Canada: projects/activities

i. Determine mercury, metals and persistent organic contaminant pollutants (POPs) concentrations in lake trout harvested from two locations (West Basin near Hay River, East Arm at Lutsel K’e) and burbot harvested from one location (West Basin at Fort Resolution) in 2015 to further extend the long-term (1993-2013 (POPs) and 1993-2014 (mercury)) database. ii. Determine POPs trends in lake trout and burbot using our 1993-2014 data base. iii. Continue our investigations of mercury trends in predatory fish to include lakes in the Deh Cho, Great Bear Lake, and other lakes as opportunities arise. iv. Participate in and contribute information to AMAP expert work groups for trend monitoring for POPs and mercury. v. Integrate our mercury trend assessments with studies we are conducting in the western provinces as part of Canada’s Clear Air Regularly Agenda for its Mercury Science Assessment. vi. Work with communities in capacity building and training.

In order to assess the spatial and temporal patterns of the a-, b- and g-isomers of hexachlorocyclohexane (HCH) in the arctic biotic and abiotic environment, it is proposed that: (1) concentrations and ratios of HCH isomers be compared over time in air, water, seals, beluga, polar bears and seabirds to determine any shifts in isomeric ratios and how those shifts interrelate among the various media, and (2) concentrations and ratios of HCH isomers be compared spatially in the abiotic and biotic media and reasons for any patterns explored.

In order to address the the question of utility of arctic seabird eggs as an indicator of contaminant temporal trends, it was proposed that: (1) archived arctic seabird egg contents be re-analyzed for organochlorines according to a standardized pooling and analytical protocol in order to confirm whether those residues have been decreasing since the mid-1970s, (2) archived arctic seabird egg contents be analyzed for mercury and selenium to determine whether or not those levels have been increasing or decreasing since the mid-1970s, (3) egg contents and adult livers be analyzed by full scan and ICP to identify any "new" or previously unidentified organochlorines (MS full scan) or metals (ICP) which may have entered the Canadian arctic food chain.

The objectives of this study are to determine temporal trends of persistent organic pollutants (POPs) and metals, especially mercury, in landlocked Arctic char in Char Lake and Resolute Lake by analysis of annual sample collections, to investigate factors influencing contaminant levels in landlocked char such as the influence of sampling time, water temperature and diet, and to provide this information on a timely basis to the community of Qausuittuq (Resolute). The rationale is that small lakes in the high arctic are replenished annually with snowmelt runoff and direct precipitation which represent significant fractions of their water budgets. Declining concentrations of POPs, or increasing levels of previously unstudied POPs, in air and precipitation should be reflected relatively quickly in changes in levels in food webs and top predator fishes, compared to the vast marine environment. We know this to be the case from the sedimentary record of POPs and mercury in small arctic lakes. This project collects landlocked arctic char from lakes near Resolute annually and analyses them for mercury, a suite of other metals as well as persistent organic pollutants (PCBs, organochlorine pesticides including toxaphene). Results will be compared over time. The first samples were collected from Char and Resolute Lakes in 1992/93. The next set were collected in 1997 and annually since then. Char are being collected from several lakes in the area because of limited sample numbers in some lakes and the possibility of local influences. Samples are also being archived for future analyses.

The objective of this project is to study long term temporal trends of persistent organic pollutants and mercury in ringed seals from the Canadian arctic. The project rationale is that there are previous results for POPs and mercury in ringed seal tissues for many locations. Furthermore there may be regional differences in temporal trends due to geographical differences in POPs and mercury in marine waters and food webs within the Canadian arctic. It is relatively cost efficient to return to the same locations for additional samples using the same sampling and anlaysis protocols are were used in previous studies (see AMAP and Canadian Assessment Reports). Samples are being collected with the help of hunters and trappers organizations in each community. During 2000-01 samples are being collected at Resolute, Arctic Bay and Pond Inlet. The study will also analyse samples collected recently (1998/99) from Pangnirtung, Arviat and Grise Fiord. Results will be compared with previous data which the Principal Investigator generated in the 1980's and early 1990's. Preliminary results will be available in mid-2001.

Among all contaminants present in different aquatic ecosystems in Canada, methylmercury (MeHg) is a major source of concern for public health. Currently, it is difficult to reliably determine the threshold of MeHg concentration at which functional changes occur. On the other hand, it is well known that chronic MeHg exposure is very harmful for the nervous system. Oxidative reactions appear to be of central importance to mercury toxicity. Therefore, it is important and urgent to determine with precision the minimal dose at which oxidative stress and neurotoxic effects can be identified since some studies suggest that MeHg toxicity can be detected at level far below the minimal exposure level proposed by the World Health Organization. The main goal of this project is to investigate the effects of mercury on sensorimotor functions in the population of Salluit. We will examine the relationship between the level of MeHg and sensorimotor performance. Afterwards, specific recommendations based on quantitative evidence will be made to the concerned populations so as to diminish long-term risk on health.

Short Term i) to provide additional information for use in updating health advisories. Long Term i)to investigate the fate and effects of contaminant deposition and transport to the Yukon, allowing Northerners to better manage the issue of contaminants. ii)to determine levels of contaminants for use in long term trend monitoring.

In September 1997, the CCGS Des Groseillers was frozen into the permanent ice-pack and started a year-long science program drifting across the southern Canada Basin. This program provided a unique opportunity to carry out a "vertical" food-chain study in a seasonal context to learn how the physical and biological systems couple to produce contaminant entry into the food web (Figure 1). "Vertical" components included the water and ice, particles, algae, zooplankton (sorted by trophic level), fish and seal.. The interpretation of contaminant data collected during SHEBA will provide information about the relationship between seasonal ice formation and melt, seasonal atmospheric transport and water column organochlorine concentrations in the Canada Basin. In addition our contaminant sampling program was integrated within a larger science plan where other SHEBA researchers studied the physical and biological properties of the water column. This means that contaminant distributions can be interpreted and modeled within the full context of physical, chemical and biological processes, and of atmospheric and oceanic transport mechanisms.

The main purpose of this research is to examine the consequences of in utero exposure to PCBs on Inuit infants, from birth to 11 months of age. Of particular interest is the impact of PCBs and mercury exposure on newborn’s thyroid hormones, physical growth, physical and central nervous system maturity, on infant’s overall health, mental, psychomotor and neurobehavioral development, and on functional and neural impairment in the domains of visual and spatial information processing. The proposed project is designed to replicate and extend previous findings by studying a more highly exposed cohort of infant, and using new infant assessment paradigms that have been linked to specific brain regions and neural pathways and, therefore, have a potential to provide information regarding possible mechanisms of action. The second objective of this research is to document the exposure to heavy metals, organochlorines and polyunsaturated fatty acids of newborns from selected communities in Nunavik. This ongoing effect study provides the opportunity to perform long time trend analysis of human exposure (data available for same communities since 1993).

LONG TERM: Determine the effects, at the individual and population level, of persistent organic pollutants (POPs) and their metabolites in the polar bear; determine trend of POPs in the Arctic marine environment using polar bear tissues as a biomonitor. SHORT TERM: a. Determine 10-year temporal trends of POPs in the Hudson Bay Sub-Arctic Ecosystem from 1990-1989 by analysis of archived polar bear biopsy samples, including changes in enantiomeric composition of -HCH and chlordane compounds and ratio of -HCH/-HCH (cross-referenced to separate proposal on HCHs). b. Determine if there is selective tissue distribution of the enantiomers of chiral contaminants in polar bears, which may influence target organ toxicity, by analysis of archived polar bear samples. c. Determine the endocrine disrupting effect of POPs on testosterone and PCB metabolite profiles by in vitro metabolism studies using polar bear liver microsomes. d. In collaboration with CWS P&N Region, the Norwegian Polar Institute and the Norwegian Veterinary Institute, determine the immunotoxic effects of PCBs and other organochlorines in polar bears throughout a gradient of exposure (Hudson Bay, low; Svalbard, high). e. Determine the effects of hydroxy-PCBs on circulating thyroid hormone and vitamin A concentrations.

This project aims to establish continuous Total Gaseous Mercury (TGM) measurements at Amderma, Russia to provide circumpolar data in concert with international sampling efforts at Alert (Nunavut, Canada), Point Barrow (Alaska, USA) and Ny-Ålesund (Svalbard/Spitsbergen, Norway). The objectives of this project are to determine spatial and temporal trends in atmospheric mercury concentrations and deposition processes of mercury in the Arctic in order to assist in the development of long-term strategies for this priority pollutant by: A) measuring ambient air TGM concentrations in the Russian Arctic; B) investigating and establishing the causes of temporal variability (seasonal, annual) in mercury concentrations so that realistic representations (models) of atmospheric pathways and processes can be formulated, tested and validated; and C) studying the circumpolar behaviour of mercury by comparison with data from other polar sites.

The objectives of the project are: A) to determine temporal trends in atmospheric mercury concentrations and deposition processes of mercury in the Arctic, and to assist in the development of long-term strategies for this priority pollutant by: i) measuring ambient air Total Gaseous Mercury (TGM) concentrations in the Canadian Arctic (Alert) and investigating the linkage to elevated levels of mercury known to be present in the Arctic food chain; ii) investigating and establishing the causes of temporal variability (seasonal, annual) in mercury concentrations so that realistic representations (models) of atmospheric pathways and processes can be formulated, tested and validated; iii) studying the chemical and physical aspects of atmospheric mercury vapour transformation (oxidation) after polar sunrise and the resultant enhanced mercury deposition to the sea, snow and ice surfaces each year during springtime; and iv) obtaining a long-term time series of atmospheric mercury (TGM) concentrations at Alert for the purpose of establishing whether mercury in the troposphere of the northern hemisphere is (still) increasing and if so, at what rate; B) to establish a sound scientific basis for addressing existing gaps of knowledge of the behaviour of mercury in the Arctic environment that will enable international regulatory actions to reflect the appropriate environmental protection strategies and pollution controls for the Arctic by: i) studying the relative roles of anthropogenic and natural sources of mercury so as to clarify understanding of the atmospheric pathways leading to the availability of mercury to Arctic biota; ii) studying tropospheric TGM depletion mechanisms/processes leading to enhanced input of mercury to the Arctic biosphere in spring; iii) undertaking essential speciated measurements of particulate-phase and/or reactive gaseous-phase mercury as well as mercury in precipitation (snow/rain) to quantify wet and dry deposition fluxes into the Arctic environment; and vi) providing the scientific basis for the information and advice used in the preparation and development of Canadian international strategies and negotiating positions for appropriate international control objectives.