Tracking Population Exposures

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. These data are often the best source of information for scientists, doctors, and health officials to help prevent or reduce exposure to some environmental chemicals. For example, public health workers could use biomonitoring data to find out what chemicals people are exposed to and the levels of the chemicals that are found. If efforts are needed to prevent or reduce exposure, biomonitoring data can show if those efforts work. Also, these data could be used to determine whether exposure levels are different among potentially vulnerable groups such as minorities and children.

Biomonitoring data come from CDC's National Health and Nutrition Examination Survey (NHANES). NHANES evaluates a nationally-representative sample of the U.S. population. It is designed for survey findings to reflect the nation as a whole rather than individual counties or states.

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. In addition, these biomonitoring data do not provide

• data about specific sources of exposure, such as hazardous chemical sites or uses.
• 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.

How-To Guide: [PDF - 1.47 MB]

Read CDC's National Report on Human Exposure to Environmental Chemicals for more details about the NHANES analysis for each environmental chemical according to age, sex, and racial/ethnic groups.

More research is needed on most of the environmental chemicals included in NHANES to determine if exposures at the reported levels are a cause for health concern.