Agency for Toxic Substances and Disease Registry 
Case Studies in Environmental Medicine (CSEM) 

Nitrate/Nitrite Toxicity
How to Use This Course

Introduction

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 aid in the evaluation of potentially exposed patients. This CSEM focuses on nitrate/nitrite toxicity.

Available Versions

Two versions of the Nitrate/Nitrite Toxicity CSEM are available

• the HTML version http://www.atsdr.cdc.gov/csem/nitrate/ provides content through the Internet;
• the downloadable PDF version provides content in an electronic, printable format, especially for those who may lack adequate Internet service.

Instructions

To make the most effective use of this course, we recommend that you

• take the Initial Check to assess your current knowledge about Nitrate/Nitrite 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 responses 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:

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

Provides 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:

Overview

• Describe what nitrates/nitrites are

Exposure Pathways

• Identify sources of nitrates/nitrites
• Describe drinking water exposure risk to nitrates/nitrites

Who Is at Risk

• Identify the population most susceptible to nitrates/nitrites

Standards and Regulations

• Describe the U.S. Environmental Protection Agency’s recommended limit for nitrates/nitrites in drinking water

Biological Fate

• Describe the mean intake of nitrates by persons in the United States
• Describe how nitrates are metabolized and excreted

Physiological Effects

• Describe the physiologic and pathologic effects of nitrates and nitrites

Clinical Evaluation

• Describe the clinical assessment of an infant exposed to nitrates or nitrites
• Describe the signs and symptoms of methemoglobinemia
• Identify the laboratory test results that indicate methemoglobinemia

Treatment and Management

• Describe two treatments for methemoglobinemia caused by nitrates/nitrites toxicity