Perfluorinated chemicals (PFCs) became recognized as contaminants of concern at the turn of the 21st century. Due to national and international regulations, production and release of several of the most significant PFCs such as PFOS and PFOA have decreased. Currently 87 chemicals that can degrade to PFOS are banned in Canada. One major source of PFCs to the environment is Aqueous Film Forming Foams (AFFFs) used in fire-fighting are commonly found associated with transportation and defence facilities or airports. Newer formulations of firefighting AFFFs contain in excess of 40 PFCs for which little is known about bioaccumulation and potential effects. In this proposal potential environmental and toxicological effects of the ‘novel’ PFCs, most commonly found in AFFFs, and as yet unregulated in Canada will be assessed. The assessment will be based on toxicity of PFCs to early life stages of 2 salmonid species, rainbow trout and Arctic char, and will look at biochemical and transcriptomic changes caused by PFC exposure. Since, in mammals, serum albumin (SA) is known to bind certain PFCs and so greatly modify their pharmacokinetics and thus toxicity, we will investigate the binding of PFCs to salmonid SA. Data will be used to generate toxicity reference values (TRVs) for these compounds. The assessment will also be based on measurement of target PFCs in environmental media and biota from Canada’s north. Concentrations of novel PFCs in the environment will be compared to thresholds for apical adverse effects on salmonid reproduction and TRVs developed based on reproduction. Project Objectives 1.Measure per- and polyfluorinated compounds (PFCs) in water, sediments and tissues of Arctic char at multiple locations in the Canadian Arctic. 2.Conduct a preliminary hazard assessment by comparing concentrations of PFCs measured in Arctic char eggs and tissues to Threshold Relative Values (TRVs) derived in our parallel laboratory-based studies. Methodology: We have initiated preliminary consultation with the Ekaluktutiak Hunters and Trappers Organization via Solomon Amuno (NIRB). We are interested in collaborating with this group for Arctic char sampling from different lakes and rivers around Cambridge Bay. We have also made contact with the local fish processing plant to collect additional Arctic char samples for the project. Our goal is to have local fishermen collect the Arctic char samples for us. We will need to collect water samples and sediment samples from the same locations as the collected fish, and we would expect that we would collect these samples with local fishermen guides. Cambridge Bay was selected as it is a prominent northern community with an airport that would have tested firefighting AFFFs. Since there is a strong possibility that these AFFFs have released PFCs into the nearby water bodies, we expect that water, sediment and fish samples from this area will contain PFCs. We will use cutting edge analytical equipment to measure the PFCs in the collected samples and determine if there is any possible risk to the community.