Photo of Robert Letcher

Robert Letcher

Adjunct Research Professor

Degrees:B.Sc. (Honours) (Chemistry) – University of Toronto, M.Sc. (Inorganic/Organic Chemistry) – Carleton University, Ph.D. (Ecotoxicology/Ecological-Environmental Chemistry) – Carleton University
Office:Wildlife and Landscape Science Directorate
Environment Canada
National Wildlife Research Centre, Bldg. 33
1125 Colonel By Drive (Raven Road)
Carleton University
Ottawa, ON, K1A 0H3
Website:Visit my lab website

Current Research

Robert Letcher is a Senior Research Scientist with Environment and Climate Change Canada (ECCC). He is the Unit and Group Head of the Organic Contaminants Research Laboratory (in ST&B/WLSD’s Ecotoxicology and Wildlife Health Division) located in the National Wildlife Research Centre at Carleton University in Ottawa. He leads a group of ECCC staff as well as (co)supervises the projects of several graduate students and postdoctoral fellow at any given time. His has engaged in collaborative research over more than two decades with numerous government and academic partners. As of the end of 2022, this work has resulted in >420 peer-reviewed journal papers, >40 review papers, numerous book chapters and other peer-reviewed publications, and many government and external reports. In 2019, Dr. Letcher was elected as a Fellow of the Royal Society and Canada (Academy of Sciences).

Dr. Letcher has made extensive contributions to the Government of Canada’s advancements in science, policy or technology. His work responds to Government of Canada and ECCC priorities and mandate to preserve, conserve and enhance the quality of the natural environment under the Canadian Environmental Protection Act (CEPA). His innovative research findings have highly influenced and informed stakeholders in various programs that monitor and are assessing the risk and management of chemicals in Canada, e.g. the Chemicals Management Plan (CMP; ECCC/HC) and the Northern Contaminants Program (NCP; ECCC/CIRNAC). The scientific information generated has also impacted and influenced international agreements and regulatory frameworks, e.g. the Great Lakes Water Quality Agreement (Canada-United States International Joint Commission), the Arctic Council’s AMAP and UNEP’s Stockholm Convention on Persistent Organic Pollutants (POPs) and Minamata Convention on mercury.

Dr. Letcher’s ECCC priority research covers a wide range of areas and topics and has advanced the understanding of the environmental/analytical chemistry, exposure, fate (metabolism/biotransformation), food web dynamics, spatial/temporal trends, environmental processes (e.g. climate change) and biological effects and impacts of legacy/emerging contaminants in wildlife/biota and their ecosystems throughout Canada and internationally (e.g. the Arctic and freshwater aquatic systems like the Great Lakes). Dr. Letcher has built up an innovative and world-class ECCC research laboratory and the following five statements summarize areas of project activities:

  • Analytical method development, discovery and the exposome of new and priority environmental contaminants in the environment focusing on biota
  • Development of chemical and biomarker assays and application to determine biological impacts of priority compounds
  • Exploration of the fate, degradation, biotransformation and metabolism of priority chemicals in priority and sentinel wildlife and their associated ecosystems
  • Exploration of biological effects and (eco)toxicology of priority chemicals and complex chemical mixtures in wildlife at different levels of biological organization
  • Climate change and other ecological, physiological and abiotic system shift and influence on contaminant exposure and behaviour in wildlife

Selected Publications (2022-2023 only)

Research Papers:

Herczegh, S.M. (MSc student), Chu, S.G., Letcher, R.J. (corresponding author). 2023. Biotransformation andmetabolites of bisphenol-A bis(diphenyl phosphate): in vitro, in silico, and non-target screening in rat and bird liver microsomal models. Chemosphere 310, 136796.

Morris, A.D. (PDF), Braune, B.M., Gamberg, M., Stow, J., O’Brien, J. and Letcher, R.J. (corresponding author). 2022. Temporal change and the influence of climate and weather factors on mercury concentrations in Hudson Bay polar bears, caribou, and seabirds. Environ. Res. 207, 112169.

Sühring, R., Baak, J.E., Letcher, R.J., Braune, B.M., De Silva, A.O., Dey, C., Fernie. K.J., Letcher, R.J., Lu, Z., Mallory, M.L., Avery-Gomm, S., Provencher, J.F. 2022. Co-contaminants of microplastics in two seabird species from the Canadian Arctic. Environ. Science Ecotechnol. 12, 100189.

Hebert, C.E., Letcher, R.J., Cyr, F., Drake, C. 2022. Fatty acid ecological tracers highlight the role of diet in perfluoroalkyl acid contaminant exposure in eggs of an omnivorous bird. J. Great Lakes Res. 48, 1270-1277.

Sonne, C., Dietz, R., Jenssen, B.M., Lam, S.S., Letcher, R.J. 2021. Emerging contaminants and biological effects in Arctic wildlife. Trends Ecol. Evol. – Opinion 26, 421-429.

Remili, A. (PhD student), Letcher, R.J., Samarra, F.I.P., Dietz, R., Sonne, C., Desforges, J.P., Vikingsson, G., Blair, D., McKinney, M.A. 2021. Individual prey specialization drives PCBs in Icelandic killer whales. Environ. Sci. Technol. 55, 4923-4931.

Marteinson, S.C., Guigueno, M. (PDF), Chu, S.G., Head, J., Fernie, K.J. and Letcher, R.J. (corresponding author). 2020. Triphenyl phosphate: Uptake and metabolism in eggs and chicks of Japanese quail (Cortunix japonica). Environ. Toxicol. Chem. 39, 565-573.


Letcher, R.J. (corresponding author), Chu, S.G. and Smyth, S.A. 2020. Side-chain fluorinated polymer surfactants in biosolids from wastewater treatment plants. J. Hazard. Mater. 388, 122044.

Smythe, T.A. (PhD student), Mattioli, L.C. and Letcher, R.J. (corresponding author). 2020. Distribution behaviour in body compartments and in ovo transfer of flame retardants in North American Great Lakes herring gulls (Larus argentatus). Environ. Pollut. 262, 114306.

Sun, J. (PDF), Letcher, R.J. (co-corresponding author), Eens, M., Covaci, A., Fernie, K.J. (co-corresponding author). 2020. Perfluoroalkyl acids and sulfonamides and dietary, biological and ecological associations in peregrine falcons from the Laurentian Great Lakes Basin. Environ. Res. 191, 110151.

Review Papers:

Smythe, T.A. (PhD student), Su, G., Bergman, Å., Letcher, R.J. (corresponding author). 2022. Metabolic transformation of environmentally relevant brominated flame retardants in fauna: A review Environ. Int. 161, 107097.

Kuo, D.T.F., Rattner, B.A., Marteinson, S.C., Letcher, R.J., Fernie, K.J., Treu, G., Deutsch, M., Johnson, M., Deglin, S.E., Embry, M. 2022. A review on bioaccumulation and biotransformation of organic chemicals in birds.  Rev. Environ. Contam. Toxicol. 260, 6.

Dietz, R., Letcher, R.J. + 54 additional coauthors. 2022. A risk assessment review of mercury exposure in Arctic marine and terrestrial mammals. Special Issue-Sci. Total Environ. 829, 154445.

Marteinson, S.C., Bodnaryk, A., Fry, M., Riddell, N., Letcher, R.J., Marvin, C., Tomy, G. and Fernie, K.J. 2021. A review of 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane in the environment and assessment of its persistence, bioaccumulation and toxicity. Environ. Res. 195, 110497.

Liu, Y. (PhD student), Gong, S., Ye, L., Li, J., Liu, C., Chen, D., Fang, M., Letcher, R.J., Su, G. 2021. Organophosphate (OP) Diesters and a review of sources, chemical properties, environmental occurrence, adverse effects, and future directions.  Environ. Int. 155, 106691.

Dominique, M. (MSc student), Letcher, R.J., Rutter, A. and Langlois, V.S. 2020. Comparative review of the distribution and burden of contaminants in the body of polar bears. Environ. Sci. Pollut. Res. 27, 32456–32466.