How to Use This Course

This page refers to a blood lead level of 5 micrograms per deciliter (μg/dL) as the CDC’s blood lead reference value. As of October 28, 2021, CDC uses a blood lead reference value of 3.5 micrograms per deciliter to identify children with blood lead levels that are higher than most children’s levels. This new level is based on the U.S. population of children ages 1–5 years who represent the top 2.5% of children with the highest blood lead levels. For more information, refer to Blood Lead Reference Value.


The goal of the ATSDR Case Studies in Environmental Medicine (CSEM) series is to increase the primary health care provider’s knowledge of hazardous substances in the environment and to promote medical practices that aid in the prevention, evaluation and care of potentially exposed patients. This CSEM focuses on lead toxicity.


Two versions of the Lead Toxicity CSEM are available.

  • The HTML version (to be added after clearance during web production) provides content through the Internet.
  • The downloadable PDF versionpdf icon provides content in an electronic, printable format, especially for those who may lack adequate Internet service.
  • The HTML version offers interactive exercises and prescriptive feedback to the user.

To make the most effective use of this course,

  • Take the Initial Check to assess your current knowledge about lead toxicity.
  • Read the title, learning objectives, text, and key points in each section.
  • Complete the progress check exercises at the end of each section and check your answers.
  • Complete and submit your assessment and posttest response online if you wish to obtain continuing education credit. Continuing education certificates can be printed immediately upon completion.
Instructional Format

This course is designed to help you learn efficiently. Topics are clearly labeled so that you can skip sections or quickly scan sections you are already familiar with. This labeling will also allow you to use this training material as a handy reference. To help you identify and absorb important content quickly, each section is structured as follows:

instructional format
Section Element Purpose
Title Serves as a “focus question” that you should be able to answer after completing the section.
Learning Objectives Describes specific content addressed in each section and focuses your attention on important points.
Text Provides the information you need to answer the progress check question(s) and achieve the learning objectives.
Key Points Highlights important issues and helps you review.
Progress Check exercises Enables you to test yourself to determine whether you exercises have mastered the learning objectives.
Progress Check Answers Provide feedback to ensure you understand the content and can locate information in the text.
Learning Objectives

Upon completion of the Lead Toxicity CSEM, you will be able to:

learning objectives
Section Title Learning Objectives
What Is Lead? Explain what lead is.
Where Is Lead Found? Describe potential sources of lead exposure in the United States today.
What Are Routes of Exposure to Lead? Identify the most common routes of exposure to lead in the United States today.
What Are U.S. Standards for Lead Levels?
  • Describe the Centers for Disease Control and Prevention’s (CDC) reference value for lead in children’s blood,
  • Describe the U.S. Occupational Safety and Health Administration’s (OSHA) Permissible Exposure Limit (PEL) for lead in workplace air,
  • Describe the U.S. Environmental Protection Agency’s (EPA) drinking water regulation for lead, and
  • Describe the Consumer Product Safety Commission’s (CPSC) regulatory limit value for lead in paint.
What Is the Biological Fate of Lead in the Body?
  • Describe how lead is absorbed,
  • Describe how lead is distributed in the body, and
  • Identify the half-life of lead in the blood.
What Are Possible Health Effects from Lead Exposure?
  • Describe how lead affects adults and children,
  • Describe what is the most sensitive organ system for lead exposure in children, and
  • Specify that there is no identified threshold or safe level of lead in blood.
Clinical Assessment – Exposure History
  • Describe how to take a screening exposure history for lead exposure, and
  • Identify lead exposure-related questions to ask during a child visit.
Clinical Assessment – Signs and Symptoms
  • Name typical signs and symptoms consistent with lead toxicity,
  • Describe how lead exposure dose and symptoms can vary, and
  • Describe key features of the physical examination for patients exposed to lead.
Clinical Assessment – Diagnostic Tests and Imaging
  • Describe guidelines for blood lead screening and confirmatory diagnostic testing on patients at risk of recent or ongoing lead exposure, and
  • Describe imaging and other clinical modalities that may assist in the diagnosis of current or past lead exposed patients.
How Should Patients Exposed to Lead Be Treated and Managed?
  • Describe a management strategy for children whose blood lead levels are equal to or greater than the current CDC reference value of 5µg/dL.
What Instructions Should Be Given to Patients?
  • Describe instructions to parents and patients to prevent or reduce lead exposure,
  • Describe instructions for patients exposed to lead, and
  • Describe communication strategies that health care providers can use to best deliver clinical information to their lead exposed or potentially exposed patients.