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Dr. David Lewis

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      The persistence, transport and fate of infectious agents and environmental toxins are my primary areas of research. This work involves all kinds of natural environments, including soils, sediments, freshwater and marine systems, and both terrestrial and aquatic vegetation.


My coworkers and I demonstrated, for example, that environmental changes alter the relative persistence of different enantiomers of chiral pollutants, including pesticides and pharmaceuticals. (Lewis et al. Nature 401:898-901, 1999) Whether these chemicals cause neurological damage and other adverse effects often depends on which enantiomer is present. Dopamine derivatives, which induce Parkinsonism in rats, are examples of chiral neurotoxins.


We also documented adverse health effects associated with heavy metals and organic chemicals found in aerosols generated by processed sewage sludges (biosolids) applied to land. Nature published a supportive editorial and news article highlighting the independent confirmation of our research linking gastrointestinal, skin and respiratory illnesses to biosolids. (Nature 453:258, 262-263, 2008).


 My coworkers and I have also investigated the survival, transport and fate of infectious agents in both clinical settings and natural environments. We discovered, for example, that dental lubricants contaminated with HIV are impervious to chemical disinfection, and can remain highly infectious when expelled by dental handpieces and attachments (drills, prophy angles) during subsequent dental procedures. This research prompted the CDC and other public health organizations worldwide to recommend that all items entering the oral cavity during dental procedures be heat sterilized or discarded after each use. (Lewis et al., Lancet 340: 1252-4, 1992; Lewis and Arens. Nature Med. 1:956-958, 1995).




February 14, 2011




(Present) Res. Associate, Neural Dynamics Research Group, The University of British Columbia. Conduct basic research concerning clinical and environmental exposures associated with neurological diseases.


(2006-Present) Board Member and Director of the Research Misconduct Project at the National Whistleblowers Center, Washington, DC. (


(1989-2008) Graduate Faculty and various adjunct faculty and visiting scientist appointments in the Department of Marine Sciences and School of Ecology (formerly Institute of Ecology) at the University of Georgia.


(1977-2003) Research Microbiologist (GS-403-15). U.S. Environmental Protection Agency, Office of Research and Development, National Exposure Research Laboratory - Athens.. Served as EPA Project Officer for climate change research at the Marine Biological Laboratory, Woods Hole, MA.



  • Documented adverse health effects of land-applied sewage sludge (biosolids)

 The U.S. House of Representatives Science Committee held two hearings concerning EPA's efforts to suppress investigations into adverse heath effects of processed sewage sludge (biosolids) applied to land. Congress passed the No Fear Act of 2002. Based public and congressional attention prompted by our research at the University of Georgia, the U.S. Department of Health and Human Services developed guidelines for protecting workers exposed to biosolids. See, Cocalis, J., et al. Workers exposed to Class B biosolids during and after field application. DHHS (NIOSH) Publication No. 2000-158 (2000). See, "The Gatekeepers" and "Why EPA was unprepared for Gulf Oil Disaster" (


Nature published a supportive editorial and news article highlighting the independent confirmation of our research findings linking gastrointestinal, skin and respiratory illnesses to land application of sewage sludge. See, Tollefson, J. Raking through sludge exposes a stink. Stuck in the mud—The Environmental Protection Agency must gather data on the toxicity of spreading sewage sludge [Editorial] Nature 453:258, 262-263 (2008). Editors described EPA's biosolids program as "a failure of three presidential administrations."

  •  Published first-authored article in Nature concerning effects of climate change on biodegradation of chiral  chemicals in soils  

This work was recognized by EPA Administrator with the Science Achievement Award for Biology/Ecology in 2000, and by EPA's Office of Research & Development with a Science & Technological Achievement Award in 2001.

  • Published first-authored articles on dental-related HIV transmission in Lancet and Nature Medicine, which led to current heat-sterilization standard for dentistry

Lancet published a supportive editorial to accompany our research article, which explained how six patients in a Florida dental practice could have acquired HIV from leaky prophylaxis angles shared by dentists and their patients. This work prompted the U.S. Department of Health and Human Services and other public health organizations worldwide to institute the current infection control standard for dentistry in which all devices entering the oral cavity must be heat-sterilized or discarded after each use. See, Recommended infection-control practices for dentistry. MMWR. 42:1-12 (1993).

  • Conducted a prospective epidemiological study of hospital-acquired hepatitis C virus in Egypt

This work was carried out in collaboration with University of Maryland's Department of Epidemiology and Preventive Medicine in Baltimore, MD, the Liver Institute at Menoufiya University in Egypt, and the WHO-sponsored Hepatitis C Prevention Project headquartered in Cairo. Our findings concerning design defects in flexible endoscopes were covered by Newsweek, USA Today and various medical journals.

  • Discovered that nitrogen and phosphorus determine adaptation lag periods for biodegradation of organic chemical pollutants in soil and water (Lewis et al. Appl. Environ. Microbiol. 51:598-603 (1986).

Our findings were confirmed by other researchers at Cornell University and the University of North Carolina. See, e.g., Wiggins, et al. Appl. Environ. Microbiol. 53:791-796 (1987); Jones and Alexander. Appl. Environ. Microbiol. 54:3177-3179 (1988); Zaidi, et al. Environ. Sci. Tech. 22:1419 (1988); Swindoll, et al. Appl. Environ. Microbiol. 545:212-217 (1988). These findings became widely employed for cleaning up environmental contamination in soil and water, including the Exxon Valdez oil spill in Alaska.


Professional Recognition


Appointed Res. Associate, Neural Dynamics Research Group, University British Columbia (2011)


Book Reviewer (2011): “They’re Poisoning Us”—From the Gulf War to the Gulf of Mexico” by Arnold Mann. Rated by editors of Annals of Internal Medicine as being among top 10% of reviewers (2010)


Director, Research Misconduct Project, National Whistleblowers Center (2006-present) Board of Directors, National Whistleblowers Center (2006-present)

U.S. EPA Science & Technology Achievement Award (2001)

U.S. EPA Science Achievement Award for Biology/ Ecology (2000)

Lexington Leadership Award presented at "The Lexington Institute with Dr. David Lewis," a dinner for members and staff of the U.S. Congress, non-profit organizations and corporate leaders in recognition of my contributions to public policy in environmental science. Hay Adams Hotel, Washington, DC (2000) Accuracy in Media Award, Washington, DC (1998)

First non-European elected to European Panel on Infection Control in Dentistry (1995)


Public Recognition


Research accomplishments have been covered in news articles, editorials and documentaries in a variety of professional, scientific and popular publications and broadcasts including Nature, Science, Lancet, JAMA,


National Geographic, Reader's Digest, Voice of America, Paul Harvey News, Time, Newsweek, U.S. News & World Report, Forbes, NY Times, Washington Post, London Times, NPR’s All Things Considered, PBS Healthweek, PBS Technopolitics, CBS Evening News, ABC's Primetime Live, and BBC Panorama.


In 1998, an overview of my research accomplishments was published in a cover story by Time, Inc.'s Hippocrates magazine, which won a national award for the year's best professional magazine cover story. In 2005, The Scientist and the International Journal of Occupational and Environmental Health focused on efforts by EPA program managers to stop the publication of my research on land application of sewage sludge E. Russo, 2005. C. Snyder, The Dirty Work of Promoting Recycling of America's Sewage Sludge. IJOEH 2: 415-27 (2005).


Selected Peer-Reviewed Scientific Articles


Mikhail, N., D.L. Lewis, N. Omar, H. Taha, A. El-Badawy, N.A. Mawgoud, M. Abdel-Hamid, and G.T. Strickland. Prospective study of cross-infection from upper-GI endoscopy in a hepatitis C–prevalent population.

 Gastrointest Endosc 65:584-588 (2007).


Gattie, D.K. and D. L. Lewis. A high-level disinfection standard for land-applied sewage sludge (biosolids).

 Environ. Health Perspect. 112:126-31 (2004).


Lewis, D.L., D.K. Gattie, M.E. Novak, S. Sanchez, and C. Pumphrey. Interactions of pathogens and irritant chemicals in land-applied sewage sludges (biosolids) BMC Public Health 2:11 (28 Jun 2002)


Lewis, D.L. & D. K. Gattie. Pathogen risks from applying sewage sludge to land Environ. Sci. Technol. 36:286A-293A (2002)


Lewis, D. L., W. Garrison, K. E. Wommack, A. Whittemore, P. Steudler & J. Melillo. Influence of environmental changes on degradation of chiral pollutants in soils. Nature 401:898-901 (1999).


Lewis, D.L. EPA Science: Casualty of election politics. Nature 381:731-2 (1996).


Lewis, D.L., and M. Arens. Resistance of microorganisms to disinfection in dental and medical devices. Nature Medicine 1:956-958 (1995).


Lewis, D.L., M. Arens, S. Appleton, K. Nakashima, J. Ryu, R.K. Boe, J. Patrick, D. Watanabe, & M. Suzuki. Cross-contamination potential with dental equipment. Lancet 340: 1252-4 (1992).


Lewis, D.L. & R.K. Boe. Cross-infection risks associated with current procedures for using high-speed dental handpieces. J. Clin. Microbiol. 30:401-406 (1992).


Lewis, D.L. and D.K. Gattie. Predicting chemical concentration effects on transformation rates of dissolved organics by complex microbial assemblages. Ecol. Mod. 55:27-46 (1991).