Biomonitoring: Population Exposures

At a glance

Scientists at CDC determine which environmental chemicals people have been exposed to by measuring how much of those chemicals actually get into people's bodies. This is called biomonitoring. The Tracking Network hosts biomonitoring data from the "National Report on Human Exposure to Environmental Chemicals."

Overhead view of many people using a city crosswalk

We Track That

Most biomonitoring involves measuring the amount of a chemical or its breakdown product (metabolite) that is in a small sample of a person's blood or urine. The amount of the chemical or metabolite in the blood or urine depends on the amount of the chemical that has entered the body.

We know that some environmental chemicals cause disease or illness in people. However, for most chemicals, we do not know if low level environmental exposures affect our health. Finding an environmental chemical in a person's blood or urine does not mean that it causes health effects or disease.

Biomonitoring data on the Tracking Network come from CDC's National Health and Nutrition Examination Survey (NHANES) as presented in CDC's National Report on Human Exposure to Environmental Chemicals.

Types of Data

National Report on Human Exposure to Environmental Chemicals

This indicator shows concentrations of different environmental chemicals in urine or blood. These data tell you what levels of those environmental chemicals are found in urine and blood samples from people who are typical examples of the U.S. population. These data are available for the United States as a whole, not by county, state, or region.

Topic Areas

  • Disinfection By-products
  • Metals and Metalloids
  • Per- and Polyfluorinated Substances (PFAS)
  • Personal Care and Consumer Products Metabolites
  • Pesticide Metabolites
  • Phthalate Metabolites
  • Polycyclic Aromatic Hydrocarbons
  • Tobacco Smoke
  • Volatile Organic Compounds (VOCs)
  • Volatile Organic Compounds Metabolites

Notes about NHANES Data

The NHANES survey design does not allow use of the data to estimate exposure by state, city, or for specific areas associated with hazardous chemical exposures. For example, you cannot extract a subset of data and examine levels of blood lead that represent a state population.

These biomonitoring data do not provide the following.

  • Data about specific sources of exposure, such as hazardous chemical sites
  • Data about specific pathways of exposure, like breathing, eating, drinking, or touching
  • Information about specific products or environments
  • Regulatory guidelines or recommendations
  • Information about health effects related to chemical exposures

Access the Data

Use the Data Explorer to create custom maps, tables, and charts.

View data in simple Quick Reports.

Get machine-readable data from the Application Program Interface (API).

Data in Action

Biomonitoring data can be used to find environmental chemical exposures and to measure how common these exposures are in groups of people, such as the U.S. population.

Biomonitoring data are often the best source of information for scientists, doctors, and health officials to help prevent or reduce exposure to some environmental chemicals. Potential actions include the following.

  • Finding out what chemicals people are exposed to
  • Assessing the levels of the chemicals found in humans
  • Determining exposure levels among groups at higher risk for experiencing poor health outcomes, like children
  • Evaluating the success of efforts to prevent or reduce exposures