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Exposure Research

Human Exposure & Atmospheric Sciences Staff

Ron Williams

Title: Research Chemist

EPA Division: Human Exposure and Atmospheric Sciences Division

EPA Branch: Exposure Measurements and Analysis Branch

Ron is an Air Climate and Energy (ACE) Task Leader with the US EPA’s National Exposure Research Laboratory. He has held senior research positions in private, academic and governmental research organizations for more than 33 years. His US EPA responsibilities have included an extended tenure (2009-2010) as an Acting Branch Chief for the Exposure Measurements and Analysis Branch where he led a multidisciplinary team of exposure scientists. His personal research focus has been upon human exposures to complex environmental mixtures. These efforts have resulted in approximately 130 peer review journal articles and hundreds of presentations at national and international conferences. He is a recognized expert in the area of human exposure monitoring and has been responsible for designing, executing and summarizing some of the US EPA’s largest human observational panel studies. His current research focuses on evaluating air quality sensors and development of novel monitoring systems for community-based research. He is continuing to develop and lead multi-pollutant human exposure measurement panel studies involving particulate matter, pollutant gases and select air toxics. The multipollutant environment is of particular interest. This research involves determining the relationships between personal exposures to air pollutants across multiple spatial settings. His efforts involve investigating the human and environmental factors that influence source exposure relationships using a multidisciplinary approach. He has extensive international experience and collaborates extensively within the US EPA and with external researchers to fully understand the impact of pollutant exposures on human health effect outcomes.


  • B.S., Chemistry, East Carolina University, 1979

Professional Experience:

  • Research Chemist, ACE Task Leader, USEPA, RTP, NC 2011-present
  • Research Chemist, Measurements Team Leader, USEPA, RTP, NC 2010-2011
  • Acting Branch Chief, USEPA, RTP, NC 2009-2010
  • Research Chemist, Measurements Team Leader, USEPA, RTP, NC 1998-2009
  • Chemist, US EPA, 1995-1999
  • Research Assistant Professor-University of North Carolina-Chapel Hill, 1994-1995
  • Senior Research Scientist, EHRT, RTP, NC 1994-1983
  • Safety Officer, EHRT, RTP, NC 1993-1982
  • Associate Scientist, Northrop Services, RTP, NC 1982-1983
  • Chemist, RTI International, 1980-1982

Professional Societies and Affiliations:

  • American Chemical Society, 1991-2012
  • International Society of Exposure Science, 1997-2012
  • American Association for Aerosol Research, 2006, 2010, 2012
  • Triangle Chromatography Discussion Group, 1987-2012
  • Air and Waste Management Association, 2003-2004, 2006-2007, 2012
  • Genotoxicity and Environmental Mutagen Society, 1985-2003
  • American Association of Pharmaceutical Scientists, 1994-1996
  • North Carolina Quality Assurance Discussion Group, 1994-1995
  • Councilor for Genotoxicity and Environmental Mutagen Society, 1990-1993

Select Awards and Honors:

  • USEPA Bronze Medal, ACE Research Action Team Award, November 2012
  • USEPA Bronze Medal, Mechanistic Indicators of Childhood Asthma, November 2011
  • USEPA NERL Goal 3, Environmental Research Leader Award, March 2011
  • USEPA Special ORD Medal, NERL/NHEERL TeamWork Award, September 2010
  • USEPA Silver Medal, The DEARS Study, September 2010
  • USEPA Science and Technology Achievement Award- Level I, May 2008
  • USEPA Silver Medal, PM Exposure Analysis Team, June 2007
  • USEPA Science and Technology Achievement Award-Level II, April 2005
  • USEPA Bronze Medal, The COPP Study, August 2005
  • USEPA Bronze Medal, PM Five-year accomplishments report, August 2004
  • USEPA Science and Technology Achievement Award- Level III, February 2003
  • USEPA Bronze Honor Award, NERL PM Longitudinal Panel Studies, August 2002
  • USEPA World Trade Center Response Special Commemorative Award, August 2002

Select Publications:

  • Williams, R., Croghan, C.,Ryan, B. Human exposures to PAHs: An eastern United States Pilot Study. J. Environmental Monitoring and Assessment. 185: 1011-1023 (2013).
  • Vallano, D., Snyder, E., Kilaru, V., Thoma, E., Williams, R., Hagler, G., Watkins, T. Air Pollution Sensors. Highlights from an EPA workshop on the evolution and revolution in low cost participatory air monitoring. Environmental Manager. December 2012. 28-33 (2012).
  • Duval, R., Olson, D., Norris, G., Burke, J., Vedantham, R., Williams, R. Determining spatial variability in PM2.5 source impacts across Detroit, MI. Atmospheric Environment, 47: 491-498 (2012).
  • Williams, R., Rappold, A., Case, M., Schmitt, M., Stone, S., Thornburg, J., Devlin, R. Multi-pollutant exposures in an asthmatic cohort. Atmospheric Environment. 61: 244-252 (2012).
  • Williams, R., Brook, RD., Bard, R., Hwashin, S., Burnett, R. Impact of nitrogen dioxide and select particulate matter component concentrations on cardiovascular function alterations in a general population. International J. Environmental Health Research, 22: No 1, 71-91 (2012).
  • Williams, R., Jones, P., Carry Croghan, Thornburg, J., Rodes, C. The influence of human and environmental exposure factors upon personal NO2 exposure. J. Exposure Science and Environmental Epidemiology. 22: 109-115 (2012).

Published & Presented Research (1999-Present)

Contact Info:
Ronald W. Williams
Human Exposure & Atmospheric Sciences Division
National Exposure Research Laboratory
US EPA Office of Research and Development
109 TW Alexander Drive
Research Triangle Park, NC 27709
Telephone: 919-541-2957
Email: williams.ronald@epa.gov

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