Skip Navigation
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.


The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Your Environment. Your Health.

Powering Research Through Innovative Methods for Mixtures in Epidemiology (PRIME) Program

Program Description

Environmental health studies tend to evaluate potential health effects one chemical at a time, but in reality, people are exposed to a mixture of chemicals every day. Studying a chemical mixture requires evaluating the effects of individual chemicals within the mixture, interactions among those chemicals, and the combined effect the mixture may have on human health.

people seated at a circular table working on math problems

Given this complexity, scientists need improved and innovative statistical methods to understand how exposure to real-world chemical mixtures may affect human health.

Building on the historical efforts of the NIEHS Mixtures Program and previous workshops, NIEHS created the Powering Research through Innovative Methods for mixtures in Epidemiology (PRIME) program, launching a funding opportunity in 2017 (RFA ES 17-001). Projects supported through PRIME will develop innovative statistical methods that incorporate toxicological information into statistical models.

PRIME encourages team science. Experts in epidemiology, biostatistics, toxicology, data science, informatics, and related fields are working together to develop and compare novel approaches, which may involve simulated, shared data, as well as real-world applications to human study populations.

The expected outcomes of PRIME include:

  • Improving quantitative methods to better understand the complex relationships between environmental exposures and health outcomes.
  • Stimulating new interdisciplinary methods for mixtures research in epidemiology.
  • Comparing existing and new approaches to identify the strengths and weaknesses across methods for various exposure and disease contexts.
  • Developing informatics tools and related software for broad implementation of methods.
  • Providing resources for the research community including publications, webinars, example datasets, and training.

Funded PRIME Projects

PRIME grantees study how exposure to mixtures of metals, pesticides, endocrine disrupting chemicals, persistent organic pollutants, and air pollution affect health. Some researchers will also examine how non-chemical exposures, like stress and nutrition, may amplify or protect against the adverse health effects of a chemical mixture.

PRIME projects will develop novel statistical approaches that:

  • Enable research to discover the biological pathways that link an exposure to a disease.
  • Determine which exposures within a mixture are most harmful, and how the mixture as a whole influences health.
  • Incorporate information on chemical toxicity to provide biological context for exposures.
  • Integrate the timing of exposures such as critical windows of development when individuals are more susceptible to exposures.
  • Share and leverage datasets capturing variability in exposures and outcomes across space, time, and populations.

Importantly, PRIME researchers share their newly developed statistical methods and software with the wider environmental health science research community to help advance mixtures research.

NIEHS Mixtures Network

The NIEHS Mixtures Network was developed after the 2020 virtual PRIME grantee meeting to facilitate a broader network for researchers interested in environmental mixtures (statistical methods, epidemiology, toxicology, and related fields). To join the list, please contact Justin P. Crane. Examples of topics covered include sharing of code, data, papers, and job opportunities.


PRIME Publications lists those demonstrating new or expanded statistical methods, notable PRIME methods in epidemiology studies, as well as RePORTER search results for all PRIME-funded publications acknowledging a PRIME R01 as a funding source.

Software and Shared Datasets

The PRIME Toolbox lists open-access software and related tools to enable broader application of the novel methods developed under PRIME. It offers NIEHS PRIME GitHub, a list of new software applications developed to address the statistical analysis of mixtures data, and PRIME related data sets.

Program Contacts

Bonnie R. Joubert, Ph.D.
Bonnie R. Joubert, Ph.D.
Health Scientist Administrator
Tel 984-287-3276
P.O. Box 12233
Mail Drop K3-12
Durham, N.C. 27709
Toccara Chamberlain
Toccara A. Chamberlain
Health Specialist
Tel 984-287-4482
P.O. Box 12233
Mail Drop K3-04
Durham, N.C. 27709
Nicholas, Aaron
Aaron Nicholas
Grants Management Officer
Tel 984-287-3297
San Diego, CA 92128
Leroy Worth
Leroy Worth Jr, Ph.D.
Scientific Review Officer
Tel 984-287-3340
Fax 301-480-3722
P.O. Box 12233
Mail Drop K3-03
Durham, N.C. 27709
to Top