How to Use This Course


The goal of Case Studies in Environmental Medicine (CSEM) is to increase the primary care provider’s knowledge of hazardous substances in the environment and to assist in the evaluation and treatment of potentially exposed patients. This CSEM focuses on nitrites/nitrates toxicity.


Two versions of the Nitrites/Nitrates Toxicity CSEM are available.

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 nitrites/nitrates 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 with which you are already familiar. 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 focus 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 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 Nitrate/Nitrite CSEM, you should be able to

instructional format
Content Area Objectives
  • Describe what nitrates and nitrites are.
Exposure Pathways
  • Identify sources of nitrates and nitrites.
  • Describe the primary routes of exposure to nitrates and nitrites.
Who Is at Most Risk of Adverse Health Effects From Overexposure
  • Identify the population most susceptible to the adverse health effects from overexposure to nitrates and nitrites.
Standards and Regulations
  • Describe the U.S. Environmental Protection Agency’s (EPA’s) recommended limit for nitrates and nitrites in drinking water.
  • Describe the U.S. Food and Drug Administration’s (FDA’s) recommended limit for nitrates and nitrites in bottled water and foodstuffs.
Biological Fate
  • Describe what happens to nitrates and nitrites once they enter the body.
Health Effects
  • Describe mechanisms contributing to health effects from exposure to nitrates and nitrites.
  • Describe the health effects from exposure to nitrates and nitrites.
Clinical Evaluation
  • Describe the clinical assessment of an infant with cyanosis due to overexposure to nitrates and nitrites.
  • Describe the signs and symptoms of methemoglobinemia.
  • Identify the laboratory test results that indicate methemoglobinemia.
Treatment and Management
  • Describe treatment modalities in the management of methemoglobinemia caused by nitrate and nitrite toxicity.
Instructions to Patients
  • Describe care advice the clinician can provide to patients to prevent overexposure to nitrates and nitrites.