The Effect of Lead Contamination in Drinking Water on a Young Population

In developing a lead sensor for our project, we were curious about the effects of lead contamination in the water supply on small children. How do their bodies metabolize it? Where does it go? We were pretty appalled by the devastating effects lead can have on the human body and how long it can persist even after the initial exposure. Many journals report that there can be devastating neurological and physiological impairments from even the smallest exposure and there is no safe dosage of lead.

Very often, a journal would give a range of blood-lead levels and say that it correlated with a specific impairment but no paper was able to show a level or duration of contamination that resulted in that blood-lead level. Without this, we couldn't really gauge what level of lead exposure and for how long a person could be exposed to lead and miss out on the devastating health benefits. So we decided to try and model it!

We began with a thorough examination of the literature, looking for important details on how much lead is absorbed into the body, where the absorbed lead goes, and how long it stays in the body. With these literature values, we were able to create a rudimentary mass balance of the human body focusing on the amount of lead ingested and the amount that is excreted. We decided to treat the blood and bones of a contaminated person as two different systems to more accurately model how the body metabolizes lead and processes it. Our simplified version of how the body metabolizes lead is shown below.

The basic format of the differential equations for the two systems are included below.

To put the differential equations into terms that could be measured, estimated, or taken from literature, the following substitutions were made.

Below is the definition of each variable used in the differential equations. Units are included (as well as conversion factors) for dimensional analysis and confirming that each term is correct

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