Previous Health Investigation Levels (HILs) have been established on the basis of both the Integrated Exposure Uptake Biokinetic (IEUBK) model and the use of a threshold provisional tolerable weekly intake (PTWI) available from the WHO. In addition, site-specific assessments of lead exposure were regularly conducted on the basis of the PTWI. The WHO withdrew the PTWI in 2010 and no other peer reviewed toxicity reference values are available. Hence the revision to the NEPM HILs in 2011/2012 has relied on the application of the IEUBK model for HILs A, B and C, where children are the most sensitive receptors. HIL D, commercial/industrial, has been derived on the basis of the adult blood lead model.
The following note presents an overview of how the IEUBK model has been set up for the derivation of the HIL A, low density residential land use. The note provides specific information on how those values have been entered into the model and identifies those parameters that can be adjusted where appropriate site-specific data is available.
IEUBK Modelling for Establishing HIL A and Site-Specific Adjustments
Cite as: enRiskS, 2011. IEUBK Modelling for Establishing HIL A and Conducting Site-Specific Adjustments to the Model. Document in Support of NEPM Review of Lead Exposure, July 2011