About the Program

CDC’s Division of Laboratory Sciences (DLS) operates the National Biomonitoring Program (NBP). Biomonitoring is the worldwide standard procedure for assessing people’s exposure to chemicals that may be toxic, and responding to environmental public health issues.


  • Involves measuring environmental chemicals, or their breakdown products (metabolites), in human tissues and fluids, such as blood and urine. Chemical exposures occur through the air, water, food, soil, dust, and use of consumer products
  • Can measure many chemicals in a very small amount—often less than a teaspoon—of blood or urine
  • Biomonitoring Factsheet pdf icon[PDF – 705 KB]
Photo of scientist working in the lab

Scientists use biomonitoring to

  • Determine which chemicals are getting into people’s bodies and how much of those chemicals are in blood and urine. Occasionally, chemical measurements have been made using breast milk, and saliva
  • Monitor people who have levels of a chemical above a level of concern or known toxicity level
  • Track exposure trends and impacts of public health programs

Activities of the NBP

  • Measures more than 400 environmental chemicals in people
  • Develops and publishes advanced laboratory methods in peer-reviewed journals so that other laboratories can use them
  • Shares knowledge and trains state public health laboratories in biomonitoring methods
  • Helps assure the quality of laboratory test data. Quality data ensures patients and healthcare providers (as well as researchers and public health officials) that the laboratory test results they receive are accurate
  • Funds and supports state-based biomonitoring programs
  • Collaborates with partners on 60–70 studies each year examining the effects of environmental exposure
  • Responds to requests for aid in epidemiological investigations where chemical exposure is suspected
  • Periodically publishes the National Report on Human Exposure to Environmental Chemicals and Updated Tables. The Report and Updated Tables provide cumulative exposure information since 1999 for more than 300 environmental chemicals in a nationally representative sample of Americans

Applied Uses

Chemical or Radiological/Nuclear Threats

Biomonitoring can provide an accurate assessment of people exposed in the event of a chemical or radiological/nuclear emergency. Biomonitoring can identify the chemical agents and radionuclides. This allows health experts to find out who was exposed, and to what extent.


Biomonitoring is used to develop methods that help diagnose, treat, and prevent diseases caused by toxins, which are chemicals produced by animals or plants. CDC does research on toxins by:

  • Developing new test methods
  • Increasing testing capacity during toxin-specific emergencies
  • Using advanced technology to improve public health outcomes to toxin-related diseases throughout the world
Tobacco Smoke

Biomonitoring can be used to assess people’s exposure to tobacco smoke, either by smoking or by inhaling smoke in the air (secondhand smoke). CDC investigates both individual and population exposures to the chemicals in tobacco products and measures toxic and addictive substances in tobacco smoke. CDC continues to monitor the U.S. population’s exposure to secondhand smoke and assesses the effects of actions and policies to reduce secondhand smoke exposure.

Reports and Data

National Biomonitoring Program (NBP) data and biomonitoring research help to develop multiple publications and reports. CDC utilizes that data to develop the National Report on Human Exposure to Environmental Chemicals and Updated Tables. This report is a series of ongoing assessments of the U.S. population’s exposure to environmental chemicals.

Biomonitoring data is also used for various studies, journal articles and publications. Biomonitoring measurements for the National Report on Human Exposure to Environmental Chemicals and Updated Tables are made using samples from participants in the National Health and Nutrition Examination Survey (NHANES), conducted by CDC’s National Center for Health Statistics. All of the biomonitoring data are publicly available at the NHANES website:

Page last reviewed: August 27, 2021