. "Appendix C. Detailed Comments on the Integrated Exposure Uptake Biokinetic Implementation Code." Superfund and Mining Megasites: Lessons from the Coeur d'Alene River Basin. Washington, DC: The National Academies Press, 2005.
The following HTML text is provided to enhance online
readability. Many aspects of typography translate only awkwardly to HTML.
Please use the page image
as the authoritative form to ensure accuracy.
Superfund and Mining Megasites: Lessons from the Coeur d’alene River Basin
tions described earlier in the TSD. If some other set of assumptions is being used, then it should be documented how those assumptions lead to the equations of p. A-18. In the computer code, both sets of equations are present, and indeed both are executed; but only the second has any effect.
On page A-19 of the TSD, equations B-7e and B-7l contradict the statements made under MCORT(t) on page B-9, and MTRAB(t) on page B-11. In both cases, it is stated that there is an assumption that the bone (cortical or trabecular) lead concentration/blood lead concentration ratio is equal to the bone (composite) lead concentration/blood lead concentration ratio (so cortical and trabecular bone lead concentration/blood lead concentration ratios should be equal). Equations B-73 and B-7l give different concentration ratios (78.9 for cortical, 51.2 for trabecular).
Equations B-4a through B-4d (p. A-9) are stated (p. B-4 and B-5) to come from an analysis of the data of Barry (1981). However, at age 0 they are contradicted by the initialization conditions given in equations B-7e through B-7l (p. A-17), which are said to be based on the same data (p. B-9, B-10, B-11). For kidney, liver, and other tissues, the tissue/blood concentration ratios implied by equations B-4a, B-4b, and B-4d at time 0 are 0.777, 1.1, and 0.931 L/kg, whereas equations B-7f, B-7g, and B-7h give 1.06, 1.30, and 1.60 L/kg, respectively. Here is another internal inconsistency, because equation B-4c gives a bone/blood concentration ratio of 6.0 L/kg at t = 0, whereas equations B-7e and B-7f give separate ratios at t = 0 of 7.89 and 5.12 L/kg for cortical and trabecular bone, respectively.
REFERENCES
Barry, P.S. 1981. Concentrations of lead in the tissues of children. Br. J. Ind. Med. 38(1): 61-71.
EPA (U.S. Environmental Protection Agency). 1994. Technical Support Document: Parameters and Equations Used in the Integrated Exposure Uptake Biokinetic (IEUBK) Model for Lead in Children (v 0.99d). EPA/540/R-94/040. OSWER 9285.7-22. PB94-963505. Office of Solid Waste and Emergency Response U.S. Environmental Protection Agency, Washington, DC [online]. Available: http://www.epa.gov/superfund/programs/lead/products/tsd.pdf [accessed Jan. 4, 2004].
EPA (U.S. Environmental Protection Agency). 2002. System Requirements and Design For The Integrated Exposure Uptake Biokinetic Model For Lead In Children (IEUBK) Windows Version – 32-Bit Version. OSWER 9285.7-43. Office of Solid Waste and Emergency Response, U.S. Environmental Protection Agency, Washington, DC. May 2002 [online]. Available: http://www.epa.gov/superfund/programs/lead/products.htm [accessed Oct. 11, 2005].
