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About the National Exposure Research Laboratory (NERL)

What We Do

EPA’s National Exposure Research Laboratory (NERL) supports EPA’s mission to protect human health and the environment by developing and applying innovations in exposure science. Exposure science sets the context for understanding and solving real-world problems, and is used to help answer three fundamental questions:

  • Is there a risk?
  • If so, how do we reduce/mitigate/prevent the risk?
  • Have our actions been successful in reducing risk?

Headquartered in Research Triangle Park (RTP), N.C., NERL has an in-house workforce of more than 315 scientists, engineers and staff across three divisions in four locations: RTP, North Carolina; Cincinnati, Ohio; Athens, Georgia; and Las Vegas, Nevada.

NERL is internationally recognized as the leader in environmental exposure science. Our multidisciplinary expertise enables the laboratory to bring cutting-edge research and technology to the field of exposure science to address the Agency’s priority environmental problems.

NERL’s Niches

Below are NERL’s scientific capabilities (i.e., our niches):

  • Analytical/Monitoring Methods Development: Research conducted in either the laboratory or field that is used to develop, refine or evaluate tools to quantify, measure, or sample stressors in the environment or in receptors.
  • Indicators/Indices of Exposure: Research conducted to determine how to combine measurements, data and/or models in a way that succinctly describes or characterizes the state or change of exposure.
  • Exposure/Dose Process Characterization: Research including field and laboratory studies and data analysis conducted to better understand and gain knowledge about fate and transport, exposure and dose in real world instances. This research is primarily hypothesis driven, and includes collection of data to elucidate the important processes in models, inputs to models, and data to evaluate models. This research is applied to both human and ecological systems.
  • Decision Support Tools: Research activities to assemble data, analytical and predictive tools and knowledge into a useable format for analysts and decision makers.
  • Predictive Modeling: Research to develop, evaluate, and apply first principle, statistical, or stochastic models. This includes models for environmental characterization, personal exposure and dose, and mechanistic elucidation but does not include source apportionment models.
  • Source Apportionment/Environmental Forensics: Research where source apportionment or environmental forensics tools are developed and applied in real world instances to identify important sources and pathways for exposure.


Location: Research Triangle Park, N.C.; Cincinnati, Ohio; Athens, Ga.; Las Vegas, Nev.

Director: Timothy Watkins

  • Biography
  • Phone: 919-541-2106

Deputy Director: Reeder Sams

  • Phone: 919-541-0661

Organization chart

NERL is anchored by three science divisions:

  • Exposure Methods and Measurement Division (EMMD)
  • Computational Exposure Division (CED)
  • Systems Exposure Division (SED)