needed to make, calibration
standards, serial dilutions, and Instrumental QC standards.
4.0 Reagents
4.1 Nitric acid, concentrated; reagent grade
4.2 Water—Unless otherwise indicated, references to water
shall be understood to mean reagent water as defined by Type 1 of
Specification D1193 (ASTM Type I Water: Minimum resistance of
16.67 megohm-cm, or equivalent).
4.3 Calibration stock solution, 100 ^tg/mL of Pb in dilute
nitric acid or equivalent (such as a multi-element stock
containing Pb).
4.4 Check standard stock solution (for ICV) , 100 /xg/mL of
Pb in dilute nitric acid or equivalent. Must be sourced from a
different lot number (or manufacturer) than the Calibration stock
solution (7.3) .
4.5 Interferant stock solution (for ICS; ICP-AES only),
10,000 /zg/mL of Al, Ca, Fe, and Mg in dilute nitric acid or
equivalent.
5.0 PROCEDURE
G-7
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5.1 Laboratory Records—Record all reagent sources (lot
numbers) used for sample preparation in a laboratory notebook.
Record any inadvertent deviations, unusual happenings, or
observations on a real-time basis as samples are processed. Use
these records to add supplement Lead data when reporting results.
5.2 Instrumental Setup
5.2.1 FAAS/GFAAS - Set the FAAS or GFAAS spectrometer up
for the analysis of Lead at 283.3 nm, according to the
instructions given by the manufacturer. Be sure to allow at
least a 30-min warmup of the hollow cathode lamp prior to
starting calibration and analysis.
5.2.2 ICP-AES - Set the ICP spectrometer up for the
analysis of Lead at a primary Lead emission line (such as
220.2 nm), according to the instructions given by the
manufacturer. Be sure to allow at least a 30-min warmup of the
system prior to starting calibration and analysis.
5.3 Preparation of Calibration and Instrumental QC
Standards
5.3.1 Calibration Standards - Prepare a series of
calibration standards covering the linear range of the
instrumentation. Prepare these standards using serial dilution
from the calibration stock solutions. Prepare these standards
using the same final nitric acid concentration present in the
sample digestates. Also prepare an Initial Calibration Blank
(ICB) as defined in Section 3 and Table F-l.
NOTE: For FAAS/GFAAS prepare a minimum of three
calibration standards plus the ICB for performing
calibration of the instrument. ICP-AES can be
performed using one high calibration standard and an
ICB. However, more are generally preferred.
5.3.2 Instrumental QC Standards - Prepare Instrumental QC
standards as summarized in Table F-l using serial dilution from
the required stock solutions. Prepare these standards using the
same final nitric acid concentration present in the sample
digestates.
NOTE: The ICV is used to assess the accuracy of the
calibration standards. Therefore, it must be made from
a different original source of stock solution than the
stock used to make the calibration standards. Use of a
G-8
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different serial dilution of the same original stock is
not acceptable.
5.4 Calibration and Instrumental Measurement - Perform
calibration and quantitative Lead measurement of sample
digestates and instrumental QC samples in the sequential order
outlined in Table F-2.
NOTE: Performance of a semi-quantitative screen prior
to quantitative analysis for sample digests containing
unknown levels of Lead generally recommended. The
purpose of this screen is to determine serial dilution
requirements of each digestate needed to keep the
instrumental response within the calibration curve.
During a semi-quantitative screen all digestates are
diluted to a constant large value (l-to-100 for
ICP/FAAS and l-to-1000 for GFAAS). The instrument is
calibrated and diluted digestates are analyzed without
inserting the instrumental QC used for a Quantitative
analysis run. Data from this screen are reviewed to
calculate the optimum serial dilution needed for each
digestate. No sample data can be reported for any
analvte value not falling within the calibration range.
Therefore, the optimum dilution is one which achieves
the maximum Lead response which is still within the
calibration curve. For ICP-AES, levels of possible
interferants (Al, Ca, Fe, and Mg) also may have to be
considered in order to make interference corrections.
For ICP-AES, digestates must be sufficiently diluted to
assure that levels of possible interferants such as Al,
Ca, Fe, and Mg are at or below the levels present in
the ICS.
5.5 Instrumental QC Evaluation and Corrective Action -
Examine the data generated from the analysis of calibration
standards and Instrumental QC standards. Evaluate the analysis
run using the criteria shown in Table F-l. Failure to achieve
the specifications shown in Table F-l will require corrective
action to be performed as described below:
5.5.1 ICB, Calibration Standards, or ICV - Failure to meet
specifications for these Instrumental QC standards requires
complete re-calibration. Sample digestates cannot be measured
under these conditions. It is recommended that standards be re-
prepared prior to re-calibration.
5.5.2 High Calibration Standard Re-run - Failure to meet
specifications for this Instrumental QC standard requires
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complete re-calibration. Sample digestates cannot be measured
under these conditions. It is recommended that standard range be
reduced prior to re-calibration.
5.5.3 ICS - Failure to meet specifications for these
Instrumental QC standards requires reanalysis of the standard
until specifications are met. Sample digestates cannot be
measured under these conditions. Re-preparation of the standard
prior to reanalysis is recommended under these conditions.
Continued failure of the ICS may require interference correction
investigation or changing of instrument parameters. Consult the
manufacturer's recommendations under these conditions. Any
change in instrument parameters must be accompanied by re-
calibration. If measured aliquots of sample digestates can be
shown not to contain interferants as high as those recommended
for the ICS making, then the interference levels in the ICS can
be lowered. Such changes must be documented in laboratory
records with data supporting the justification for the change.
All measurements on sample digests must be bracketed by an ICS
which meets specifications (called a "passing" ICS) . Failure to
meet specifications on the ICS run after the sample digestates
requires rerunning of all sample digestates since the last
passing ICS was measured. Since the ICS only is required to be
analyzed twice, much data could be lost if the analytical run
were long and the second ICS failed specifications. This is good
reason for including periodic analysis of the ICS as shown in
Table F-2.
5.5.4 CCV - Failure to meet specifications for these
Instrumental QC standards indicates excessive instrumental drift.
Sample digestates cannot be measured under these conditions and
any sample digestates measured since the last passing CCV must be
reanalyzed. This situation requires either reanalysis of the
standard until specifications are met or re-calibration. All
measurements on sample digests must be bracketed by an CCV which
meets specifications.
5.5.5 CCB - Failure to meet specifications for these
Instrumental QC standards indicates the presence of possible
instrumental carryover or baseline shift. Such a failure will
have the most impact on sample digestates at the lower end of the
calibration curve. The first corrective action is to reanalyze
the CCB. If the CCB passes, then the rinse time between the
samples should be increased and the analysis continued. If the
instrument response is still elevated and has not significantly
changed, then the instrument can be re-zeroed followed by a
CCV-CCB and reanalysis of all samples since the last passing CCB
which are within 5 times the response of the failed CCB.
G-10
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6.0 CALCULATIONS
For FAAS/GFAAS : Prepare a calibration curve to convert
instrument response (absorbance) to concentration (/xg/mL) using a
linear regression fit. Convert all instrumental measurements on
instrumental QC standards and sample digests to Lead
concentration (£tg/mL) using the calibration curve.
NOTE: Some instruments will automatically prepare a
calibration curve based on a linear regression fit.
For ICP-AES: All modern ICPs automatically prepare a calibration
curve to convert instrumental responses (emission intensity) to
concentration
G-ll
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TABLE G-l. SUMMARY OF LABORATORY INSTRUMENTAL MEASUREMENT QC STANDARDS
Name
Use
Specification
ICB -
Initial
Calibration
Blank
Used for initial
calibration and
zeroing
instrument
response.
Calibration Standard which contains no
lead.
Must be measured during calibration and
after calibration.
Measured value to be less than 5 times
the IDL.
Calibration
Standards
Used to Calibrate
instrument.
The high standard
re-run is used to
check for
response
linearity.
Acid content must be approximately the
same as that in the sample digests.
Must be measured prior to measuring any
sample digests.
Correlation Coefficient of ^0.995, as
measured using linear regression on
instrument response(y) versus
concentration(x).
The highest level Calibration standard
must be measured after calibration. The
measured value to fall within ,+10% of
known value.
ICV -
Initial
Calibration
Verification
Used to verify
calibration
standard levels.
Concentration of lead to be near the
middle of calibration curve. It is made
from a stock solution having a different
manufacturer or manufacturer lot
identification than the calibration
standards.
Must be measured after calibration and
before measuring any sample digests.
Measured value to fall within +.10% of
known value.
ICS -
Interference
Check
Standard
Used to verify
accurate lead
response in the
presence of
possible spectral
interferences
from other
analytes present
in samples.
Concentration of lead to be less than
25% of the highest calibration standard,
concentrations of interferant are 200
fig/mL of Al, Ca, Fe, and Mg.
Must be analyzed at least twice, once
before and once after all sample
digestates.
Measured lead value to fall within ±20%
of known value.
CCV -
Continuing
Calibration
Verification
Used to verify
freedom from
excessive
instrumental
drift.
Concentration to be near the middle of
the calibration curve.
Must be analyzed before and after all
sample digestates and at a frequency not
less than once every ten samples.
Measured value to fall within ±10% of
known value.
CCB -
Continuing
Calibration
Blank
Used to verify
blank response
and freedom from
carryover.
Calibration Standard which contains no
lead.
Must be analyzed after each CCV and each
ICS.
Measured value to be less than 5 times
the instrumental detection limit.
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TABLE G-2. EXAMPLE OF A TYPICAL ANALYSIS ORDER FOR MEASUREMENT
Run Order No.
(relative)
l
2-4
5
6
7
8
9
10
11
12
Sample ID
ICB
low, med,
high
ICB
ICV
high
standard
CCB
ICS
CCB
CCV
CCB
Comments
Calibration Blank
Calibration Standards
Calibration Blank
made from different stock,
level is near mid-point of
curve
Calibration Standard
Same as Calibration Blank
Interference Check Standard
Carryover Check
Drift Check, same as near
midpoint calibration standard
Carryover check
Instrument
Calibration
Calibration
Verification
Linearity
Check
Interferant
check for
ICP only
Continuing
Calibration
Verification
*** start repeating cycle of samples -Instrumental QC here ***
13-22
23-24
25-34
35-36
37-38
Sample IDs
CCV
CCB
Sample IDs
ICS
CCB
CCV
CCB
Sample digestates
Drift Check +
Carryover Check
Sample digestates
Interferant Check +
Carryover Check
Drift Check +
Carryover Check
Max. of 10
samples
See run
# 11-12
Max. of 10
samples
See run
# 9-10
See run
# 11-12
*** end repeating cycle of samples-QC standards here ***
G-13
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APPENDIX H
FULL STUDY PROTOCOLS:
PROTOCOL FOR PACKAGING AND SHIPPING OF SAMPLES FROM THE FIELD
H-l
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H-2
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PROTOCOL FOR PACKAGING AND SHIPPING OF SAMPLES
1.0 INTRODUCTION
Collection and analysis of paint chip samples as specified by the
QAPjP will require packaging and shipping of samples from
sampling sites. The field team will be responsible for packaging
and shipping the samples from each sampling site to the Sample
Custodian at MRI. The following are protocols for packaging and
shipping samples from the field.
2.0 SAMPLE PACKAGING PROTOCOL
The field team is responsible for preparing the samples for
shipment back to MRI. Samples that are collected will be shipped
on a routine basis by the acting field supervisor. The same
shipping container that was used to ship sample collection
containers to the field will generally be used to ship them back
to MRI. All sampling materials will be packaged in accordance
with Department of Transportation (DOT) regulations. The field
team will include copies of the field sampling forms with the
samples to identify the contents of the shipping containers. The
original field sampling forms will be held by the field
supervisor and, ultimately, hand carried to MRI. Do not send
original copies of sample data forms or other important records
with the samples.
3.0 SAMPLE SHIPPING METHODS
All samples will be shipped to MRI via Federal Express Economy
Distribution Service in accordance with DOT shipping regulations.
The MRI field team will be responsible for making the shipping
arrangement with the local Federal Express office. Pre-printed
Federal Express Air Bills can be obtained from the MRI Shipping
and Receiving Department. All Federal Express shipments will use
the standard Federal Express Air Bill. For further details,
consult with MRI's S & R Department.
H-3
-------
H-4
-------
APPENDIX I
FULL STUDY PROTOCOLS:
GLASSWARE/PLASTICWARE CLEANING PROCEDURE
INFORMATION NOT PRESENT : PROPRIETARY INFORMATION
1-1
-------
APPENDIX J
FULL STUDY PROTOCOLS:
ACID BATH CLEANING PROCEDURES
INFORMATION NOT PRESENT : PROPRIETARY INFORMATION
J-l
-------
APPENDIX AA
PILOT STUDY PROTOCOLS:
SELECTION OF MEASUREMENT AND SAMPLING LOCATIONS
AA-1
-------
AA-2
-------
SELECTION OF MEASUREMENT AND SAMPLING LOCATIONS
1.0 INITIAL SURVEY
Selection of interior and exterior sampling sites will be made
from as many painted substrate types as can be found in the test
structure (wood, plaster, drywall, brick, steel, masonry).
The field team Leader (field statistician, provided by David C.
Cox & Associates) will be responsible for drawing a rough floor
plan of the targeted structure, selecting and marking the
sampling locations within the structure, indicating the sampling
locations on the floor plan, making a backup copy of the floor
plan, and posting the floor plan for use by other field crew
personnel.
The field team Leader will be responsible for drawing a rough
plan of the exterior of the structure, selecting and marking
exterior sampling locations, indicating the exterior sampling
locations on the drawings, making a backup copy of the drawings,
and posting the exterior drawings for use by other field crew
personnel. The David C. Cox & Associates field team Leader will
also assist the MRI supervisor during the course of the field
sampling efforts.
Sampling locations corresponding to those portrayed on the
drawings will be outlined on the sampling location with marking
pen. A typical testing location will be a rectangle
approximately 4 inches high by 14 inches long as shown in Figure
A-l. The rectangle will be divided into 2 squares approximately
4 inches by 4 inches, and 6 rectangles approximately 4 inches
high by 1 inch wide. The field team Leader will mark one of the
4-inch squares with an "X" for use in XRF paint surface
measurements, and the other 4-inch square with an "L" for use in
side by side paint chip collection. In addition, the "L" square
will be subdivided into 4 smaller squares. Two of these squares
will be marked with arrows to denote sub-squares to be sampled.
The 6 smaller rectangles will be marked with an "S" to designate
use for test-kit sampling. For components where a. 4" x 14"
rectangle cannot be obtained, the field statistician will
exercise judgement in defining a comparable sampling area. Wood
trim/baseboard/mantles, brickwork, metal trim and beams, and
other such narrow, or otherwise irregular surfaces must be marked
for sampling on a case-by-case basis.
AA-3
-------
Appro x. 14"
Approx.
4"
Testing Location
S = Spot Test Kit Location
X = XRF Testing Location
L = Paint Chip Samples
(arrows denote subsquares to be sampled)
-------
The field team Leader will be responsible for attaching the
correct bar-code set corresponding to each location. The bar
codes will be removed by the various samplers and applied to the
individual's test results data form at the time the test is
performed. The team Leader will attempt to numerically order the
sampling locations so that all locations with the same substrate
material will be tested sequentially by the XRF instruments. The
order in which the substrates are tested in the pilot will be:
wood, drywall, plaster, concrete, and metal. This ensures that
denser substrates will be tested towards the end of the day in
order to minimize operational problems with the XRF instruments.
Test kit operators will follow a staggered starting sequence so
that the 6 kits will not always be tested in the same order.
AA-5
-------
APPENDIX BB
PILOT STUDY PROTOCOLS:
MEASUREMENT PROTOCOLS FOR XRF TESTING
BB-1
-------
MEASUREMENT PROTOCOLS FOR XRF TESTING
1.0 SUMMARY
This document describes the standard protocol for collecting XRF
measurement data on painted surfaces and corresponding substrate
surfaces. This standard also includes instructions for recording
the measurements, making QC checks and data release requirements
for two different classes of instruments: Direct Readers and
Spectrum Analyzers.
2.0 MATERIALS AND EQUIPMENT
• Portable field XRF instrument with any extra required
supporting equipment. (To be provided by XRF
contractor.)
• One set of NIST paint films (SRM 2579) ; contains 5 films
of different Lead levels. (To be provided by XRF
contractor.)
• Reporting forms; see attached. (To be provided by MRI.)
• Dosimeter Badges; one for each XRF operator and one for
each individual working within the same unit where XRF
testing takes place. (Operator badge to be provided by
XRF contractor, MRI will provide any other needed
badges).
• Adhesive labels or barcode labels for identifying
samples. (To be provided by MRI, will be available at
each sampling location.)
• Waterproof (indelible) permanent marking pen. (To be
provided by MRI, will be available at site.)
• Watch, clock or other equivalent timepiece. (Each member
in the field will be required to have a timepiece for
reporting the sampling times on the data forms.)
• Sling Psychrometer; or equivalent for room temperature
and relative humidity measurements. (To be provided by
MRI, will be available at site.)
• Pre-moistened wipes for cleaning of tools or hands. (To
be provided by MRI, will be available at site.)
• QC test blocks, each approximately 4"x4", loaded on
wheeled type carrier; thicknesses are approximate: 3/4"
wood (pine) , 2" concrete (with aggregate), 1/2" sheet
rock, 20-25 gauge metal, 1" plaster and 12" thick
styrofoam block. (To be provided and numbered by MRI,
will be available at site.)
BB-2
-------
• One 12" thick styrofoam block for holding QC test blocks
under measurement. (To be provided and numbered by MRI,
will be available at site.)
3.0 MEASUREMENT PROCEDURES FOR DIRECT READERS
3.1 BEGINNING OF EACH DAY ON SITE PROCEDURES
At the beginning of the sampling day at a given site, perform
whatever tests and instrument checks are required by the
manufacturer of the XRF to prepare the instrument for taking Lead
measurements. In addition, perform the initial drift check
determinations procedure as described in Section 3.4.1.
3.2 PROCEDURE FOR NORMAL MEASUREMENTS AT EACH SAMPLING LOCATION
At each sampling location perform the following steps:
1. For each new "XRF DATA-DIRECT READERS" form needed (see
attached), complete the header of the form.
2. Record the sampling location/identification (ID) on an open
line of the form. Use barcode labels corresponding to the
specific sampling location whenever possible. These barcode
labels should be present in close proximity to the sampling
location marked by the field team leader (see Note 1) .
3. Perform whatever normal instrument checks are required by the
manufacturer of the XRF to prepare the instrument for taking
Lead measurements.
4. Perform 3 read cycles each on two surfaces as follows:
• Perform 3 read cycles on the painted surface at the
sampling location. Record each read cycle on the "XRF
DATA-DIRECT READERS" form along with the other
information requested on the form.
• Perform 3 read cycles on the exposed substrate surface
covered with the 1.02 mg/cm2 NIST standard film (red) at
the sampling location. Record each read cycle on the
"XRF DATA-DIRECT READERS" form along with the other
information requested on the form.
BB-3
-------
IF the exposed substrate is concrete,
THEN perform 3 additional read cycles on the exposed
substrate as follows:
• Perform 3 read cycles on the exposed substrate surface
covered with the 3.53 mg/cm2 NIST standard film at the
sampling location. Record each read cycle on the "XRF
DATA-DIRECT READERS" form along with the other informa-
tion requested on the form.
NOTE: The sampling location will be marked in advance by
the field team leader using a dark colored marking
pen. The marking will be in the form of squares and
rectangles with letters. The painted surface
location to be used for XRF measurements will be
indicated with an "X" placed adjacent to a large
square or rectangle. The exposed substrate surface
location to be used for XRF measurements will be the
largest exposed area present at the sampling
location.
5. Special location requirements:
IF, during testing activities, the following conditions
exist:
• The location is marked as a "SPECIAL" location;
THEN perform the SPECIAL MEASUREMENTS as described in the
Section 3.3
6. Continuing QC drift check requirements:
IF, during testing activities, the following conditions
exist:
• The surface substrate is of a different type than the
previous location.
THEN perform the CONTINUING DRIFT CHECKS as described in the
Section 3.4.2
BB-4
-------
7. End of day QC drift check requirements:
IF, during testing activities, the following conditions
exist:
• All surfaces to be measured in a given day have been
completed (end of sampling day);
THEN perform the END OF DAY DRIFT CHECKS as described in the
Section 3.4.1
8. QC variability check requirements:
IF, during testing activities, the following conditions
exist:
• The surface substrate is of a different type than the
previous location;
THEN perform a QC VARIABILITY CHECK as described in the
Section 3.5
3.3 PROCEDURE FOR SPECIAL MEASUREMENTS AT SPECIFIC SAMPLING
LOCATIONS
At specially marked sampling locations perform the following
steps:
1. For each new "XRF DATA, SPECIAL LOCATIONS-DIRECT READERS"
form needed (see attached), complete the header of the form.
2. Record the sampling location/identification (ID) on an open
line of the form. Use barcode labels corresponding to the
specific sampling location when ever possible. These barcode
labels should be present in close proximity to the sampling
location marked by the field team leader.
3. Perform what ever normal instrument checks are required by
the manufacturer of the XRF to prepare the instrument for
taking Lead measurements.
4. Perform 4 read cycles each on two surfaces (total of 8
readings) as follows:
• Perform 4 read cycles on the painted surface at the
sampling location. Record each read cycle on the "XRF
BE-5
-------
DATA SPECIAL LOCATIONS-DIRECT READERS" form along with
the other information requested on the form.
• Perform 4 read cycles on the exposed substrate surface
covered with the 1.02 mg/cm2 NIST standard film (red) at
the sampling location. Record each read cycle on the
"XRF DATA, SPECIAL LOCATIONS-DIRECT READERS" form along
with the other information requested on the form.
IF the exposed substrate is concrete,
THEN perform 4 additional read cycles on the exposed
substrate as follows:
• Perform 4 read cycles on the exposed substrate surface
covered with the 3.53 mg/cm2 NIST standard film at the
sampling location. Record each read cycle on the "XRF
DATA, SPECIAL LOCATIONS-DIRECT READERS" form along with
the other information requested on the form.
NOTE: The special sampling locations will be marked in
advance by the field team leader using a dark colored
marking pen. The word "SPECIAL" in addition to
squares and rectangles will be present at the
location.
3.4 QC DRIFT CHECK PROCEDURES
3.4.1 INITIAL AND END OF DAY DRIFT CHECK DETERMINATIONS
At the beginning and end of sampling day, the instrument response
on several test surfaces must be determined for use as a
reference point to monitor instrumental drift. Make this
determination as described below:
1. Complete the header of a new "XRF QC DATA: INITIAL\END DRIFT
CHECK-DIRECT READERS" form.
2. Perform and record room temperature and humidity measurements
in the same general vicinity as intended for the first
sampling location.
3. Determine the reading of the XRF instrument for a NIST
standard film placed on each of six test blocks as described
below:
BB-6
-------
Perform 9 read cycles on each test block (total of 54
readings) as follows:
• Place the QC test block on a 12" thick (nominal
thickness) styrofoam block. Place the 1.02 mg/cm2 NIST
standard film (red) on the block. Perform 3 sets of 3
read cycles each down through the film and record each
reading on the "XRF QC DATA: INITIAL\END DRIFT CHECK-
DIRECT READERS" form.
Perform 9 additional read cycles on the concrete test block
as follows:
• Place the QC test block on a 12" thick (nominal
thickness) styrofoam block. Place the 3.53 mg/cm2 NIST
standard film on the block. Perform 3 sets of 3 read
cycles each down through the film and record each reading
on the "XRF QC DATA: INITIAL\END DRIFT CHECK-DIRECT
READERS" form.
3.4.2 CONTINUING DRIFT CHECKS PROCEDURES
Perform continuing drift checks as described below:
1. For each new "XRF QC DATA: CONTINUING DRIFT CHECKS-DIRECT
READERS" form needed, complete the header of the form.
2. Perform and record room temperature and humidity measurements
in the same general vicinity as intended for the first
sampling location.
3. Determine the reading of the XRF instrument for a NIST
standard film placed on one test block as described below:
Use the test block that represents the closest match to the
new sample location. Perform 3 read cycles on the selected
test block as follows:
• Place the QC test block on a 12" thick (nominal
thickness) styrofoam block. Place the 1.02 mg/cm2 NIST
standard film (red) on the block. Perform 3 read cycles
down through the film and record each reading on the "XRF
QC DATA: CONTINUING DRIFT CHECKS-DIRECT READERS" form.
BB-7
-------
IF the selected test block is concrete,
THEN perform 3 additional read cycles on the test block as
follows:
• Place the QC test block on a 12" thick (nominal
thickness) styrofoam block. Place the 3.53 mg/cm2 NIST
standard film on the block. Perform 3 read cycles down
through the film and record each reading on the "XRF QC
DATA: CONTINUING DRIFT CHECKS-DIRECT READERS" form.
3.5 QC VARIABILITY CHECK PROCEDURES
Perform a QC VARIABILITY CHECK as follows:
1. Repeat the normal testing measurements at each location as
described in section 3.2 step 4. five more times for a total
of 6 separate Lead tests on both the painted and substrate
surfaces at that location.
Record the data on the "XRF DATA-DIRECT READERS" form by
using the open lines directly below (in sequence) the
original test data for that sampling location. Fill in the
"Location ID" using a pen (use arrow or ") to indicate the
same ID number as above whenever possible (avoid using up
barcode labels for the QC variability checks).
Mark the "Comments" column with a "QC-VC" to indicate that
the data on that line is a QC variability check for the
location.
4.0 MEASUREMENT PROCEDURES FOR SPECTRUM ANALYZERS
4.1 BEGINNING OF EACH DAY ON SITE PROCEDURES
At the beginning of the sampling day at a given site, perform
whatever tests and instrument checks are required by the
manufacturer of the XRF to prepare the instrument for taking Lead
measurements. In addition, perform the initial drift check
determinations procedure as described in Section 4.4.1.
BB-8
-------
4.2 PROCEDURE FOR NORMAL MEASUREMENTS AT EACH SAMPLING LOCATION
At each sampling location perform the following steps:
1. For each new "XRF DATA-SPECTRUM ANALYZERS" form needed (see
attached), complete the header of the form.
2. Record the sampling location/identification (ID) on an open
line of the form. Use barcode labels corresponding to the
specific sampling location whenever possible. These barcode
labels should be present in close proximity to the sampling
location marked by the field team leader.
3. Perform whatever normal instrument checks are required by the
manufacturer of the XRF to prepare the instrument for taking
Lead measurements.
4. Perform 1 measurement each on two surfaces (total of 2
measurements) as follows:
• Perform 1 test mode reading on the painted surface at the
sampling location. Record the data on the "XRF DATA-
SPECTRUM ANALYZERS" form along with the other information
requested on the form.
• Perform 1 test mode reading on the exposed substrate
surface covered with the 1.02 mg/cm2 NIST standard film
(red) at the sampling location. Record the data on the
"XRF DATA-SPECTRUM ANALYZERS" form along with the other
information requested on the form.
IF the exposed substrate is concrete.
THEN perform 1 additional reading on the exposed substrate as
follows:
• Perform 1 test mode reading on the exposed substrate
surface covered with the 3.53 mg/cm2 NIST standard film
at the sampling location. Record the data on the "XRF
DATA-SPECTRUM ANALYZERS" form along with the other
information requested on the form.
NOTE: The sampling location will be marked in advance by
the field team leader using a dark colored marking
pen. The marking will be in the form of squares and
rectangles with letters. The painted surface
location to be used for XRF measurements will be
indicated with an "X" placed adjacent to a large
BB-9
-------
square or rectangle. The exposed substrate surface
location to be used for XRF measurements will be the
largest exposed area present at the sampling
location.
5 . Special Location requirements:
IF, during testing activities, the following conditions
exist:
• The location is marked as a "SPECIAL" location;
THEN perform the SPECIAL MEASUREMENTS as described in the
Section 4.3
6. Continuing QC Drift Check requirements:
IF, during testing activities, the following conditions
exist:
• The surface substrate is of a different type than the
previous location.
THEN perform the CONTINUING DRIFT CHECKS as described in the
Section 4.4.2
7. End of Day QC Drift Check requirements:
IF, during testing activities, the following conditions
exist:
• All surfaces to be measured in a given day have been
completed (end of sampling day) ;
THEN perform the END OF DAY DRIFT CHECKS as described in the
Section 4.4.1
8. QC Variability Check requirements:
IF, during testing activities, the following conditions
exist:
• The surface substrate is of a different type than the
previous location;
THEN perform a QC VARIABILITY CHECK as described in the
Section 4.5
BB-10
-------
4.3 PROCEDURE FOR SPECIAL MEASUREMENTS AT SPECIFIC SAMPLING
LOCATIONS
At each sampling location perform the following steps:
1. For each new "XRF DATA, SPECIAL LOCATIONS-SPECTRUM ANALYZERS"
form needed (see attached), complete the header of the form.
2. Record the sampling location/identification (ID) on an open
line of the form. Use barcode labels corresponding to the
specific sampling location whenever possible. These barcode
labels should be present in close proximity to the sampling
location marked by the field team leader.
3. Perform whatever normal instrument checks are required by the
manufacturer of the XRF to prepare the instrument for taking
Lead measurements.
4. Perform 3 measurements each on two surfaces (total of 6
measurements) as follows:
• Perform 3 test mode readings on the painted surface at
the sampling location. Record each reading on the "XRF
DATA, SPECIAL LOCATIONS-SPECTRUM ANALYZERS" form along
with the other information requested on the form.
• Perform 3 test mode readings on the exposed substrate
surface covered with the 1.02 mg/cm2 NIST standard film
(red) at the sampling location. Record each reading on
the "XRF DATA, SPECIAL LOCATIONS-SPECTRUM ANALYZERS" form
along with the other information requested on the form.
IF the exposed substrate is concrete,
THEN perform 3 additional measurements on the exposed
substrate as follows:
• Perform 3 test mode readings on the exposed substrate
surface covered with the 3.53 mg/cm2 NIST standard film
at the sampling location. Record each reading on the
"XRF DATA, SPECIAL LOCATIONS-SPECTRUM ANALYZERS" form
along with the other information requested on the form.
NOTE: The special sampling locations will be marked in
advance by the field team leader using a dark colored
marking pen. The word "SPECIAL" in addition to
squares and rectangles will be present at the
location.
BB-11
-------
4.4 QC DRIFT CHECK PROCEDURES
4.4.1 INITIAL AND END OF DAY DRIFT CHECK DETERMINATIONS
At the beginning and end of sampling day, the instrument
response on several test surfaces must be determined for use as a
reference point to monitor instrumental drift. Make this
determination as described below:
1. Complete the header of a new "XRF QC DATA: INITIAL\END DRIFT
CHECK-SPECTRUM ANALYZERS" form.
2. Perform and record room temperature and humidity measurements
in the same general vicinity as intended for the first
sampling location.
3. Determine the reading of the XRF instrument for a NIST
standard film placed on each of five test blocks as described
below:
Perform 3 measurements on each test block (total of 15
readings) as follows:
• Place the QC test block on a 12" thick (nominal
thickness) styrofoam block. Place the 1.02 mg/cm2 NIST
standard film (red) on the block. Perform 3 test mode
readings down through the film and record each reading on
the "XRF QC DATA: INITIAL\END DRIFT CHECK-SPECTRUM
ANALYZERS" form.
Perform 3 additional measurements on the concrete test block
as follows:
• Place the QC test block on a 12" thick (nominal
thickness) styrofoam block. Place the 3.53 mg/cm2 NIST
standard film on the block. Perform 3 test mode reads
down through the film and record each reading on the "XRF
QC DATA: INITIAL\END DRIFT CHECK-SPECTRUM ANALYZERS"
form.
4.4.2 CONTINUING DRIFT CHECKS PROCEDURES
Perform continuing drift checks as described below:
1. For each new "XRF QC DATA: CONTINUING DRIFT CHECKS-SPECTRUM
ANALYZERS" form needed, complete the header of the form.
BB-12
-------
2. Perform and record room temperature and humidity measurements
in the same general vicinity as intended for the first
sampling location.
3. Determine the reading of the XRF instrument for a NIST
standard film placed on one test block as described below:
Use the test block that represents the closest match to the
new sample location. Perform 1 measurements on the selected
test block as follows:
• Place the QC test block on a 12" thick (nominal
thickness) styrofoam block. Place the 1.02 mg/cm2 NIST
standard film (red) on the block. Perform 1 test mode
reading down through the film and record the data on the
"XRF QC DATA: CONTINUING DRIFT CHECKS-SPECTRUM ANALYZERS"
form.
IF the selected test block is concrete,
THEN perform 1 additional measurement on the test block as
follows:
• Place the QC test block on a 12" thick (nominal
thickness) styrofoam block. Place the 3.53 mg/cm2 NIST
standard film on the block. Perform 1 test mode reading
down through the film and record the data on the "XRF QC
DATA: CONTINUING DRIFT CHECKS-SPECTRUM ANALYZERS" form.
4.5 QC VARIABILITY CHECK PROCEDURES
Perform a QC VARIABILITY CHECK as follows:
1. Repeat the normal testing measurements at each location as
described in section 4.2 step 4. five more times for a total
of 6 separate Lead tests on both the painted and substrate
surfaces at that location.
Record the data on the "XRF DATA-SPECTRUM ANALYZERS" form by
using the open lines directly below (in sequence) the
original test data for that sampling location. Fill in the
"Location ID" using a pen (use arrow or ") to indicate the
same ID number as above whenever possible (avoid using up
barcode labels for the QC variability checks).
Mark the "Comments" column with a "QC-VC" to indicate that
the data on that line is a QC variability check for the
location.
BB-13
-------
XRF Data - Spectrum Analyzers
Date House No.
Field Sampler (printed nai
Manufacturer
ne)
Model No.
Source Type Source SN
Surface Types: P=Plaster, S=Wall Board, W=
Location ID
(Barcode)
Surface
Type
(•Surface
Flat?(Y/N)
=Wood, B=Brick, C=Cc
Time of
Meaiurement
Sampling
Time (Sec)
60
60
60
60
60
60
Field £
Serial No.
Detector 7
increte, M=
Paint Surface
Reading*
Jampler (signature)
Vpe
Metal
NIST Std.
Film Uted
Substrate + NIST
Readings
F
Batter
Detec
NIST Std.
Film Uted
>aqe of
V Info
torSN
Substrate + NIST
Readings
Comments
-------
XRF QC Data: Initial/End Drift Check - Spectrum Analyzers
Date Site Initial Temp. End Temp. Initial RH End RH
Field Sampler (printed narr
Manufacturer
ie) Field Sampler (signature)
Model No. Serial No.
Source Type Source SN Detector Type
Battery Info
Detector SN
Test Block Type: S=Wall Board, W=Wood, B=Brick, C=Concrete, M=Metal
Time of
Measurement
Test Block
Type
Sampling
Time (Sec)
60
60
60
60
60
60
NISTStd.
Film Used
Beginning of Day Readings
Set
1
Set
2
Set
3
End of Day Readings
Set
1
Set
2
Set
3
Comments
03-5 SEV dewalt Irm 4 030593
-------
XRF QC Data: Continuing Drift Check - Spectrum Analyzers
Date Site
Field Sampler (printed narr
Manufacturer
ie)
Model No.
Source Type Source SN
Test Block Type: S=Wall Board, W=Wood, B=Brick, C=Concrete,
Tlmeof
Measurement
Test Block
; Typo
Sampling
Time (Sec)
60
60
60
60
60
NISTStd.
Him Used
Readings
Temperature
Field Sampler (sianature)
Serial
Detect
M=Melal
Relative
Humtdty
No. Battery Info
or Type Detector SN
Comments
93-5 SEV Aswan Irm B 031193
-------
Date House
Field Sampler (printed name)
Manufacturer
XRF Data - Direct Readers
No.
Paae of
Field Sampler (signature)
Model No. Serial No.
Source Type Source SN
Battery Info
Detector Type Detector SN
Surface Types: P=Plaster, S=Wall Board, W=Wood, B=Brick, C=Concrete, M=Metal
Location ID
(Barcode)
Surface
Type
It Surface
Flat? (Y/N)
Time of
Measurement
Sampling
Time (Sec)
15
15
15
15
15
15
Paint Surface
Readings
NIST Std.
.Film Used
Substrate + NIST
Readings
NIST Std.
Rim Used
Substrate 4 NIST
Readings
Comments
93-5 SEV dewsN Irm 1 030593
-------
XRF QC Data: Initial/End Dri
Date Site Initial Temp.
Field Sampler (printed name) F
Manufacturer
Model No. Serfs
Source Type Source SN Dete
Test Block Type: S-Wall Board, W=Wood, B=Brick, C=Concrete, M=MeI
Time of
Measurement
Test Block
;.;.Typ«jy;;.
Sampling
Time (Sec)
15
15
15
15
15
15
NISTStd.
Film Used
Beginning of Day Readings
Set
Set
2
Set
3
ft Check
End Temp
;ield Samp
ilNo.
ctor Type
al
; - Direct Readers
>. Initial RH End RH
tier (signal
ure)
Battery Info
Detector SN
End of Day Readings
Set
1
Set
2
Set
3
Comments
£3-5 SEV dewall Irm 3 030593
-------
XRF QC Data: Continuing Drift Check - Direct Readers
Date Site
Field Sampler (printed name)
Manufacturer
Model No.
Source Type Source SN
Test Block Type: S=Wall Board, W=Wood, B=Brick, C=Concrete,
Time of
Measurement
Test Block
Type
Sampling
Time (Sec)
15
15
15
15
15
NISTStd.
Film Used
Readings
Temperature
Field Sampler (signature)
Serial No. Battery Info
Detecl
M=Metal
Relative
Humldty
or Type Detector SN
Comments
93-5 SEV d«wa« frm 7 031193
-------
APPENDIX CC
PILOT STUDY PROTOCOLS:
MEASUREMENT PROTOCOLS FOR SPOT TEST KITS
CC-1
-------
MEASUREMENT PROTOCOLS FOR SPOT TEST KITS
1.0 SUMMARY
This appendix describes the pilot protocols which will be used
with commercial test kits for testing in situ painted surfaces
for Lead content. The chemistry and instructions vary from kit
to kit but basic steps common to all kits are:
1. Select the area or item to be tested,
2. Prepare the test kit reagents,
3. Perform the quality control test included in the package,
4. Clean the surface to be tested,
5. Expose all layers of the paint by sanding or cutting,
6. Test the paint,
7. Record results of test, and
8. Hide tested surface from next tester.
The actual test methods involve reaction of Lead in the paint
with the active reagent (s) in the test kit to produce a color
change, a precipitate, or both. Methods of reacting the Lead
with the reagents vary and include:
• Swabbing in situ with a reagent soaked applicator
• Pressing a reagent-impregnated pad to the in situ
surface for a specified length of time
• Adding drops of one or more solutions to the in situ
paint
• Removal of paint chip or dust to a vial to which reagents
are added to produce the precipitate or color change
1.1 MATERIALS AND EQUIPMENT
Materials and equipment needs vary from kit-to-kit. Equipment
and supplies are listed under the individual kit protocols.
1.2 TEST KITS SELECTED FOR THE STUDY
Five Lead test kits have been selected for inclusion in the Pilot
Study. Table CC-1 lists the kits by manufacturer along with
summary information. In addition to the kits listed in Table CC-
1, a Massachusetts licensed Lead inspector will be contracted to
perform Lead testing with the Massachusetts state-approved
sulfide reagents and procedures. The protocol for the Lead
inspector will be the state-approved protocol. Although the
Massachusetts protocol is not physically incorporated in this
QAPjP, it is incorporated by reference.
CC-2
-------
TABLE CC-1.
LEAD TEST KITS TARGETED FOR USE IN THE
PILOT AND FULL STUDY
MANUFACTURER
ENZONE
Frandon/Pace
Frandon/Pace
HybriVet
Systems
Innovative
Synthesis
KIT NAME
Lead- Zone
Lead Alert
Lead Alert
Lead Check
Lead Detective
TEST
Proprietary
Rhodizonate
Rhodizonate
Rhodizonate
Sodium Sulfide
KIT METHOD
CHOSEN
Reagent -
impregnated
pad
Home -owner
in-situ
notched paint
layers
Professional-
core sample
paint chip
Reagent -
impregnated
swabs
Drop reagent
into notched
paint layers
2.0 TESTING PAINTED SURFACES FOR LEAD
In order to provide a reasonably uniform comparison of methods
for this study, differences among the kit instructions preclude
use of only the package-insert instructions for training and
testing. For purposes of this Pilot Study, instructions supplied
by the manufacturers were edited to conform to the eight steps
listed above in the Appendix CC Summary.
2.1 ENZONE "LEAD-ZONE" (PROPRIETARY CHEMICAL COMPOSITION)
2.1.1 List of Supplies
Clipboard,
Map of dwelling and/or instructions from supervisor,
"Lead-Zone" WA57 field testing protocol,
Test Kit Results Recording Form (will be several pages),
Ball point pens (2),
Box of wet-wipes (200),
Disposable gloves (100 pr),
Lighted magnifying glass or other light source with
magnifying glass,
CC-3
-------
Extension cord,
50 mL ASTM Type I water in dropping bottle,
Scissors,
Resealable plastic bags,
Trash bag,
Duct tape,
17 "Lead-Zone" test kits -- enough to perform 100 tests,
Stopwatch, and
Watch or other time piece.
2.1.2 Performing the Lead Zone Tests
Perform Lead testing in a safe manner as instructed in the
training class including wearing of plastic gloves and safety
glasses at all time, and leather gloves with respirator during
cutting or scraping activities.
1. Obtain the "Lead-Zone" test kits, data recording forms,
and supplies in the above list of supplies from the field
supervisor.
2. Obtain sampling location instructions (starting point,
other) from the field supervisor.
3. Fill out the header information on the data recording
form.
4. Find the first location to be tested according to
instructions received from the field supervisor. The
location map will be provided by the supervisor, or
alternately, may be posted in the dwelling.
5. Remove one barcode from the strip attached to the test
location and affix it in the barcode column on the data
recording form.
6. Prepare the test kit reagents. Take care not to
contaminate the test pads or painted surfaces with Lead
from the test spots on the verification card enclosed in
the package!
a. Use scissors to cut each of the 2 Lead Zone Test Pads
into 3 equal sized pieces, creating 6 smaller Lead
zone test pads.
b. Store the test pad pieces in a resealable plastic bag
until needed.
CC-4
-------
7. Perform the quality control (QC) test contained in the
kit before the first location is tested and after each
negative result to verify that the test reagents are
working.
a. Remove one test pad piece from the plastic bag
b. Moisten the test pad with a few drops of ASTM Type I
water
c. Press the moistened pad against one of the test dots
on the verification card. Hold the pad against the
surface for two minutes. IF a pink to purple color
develops on the test dot or pad (or both) the
reagents are working correctly. If not, consult
supervisor.
8. Clean the surface to be tested by wiping with a pre-
moistened wipe.
9. Expose all layers of the paint by cutting through all
paint layers down to the substrate. Use the bevelled V-
cut as taught in the training class.
a. Record observations of native colors of paint layers
before testing.
b. Record substrate type {e.g. wallboard, plaster, wood,
metal, brick, masonry)
10. Test the exposed paint layers:
a. Remove one test pad piece from the plastic bag
b. Moisten the test pad with a few drops of ASTM Type I
water
c. Press the moistened pad against the exposed paint
layers. Hold for two minutes. IF a pink to purple
color develops in any of the paint layers, or on the
test pad, the test is positive for Lead. If not,
then the test is negative for Lead.
11. Record the test results -- color observed on pad, color
observed in any of the paint layers and any comments on
the test form in the appropriate columns (use the lighted
magnifying glass or equivalent to inspect for native and
reagent-developed colors).
12. Cover the tested spot with duct tape to conceal the
results from the next tester.
CC-5
-------
13. Test the remaining locations in the structure as
instructed by the supervisor. Follow steps 5 through 13
until all locations in the structure have been tested.
Record the temperature and relative humidity within the
building at the beginning, end, and during the middle of
the day. Use the comments column of the most current
test kit data recording form to record this information.
Six tests may be performed with each Lead-Zone kit. Use
the verification cards prior to the first test in the
structure and after any negative tests to verify that the
reagents are working correctly. As long as positive
tests are being obtained, it is not necessary to use the
verification card for each kit opened. IF the test does
not work on the painted surface (sampling location),
consult the supervisor.
14. At the end of the testing day, check the test results
recording form for completeness. Return the completed
form and all supplies and remaining test kits to the
supervisor.
Figure CC-1 is a photocopy of the Lead-Zone Lead Test Kit
instructions provided with the test kit.
> c
— o
-------
Lead Zone Test Kit—package insert copy removed because of
copyright considerations.
Figure CC-1 was presented on 1 page.
(Insert from packages obtained in March 1993 from Enzone
Corporation, College Point, NY 11356)
Figure CC-1. Photocopy of Lead Zone Test Kit instructions
CC-7
-------
2.2 FRANDON/PACE LEAD ALERT (RHODIZONATE)
2.2.1 List of Supplies
Clipboard,
Map of dwelling and/or instructions from supervisor,
"Lead-Alert" WA57 field testing protocol,
Test Kit Results Recording Form (will be several pages),
Ball point pens (2),
Box of wet-wipes (200),
Disposable gloves (100 pr) ,
Lighted magnifying glass or other light source with
magnifying glass,
Extension cord,
Resealable plastic bags,
Trash bag,
Duct tape,
Scissors,
"Lead-Alert" homeowner test kits -- enough to perform 100
tests,
Stopwatch, and
Watch or other time piece.
2.2.2 Performing the "Lead-Alert" Test
Perform Lead testing in a safe manner as instructed in the
training class. Although two types of tests can be performed
with the Frandon Lead Alert Kit including wearing of plastic
gloves and safety glasses at all times, and leather gloves with
respirator during cutting or scraping activities-- a Surface test
and an Underlying Layers test-only the Underlying Layers Test
will be performed in this study.
1. Obtain the "Lead-Alert" test kits, data recording forms,
and supplies from the field supervisor.
2. Obtain sample location instructions (starting point,
other) from the field supervisor.
3. Fill out the header information on the data recording
form.
4. Find the first location to be tested according to
instructions received from the field supervisor. The
location map will be provided by the supervisor, or .
alternately, may be posted in the dwelling.
CO 8
-------
5. Remove one barcode from the strip attached to the test
location and affix it in the barcode column on the data
recording form.
6. Prepare the indicating solution:
a. Remove red cap from plastic bottle labelled
"Indicating Solution."
b. Carefully remove the dropper insert by
rolling/twisting it to the side.
c. Open the tablet container and place only one tablet
into the solution.
d. Replace the dropper insert and the red cap and shake
the bottle for one minute. Allow the bottle to stand
for approximately five minutes and then shake it
again until the solution turns yellow. The tablet
will not be completely dissolved. This is normal.
7. Clean the test area with a pre-moistened wipe.
8. Perform a Positive Control Test (before the first test of
the day and after each negative test on painted test
areas in the structure)
a. Apply two drops of Leaching Solution and two drops of
Indicating solution to a cotton tipped applicator or
test paper (avoid touching the dropper to any
surface).
b. Press the cotton tip or test paper on an unused test
circle for 10-15 seconds
c. Add two drops of Indicating Solution to the
applicator or test paper. Do not touch the dropper
to the applicator.
d. Interpret the results. Use the lighted magnifying
glass or equivalent to observe the color change. A
pinkish to rose/red color is a positive test,
indicating that the reagents are performing
correctly. IF reagents are not performing correctly
consult the supervisor. Record the results in the
comments column of the data reporting form.
9. Perform the underlying layers test:
a. Cut through all layers of the paint down to the
substrate with a bevelled V-notcha. Record native
paint layer colors, substrate type (wallboard,
plaster, wood, brick, metal, masonry) in appropriate
blocks.
CC-9
-------
b. Apply two drops of Leaching Solution to a cotton
tipped applicator or test paper
c. Rub the cotton tip or test paper on the exposed paint
layers for 10-15 seconds.
d. Add two drops of Indicating Solution to the
applicator or test paper. Do not touch the dropper to
the applicator.
e. Interpret the results. Use the lighted magnifying
glass or equivalent to observe the color change.
Pinkish to rose/red color on the paint layers and/or
the cotton tip (or test paper) is a positive test for
Lead.
10. Record the results on the data form with any comments in
the appropriate columns.
11. Cover the completed test spot with duct tape to conceal
the results from the next tester.
12. Test the remaining locations in the structure as
instructed by the supervisor. Follow steps 5 through 12
until all locations in the structure have been tested.
Record the temperature and relative humidity within the
building at the beginning, end, and during the middle of
the day. Use the comments column of the most current
test kit data results form to record this information.
Use the Positive Control Strips only prior to the first
test in the structure and after any negative tests to
verify that the reagents are working correctly. After
the initial Positive Control Strip test, it is not
necessary to use the control strips with each kit opened
as long as positive tests are being obtained on the
painted surfaces and underlying layers. IF the test does
not work on the painted surface (sampling location),
consult the supervisor.
13. At the end of the testing day, check the test results
recording form for completeness. Return the completed
form and all supplies and remaining test kit to the
supervisor.
Figure CC-2 is a photocopy of the Frandon Lead-Alert kit
instructions.
These protocols include formalized modifications made the to
protocols shown in the QAPjP, Revision No. 0, dated March 15,
1993
CC-10
-------
Frandon Lead Alert Kit package insert copy removed
because of copyright considerations.
Figure CC-2 was presented on 4 pages.
(Insert from packages obtained in March 1993 from Pace
Environs, 207 Rutherglen Drive, Gary, NC 27511)
Figure CC-2. Photocopy of Frandon Lead-Alert Kit instructions
CC-11
-------
2.3 FRANDON/PACE LEAD ALERT ALL-IN-ONE (RHODIZONATE)
2.3.1 List of Supplies
Clipboard,
Map of dwelling and/or instructions from supervisor,
"Lead-Alert" All-in-One WA57 field testing protocol,
Test Kit Results Recording Form (will be several pages),
Ball point pens (2),
Box of wet-wipes (200) ,
Disposable gloves (100 pr),
Lighted magnifying glass or other light source with
magnifying glass,
Extension cord,
Resealable plastic bags,
Trash bag,
Duct tape,
Scissors,
"Lead-Alert" All-In-One test kits -- enough to perform 100
tests, and
Stopwatch.
2.3.2 Performing the "Lead-Alert" All-In-One Test
The Lead-Alert All-In-One kit contains three tests. Only one of
the three -- removal of a paint chip and testing in the supplied
vials -- will be performed in this study.
1. Obtain the "Lead-Alert" All-in-One test kits, data
recording forms, and supplies from the field supervisor.
2. Obtain instructions (starting point, other) from the
field supervisor.
3. Fill out the header information on the data recording
form.
4. Find the first location to be tested according to
instructions received from the field supervisor. The
location map will be provided by the supervisor, or
alternately, may be posted in the dwelling.
5. Remove one barcode from the strip attached to the test
location and affix it in the barcode column on the data
recording form.
CC-12
-------
6. Prepare the indicating solution:
a. Remove red cap from plastic bottle labelled
"Indicating Solution."
b. Carefully remove the dropper insert by
rolling/twisting it to the side.
c. Open the tablet container and place only one tablet
into the solution.
d. Replace the dropper insert and the red cap and shake
the bottle for one minute. Allow the bottle to stand
for five minutes and then shake it again until the
solution turns yellow. The tablet will not be
completely dissolved. This is normal.
7. Clean the test area with a pre-moistened wipe.
8. Perform a Positive Control Test {before the first test of
the day and after each negative test on painted test
areas in the structure).
a. Apply two drops of Leaching Solution and two drops of
Indicating solution to a cotton tipped applicator or
test paper (do not touch the dropper to any surface).
b. Press the cotton tip or test paper on an unused test
circle for 10-15 seconds
c. Add two drops of Indicating Solution to the
applicator or test paper {do not touch the dropper to
any surface).
d. Interpret the results. Use the lighted magnifying
glass or equivalent to observe the color change. A
pinkish to rose/red color is a positive test,
indicating that the reagents are performing
correctly. IF the reagents are not performing
correctly consult the supervisor. Record the results
in the comments column of the data form.
9. Perform the Paint Chip Test
a. Remove one of the adhesive backed collection papers
and fold it in half. Apply the paper close to the
area to be tested as shown in the package
instructions.
b. Using the circular boring tool, cut down into the
surface. Scrape the paint inside the circle onto the
paper. Be sure to remove all layers of paint.
c. Transfer the paint from the paper to a plastic vial.
Grind up the paint with a plastic rod for about 10
CC-13
-------
seconds (Lead paint grinds easily whereas Latex based
paint will be harder to grind).
d. Add 3 drops of Leaching Solution to the vial (do not
touch the dropper to the vial or contents) and grind
the contents for another 10 seconds. Let the vial
sit for 20 seconds.
e. Add 3 drops of Indicating Solution to the tip of an
applicator (do not touch the applicator or any other
surface with the dropper), then touch the surface of
the liquid in the plastic vial with the tip of the
applicator.
f. Interpret the results. Use the lighted magnifying
glass or equivalent to observe the color changes.
Pinkish to rose red color on the applicator tip is a
positive test for Lead.
10. Record the results on the data form with any comments in
the appropriate columns.
11. Cover the completed test spot with duct tape to conceal
the results from the next tester.
12. Test the remaining locations in the structure as
instructed by the supervisor. Follow steps 5 through 12
until all locations in the structure have been tested.
Record the temperature and relative humidity within the
building at the beginning, end, and during the middle of
the day. Use the Positive Control Strips only prior to
the first test in the structure and after any negative
tests to verify that the reagents are working correctly.
After the initial Positive Control Strip test, it is not
necessary to use the control strips with each kit opened
as long as positive tests are being obtained on the
painted surfaces and underlying layers. IP the test does
not work on the painted surface (sampling location),
consult the supervisor.
13. At the end of the testing day, check the data recording
form for completeness. Return the completed form and all
supplies and remaining test kits to the supervisor.
A photocopy of the package instructions is shown in Figure CC-3.
CC-14
-------
Frandon Lead Alert Kit package insert copy removed
because of copyright considerations.
Figure CC-3 was presented on 4 pages.
(Insert from packages obtained in March 1993 from Pace
Environs, 207 Rutherglen Drive, Gary, NC 27511)
Figure CC-3. Photocopy of Frandon Lead-Alert All-in-One Kit
instructions.
CC-15
-------
2.4 LEAD DETECTIVE (Sodium Sulfide)
2.4.1 List of Supplies
Clipboard,
Map of dwelling and/or instructions from supervisor,
"Lead-Detective" WA57 field testing protocol,
Test Kit Results Recording Form (will be several pages),
Ball point pens (2),
Box of wet-wipes (200),
Disposable gloves (100 pr),
Disposable beakers, 10 mL,
Lighted magnifying glass or other light source with
magnifying glass,
Extension cord,
Resealable plastic bags,
Trash bag,
Duct tape,
Scissors,
One "Lead-Detective" test kit,
Stopwatch, and
Watch or other time piece.
2.4.2 Performing the Lead Detective Tests
The Lead Detective kit detects Lead (and other heavy metals) by
reacting with the Lead to form a black insoluble precipitate of
Lead sulfide. Perform Lead testing in a safe manner as
instructed in the training class including wearing of plastic
gloves and safety glasses at all times, and leather gloves with
respirator during cutting or scraping activities. The package
instructions included with the Lead Detective are contained in a
33-page instruction booklet. A photocopy of this booklet is
included in this Appendix CC as an attachment.
1. Obtain the "Lead-Detective" test kits, data recording
forms, and supplies from the field supervisor.
2. Obtain sample location instructions (starting point,
other) from the field supervisor.
3. Fill out the header information on the test form.
4. Find the first location to be tested according to
instructions received from the field supervisor. The
location map will be provided by the supervisor, or
alternately, may be posted in the dwelling.
CC-16
-------
5. Remove one barcode from the strip attached to the test
location and affix it in the barcode column on the data
recording form.
6. Carefully add the contents of the kit water bottle to the
bottle containing the sodium sulfide crystals. Screw on
the dropper cap and shake vigorously for 5 minutes or
until the crystals are dissolved.
7. Perform the quality control check.
a. Remove a quality control strip (or the paint chip)
from the plastic bag
b. While holding the strip in the forceps, Add a few
drops of the sodium sulfide solution to the strip.
c. IF black coloring appears, the QC test is positive
and the reagents are working. Record the results in
the comments column of the data report form. IF a
black color does not appear, do not use the kit for
testing. Consult the supervisor.
8. Clean the surface of the test location with a pre-
moistened wipe.
9. Cut through all layers of the paint down to the substrate
with a bevelled V-notch.
10. Add a few drops of the sodium sulfide solution to the
notch, being very careful not to drip the reagent on the
surfaces below or adjacent to the test spot. Use a
plastic stirring rod or toothpick as needed to direct the
solution into the notch3.
11. Use the lighted magnifying glass or equivalent to observe
the paint for changes. A black or gray color is a
positive test for Lead.
12. Record the results on the data form with any comments in
the appropriate columns.
13. Cover the completed test spot with duct tape to conceal
the results from the next tester.
These protocols include formalized modifications made the to
protocols shown in the QAPjP, Revision No. 0, dated March 15,
1993
CC-17
-------
14. Test the remaining locations in the structure as
instructed by the supervisor. Follow steps 5 through 14
until all locations in the structure have been tested.
Record the temperature and relative humidity within the
building at the beginning, end, and during the middle of
the day. Use the comments column of the most current
testing data results form to record this information.
One Lead Detective kit should be sufficient to test one
structure (approximately 100 tests) Test the QC strip in
the kit only prior to the first test in the structure and
after any negative tests to verify that the reagents are
working correctly. After the initial Positive Control
Strip test, it is not necessary to use the control strips
with each kit opened as long as positive tests are being
obtained on the painted surfaces and underlying layers.
IF the test does not work on the paint surface (sampling
location), consult the supervisor.
15. At the end of the testing day, check the test results
recording form for completeness. Return the completed
form and all supplies and remaining test kits to the
supervisor.
CC-18
-------
Lead Detective Lead Paint Detection Kit-booklet: package
insert copy removed because of copyright considerations.
Attachment to Appendix CC was presented on 20 pages.
(Insert from packages obtained in March 1993 from
Innovative Synthesis Corporation, 1425 Beacon Street,
Newton, MA 02168)
Appendix CC Attachment. The Lead Detective, Lead Paint Detection
Kit (booklet)
CC-19
-------
2.5 LEAD CHECK SWABS
2.5.1 List of Supplies
Clipboard
Map of dwelling and/or instructions from supervisor,
"Lead-Check'-' swabs WA57 field testing protocol,
Test Kit Results Recording Form (will be several pages),
Ball point pens (2),
Box of wet-wipes (200),
Disposable gloves (100 pr) ,
Lighted magnifying glass or other light source with
magnifying glass,
Extension cord,
Resealable plastic bags,
Trash bag,
Duct tape,
Scissors,
100 "Lead Check" swabs and several control cards,
Stopwatch, and
Watch or other time piece.
2.5.1 Performing the Lead Check Test
The Lead Check Swabs contain rhodizonate which reacts with Lead
to form a pink to red color. Perform Lead testing in a safe
manner as instructed in the training class including wearing of
plastic gloves and safety glasses at all time, and leather gloves
with respirator during cutting or scraping activities.
1. Obtain the "Lead-Check" rhodizonate test swabs, data
recording forms, and supplies from the field supervisor.
2. Obtain sample location instructions (starting point,
other) from the field supervisor.
3. Fill out the header information on the data recording
form.
4. Find the first location to be tested according to
instructions received from the field supervisor. The
location map will be provided by the supervisor, or
alternately, may be posted in the dwelling.
5. Remove one barcode from the strip attached to the test
location and affix it in the barcode column on the data
recording form.
CC-20
-------
6. Clean the test surface with a wet-wipe.
7. Cut a beveled V notch through all paint layers down to
the substrate. Use the lighted magnifying glass to
examine the paint layers revealed in the notch and record
native paint colors and substrate information.
8. Remove one Lead Check Swab and reseal the package.
9. With the swab pointing up, squeeze points A and B to
crush the internal glass ampoules .
10. With the swab pointing down, shake the swab twice, then
gently squeeze it until the yellow liquid appears on the
Swab tip.
11. While gently squeezing, rub the Swab tip on the test area
for 30 seconds.
12. Observe Swab tip for coloration. Use the lighted
magnifying glass or equivalent to read the results. Pink
to red indicates positive test for Lead.
13. Record the results in the appropriate box on the data
form.
IF the test is positive for Lead, tape a plastic
disposable beaker over the tested notch to conceal the
test result from the next tester. IF no color change is
observed within 2 minutes, touch the swab to one of the
dots on the Lead confirmation card. IF no color develops
on the QC dot, discard the swab and retest the paint
layers (steps 8 through 13). IF color develops on the QC
dot, tape a plastic disposable beaker over the tested
notch and go on to the next spot. Record the time and
return to re-observe this spot in approximately 30
minutes and if still no color change, cover and return to
check the paint after approximately another 30 minute
time period. IF, after 1 hour, no color has developed,
the spot tested negative for Lead. Record all
observations, subsequent examinations, and other comments
in the data form.
14. Test the remaining locations in the structure as
instructed by the supervisor. Follow steps 5 through 14
until all locations in the structure have been tested.
Record the temperature and relative humidity within the
building at the beginning, end, and during the middle of
CC-21
-------
the day. Use the comments column of the most current
test kit data results form to record this information.
Do not reuse any of the Swabs, even if no color change
was observed. As long as positive tests are being
obtained on the painted surfaces and underlying layers,
there is no need to perform the Lead confirmation test on
the test confirmation card. IF the test does not work on
the painted surface (sampling location), consult the
supervisor.
A photocopy of the Lead Check Swabs Test Kit package instructions
is shown in Figure CC-4.
CC-22
-------
Lead Check Swabs—test kit package insert copy removed
because of copyright considerations.
Figure CC-4 was presented on 2 pages.
(Insert from packages obtained in March 1993 from
Hybrivet Systems, Inc., P.O. Box 1210, Framingham, MA
01701)
CC-23
-------
Date
Spot Test Kit Rep
House No. Initi
Field Sampler (printed name)
Name of Test Kit
ortinc
alTem
Field
Serie
j Results Form page of
perature Initial RH
Sampler (signal
il/Lot No.
ure)
Surface Types: P=Plaster, S=Wall Board, W=Wood, B=Brick, C=Concrete, M=Metal
Location ID (Barcode)
Surface
Typo
Paint
Surface
Color
Is the
Surface Flat?
(Y/N)
Start
Time
Testing Results
time of
Obs.
Color
LBP Determination-
(Y/N or Level)
Tape
Cover?
(Y/N)
Comments
(place during day temp. And RH data In this column)
93-7SEVd«waltlrm10031193
-------
APPENDIX DD
PILOT STUDY PROTOCOLS:
COLLECTION OF PAINT CHIP SAMPLES IN AND AROUND
BUILDINGS AND RELATED STRUCTURES
DD-1
-------
COLLECTION OF PAINT CHIP SAMPLES IN AND AROUND
BUILDINGS AND RELATED STRUCTURES
SUMMARY
This document describes the standard protocol for obtaining a
single paint chip sample from a painted substrate. This standard
also includes instructions for sample storage and transport
requirements.
MATERIALS AND EQUIPMENT
TABLE DD. EQUIPMENT- SUPPLIES LIST FOR COLLECTION OF
PAINT CHIP SAMPLES
ITEM
Safety goggles
Disposable gloves
Respirator with HEPA filters
Single-edged razor blades
Razor blade holder
Cold chisels
Hammer
Wax Paper
OR
clean white paper, 8.5 x 11
Masking tape
Duct tape
Marking pens
Pencils
Pencil sharpener
Clip board
Recording forms
Sample containers {plastic
centrifuge tubes, plastic
resealable bags)
NUMBER
I/tester + 1 extra
150 pair/tester
I/tester
150/tester
I/tester + 1 extra
several, various blade
widths in duplicate
I/tester
150/tester
5 rolls, 1-inch
5 rolls, 2-inch
3/tester
3/tester
1 at site
I/tester + 1 extra
Enough for 250 samples
250
DD-2
-------
TABLE DD. EQUIPMENT -SUPPLIES LIST FOR COLLECTION OF
PAINT CHIP SAMPLES
ITEM
Resealable bags for sample
containers
Extra shipping container for
paint chip samples
Trouble lights and spare bulbs
Extension cords
Magnifying glass with light
source or lighted magnifying
glass
Power generator
Small plane
Pocket knife
Wire brush
Coarse soft bristle brush
Heat gun
Replacement heat gun element
Metal paint chip collection
tray
Tool pouch with belt
Face shield
Fire extinguisher
NUMBER
250
3
3
200 ft.
I/tester
1 at site
I/tester
2/tester + 1 extra
I/tester
2/tester
I/tester
I/tester
I/tester
I/tester
1 at site
2 at site
Note: Other items as needed.
PROCEDURES
At each sampling location perform the following steps:
1. For each new "Paint Sampling Record" form needed (see
attached), complete the header of the form.
2. Record the sampling location/identification (ID) on an open
line of the form. Use barcode labels corresponding to the
specific sampling location when ever possible. These barcode
DD-3
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labels should be present in close proximity to the sampling
location marked by the field team leader.
4. Complete "Surface Type","Paint Surface Color" and "Is Surface
Flat" sections of the Paint Chip Collection Reporting form.
Any irregularities should be noted in the Comments column.
The "Area Sampled with Units" column should be completed
after the sample has been taken and can be accurately
measured.
5. Affix an ID label to the outside of the container into which
the sample is to be placed, and ensure that the label adheres
well. If barcode labels are present at the sampling site,
then affix 2 extra identical labels to the outside of the
container for later use by the laboratory.
6. Don a pair of new vinyl gloves for removal of each paint
sample for the laboratory.
7. Place the template (nominally 5 cm x 5 cm inside dimensions)
over the sampling site and hold firmly, tape can be used to
hold template in position. Do not place tape over adjacent
areas marked for sampling. Using a cutting tool and the
template as a guide, score the perimeter of the area to be
removed. If it is impractical to use the template, the score
can be made using a metal ruler as a guide. The area scored
using the alternative method should be approximately
equivalent to the area scored when using the template. Avoid
using pencil or pen to mark the sample outline.
8. Affix a tray, paper funnel or equivalent collection device
directly below the sampling location. The collection device
should be located as close as possible to the sampling site
but should not interfere with the removal procedure. If a
paper funnel is used, either fold and tape closed the bottom
of the funnel or affix a labeled open sampling container to
the bottom of the funnel in a manner that will result in
collection of the paint directly into the container. The
collection device should be firmly secured to avoid being
upset.
9. Using the appropriate cutting tool for a particular substrate
or condition of the sample site, begin removing the paint
from the substrate. If possible peel the paint off of the
substrate by sliding the blade along the score and underneath
the paint. Remove all paint down to the bare substrate.
DD-4
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Avoid the inclusion of the substrate in the collection
device. If substrate does fall into the collection device,
remove only that substrate which can be easily removed
without losing any of the paint sample. Do not remove any
substrate which cannot be separated from the paint sample.
The laboratory will remove extraneous substrate if possible,
under laboratory conditions.
If problems are encountered in removing the paint sample,
other tools may be used. The use of a heat gun may
facilitate the removal process. Extreme caution should be
exercised when using the heat gun. Do not overheat the
sample area, heat only until the paint becomes soft and
supple. If the paint does not become soft and supple in a
minute or two, discontinue the use of heat and try another
means to remove the sample.
In areas where extreme difficulty is experienced in removing
the paint sample, consult with the field supervisor for
advice.
10. If sample is not directly collected in the sample container
using the funnel approach, transfer the collected paint
sample to the sample container and seal. Exercise care to
insure that all paint taken from the recorded area is placed
into the sample container.
If the funnel procedure was used, make sure all of the sample
is in the collection container. Seal the container.
11. Carefully and accurately measure the sampling area
dimensions. Do not attempt to calculate areas in the field.
Record the dimensions including units used (e.g., 2" x 2" or
5 cm x 5 cm) on the sampling container using a permanent
marker. Try and use only centimeters for recording data.
Avoid making measurement in inches. Also, enter the
dimensions (including the units used) on the "Paint Chip
Collection" Reporting form in the column "Area Sampled with
Units." Any irregularities or problems which arise in the
process, should be noted in the Comments column.
12. Seal the container.
13. Wrap tape around the container lid rim to ensure that the
container remains sealed. Place sample container into a
resealable plastic bag and seal. Place the sample container
and bag into another resealable plastic bag and seal.
DD-5
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14. Generate a duplicate paint chip sample immediately adjacent
to the first sample site, using the same procedure used to
obtain the first sample. The preparations of the sample
container remains unchanged except for the addition of the
duplicate designation "DUP" to the sampling container and use
of the "DUP" row on the reporting form. Irregularities and
problems should be noted in the Comments column.
15. Enlarge the exposed substrate area made during paint chip
collection to a minimum of 4" by 4" using the same general
cutting and scraping methods followed for paint chip
collection. Avoid pitting or significantly damaging the
substrate surface. This area will be used by XRF testers for
taking substrate measurements.
NOTE: For some locations, a full 4"x 4" area may not be
possible. For these locations, make the largest exposed area
possible up to the desired 4"x 4" exposed surface.
16. Remove and dispose of the vinyl gloves, paper funnels, tape
or other used disposable equipment prior to moving to the
next sampling location. Avoid cross-contamination of samples
by carefully cleaning all sampling and collection tools
between each sample taken. Use pre-moistened wipes for this
purpose.
17. Store the samples in a safe place during sampling until
shipment can be made back to the laboratory. Turn over all
completed "Paint Chip Collection Reporting" forms by the end
of each sampling day to the field supervisor. Ensure that a
copy of the form is made and placed into the box used for
shipment back to the laboratory.
DD-6
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Paint Chip Collection Reporting Form
page of
Date House No.
Field Sampler {printed name)
Field Sampler (signature)
Surface Types: P=Plaster, S=Wall Board, W=Wood, B=Brick, C=Concrete, M=Metal
Location ID (Barcode)
Surface
Type
Paint
Surface
Color
Sub-
Sample
NoT .
Original
Dup
Original
Dup
Original
Dup
Original
Dup
Original
Dup
Original
Dup
Original
Dup
Original
Dup
is the
Surface Rat?
OfTN)
Area Sampled
with Units
Comments
93-7 SEV dewa« frm 11 031193
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APPENDIX EEa
PILOT STUDY PROTOCOLS:
PREPARATION OF PAINT CHIP SAMPLES FOR SUBSEQUENT
ATOMIC SPECTROMETRY LEAD ANALYSIS
Protocols shown in this appendix include formalized
modifications made the to protocols shown in the QAPjP,
Revision No. 0, dated March 15, 1993
EE-1
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PREPARATION OF PAINT CHIP SAMPLES FOR SUBSEQUENT
ATOMIC SPECTROMETRY LEAD ANALYSIS
1.0 SUMMARY
Lead in paint chip samples (chips, powder, etc.) is solubilized
by extraction with nitric acid and hydrogen peroxide facilitated
by heat after sample homogenization. The lead content of the
digested sample is then in a form ready for measurement by Atomic
Spectrometry. This procedure is similar to NIOSH Method 7082.
Modifications have been made to convert this air particulate
method to a method appropriate for processing paint chip samples.
2.0 APPARATUS
2.1 Instrumentation
• Electric hot plate; suitable for operation at temperatures up
to at least 100°C as measured by a thermometer inside a
solution filled container placed on the surface of the hot
plate.
2.2 Glassware, and Supplies
• 150 mL or 250 mL beakers {borosilicate glass) equipped with
watch glass covers.
Class A borosilicate 250 mL volumetric flasks.
Class A borosilicate volumetric pipets; volume as needed.
50 mL or 100 mL linear polyethylene tubes or bottles with
caps.
Borosilicate or plastic funnels.
Glass rods and appropriate devices for breaking up paint chip
samples.
2.3 Reagents
• Concentrated nitric acid (16.0 M HN03) ; spectrographic grade
or equivalent.
• Nitric acid, 10% (v/v) : Add 100 mL concentrated HNO3 to 500
mL ASTM Type I water and dilute to 1 L.
• Hydrogen peroxide, 30% H2O2 (w/w); ACS reagent grade.
• ASTM Type I water (D 1193).
EE-2
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3.0 SAMPLE PREPARATION
3.1 SAMPLE HOMOGENIZATION
For each field sample, homogenize the paint chips inside the
original sample container as described below.
1. Don a new clean pair of vinyl gloves to perform sample
handling.
2. Remove any large amounts of substrate which may be present in
the sample. Exercise care when removing substrate to avoid
any paint losses. Leaving substrate in the sample is
preferred over paint chip loss. If required, use a clean
safety razor blade or equivalent tool to aid in substrate
removal.
3. Immerse the bottom portion of sample container into a
container containing dry ice. The depth of the container
should be sufficient to cover all paint present within the
sample container.
4. Allow the paint chip sample to freeze for a minimum of 10
minutes. Add more dry ice as needed to freeze the paint chip
sample.
5. Using a clean glass rod or other appropriate clean tool,
breakup the frozen paint chip sample inside the sample
container into a fine powder. Samples or sample portions
that resist homogenization should be noted in laboratory
records.
6. After completing breakup of the sample, tap off any powder
remaining on the tool used for breaking up the paint chips
back into the sample container.
7. Seal the container and roll for about a minute or two to mix
the samples. Rolling can be done by hand or using automated
equipment.
3.2 WEIGHING PROCEDURE
For each sample, determine the total field sample weight, and
weigh out a subsample for digestion as described below:
1. Don a new clean pair of vinyl gloves.
EE-3
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2. Label a clean beaker for use in digesting the sample and a
new clean centrifuge tube with lid.
3. Wipe off the outside of the paint sample container with a
clean laboratory paper wipe to remove any foreign material or
oils. Using an analytical balance shown to be operating
within normal calibration specifications, weigh the sample
container containing the entire homogenized paint sample.
Record the total paint sample plus container weight (and if
provided, the area sampled) in a laboratory data form,
notebook or equivalent recording device.
4. Weigh a sub-sample of homogenized paint from the contents of
the sample container into a tared beaker labeled with the
sample ID. Weigh approximately 0.5 grams to 0.0001 grams.
Record the sub-sample weight (and if provided, the area
sampled) in a laboratory data form, notebook or equivalent
recording device.
5. Transfer the remaining homogenized paint sample into a new
clean labeled centrifuge tube by carefully pouring the
contents of the original sample container into the new tube.
Use a clean glass rod to assist in the transfer as needed.
Seal the new tube an store for archival use.
6. Remove any remaining sample powder from the original sample
container (from the field) by rinsing with ASTM Type I water.
Set the container aside and allow it to dry at room
temperature.
7. After the original sample container has completely dried, re-
weigh the container and record the empty container weight.
8. Determine the total field sample weight by subtracting the
empty container weight from the total paint sample plus
container weight generated in step 3.
3.3 SAMPLE DIGESTION
For each sample weighed into beakers, plus any QC samples,
perform digestion as described below:
1. Wet the sample with about 2-3 mL of water from a squirt
bottle filled with ASTM Type I water.
2. Add 7.5 mL of concentrated HN03 and 2.5 mL 30% H2O2, and cover
with a watch glass.
EE-4
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Gently reflux on a hot plate for about 15 minutes (See Note
1) -
Remove the watch glass and evaporate gently on a hot plate
until the sample volume is reduced to about 1-2 mL (See Note
2) .
Replace the watch glass and remove the beaker containing
sample from the hot plate and allow it to cool (See Note 3).
NOTE 1: The original NIOSH method called for temperatures of
140°C as based on the use of digitally programmable
hot-plates which measure the temperature on the
inside of the hot plate head. A temperature drops of
40-50°C are not unusual between the inside of the hot
plate head and the temperature actually experienced
by the sample solution. The temperatures of sample
solution should be between 85-100°C to prevent
spattering of the solution. Monitor solution
temperature on the hot plate by placing a thermometer
in a flask or beaker filled with water during
digestion activities.
NOTE 2: The original NIOSH method calls for evaporation until
most of the acid has been evaporated. However, in
order to avoid potential losses caused by sample
splattering at low volumes, the method has been
modified to specifically leave some solution
remaining in the digestion vessels. Reduction volumes
given are approximate and can be dependent on the
sample size and beaker size used for preparation.
Volumes should be reduced to as low a level as
comfortably possible without causing sampling
splattering or complete drying out of the sample.
NOTE 3: Cooling the sample is performed to avoid potential
splattering losses and resulting safety hazards
caused by addition of reagents to a partially
digested hot sample during subsequent processing
steps. Samples do not have to be cooled completely
to room temperature for safe further processing of
paint chip samples. However, the operator must be
aware that the potential for splattering losses and
resulting safety hazards increases with increasing
temperature of the sample digest.
Add 5 mL of concentrated HNO3
cover with a watch glass.
and 2.5 mL 30% H202, and re-
EE-5
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7. Gently reflux on a hot plate for about 15 minutes (See Note
1) .
8. Remove the watch glass and evaporate gently on a hot plate
until the sample volume is reduced to about 1-2 mL (See Note
2) .
9. Replace the watch glass and remove the beaker containing
sample from the hot plate and allow it to cool (See Note 3).
10. Add 5 mL of concentrated HN03 and 2.5 mL 30% H202/ and re-
cover with a watch glass.
11. Gently reflux on a hot plate for about 15 minutes (See Note
1) .
12. Remove the watch glass and evaporate gently on a hot plate
until the sample volume is reduced to about 1-2 mL (See Note
2) .
13. Replace the watch glass and remove the beaker containing
sample from the hot plate and allow it to cool (See Note 3).
14. Rinse the watch glass and beaker walls with 3 to 5 mL of 10%
HNO3 into the beaker.
15. Remove the watch glass and evaporate gently on a hot plate
until the sample volume is reduced to about 1-2 mL (See Note
2) .
16. Replace the watch glass and cool to room temperature.
17. Add 1 mL concentrate HNO3 to the residue; swirl to dissolve
soluble species.
18. Use a wash bottle filled with ASTM Type I water, rinse the
beaker walls and underside of the watch glass with Type I
water into the beaker.
19. Quantitatively transfer the digested sample into a 250-mL
volumetric flask using several rinses with ASTM Type I water
(See Note 4). A plastic or glass funnel should be used to
avoid spillage during transfer from the beaker to the
volumetric flask.
20. Dilute to volume with ASTM Type I water and mix thoroughly.
The sample digest'contains approximately 1 % (v/v) HN03.
EE-6
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21. Portions used for analysis must be filtered or centrifuged
prior to instrumental measurement to remove undissolved
material. Instrumental measurement should be performed using
calibration standards that are matched to the same
approximate acid levels as those in sample digest aliquot
analyzed for analyte content.
NOTE 4: Due to potential losses during filtration, it is
recommended to filter samples after dilution to final
volume. Additional volume consumed by undissolved
material will not cause any significant bias.
EE-7
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APPENDIX FF
PILOT STUDY PROTOCOLS:
STANDARD TEST PROTOCOL FOR THE ANALYSIS
OF DIGESTED SAMPLES FOR LEAD BY
INDUCTIVELY COUPLED PLASMA (ICP-AES) ,
FLAME ATOMIC ABSORPTION (FAAS) , OR
GRAPHITE FURNACE ATOMIC ABSORPTION (GFAAS) TECHNIQUES
FF-1
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STANDARD TEST PROTOCOL FOR THE ANALYSIS
OF DIGESTED SAMPLES FOR LEAD BY
INDUCTIVELY COUPLED PLASMA (ICP-AES),
FLAME ATOMIC ABSORPTION (FAAS), OR
GRAPHITE FURNACE ATOMIC ABSORPTION (GFAAS) TECHNIQUES
1.0 SUMMARY
A sample digestate is analyzed for Lead content using ICP-AES,
Flame-AAS, or Graphite Furnace-AAS techniques. Instrumental
Quality Control samples are analyzed along with sample digestates
to assure adequate instrumental performance. This procedure is
similar to SW-846 Method 6010. It is equivalent to the draft
procedure currently under consideration in ASTM Subcommittee
E06.23.
2.0 DEFINITIONS
2.1 Digestion - The sample preparation process which will
solubilize targeted analytes present in the sample and
results in an acidified aqueous solution called the
digestate.
2.2 Digestate - An acidified aqueous solution which results
from performing sample preparation (digestion)
activities. Lead measurements are made using this
solution.
2.3 Batch - A group of field or QC samples which are
processed together using the same reagents and
equipment.
2.4 Serial Dilution - A method of producing a less
concentrated solution through one or more consecutive
dilution steps. Dilution step for a standard or sample
is performed by volumetrically placing a small aliquot
of a higher concentrated solution into a volumetric
flask and diluting to volume with water containing the
same acid levels as found in original sample
digestates.
2.5 Method Blank - A digestate which reflects the maximum
treatment given any one sample within a sample batch
except that it has no sample initially placed into the
digestion vessel." (The same reagents and processing
conditions which are applied to field samples within a
FF-2
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batch are also applied to the method blank.) Analysis
results from method blanks provide information on the
level of potential contamination experienced by samples
processed within the batch.
2.6 No-Spiked Sample - A portion of a homogenized sample
which was targeted for addition of analyte but which is
not fortified with all the target analytes before
sample preparation. A method blank serves as a no-
spike sample in cases where samples cannot be uniformly
split as described in section 2.7. Analysis results
for this sample is used to correct for native analyte
levels in the spiked and spiked duplicate samples.
2.7 Spiked Sample and Spiked Duplicate Sample - Two
portions of a homogenized sample which were targeted
for addition of analyte and are fortified with all the
target analytes before preparation. In cases where
samples cannot be uniformly split (such as paint chip
samples taken for Lead per area determinations, a
method blank can be used in place of the homogenized
sample split. Use of a method blank for a spiked
sample should be referred to as a "spiked method blank"
or "spiked method blank duplicate". Analysis results
for these samples are used to provide information on
accuracy and precision of the overall analysis process.
2.8 Analysis Run - A period of measurement time on a given
instrument during which data is calculated from a
single calibration curve (or single set of curves).
Re-calibration of a given instrument produces a new
analysis run.
2.9 Instrumental QC Standards - Solutions analyzed during
an instrumental analysis run which provide information
on measurement performance during the instrumental
analysis portion of the overall Lead measurement
process.
2.10 Semi-quantitative Screen - An analysis run which is
performed on highly diluted sample digestates for the
purpose of determining the approximate analyte level in
the digest. This analysis run is generally performed
without inserting Instrumental QC standards except for
calibration standards. Data from this run are used for
determining serial dilution requirements for sample
digestates to keep them within the linear range of the
instrument.
FF-3
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2.11 Quantitative Analysis - An analysis run on sample
digestates (or serial dilutions of sample digest ates)
which includes Instrumental QC standards . Data from
this run are used to calculate and report final Lead
analysis results.
2.12 Initial Calibration Blank (ICB) - A Standard solution
which contains no analyte and is used for initial
calibration and zeroing instrument response. The ICB
must be matrix matched to acid content present in
sample digestates. The ICB must be measured during
calibration and after calibration. The measured value
is to be less than 5 times the instrumental detection
limit.
2.13 Calibration Standards - Standard solutions used to
Calibrate instrument. Calibration Standards must be
matrix matched to acid content present in sample
digestates and must be measured prior to measuring any
sample digestates.
2.14 Initial Calibration Verification (ICV) - A Standard
solution (or set of solutions) used to verify
calibration standard levels. Concentration of analyte
to be near mid-range of linear curve which is made from
a stock solution having a different manufacturer or
manufacturer lot identification than the calibration
standards. The ICV must be matrix matched to acid
content present in sample digestates. The ICV must be
measured after calibration and before measuring any
sample digestates. The measured value to fall within
of known value.
2.15 Interference Check Standard (ICS) - A standard solution
(or set of solutions) used for ICP-AES to verify
accurate analyte response in the presence of possible
spectral interferences from other analytes present in
samples. The concentration of analyte to be less than
25% of the highest calibration standard, concentrations
of interferant will be 200 /ig/Ml of Al, Ca, Fe, and Mg.
The ICS must be matrix matched to acid content present
in sample digestates. The ICS must be analyzed at
least twice, once before and once after all sample
digestates. The measured analyte value is expected to
be within ±20% of known value.
2.16 Continuing Calibration Verification (CCV) - A standard
solution (or set of solutions) used to verify freedom
FF-4
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from excessive instrumental drift. The concentration
to be near mid-range of linear curve. The CCV must be
matrix matched to acid content present in sample
digestates. The CCV must be analyzed before and after
all sample digestates and at a frequency not less than
every ten sample digestates. The measured value to
fall within ±10% of known value for ICP-AES or FAAS
(±20% for GFAA) , run once for every 10 samples.
2.17 Continuing Calibration Blank (CCB) - A standard
solution which has no analyte and is used to verify
blank response and freedom from carryover. The CCB
must be analyzed after the CCV and after the ICS. The
measured value is to be less than 5 times the
instrumental detection limit.
3 . 0 APPARATUS AND MATERIALS
3.1 Analytical Instrumentation
3.1.1 Inductively Coupled Plasma Atomic Emission
Spectrometer (ICP-AES) - Either sequential or simultaneous
capable of measuring at least one of the primary ICP Lead
emission lines. Emission line used must be demonstrated to have
freedom from common major interferants such as Al, Ca, Fe and Mg
or the ability to correct for these interferants.
3.1.2 Flame Atomic Absorption Spectrometer (FAAS) - Equipped
with an air-acetylene burner head, Lead hollow cathode lamp or
equivalent and capable of making Lead absorption measurements at
the 283.3nm absorption line.
NOTE: The 283.3nm line is preferred over the 217nm line
because of the increased noise levels commonly observed at
the 217nm line for FAAS and GFAAS.
3.1.3 Graphite Furnace Atomic Absorption Spectrometer
(GFAAS) - Equipped with background correction, Lead hollow
cathode lamp or equivalent and capable of making Lead absorption
measurements at the 283.3nm absorption line.
3.2 Gases
Grades specified by manufacturer of the instrument employed.
3.2.1 Compressed air and acetylene for FAAS.
FF-5
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3.2.2 Compressed or liquid argon for ICP-AES and GFAAS.
3.2.3 Minimum of two stage regulation of all gases.
3.3 Glassware and Miscellaneous Supplies
3.3.1 Vinyl Gloves , Powderless .
3.3.2 Micro-pipettors with Disposable Plastic Tips, sizes
needed to make reagent additions, and spiking standards. In
general, the following sizes should be readily available: l-5mL
adjustable, 1000/zL, SOOpiL, 250ML, and 100/iL.
3.3.3 Volumetric Flasks, sizes needed to make, calibration
standards, serial dilutions and Instrumental QC standards.
4 . 0 Reagents
4.1 Nitric acid, concentrated; reagent grade
4.2 Water—Unless otherwise indicated, references to water
shall be understood to mean reagent water as defined by Type 1 of
Specification D1193 . (ASTM Type I Water: Minimum resistance of
16.67 megohm-cm, or equivalent.)
4.3 Calibration stock solution, lOO/zg/mL of Pb in dilute
nitric acid or equivalent (such as a multi-element stock
containing Pb) .
4.4 Check standard stock solution (for ICV) , 100/xg/mL of Pb
in dilute nitric acid or equivalent. Must be sourced from a
different lot number (or manufacturer) than the Calibration stock
solution (7.3) .
4.5 Interferant stock solution (for ICS; ICP-AES only),
10000/zg/mL of Al, Ca, Fe, and Mg in dilute nitric acid or
equivalent .
5 . 0 Procedure
5.1 LaJboratory .Records—Record all reagent sources (lot
numbers) used for sample preparation in a laboratory notebook.
Record any inadvertent deviations, unusual happenings or
observations on a real-time basis as samples are processed. Use
these records to add supplement Lead data when reporting results.
FF-6
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5.2 Instrumental Setup
5.2.1 FAAS/GFAAS - Set the FAAS or GFAAS spectrometer up
for the analysis of Lead at 283.3nm according to the instructions
given by the manufacturer. Be sure to allow at least a 30 minute
warmup of the hollow cathode lamp prior to starting calibration
and analysis.
5.2.2 ICP-AES - Set the ICP spectrometer up for the analysis
of Lead at a primary Lead emission line (such as 220.2nm)
according to the instructions given by the manufacturer. Be sure
to allow at least a 30 minute warmup of the system prior to
starting calibration and analysis.
5.3 Preparation of Calibration and Instrumental QC Standards
5.3.1 Calibration Standards - Prepare a series of
calibration standards covering the linear range of the
instrumentation. Prepare these standards using serial dilution
from the calibration stock solutions. Prepare these standards
using the same final nitric acid concentration present in the
sample digestates. Also prepare an Initial Calibration Blank
(ICB) as defined in section 3 and Table FF-1.
NOTE: For FAAS/GFAAS prepare a minimum of 3 calibration
standards plus the ICB for performing calibration of the
instrument. ICP-AES can be performed using one high
calibration standard and an ICB. However, more are
generally preferred.
5.3.2 Instrumental QC Standards - Prepare Instrumental QC
standards as summarized in Table FF-1 using serial dilution from
the required stock solutions. Prepare these standards using the
same final nitric acid concentration present in the sample
digestates.
NOTE: The ICV is used to assess the accuracy of the
calibration standards. Therefore, it must be made from a
different original source of stock solution than the
stock used to make the calibration standards. Use of a
different serial dilution of the same original stock is
not acceptable.
5.4 Calibration and Instrumental Measurement - Perform
calibration and quantitative Lead measurement of sample
digestates and instrumental QC samples in the sequential order
outlined in Table FF-2.
FF-7
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NOTE: Performance of a Semi-quantitative screen prior to
quantitative analysis for sample digests containing
unknown levels of Lead generally recommended. The
purpose of this screen is to determine serial dilution
requirements of each digestate needed to keep the
instrumental response within the calibration curve.
During a semi-quantitative screen all digestates are
diluted to a constant large value (l-to-100 for ICP/FAAS
and l-to-1000 for GFAAS) . The instrument is calibrated
and diluted digestates are analyzed without inserting the
instrumental QC used for a Quantitative analysis run.
Data from this screen are reviewed to calculate the
optimum serial dilution needed for each digestate. No
sample data can be reported for any analyte value not
falling within the calibration range. Therefore, the
optimum dilution is one which achieves the maximum Lead
response which is still within the calibration curve.
For ICP-AES, levels of possible interferants (Al, Ca, Fe
and Mg) may have to also be considered in order to make
interference corrections. For ICP-AES, digestates must be
sufficiently diluted to assure that levels of possible
interferants such as Al, Ca, Fe and Mg are at or below
the levels present in the ICS.
5.5 Instrumental QC Evaluation and Corrective Action -
Examine the data generated from the analysis of calibration
standards and Instrumental QC standards. Evaluate the analysis
run using the criteria shown in Table FF-1. Failure to achieve
the specifications shown in Table FF-1 will require corrective
action to be performed as described below:
5.5.1 ICE, Calibration standards, or ICV - Failure to meet
specifications for these Instrumental QC standards requires
complete re-calibration. Sample digestates cannot be measured
under these conditions. It is recommended that standards be re-
prepared prior to re-calibration.
5.5.2 High Calibration Standard Re-run - Failure to meet
specifications for this Instrumental QC standard requires
complete re-calibration. Sample digestates cannot be measured
under these conditions. It is recommended that standard range be
reduced prior to re-calibration.
5.5.3 ICS - Failure to meet specifications for these
Instrumental QC standards requires re-analysis of the standard
until specifications are met. Sample digestates cannot be
measured under these"conditions. Re-preparation of the standard
prior to re-analysis is recommended under these conditions.
FF-8
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Continued failure of the ICS may require interference correction
investigation or changing of instrument parameters. Consult the
manufacturers recommendations under these conditions. Any change
in instrument parameters must be accompanied by re-calibration.
If measured aliquots of sample digestates can be shown not to
contain interferants as high as those recommended for the ICS
making, then the interference levels in the ICS can be lowered.
Such changes must be documented in laboratory records with data
supporting the justification for the change. All measurements on
sample digests must be bracketed by an ICS which meets
specifications (called a "passing" ICS). Failure to meet
specifications on the ICS run after the sample digestates
requires re-running of all sample digestates since the last
passing ICS was measured. Since the ICS only is required to be
analyzed twice, much data could be lost if the analytical run
were long and the second ICS failed specifications. This is good
reason for including periodic analysis of the ICS as shown in
Table FF-2.
5.5.4 CCV - Failure to meet specifications for these
Instrumental QC standards indicates excessive instrumental drift.
Sample digestates cannot be measured under these conditions and
any sample digestates measured since the last passing CCV must be
reanalyzed. This situation requires either re-analysis of the
standard until specifications are met or re-calibration. All
measurements on sample digests must be bracketed by an CCV which
meets specifications.
5.5.5 CCB - Failure to meet specifications for these
Instrumental QC standards indicates the presence of possible
instrumental carryover or baseline shift. Such a failure will
have the most impact on sample digestates at the lower end of the
calibration curve. The first corrective action is to re-analyze
the CCB. If the CCB passes, then the rinse time between the
samples should be increased and the analysis continued. If the
instrument response is still elevated and has not significantly
changed, then the instrument can be re-zeroed followed by a CCV-
CCB and re-analysis of all samples since the last passing CCB
which are within 5 times the response of the failed CCB.
6.0 Calculations
For FAAS/GFAAS : Prepare a calibration curve to convert
instrument response (absorbance) to concentration (/*g/mL) using a
linear regression fit. Convert all instrumental measurements on
instrumental QC standards and sample digests to Lead
concentration (^tg/mL) using the calibration curve.
FF-9
-------
NOTE: Some instruments will automatically prepare a
calibration curve based on a linear regression fit.
For ICP-AES: All modern ICPs automatically prepare a calibration
curve to convert instrumental responses (emission intensity) to
concentration (/ig/g) .
FF-10
-------
TABLE FF-1. SUMMARY OF LABORATORY INSTRUMENTAL MEASUREMENT QC STANDARDS
Name
Use
Specification
ICE -
Initial
Calibration
Blank
Used for initial
calibration and
zeroing
instrument
response.
Calibration Standard which contains no
lead.
Must be measured during calibration and
after calibration.
Measured value to be less than 5 times
the IDL.
Calibration
Standards
Used to Calibrate
instrument.
The high standard
re-run is used to
check for
response
linearity.
Acid content must be approximately the
same as that in the sample digests.
Must be measured prior to measuring any
sample digests.
Correlation Coefficient of .>0.995, as
measured using linear regression on
instrument response(y) versus
concentration(x).
The highest level Calibration standard
must be measured after calibration. The
measured value to fall within +10% of
known value.
ICV -
Initial
Calibration
Verification
Used to verify
calibration
standard levels.
Concentration of lead to be near the
middle of calibration curve. It is made
from a stock solution having a different
manufacturer or manufacturer lot
identification than the calibration
standards.
Must be measured after calibration and
before measuring any sample digests.
Measured value to fall within +10% of
known value.
ICS -
Interference
Check
Standard
Used to verify
accurate lead
response in the
presence of
possible spectral
interferences
from other
analytes present
in samples.
Concentration of lead to be less than
25% of the highest calibration standard,
concentrations of interferant are 200
/zg/mL of Al, Ca, Fe, and Mg.
Must be analyzed at least twice, once
before and once after all sample
digestates.
Measured lead value to fall within ±20%
of known value.
CCV -
Continuing
Calibration
Verification
Used to verify
freedom from
excessive
instrumental
drift.
Concentration to be near the middle of
the calibration curve.
Must be analyzed before and after all
sample digestates and at a frequency not
less than once every ten samples.
Measured value to fall within ±10% of
known value.
CCB -
Continuing
Calibration
Blank
Used to verify
blank response
and freedom from
carryover.
Calibration Standard which contains no
lead.
Must be analyzed after each CCV and each
ICS.
Measured value to be less than 5 times
the instrumental detection limit.
FF-11
-------
TABLE FF-2. EXAMPLE OF A TYPICAL ANALYSIS ORDER FOR MEASUREMENT
Run Order No.
(relative)
1
2-4
5
6
7
8
9
10
11
12
Sample ID
ICB
low, med,
high
ICB
ICV
high
standard
CCB
ICS
CCB
CCV
CCB
Comments
Calibration Blank
Calibration Standards
Calibration Blank
made from different stock,
level is near mid-point of
curve
Calibration Standard
Same as Calibration Blank
Interference Check Standard
Carryover Check
Drift Check, same as near
midpoint calibration standard
Carryover check
Instrument
Calibration
Calibration
Verification
Linearity
Check
Interferant
check for
ICP only
Continuing
Calibration
Verification
*** start repeating cycle of samples- Instrumental QC here ***
13-22
23-24
25-34
35-36
37-38
Sample IDs
CCV
CCB
Sample IDs
ICS
CCB
CCV
CCB
Sample digestates
Drift Check +
Carryover Check
Sample digestates
Interferant Check +
Carryover Check
Drift Check +
Carryover Check
Max. of 10
samples
See run
# 11-12
Max. of 10
samples
See run
# 9-10
See run
# 11-12
*** end repeating cycle of samples-QC standards here ***
FF-12
-------
APPENDIX GG
PILOT STUDY PROTOCOLS:
PROTOCOL FOR PACKAGING AND SHIPPING OF SAMPLES
GG-1
-------
PROTOCOL FOR PACKAGING AND SHIPPING OF SAMPLES
1.0 INTRODUCTION
Collection and analysis of paint chip samples as specified by the
QAPjP will require packaging and shipping of samples from
sampling sites. The field team will be responsible for packag-
ing and shipping the samples from each sampling site to the
Sample Custodian at MRI. The following are protocols for
packaging and shipping samples from the field.
2.0 SAMPLE PACKAGING PROTOCOL
The field team is responsible for preparing the samples for
shipment back to MRI. Samples that are collected will be shipped
at the end of each sampling day. The same shipping container
that was used to ship sample collection containers to the field
will be used to ship them back to MRI. All sampling materials
will be packaged in accordance with Department of Transportation
(DOT) regulations. The field team will include copies of the
field sampling forms with the samples to identify the contents of
the shipping containers. The original field sampling forms will
be held by the field supervisor and ultimately hand carried back
to MRI. Do not send original copies of sample data forms or
other important records with the samples.
3.0 SAMPLE SHIPPING METHODS
All samples will be shipped to MRI via Federal Express Economy
Distribution Service in accordance with DOT shipping regulations.
The MRI field team will be responsible making the shipping ar-
rangement with the local Federal Express Office. Pre-printed
Federal Express Air Bills can be obtained from the MRI Shipping
and Receiving Department. All Federal Express shipments will use
the standard Federal Express Air Bill. For further details
consult with MRI's S & R Department.
GG-2
-------
APPENDIX HH
PILOT STUDY PROTOCOLS:
GLASSWARE/PLASTICWARE CLEANING PROCEDURE
INFORMATION NOT PRESENT : PROPRIETARY INFORMATION
HH-1
-------
APPENDIX II
PILOT STUDY PROTOCOLS:
ACID BATH CLEANING PROCEDURES
INFORMATION NOT PRESENT : PROPRIETARY INFORMATION
II-l
-------
APPENDIX AAA
LABORATORY SAMPLE PREPARATION EXPERIMENTS
AAA-1
-------
LABORATORY SAMPLE PREPARATION EXPERIMENTS
1.0 Introduc tion
At the initiation of this study, a draft EPA report [3] ,
indicated that a NIOSH method 7082 would be an acceptable sample
preparation method for the study since it was shown to produce
high lead recoveries from paint samples. NIOSH method 7082 is
designed to prepare and analyze air filter samples for analysis
of a wide variety of inorganic components that also included
lead. Because it is specifically written for air filter samples,
modifications to NIOSH 7082 are required to make it applicable to
processing paint chip samples. Based on the EPA report, this
method with appropriate modifications, was selected to digest
paint samples for this study.
Prior to initiation of laboratory analysis on collected field
samples, a set of four experiments were conducted for the
following three reasons:
1. To familiarize the laboratory with the modified NIOSH
method 7082.
2. To assure that the modifications to the method were
appropriate.
3. To determine the appropriate sample mass that could be
processed using the modified NIOSH method 7082.
A discussion of the four experiments, referred to as Tests 1,
2, 3 and 4, performed on account of the three reasons listed
above, are presented in this appendix. Since the laboratory
targeted for the paint analysis activities in this study had a
great deal of experience using EPA SW846 method 3050, a commonly
used sample preparation procedure for the analysis of metals in
solid samples, this method was used in these experiments to
provide a basis of comparison to the selected modified NIOSH
method 7082.
These experiments were not intended to be an exhaustive
comparison study for determining the optimal sample preparation
of paint chips for lead analysis. Rather, the experiments were
used to familiarize the laboratory with the modified NIOSH method
7082 and to identify any obvious factors that could affect lead
recoveries from paint samples.
1.1 General Experimental Approach
Two general design elements were included into each of the
four experiments: (1) Use of paint sample materials well
AAA-2
-------
characterized for lead concentrations, and (2) Use of sample
aliquots of variable mass. Each of these general design elements
are discussed in the following subsections 1.1.1 and 1.1.2.
1.1.1 Use of Paint Sample Materials with Known Lead
Concentrations
Paint sample materials well characterized for lead
concentrations were included in the experiments to evaluate the
sample preparation procedures by measuring lead recoveries.
National Institute of Standards and Technology (NIST), standard
reference material (SRM) No. 1579a lead-based paint, 11.995
percent lead by weight, was included in all four experiments for
two reasons. First, NIST SRM No. 1579a was the only lead based
paint material available that had a certified lead concentration.
Second, difficulties in obtaining lead recoveries from this
material had been reported by a few persons1 which made it a
good material to differentiate between rigorous and marginal
methods, i.e., sample preparation methods that could obtain good
recoveries from this material would provide increased confidence
that high lead recoveries would be obtained from collected paint
chip samples.
In addition to NIST SRM No. 1579a, paint performance
evaluation samples, from rounds 02 and 03 prepared for the
American Industrial Hygiene Association (AIHA) Environmental Lead
Proficiency Analytical Testing (ELPAT) program, were included in
two of the experiments. The ELPAT samples were included to
provide additional lead recovery data on which to differentiate
between the methods being examined during the experimentation.
1.1.2 Use of Sample Aliquots of Variable Mass
Sample preparation methods are sample size limited because
procedures include fixed amounts of acidic reagents and
extraction volumes. For a given matrix using a specific method,
it is expected that, above a given sample mass, analyte
recoveries would be poor. Collection of a large surface area,
approximately 25 cm2, was incorporated as a study design element
to aid in reducing variation caused by potential spatial lead
variations as discussed in section 3.2.2.1 and collection error.
Therefore, average total collected sample mass was expected to be
high which would require sample homogenization and subsampling to
obtain a sample mass that could be effectively prepared for lead
analysis in the laboratory. As a consequence, the effect of
Personal communications between Midwest Research Institute in Kansas
City, MO and NIOSH in Cincinnati, OK and EPA/ORD in Research Triangle Park, NC
AAA-3
-------
sample mass was investigated during all experiments to determine
the mass limits of the tested procedures.
2.0 Discussion of Experimental Results
The first two experiments included investigations using two
different hot-plate type extraction sample preparation methods,
EPA SW846 method 3050 and a modified NIOSH method 7082, while the
later two focused on refining procedures only for the selected
method, modified NIOSH method 7082. Instrumental lead
measurements for all four experiments were conducted using ICP-
AES.
2.1 Discussion of Test 1
The purpose of Test 1 was to compare the two selected hot-
plate digestion (extraction) methods by examining the lead
recoveries from NIST SRM No. 1579a and ELPAT samples. A summary
of the two extraction methods used in Test 1 are shown in Table
AAA-1. The modifications to NIOSH 7082, as shown in the table,
were made to convert this air filter sample method to a method
that is applicable for processing paint chip samples.
Test 1 included a set of triplicate extractions for three (3)
different nominal sample masses ranging from 0.5 to 5 grams for
NIST SRM No. 1579a and 0.5 to 1 gram for ELPAT samples. This set
of samples was prepared by a single technician using SW846 method
3050 within a single sample preparation batch to minimize any
potential between batch effects. This entire set was duplicated
by a second technician using the modified NIOSH method 7082 as
summarized in Table AAA-2.
The following conclusions are suggested from the Test 1
results presented in Tables AAA-3 and AAA-4:
(1) Results from ELPAT samples, shown in Table AAA-3, are
erratic with mean lead recoveries ranging from 77.3% to
100.8% and relative standard deviations ranging from 0.6%
to 29.2% across both hot-plate extraction methods over the
0.5 to 1 gram mass range.
AAA-4
-------
Table AAA-1. Summary of Modifications made to Methods for Test 1.
Sample
Extraction
Method
EPA SW846 method
3050 with HC1
option
NIOSH method
7082
Modification, to Method
None.
References to use 140°C hot-plates were
replaced with temperatures of 85-100°C.
References for evaporation to dryness
were replaced by evaporation to near
dryness .
For nominal sample mass <1 gram: increase
total concentrated nitric acid volume
from 6 to 9 mL and increase final
dilution volume from 10 to 100 mL.
For nominal sample mass al gram:
increase total concentrated nitric acid
levels from 6 to 18 mL and increase final
dilution volume from 10 to 200 mL.
Reason for
Modi f ication
To avoid
potential
losses
caused by
spattering
To allow for
increased
sample mass
Table AAA-2.
Summary of Design Parameters for Test
Method"
SW846-B
NIOSH- C
Sample Type"
NIST
ELPAT
NIST
ELPAT
Nominal Sample
Mass (grams)
0.5, 1, 5
0.5, 1
0.5, 1, 5
0.5, 1
No. of Replicates
at Each Mass
3
3
3
3
a SW846-B = method SW846 method 3050 performed by technician B
NIOSH-C = modified NIOSH method 7082 performed by technician C
b NIST = SRM No. 1579a, lead level of 11.995%
ELPAT = performance samples from round 1, samples 3 and 4,
reference values given as 0.7026% and 5.4744%
respectively, triplicate samples were from either sample 3
or sample 4 .
(2) Results from NIST SRM 1579a, shown in Table AAA-4, are also
erratic with mean lead recoveries ranging from 54.6% to
82.8% and relative standard deviations ranging from 9.0% to
49.0% across both hot-plate extraction methods over the 0.5
to 1 gram mass range.
(3) Results for the nominal 5 gram mass showed very low lead
recoveries ranging from 8.7% to 21.1%, strongly suggesting
that neither extraction procedure was capable of extracting
lead from a sample mass of 5 grams.
AAA-5
-------
Table AAA-3.
Summary Results for Test 1: The Effect of Lead Recovery from
ELPAT Samples at Variable Sample Mass using SW846 method 3050
and modified NIOSH method 7082.
Nominal
Sample
Mass*
(grams)
0.5
1
Lead Recovery Results for ELPAT Samples
SW846 method 3050
Person
Code"
B
B
Mean
Recovery0
82.2%
99.0%
Relative
Standard
Deviation11
13.5%
0.6%
modified NIOSE method 7082
Person
Codeb
C
C
Mean
Recovery0
100.8%
77.3%
Relative
Standard
Deviation4
12.8%
29.2%
* Actual sample mass was within ±25% of the nominal sample mass.
b Codes represent preparation of samples by specific technicians.
c Mean of three replicates .
d [(standard deviation of three replicates) / (mean recovery)] (100)
Table AAA-4.
Summary Results for Test 1: The Effect of Lead Recovery from
NIST SRM 1579a at Variable Sample Mass using SW846 method
3050 and modified NIOSH method 7082.
Nominal
Sample
Mass*
(grams)
0.5
1
5
Lead Recovery Results for NIST SRM 157 9a
SW846 method 3050
Person
Code"
B
B
B
Mean
Recovery0
64.4%
80.9%
21.1%
Relative
Standard
Deviation"
49.0%
9.0%
18.0%
modified NIOSH method 7082
Person
Codeb
C
C
C
Mean
Recovery0
82.8%
54.6%
8.7%
Relative
Standard
Deviation*1
36.0%
33.5%
23.0%
a Actual sample mass was within ±10% of the nominal sample mass .
b Codes represent preparation of samples by specific technicians .
c Mean of three replicates.
d [(standard deviation of three replicates) / (mean recovery)] (100)
Because of the inconsistent results obtained from Test 1,
decisions were made to modify the two extraction methods with the
aim of improving lead recoveries. The modifications made to the
methods are shown in Table AAA-5.
2.2 Discussion of Test 2
The purpose of Test 2 was to compare the two selected hot-
plate digestion (extraction) methods after modification by
examining the lead recoveries from NIST SRM No. 1579a. A summary
of the two extraction procedures used in Test 2 are shown in
Table AAA-5.
AAA-6
-------
The effect of variation in sample mass on lead recovery was
examined more carefully in Test 2 than in Test 1. Test 2
included a set of triplicate extractions for four (4) different
nominal sample masses ranging from 1 to 4 grams for NIST SRM No.
1579a. This set of samples was prepared by a single technician
using the modified SW846 method 3050 within a single sample
preparation batch to minimize any potential between batch
effects. This entire set was duplicated by a second technician
and a third technician using the modified SW846 method 3050 and
the modified NIOSH method 7082, respectively as summarized in
Table AAA-6. The replication of the sample set using the same
extraction method, modified SW846 method 3050, was done to help
rule out a potential technician processing problem which was
proposed as a potential cause of the inconsistent results
obtained in Test 1 for this commonly used method of sample
preparation.
The following conclusions are suggested from the Test 2
results presented in Table AAA-7:
(1) Mean recoveries of lead in NIST SRM 1579a extracted by
modified SW846 method 3050 and the modified NIOSH method
7082 decreased with increases in sample mass.
(2) Lower lead recoveries for the modified SW846 method 3050
were a result of the sample preparation methodology and not
a technician processing problem since the two technicians
using the same procedure obtained similar results.
(3) Lead recovery using the modified NIOSH method 7082 for the
nominal 1 and 2 gram sample mass was higher than for the
modified SW846 method 3050 at 98.6% and 79.8% compared to
76.3%, 89.3% and 56.1%, 58.8%, respectively.
(4) Precision of the lead recovery was also better using the
modified NIOSH method 7082 for the nominal 1 and 2 gram
sample mass than for the modified SW846 method 3050 as
measured by the relative standard deviations at 3.0% and
3.5% compared to 19.7%, 4.1% and 8.4%, 17.9%, respectively.
AAA-7
-------
Table AAA-5.
Summary of Modifications made to Methods for
Tests 2, 3, and 4.
Sample
Extraction
Method
EPA SW846
method 3050
(Test 2 only)
NIOSH method
7082
Modification to Method
For nominal sample mass a2 gram: 2.5 fold
increase in reagents and final dilution
volume .
References to use 140°C hot-plates were
replaced with temperatures of 85-100°C.
References for evaporation to dryness were
replaced by evaporation to near dryness .
Increased total concentrated nitric acid
volumes from 6 to 22.5 mL, increased total
hydrogen peroxide volumes from 3 to 7 . 5 mL
and increase final dilution volume from 10
to 250 mL.
Reason for
Modification
To allow for
the increased
sample mass
To avoid
potential
losses caused
by spattering
To allow for
the increased
sample mass .
Table AAA-6.
Summary of Design Parameters for Test 2.
Method*
SW846-A
SW846-B
NIOSH-D
Sample Typeb
NIST
NIST
NIST
Nominal Sample
Mass (grams)
1, 2, 3, 4
1. 2, 3, 4
1, 2, 3, 4
No. of Replicates at
Each Mass
3
3
3
a SW846-A = modified SW846 method 3050 performed by technician A
SW846-B = modified SW846 method 3050 performed by technician B
NIOSH-D = modified NIOSH method 7082 performed by technician D
b NIST = SRM No. 1579a, lead level of 11.995%
AAA-8
-------
Table AAA-7.
Summary Results for Test 2: The Effect of Lead Recovery from
NIST SRM 1579a at Variable Sample Mass using modified SW846
method 3050 and modified NIOSH method 7082
Nominal
Sample
Mass*
(grams)
1
2
3
4
Lead Recovery Results for NIST SRM 1579a
modified SW846 method 3050
Person
Code*
A
B
A
B
A
B
A
B
Mean
Recoveryc
76.3%
89.3%
56.1%
58.8%
23.7%
44.3%
29.9%
27.6%
Relative
Standard
Deviation*
19.7%
4.1%
8.4%
17.9%
26.6%
37.2%
10.0%
20.3%
modified NIOSH method 7082
Person
Code*
D
D
D
D
Mean
Recovery0
98.6%
79.8%
48.1%
34.8%
Relative
Standard
Deviation3
3.0%
3.5%
2.7%
2.6%
a Actual sample mass was within ±12% of the nominal sample mass.
b Codes represent preparation of samples by specific technicians.
c Mean of three replicates.
d [(standard deviation of three replicates) / (mean recovery)] (100)
Based on the conclusions presented above, the modified NIOSH
method 7082 appeared to be adequate for use in this study as
compared to EPA SW846 method 3050. Further experiments, Tests 3
and 4, were performed without including SW846 method 3050 and
were used to determine the appropriate sample mass for the
modified NIOSH method 7082.
2.3
Discussion of Test 3
The purpose of Test 3 was to determine the appropriate sample
mass for the modified NIOSH method 7082 by examining the lead
recoveries from NIST SRM No. 1579a and ELPAT samples. A summary
of the modified NIOSH method 7082 used in Test 3 is shown in
Table AAA-5.
Test 3 included a set of triplicate extractions for five (5)
different nominal sample masses ranging from 0.25 to 1.25 grams
for NIST SRM No. 1579a as summarized in Table AAA-8. This set of
samples was prepared by a single technician using the modified
NIOSH method 7082 within a single sample preparation batch to
minimize any potential between-batch effects. This entire set
was duplicated by a second technician and a third technician to
provide multiple data sets on the effect of sample mass on lead
recovery using the modified NIOSH method 7082 and to identify
differences in recoveries associated with individual technicians.
AAA-9
-------
Table AAA-8.
Summary of Design Parameters for Test 3.
Method*
NIOSH-A
NIOSH-B
NIOSH-D
Sample Type"
NIST
NIST
NIST
Nominal Sample
Mass (grams)
0.25, 0.5,
0.75, 1, 1.25
0.25, 0.5,
0.75, 1, 1.25
0.25, 0.5,
0.75, 1, 1.25
No. of Replicates
at Each Mass
3
3
3
a NIOSH-B = modified method 7082 performed by technician A
NIOSH-D = modified method 7082 performed by technician B
NIOSH-A = modified method 7082 performed by technician D
b NIST = SRM No. 1579a, lead level of 11.995%
The following conclusions are suggested from the Test 3
results presented in Table AAA-9:
(1) Mean recoveries of lead in NIST SRM 1579a extracted by the
modified NIOSH method 7082 decreased with increases in
sample mass. This conclusion is consistent with results
from Test 2.
(2) Lead recoveries for the 0.25 gram sample mass gave the
highest lead recoveries for all three technicians ranging
from 99.0% to 100.3%.
(3) Lead recoveries for the 0.25 gram and 0.5 gram sample
masswere above the 90% level for all three technicians
ranging from 92.8% to 100.3%.
(4) For two out of three technicians, lead recoveries for the
0.75 gram sample mass dropped below 80% at 74.4% and 75.4%
compared to 94.6%, respectively.
(5) Lead recoveries for the 1.0 and 1.25 gram sample mass gave
the lowest lead recoveries for all three technicians
ranging from 50.2% to 87.9%.
(6) Precision of the lead recovery, as measured by the relative
standard deviations from triplicate samples, was below 15%
for all three technicians at all sample masses, ranging
from 0.6% to 13.0%, with one exception at 49.6%.
Data presented above suggest that sample mass should not
exceed 0.5 grams.
AAA-10
-------
Table AAA-9.
Summary Results for Test 3: The Effect of Lead Recovery from
NIST SRM 1579a at Variable Sample Mass using modified NIOSH
method 7082.
a
Nominal
Sample Mass
(grams)
0.25
0.5
0.75
1.0
1.25
Lead Recovery Results for NIST SRM 1579a
modified NIOSH method 7082
b
Person Code
A
B
D
A
B
D
A
B
D
A
B
D
A
B
D
c
Mean Recovery
100.3%
99.0%
99.6%
92.8%
97.9%
93.7%
75.4%
94.6%
74.4%
68.9%
87.9%
83.9%
56.6%
73.7%
50.2%
d
Relative Standard Deviation
0.4%
3.1%
2.2%
13.0%
0.6%
1.6%
8.9%
8.8%
7.1%
5.7%
10.5%
49.6%
6.0%
8.1%
10.6%
a Actual sample mass was within ±10% of the nominal sample mass.
b Codes represent preparation of samples by specific technicians.
c Mean of three replicates
d [(standard deviation of three replicates) / (mean recovery)] (100)
AAA-11
-------
2.4 Discussion of Test 4
The purpose of Test 4 was to examine the extraction efficiency
for the 0.5 and 0.25 gram sample mass using the modified NIOSH
method 7082 in more detail than Test 3. Because the contribution
to variability from sample inhomogeneity increases with
decreasing aliquot mass, as discussed in subsection 3.3.1.2.3,
use of a 0.5 gram mass is more desirable than a 0.25 gram sample
mass even though data from Test 3 show that the 0.25 gram mass
produces the highest lead recoveries from the NIST SRM No. 1579a.
Data from Test 3 suggests that a 0.5 gram aliquot should provide
lead recoveries greater than 90% from field samples assuming that
recovery from field samples is at least as high as that from NIST
SRM No. 1579a. Test 4 was performed to provide additional
confidence that the use of the 0.5 gram sample mass would achieve
high recovery of lead from field samples.
Test 4 included a set of duplicate extractions for 10
homogenized field samples at two (2) different nominal sample
masses, 0.25 gram and 0.5 gram as summarized in Table AAA-10. In
addition, one extraction for NIST SRM No. 1579a at 0.25 gram mass
and duplicate extractions for ELPAT samples at the 0.5 gram mass
were included to assess the processing control for the sample
set. This set of samples was prepared by a single technician
using the modified NIOSH method 7082 within a single sample
preparation batch to minimize any potential between-batch
effects. A similar set was prepared by a second technician using
a different set of 10 homogenized field samples to generate
additional data. A different set of field samples was required
due to limits in the total mass of sample material available for
individual samples.
The following conclusions are suggested from the Test 4
results presented in Tables AAA-11, AAA-12 and AAA-13:
(1) Recoveries greater than 90% suggest efficient extraction
occurred in each batch using the modified NIOSH method 7082
for the NIST SRM No. 1579a and ELPAT samples at the 0.25
gram and 0.5 gram sample mass, consistent with the
recoveries observed in Test 3 for the extraction of 0.25
gram and 0.5 gram NIST SRM No. 1579a.
(2) There is no significant difference in variability between
pairs of samples weighing 0.25 grams and pairs weighing 0.5
grams. The root-mean-square relative percent difference
between duplicates weighing 0.25 grams in Table AAA-12 is
21.9% as compared to 25.9% for duplicates weighing 0.5
grams. The difference is not statistically significant.
AAA-12
-------
!3) Variability between laboratory duplicate samples, as
measured by relative % differences in lead results for
subsamples taken from the same homogenized parent sample,
is inconsistent. Relative % differences between like
sample masses and between different samples masses ranged
from 0.1% to 47.5% and 0.2 and 66.2%, respectively.
AAA-13
-------
Table AAA-10. Summary of Design Parameters for Test 4.
Method*
NIOSH-B
NIOSH-D
Sample Type13
NIST
ELPAT
10 FIELD SAMPLES
NIST
ELPAT
10 FIELD SAMPLES
Nominal Sample
Mass (grams)
0.25, 0.5
0.25
0.25, 0.5
0.25, 0.5
0.25
0.25, 0.5
No. of Replicates
at Each Mass
1
2
2
1
2
2
• NIOSH-B = modified method 7082 performed by technician B
NIOSH-D = modified method 7082 performed by technician D
b NIST = SRM No. 1579a, lead level of 11.995%
ELPAT = samples from round 1, sample 2, reference value of 0.5568%
FIELD SAMPLES = field samples from Louisville
Table AAA-11.
Summary Results for Test 4: The Effect of Lead Recovery from
NIST SRM 1579a and ELPAT samples at Variable Sample Mass
using modified NIOSH method 7082.
Nominal
Sample Mass*
(grams)
0.25
0.5
Lead Recovery Results using modified NIOSH method 7082
NIST SRM No. 157 9a
Person Codec
B
D
B
D
Lead Recovery
97.9%
nad
93.0%
91.0%
ELPAT*
Person Codec
B
D
B
D
Lead Recovery
100.9%
94.1%
95.7%
93.9%
nae
nae
* Actual sample mass was within ±13% of the nominal sample mass.
B ELPAT samples from round 1, sample 2, reference value of 0.5568%
e Codes represent preparation of samples by specific technicians .
d Not available, sample was inadvertently missed by technician.
e Not available - not planned for extraction at this mass because of
insufficient material
AAA-14
-------
Table AAA-12.
Summary Results for Test 4: The Effect of Lead Results from
Filed Samples at Variable Sample Mass using modified NIOSH
method 7082 Performed by Technician Ba,
Field Sample
ID No.
905545
905541
905533
905597
905604
905524
905605
905564
905592
905501
Nominal
Sample
Massb
0.25
0.5
0.25
0.5
0.25
0.5
0.25
0.5
0.25
0.5
0.25
0.5
0.25
0.5
0.25
0.5
0.25
0.5
0.25
0.5
Mean Lead
Results
(mg/g) c
3.884
3.804
3.384
6.735
1.709
na£
1.962
1.864
2.038
1.949
4.249
4.266
1.495
1.644
131.213
137.033
21.672
31.556
67.722
89.186
Relative %
Difference
between same
Mass*
1.2
24.6
43.5
44.2
33.7
naf
4.9
0.7
0.1
0.4
1.3
0.4
33.7
26.5
16.9
23.1
8.0
46.9
16.0
5.1
Relative %
Difference
between different
Mass*
2.1
66.2
na£
5.1
4.5
0.4
9.5
4.3
37.1
27.4
a Codes represent preparation of samples by specific technicians.
b Actual sample mass was within ±13% of the nominal sample mass.
c Mean of two replicates
d Absolute value calculated using the following:
{mq/a of 1st duplicate - rnq/q for 2nd duplicate) (100)
(mean mg/g for both duplicates)
e Absolute value calculated using the following:
(mean mq/a for 0.25q - mean mq/q for 0 . 5q) (100)
(mean mg/g for both 0.25g and 0.5g)
£ na = not available, sample was inadvertently spilled
by a technician.
AAA-15
-------
Table AAA-13.
Summary Results for Test 4: The Effect of Lead Results from
Filed Samples at Variable Sample Mass using modified NIOSH
method 7082 Performed by Technician Da.
Field Sample
ID No.
905591
905593
905507
905527
905528
905587
905531
905521
905523
905590
Nominal
Sample
Mass"
0.25
0.5
0.25
0.5
0.25
0.5
0.25
0.5
0.25
0.5
0.25
0.5
0.25
0.5
0.25
0.5
0.25
0.5
0.25
0.5
Mean Lead
Results
(mg/g) c
2.253
2.418
1.255
1.324
4.224
4.215
3.380
3.504
44.385
48.468
63.907
40.253
2.275
2.663
38.138
42.845
32.319
37.360
34.178
48.429
Relative %
Difference
Between Same
Mass*
30.8
3.1
5.7
0.1
19.7
21.0
4.2
8.2
4.9
0.5
40.3
17.3
3.4
4.5
27.2
8.9
1.2
3.6
47.5
8.4
Relative %
Difference
Between Different
Mass"
7.1
5.3
0.2
3.6
8.8
45.4
15.7
11.6
14.5
34.5
* Codes represent preparation of samples by specific technicians.
6 Actual sample mass was within ±13% of the nominal sample mass.
c Mean of two replicates
" Absolute value calculated using the following:
(mq/q of 1st duplicate - mq/q for 2nd duplicate) (100)
(mean mg/g for both duplicates)
e Absolute value calculated using the following:
(mean mq/a for 0.25q - mean mq/q for 0.5q) (100)
(mean mg/g for both 0.25g and 0.5g)
AAA-16
-------
Inconsistencies are suspected to be a result of matrix variations
and sample homogeneity variations among the field samples.
Based on the conclusions obtained from Tests 3 and 4 combined
with the logical assumption that the contribution to variability
from sample inhomogeneity increases with decreasing aliquot mass,
a decision was made to limit sample aliquots to a nominal 0.5
gram sample mass for processing paint chip samples using the
modified NIOSH method 7082 summarized in Table AAA-5. If a
homogenized individual paint chip sample was less than 0.5 gram,
then all of the sample was extracted. Otherwise, a nominal 0.5
gram subsample was extracted.
AAA-17
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50272-101
REPORT DOCUMENTATION
PAGE
1. REPORT NO.
EPA 747-R-95-002b
3. Recipient's Accession No.
4. Title and Subtitle
A FIELD TEST OF LEAD-BASED PAINT TESTING TECHNOLOGIES-
TECHNICAL REPORT
5. Report Date
May 1995
7. Author(s)
Cox, D.C.; Dewalt, F.G.; Haugen, M.M.; Koyak, R.A.; Schmehl, R.L.
8. Performing Organization Rept. No.
9. Performing Organization Name and Address
QuanTech, Inc.
1911 North Fort Myer Drive, Suite 1000
Rosslyn, Virginia 22209
10. Project/Task/Work Unit No.
Midwest Research Institute
& 425 Volker Boulevard
Kansas City, Missouri 64110
11. Contract (C) or Grant (G) No.
68-DO-0137
12. Sponsoring Organization Name and Address
U.S. Environmental Protection Agency
Office of Pollution, Pesticides and Toxic Substances
Washington, DC 20460
13. Type of Report & Period Covered
Technical Report
14.
15. Supplementary Notes
In addition to the authors listed above, the following key staff members were major contributors to the
study: Paul Constant, Donna Nichols, Jack Balsinger, Nancy Friederich, and John Jones of Midwest
Research Institute; and Connie Reese of QuanTech.
16. Abstract (Limit: 200 words)
A large field study was conducted to compare three methods commonly used to test for lead in paint:
portable X-ray fluorescence (XRF) instruments, lead paint test kits, and laboratory analysis of paint
chip samples. Laboratory analysis is considered to be the most accurate of the three methods and was
the benchmark for comparisons. The study concludes that use of K-shell XRFs, with laboratory
confirmation of readings designated as inconclusive and with correction of substrate biases where
appropriate, is an acceptable way to classify painted architectural components versus the federal
threshold of 1.0 mg/cm2. The study concludes that test kits should not be used to test for lead in paint.
No test kit in the study achieved low rates of both false positive and false negative results. Some kits
yielded a positive result at low levels of lead. Other kits were prone to a negative result when lead in
paint was above the federal thresholds of 1.0 mg/cm2 and 0.5% by weight.
17. Document Analysis a. Descriptors
Lead-based paint, lead-based paint testing, comparability study, field evaluation, recommendations for testing
for lead in paint
b. Identifiers/Open-Ended Terms
X-ray fluorescence instrument, XRF instrument, portable XRF, lead paint test kit, chemical test kit, test kit,
inductively coupled plasma-atomic emission spectrometry, ICP-AES, ICP
c. COSATI Field/Group
18. Availability Statement
19. Security Class (This Report)
Unclassified
20. Security Class (This Page)
Unclassified
21. No. of Pages
1156
22. Price
(See ANSI-Z39 18)
OPTIONAL FORM 272 (4-77)
(Formerly NTIS-35)
Department of Commerce
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