Page 16 - Lake Roosevelt Forum 2020 Public Guide

Human Health Risk Assessment
Calculating Lead Risk
EPA assesses lead risk by calculating the probability of exposure to lead through a combination of dietary intake, air, dust, and soil. Lead is particularly dangerous to children under six because their growing bodies absorb more lead than adults. Numerous studies show exposure negatively affecting the development of brain and other body functions.
The widely used Integrated Exposure Uptake Biokinetic (IEBUK) model was used by EPA to estimate blood lead levels in children. This model is commonly used by risk assessors to calculate possible lead exposure risks. The graphic below shows exposure pathways evaluated, then the use of complex mathematical computations to characterize risk.
The section Upper Columbia Valley Lead Exposure summarizes findings and risks from this modeling.
IEUBK Modeling of Blood Lead Levels in Children
FROM AIR
FROM DUST
FROM SOIL
FROM WATER
FROM DIET
FROM OTHER
AIR DUST SOIL WATER DIET OTHER
Environment
Inhalation Ingestion Ingestion Ingestion Ingestion Ingestion
Exposure/ Intake
LUNG
Plasma + Extra-Cellular Fluid
GUT
Red Blood Cells
Cortical and Trabecular Bone
Urine, Hair, Sweat, Nails
Feces
Liver, Kidney, Other Soft Tissues
Absorption/ Uptake
Blood
Tissues Biokinetics
Blood Lead
Elimination
Source: EPA, 1994a. Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children.
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