Calculations of Preliminary Remediation Goals (PRGs)
Calculations of Preliminary Remediation Goals (PRGs)
U.S. EPA Technical Review Workgroup for Lead, Adult Lead Committee Version date 05/19/03
Exposure Variable PbBfetal, 0.95 Rfetal/maternal BKSF GSDi PbB0 IRS IRS+D WS KSD AFS, D EFS, D ATS, D
PRG
1
PRG 1 Equation 1* 2**
X X X X X X X X X X X X X X X X X X X X
Description of Exposure Variable
95th percentile PbB in fetus Fetal/maternal PbB ratio Biokinetic Slope Factor Geometric standard deviation PbB Baseline PbB Soil ingestion rate (including soil-derived indoor dust) Total ingestion rate of outdoor soil and indoor dust Weighting factor; fraction of IRS+D ingested as outdoor soil Mass fraction of soil in dust Absorption fraction (same for soil and dust) Exposure frequency (same for soil and dust) Averaging time (same for soil and dust) Preliminary Remediation Goal
Units
ug/dL -ug/dL per ug/day -ug/dL g/day g/day ---days/yr days/yr ppm
Values for Non-Residential Exposure Scenario Using Equation 1 Using Equation 2 GSDi = Hom GSDi = Het GSDi = Hom GSDi = Het 10 0.9 0.4 2.1 1.5 0.050 ---0.12 219 365 1,235 10 0.9 0.4 2.3 1.7 0.050 ---0.12 219 365 780 10 0.9 0.4 2.1 1.5 -0.050 1.0 0.7 0.12 219 365 1,235 10 0.9 0.4 2.3 1.7 -0.050 1.0 0.7 0.12 219 365 780
Equation 1 does not apportion exposure between soil and dust ingestion (excludes WS, KSD). When IRS = IRS+D and WS = 1.0, the equations yield the same PRG.
*Equation 1, based on Eq. 4 in USEPA (1996).
PRG =
([PbB95fetal/(R*(GSDi1.645)])-PbB0)*ATS,D BKSF*(IRS+D*AFS,D*EFS,D)
**Equation 2, alternate approach based on Eq. 4 and Eq. A-19 in USEPA (1996).
PRG =
([PbBfetal,0.95/(R*(GSDi1.645)])-PbB0)*ATS,D BKSF*([(IRS+D)*AFS*EFS*WS]+[KSD*(IRS+D)*(1-WS)*AFD*EFD])
Source: U.S. EPA (1996). Recommendations of the Technical Review Workgroup for Lead for an Interim Approach to Assessing Risks Associated with Adult Exposures to Lead in Soil
Calculations of Preliminary Remediation Goals (PRGs)
Calculations of Blood Lead Concentrations (PbBs)
U.S. EPA Technical Review Workgroup for Lead, Adult Lead Committee Version date 05/19/03
Exposure Variable PbS Rfetal/maternal BKSF GSDi PbB0 IRS IRS+D WS KSD AFS, D EFS, D ATS, D PbBadult PbBfetal, 0.95 PbBt
1
PbB Equation1 1* 2**
X X X X X X X X X X X X X X X X X X X X
Description of Exposure Variable
Soil lead concentration Fetal/maternal PbB ratio Biokinetic Slope Factor Geometric standard deviation PbB Baseline PbB Soil ingestion rate (including soil-derived indoor dust) Total ingestion rate of outdoor soil and indoor dust Weighting factor; fraction of IRS+D ingested as outdoor soil Mass fraction of soil in dust Absorption fraction (same for soil and dust) Exposure frequency (same for soil and dust) Averaging time (same for soil and dust) PbB of adult worker, geometric mean 95th percentile PbB among fetuses of adult workers Target PbB level of concern (e.g., 10 ug/dL)
Units
ug/g or ppm -ug/dL per ug/day -ug/dL g/day g/day ---days/yr days/yr ug/dL ug/dL ug/dL %
Values for Non-Residential Exposure Scenario Using Equation 1 Using Equation 2 GSDi = Hom GSDi = Het GSDi = Hom GSDi = Het 750 0.9 0.4 2.1 1.5 0.050 ---0.12 219 365 2.6 7.9 10.0 2.5% 750 0.9 0.4 2.3 1.7 0.050 ---0.12 219 365 2.8 9.8 10.0 4.8% 750 0.9 0.4 2.1 1.5 -0.050 1.0 0.7 0.12 219 365 2.6 7.9 10.0 2.5% 750 0.9 0.4 2.3 1.7 -0.050 1.0 0.7 0.12 219 365 2.8 9.8 10.0 4.8%
P(PbBfetal > PbBt) Probability that fetal PbB > PbBt, assuming lognormal distribution
Equation 1 does not apportion exposure between soil and dust ingestion (excludes W S, KSD). When IRS = IRS+D and WS = 1.0, the equations yield the same PbBfetal,0.95.
*Equation 1, based on Eq. 1, 2 in USEPA (1996).
PbB adult = PbB fetal, 0.95 =
(PbS*BKSF*IRS+D*AFS,D*EFS/ATS.D) + PbB0 PbBadult * (GSDi1.645 * R)
**Equation 2, alternate approach based on Eq. 1, 2, and A-19 in USEPA (1996). PbS*BKSF*([(IRS+D)*AFS*EFS*WS]+[KSD*(IRS+D)*(1-WS)*AFD*EFD])/365+PbB0 PbB =
adult
PbB fetal, 0.95 =
PbBadult * (GSDi1.645 * R)
Source: U.S. EPA (1996). Recommendations of the Technical Review Workgroup for Lead for an Interim Approach to Assessing Risks Associated with Adult Exposures to Lead in Soil
Printed 8/13/2008 6:55 AM
Copy Range Defaults (DO NOT CHANGE THESE!!)
PRG for Lead
Values for Non-Residential Exposure Scenario Using Equation 1
GSDi = Hom GSDi = Het
PbB Calculation
Values for Non-Residential Exposure Sc Using Equation 1
GSDi = Hom GSDi = Het
Using Equation 2
GSDi = Hom GSDi = Het
Using Equati
10 0.9 0.4 2.1 1.5 0.050 ---0.12 219 365 1,235
10 0.9 0.4 2.3 1.7 0.050 ---0.12 219 365 780
10 0.9 0.4 2.1 1.5 -0.050 1.0 0.7 0.12 219 365 1,235
10 0.9 0.4 2.3 1.7 -0.050 1.0 0.7 0.12 219 365 780
750 0.9 0.4 2.1 1.5 0.050 ---0.12 219 365 2.6 7.9 10.0 2.5%
750 0.9 0.4 2.3 1.7 0.050 ---0.12 219 365 2.8 9.8 10.0 4.8%
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Copy Range
Non-Residential Exposure Scenario Using Equation 2
GSDi = Hom GSDi = Het
750 0.9 0.4 2.1 1.5 -0.050 1.0 0.7 0.12 219 365 2.6 7.9 10.0 2.5%
750 0.9 0.4 2.3 1.7 -0.050 1.0 0.7 0.12 219 365 2.8 9.8 10.0 4.8%
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