#
ae Be tee Mckee nti atte Lad a.hi ee
.
46
TABLE 19.
Linear REGRESSION PARAMETERS FOR Various Data Groupings oF LEAD CoxNcUNTRATION IN BON!
Linear regression cvefficients
Type (No. of samples)
All samples (105)
Normal
All (73)
Cortical, M + F (19)
Trabecular, M + F (54)
Vertebra, M + F (18)
Rib, M (19}
Rib, F (17)
Osteogenic sarcoma (cortical)
All (82)
Male (32)
Female (14)
Other data
Horiuchi et al.
Schroeder and Tipton?
Rib, 0-49 yr
Rib, 0-69 yr
Correlation
Intercept
Slope
A + S.D., ug Pb
(g ash)!
B+ SD.,
ug Pb ye! (g ash)?
4.9 + 2.9
3.63
—1.70
5.538
11.04
7.06
8.25
+
+
+
+
+
+
—0.65
(0.00)
9.3 + 9.8
probability,
r=
0.552 + 0.065
0.70
0.0005
0.605
0.709
0.562
0.600
0.5386
0.276
0.089
0.188
0.103
0.151
0.194
0.187
0.02
0.71
0.64
0.67
0.45
0.33
0.0008
0.0005
0.0005
0.005
=0.025
0.10
0.371 + 0.078
0.456 + 0.094
0.248 + 0.115
0.69
0.77
0.50
0.0025
0.005
0.05
4.13
9.48
4.63
7.78
7.98
7.67
8.62 + 2.67
4.47 + 3.96
13,15 + 3.56
Maximum
coefficient,
r
+
+
+
+
+
+
|
i
|
|
0.61
—
1.03 + 0.10
0.59 + 0.26
—
|
-_
~—
—
_—
|
(o) Reference &.
{b) Reference 7, Table 5.
‘) Forced zero intercept.
for the “sarcoma” bone, but it is not significant at the
5% level of confidence. The concentration of lead in
TABLE 20.
ConcenTRATION OF LEAD IN TEET.
bone of female sarcoma cases increases more slowly
No.
agen
No.oie
pejeish
tially identical to the “normai” female rib bone.
The lead concentration for subjects over age 30
shows a similar increase with age. For “normal” sub-
1
2
3
4
6
24
2
3
4
9.6
2.9
21-4
than “normal”cortical bone (P < 0.05) and is essen-
jects the rate of increase is b = (0.56 + 0.17) ne Pb
g—-l yr—1, and for the “sarcoma” cases, b = (0.50 =
0.21) ng Pb g~? yr7".
The rate of increase of concentration estimated in
“normal” bone of about 0.6 ng g~! yr~1 bone ash, is
equivalent to the 0.37 ng g-! yr—1 in wet bone (femur)
found by Horiuchi et al.) if one assumes that femur
has about 60% ash content.“*) Schroeder and Tipton’s
data in their Table 6 give estimated rates by weighted
least squares analysis of 1.03 »g g~! yr~! im the 0-49
year group and 0.59 g—! yr—? in the 0-69 group (Table
19). Their higher values may be caused by some high
measurements in the 40- to 59-year group which range
to 265 wg g—*. The yearly increases observed by Hori-
uchi, et al."®? and in this study amount to an accumula-
tion in “normal” subjects of about 1.9 mg of lead per
year in a “Standard Man” with 2600 g of total skeletal
ash. The estimated total skeletal lead of 96 mg in a
“Standard Man,” aged 50, in this study, compares
favorably with the 92 mg of skeletal lead from a previous report? and a little less favorably with the 110
‘
;
im
8
64
6
7
Mean (ages 4-6)
Mean (ages 24-64)
44
62
i
tos
4
4
92.7
21.9
4
14.2
6.3
23.0 + 9.2 (6.1.
(®) Mean of age at time of tooth extraction.
mg of Schroeder and Tipton based on their m
concentrations of 43 ppm of ash and 2600 g of sk:
ash.
Unlike that in bone, the lead concentration in
did not increase with age after the second decad
shown in Table 20, the concentration appears to
off at 28 + 9yg/g ash, which is equivalent to
reached in bone at about age 27. The constant an:
concentration is to be expected because of the gr
reduced mineral metabolism in the teeth of adults
low values in the deciduous teeth are consistent
a