Laboratories and Research Support

Article Title

Organic Contaminants Research Laboratory

Dr. Robert Letcher and research analysis using LC-tandem quadrupoleThe Organic Contaminants Research Laboratory (OCRL) is located at the National Wildlife Research Centre. The OCRL conducts research on the characterization, physiological and food web bioaccumulation pharmaco(toxico)kinetics (e.g., tissue distribution, metabolism, biotransformation enzymes and protein binding), ecological pathways and sources, and spatiotemporal trends of established and emerging contaminants (including isomers, precursors, degradation products and metabolites) in top predators, wildlife, food webs, and aquatic ecosystems.

Priority contaminants include flame retardants, poly- and per-fluorinated compounds and legacy contaminants, and studies in key wildlife biosentinel species such as polar bears and bird species, and priority ecosystems including the Arctic and Great Lakes.

Dr. Shaogang Chu and emerging contaminant characterizationFor example, the rate of temporal change in the concentration and patterns of brominated flame retardants and organochlorines in Hudson Bay polar bears was shown to be influenced by temporal shifts in diet as a result of increasingly earlier sea-ice break up.

In addition, it was found that bioaccumulation and biotransformation of brominated and chlorinated contaminants and their metabolites is compound-specific between polar bears and their ringed seal prey. Also, the congener composition of organohalogen and metabolite contaminants in polar bears is tissue-specific.

Research from the OCRL has contributed to a circumpolar assessment of the exposure and effects of persistent organic pollutants in Arctic wildlife and fish.

Research carried out in the OCRL contributes to Environment Canada’s objective of ensuring that wildlife and their ecosystems are conserved and protected, and that wildlife health is assessed from a chemical exposure and stress standpoint.

Current research and methodology

  • Analytical chemistry and method development, and environmental and forensic chemistry of established (legacy) and emerging organic contaminants in wildlife
  • Investigating and assessing the ecotoxicology and effects of contaminant and metabolite exposure and assessments in specific species and ecosystems
  • Investigating the spatiotemporal trends of various contaminants, precursors, degradation products and isomers in key wildlife species, such as polar bears and birds, and priority ecosystems, such as the Arctic and the Great Lakes
  • Investigating the role of ecological factors such as climate and diet changes in spatiotemporal trends of contaminants
  • Species-specific, contaminant-mediated enzyme induction and associated mechanistic pathways of contaminant metabolism/biotransformation and pharmaco(toxico)kinetics in wildlife
  • Development of an in vitro hepatic microsomal assay to demonstrate substrate selective metabolism of various brominated contaminants as well as perfluorinated compound precursors, in wildlife such as the beluga whale, ringed seal and polar bear
  • In vitro metabolism approaches have shown that PCB and PCB metabolite formation are linked to specific xenobiotic-metabolizing enzymes in, for example, dietary-exposed sled dogs in Greenland and model beagle dogs
  • An in vitro competitive binding assay was developed using recombinant thyroid hormone transport proteins from a bird model and compared to humans. Substrate competitive binding studies demonstrated that there are several chlorinated, brominated or fluorinated compounds, and especially phenolic metabolites and complex mixtures from wildlife, that can effectively compete with thyroid hormone binding
  • Development of high-sensitivity methods to detect and track several emerging and current-use flame retardants, e.g., tetrabromobisphenol-A (TBBP-A) and TBBP-S and TBBP-A derivatives, halogenated and non-halogenated organophosphates
  • Development of novel methods to characterize and determine linear and branched isomers and precursors of perfluoroalkyl acids found in wildlife
  • Characterizing the fate and trends of current-use and novel halogenated flame retardants and perfluorinated compounds in sentinel wildlife including Great Lakes and Arctic mammals, birds, reptiles and/or fish
  • Examination in vivo of the uptake and pharmacokinetics of, for example, hexabromocyclododecane (HBCD) flame retardant in model mammals (e.g., mink) or birds (e.g., American kestrels) are tissue and/or isomer-specific

Instrumentation

  • Lewis Gauthier engaged in sample fraction analysisAgilent Technologies 6890N GC system with G2985A single quadrupole mass spectrometer (GC-MS; electron impact and chemical ionization modes) system
  • Agilent Technologies 1200 Series HPLC with 6520 Accurate Mass quadrupole-time-of-flight mass spectrometer (LC-Q-ToF-MS) system
  • Waters 2695 Alliance HPLC with Micromass QuattroUltima tandem quadrupole mass spectrometer (LC-MS/MS) system
  • Dionex accelerated solvent extraction (ASE 200) system
  • O.I. Analytical Autoprep 2000 gel permeation chromatograph system
  • (2) Organomation Associates, N-EVAP III systems
  • (2) Buchi rotary evaporation units

Collaboration

Luke Periard engaged in sample preparation in the ECRLStaff, student, and postdoctoral researchers at the OCRL work collaboratively on various initiatives and projects under the supervision of Dr. Robert Letcher. They often work with other Environment Canada researchers, academics and other partners at national and international institutions.

 

Experts in laboratory

Further reading