- On Friday, the Centers for Disease
Control (CDC) reported the results of a new study on harmful
chemicals found in the human body. According to the
study, 2.2 percent of children in the United States
between the ages of 1 and 5 have too much lead in their
This is good news and bad news. Ten
years ago 4.4 percent of U.S. children had too much lead
in their blood. Things are improving, but when the amount
of lead in the blood is greater than or equal to 10
micrograms per deciliter (10 µg/dL) that is a
thing. And there are still
434,000 children in the United States who have 10 or more
micrograms of lead in every deciliter of their
For additional information, visit the CDC.
You are a mathematician who works in
the Office of Research and Evaluation of your local medical
laboratory. As the lab's only mathematician, you have been
asked to process some irregular data that has just arrived. You have the results of the lead-level tests from
ten patients, but the results are not expressed in the
customary units of micrograms per deciliter. They are
expressed in a variety of different units.
Your job is to convert the results
into the standard units of micrograms per deciliter and
then decide whether or not the patient has lead levels
that are too high.
- You will also select patients who
need to be re-tested.
- Begin by opening the file
containing the official Discrepant
Unit Correction Form.
(This is a Microsoft
Word file.) Print a copy of the
form to use as you complete the activity.
- Examine the lead level for each
patient on the form. Determine which unit is incorrect
and convert it to the correct unit. Your goal is to end
up with the units µg/dL.
If both units are incorrect, convert
- Use the Metric Units Tutor to make
sure that you are converting units correctly. If you are
making mistakes, the Metric Units Tutor will help you get
the right answer. The Metric Units Tutor will can be
found at a web address that your teacher will provide to
- Note: When you want to enter
micrograms (µg) into the Metric Units Tutor you must
Once that you are sure that your
conversions are correct, enter them on the form, check
column for those patients whose
lead levels are too high, then select patients who should
- Submit the "Discrepant Unit
Correction Form" to the laboratory supervisor (your
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