Lindsay Pasquale
Blog
IEUBK Model
The Integrated Exposure Uptake Biokinetic (IEUBK) model is commonly
used to estimate blood lead concentrations of children who have been exposed.
The model calculates the probability that the child’s blood lead concentration
will exceed the selected level of concern. This model can be used as a risk
assessment tool. It can be useful for remediation strategies for lead in the
human environment. The purpose of this model is to predict the likely blood
lead distribution for children given the exposure to lead at the site, and the
probability that children exposed to lead in that environment will have blood
lead concentrations exceeding a health- based level of concern, according to
EPA. The IEUBK model has previously been used by the Environmental Protection
Agency as one of its methods for developing the National Ambient Air Quality
Standard for lead and the National Primary Drinking Water Regulation for lead.
Validation is important, there are many factors to which makes
something valid. To determine that, the model is biologically and physically plausible
and consolidates the best available data. The model uses numerically accurate,
and the accuracy of the computer codes have been verified. Lastly, the IEUBK
model provides useful comparisons of model output with real world data.
The IEUKB model is structured so that the environmental concentration
blood lead relationship in children is established through four distinct
components: exposure, uptake, biokinetics, and blood lead distributions. The
four model components just stated are designed to run as distinct but interrelated
modules according to NCBI. The exposure/intake dose is expressed in micro-grams of lead per day, all based on media specific lead concentrations and consumption
rates; cubic meters of air inhaled per day, grams of soil ingested per day,
liters of water per day. The uptake component estimates the transfer of lead
through the body, the gastrointestinal tract or lungs to the blood in micro-grams per day in children. Now the biokinetic component, which estimates
the transfer of absorbed lead between blood and other vital tissues and its
elimination through excretory pathways. In addition, the outcomes are calculated
in various time fractions for the period of 0 to 84 month old children. The probability
distribution component produces graphic illustration of the probability
exceeding blood levels over the level of concentration.
The model is a product of many years of development within the US
EPA. This is a tool for making accelerated calculations and recalculations of a
complicated set of equations that include a extensive number of exposure,
uptake, and biokinetic parameters. Lead is one of the most common toxic
chemicals found at Superfund sites. EPA’s data shows that lead is among the
most frequently used contaminant in the scoring of the sites with the Hazard
Ranking Systems. The IEUKB model results can be used as a useful tool to assist
in determining site specific cleanup levels.
I think this is a very useful tool for lead exposures. It’s
frightening knowing how destructible it can be to children and how easy it can
be to get exposed to high levels. It’s all around us even when we think it’s
not.
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