Appendix D Food Codes for NHANES - OEHHA

Scientific Review PanelSRP Draft Version 2 February,June 2012
Chemical/group
Tcos
(GM)
based
on slope
factors
Tco based
on median
reference
half life
(Milbrath et
al 2007)
J-17
Tco
based
on
t1/2
GM*
Tco
based
on
t1/2
GSD
Tco
based
on
t1/2
LCL
Tco
based
on
t1/2
UCL
PCB-126 NA 2.30 0.34 2.61 0.11 1.01
PCB-169 NA 8.85 5.60 1.27 4.28 7.32
PCB-105 NA 2.04 1.07 3.02 0.36 3.16
PCB-114 NA 2.04 2.74 3.11 0.57 13.20
PCB-118 0.01 1.36 0.55 6.17 0.18 1.70
PCB-123 NA 1.36 2.93 2.63 0.77 11.18
PCB-156 NA 4.55 3.23 7.10 0.76 13.81
PCB-157 NA 17.02 14.10 1.21 10.84 18.34
PCB-167 NA 10.21 5.93 1.76 2.70 13.00
PCB-189 NA 34.90 4.23 2.77 1.03 17.33
# slope factors obtained from the longest interval between measures of diet (1978-1994)
and milk (1988-1993) in the Dutch population; * GM, geometric mean, GSD, geometric
standard deviation derived from natural log of three half-life values, low, high and
median reported in Milbrath et al. (Milbrath et al., 2009) LCL, lower 95% confidence limit
of the mean Tco; UCL, upper 95% confidence limit of the mean Tco
OEHHA evaluated the relationship between Tcos predicted by Equation J-6
(column 3) using median reference half-lives and those derived from slope
factors (column 2). Briefly, slope factors were calculated by taking the difference
between cross-sectional dietary intake estimates taken in 1978 and 1994 and the
difference between cross-sectional human milk concentrations taken in 1988 and
1993 from the Dutch population. Most Tcos derived from reference half-lives
compare reasonably well with those derived from slope factors.
In columns 4-7 of Table J.2-3 the GM, GSD and 95%CLs of transfer coefficients
(Tcos) for individual dioxins and dioxin-like congeners are derived from equation
J-6 and geometric distribution estimates and 95% confidence intervals of halflives
provided in (Milbrath et al., 2009).
A Random-effects model derived summary estimates shown in Table J.2-4 from
individual summary estimates shown in columns 4-7 of Table J.2-3.
Table J.2-4: Tco Estimates Stratified by Dioxin, Furan and Dioxin-like PCB
Congeners (mean, 95%CI from Random-effects Model)
Chemical group N congeners Tco LCL UCL
PCDDs - oral 7 3.7 2.68 5.23
PCDFs - oral 9 1.8 1.27 2.43
Dioxin-like PCBs - oral 12 1.7 0.69 4.40
LCL, lower 95% confidence limit of the mean Tco; UCL, upper 95% confidence
limit of the mean Tco