Human Exposure and Atmospheric Sciences
Research in Action
Biomonitoring: An Exposure Science Tool
Every day, people come in contact with natural and man-made chemicals in air, water, food, and consumer products. Health risks from these chemicals are determined, in part, from the frequency, magnitude and duration of contact events. Scientists sometimes determine the extent of human exposure by measuring chemicals in a given environment, and monitoring human behavior in that same environment. In these situations, the chemicals are measured before they enter the human body.
However, biomonitoring offers a way of characterizing exposure by measuring chemicals after they enter the human body. This process involves looking for biomarkers of exposure in biological samples such as hair, fingernails, urine, breath, breast milk, and blood.
Exposure biomarkers are often the actual chemical or their breakdown products (metabolites) in human tissues or fluids. Exposure biomarkers are most commonly used to determine whether an individual has been exposed to a chemical; if exposure has changed over time; or if exposure is different between groups of people (men vs. women, children vs. adults). Additionally, exposure biomarkers help identify primary sources of exposure (food, air, consumer products, etc.). This information can then be used to mitigate exposure sources that pose elevated human health risks.
In the past, biomonitoring data have had limited applications, mainly being used as a surveillance tool for monitoring exposures to chemicals over time. Recent scientific advances have allowed biomonitoring data to be used as a tool for improving linkages between human exposures to chemicals and potential health effects. However, there is still a need for additional research in order to use biomonitoring data more effectively.
Under EPA’s Chemical Safety for Sustainability (CSS) research program, EPA scientists are developing a suite of biomonitoring tools for assessing human exposures to environmental chemicals and their likely health responses. Specifically, EPA scientists are working to identify the chemicals to which humans are most commonly exposed; exposure levels across various groups of people; and the likely biological responses of individuals following exposure.
Examples of biomonitoring research and tools used by EPA scientists include:
- Laboratory methods for measuring biomarkers in various tissues and fluids;
- Human observational studies for identifying major exposure sources (e.g., food, air, dust) and exposure routes (e.g., ingestion, inhalation, skin contact); and
- Computational models for simulating absorption, distribution, metabolism, and excretion of a given chemical over time.
Results and Impact
EPA scientists have generated new biomonitoring data and computational models for a number of chemicals and chemical classes, including insecticides, perfluorinated compounds, and volatile organic compounds. Additionally, EPA scientists have developed a biomonitoring framework for integrating and interpreting existing data, and designing new studies to answer specific research questions.
This research will help identify linkages between human exposures to environmental chemicals and adverse health responses. These science-based tools will also support EPA exposure and risk assessments designed to protect human health.
- EPA Exposure Research
- EPA’s Chemical Safety for Sustainability Research Program
- EPA report: Biomonitoring – An exposure science tool for exposure and risk assessment
- Journal article: A biomonitoring framework to support exposure and risk assessments
- Defining Biomarkers
- Tool: Probabilistic Reverse Dosimetry Estimating Exposure Distribution (PROcEED)
- Journal article: Breath biomarkers in environmental health science
- Journal article: Review of pesticide urinary biomarker measurements from selected EPA children’s observational exposure studies