Spatial trends in loadings and historical inputs of mercury inferred from Arctic lake sediment cores

Updated 2000-06-01

1. To determine the depth profiles of mercury (Hg) and lead (Pb) as well as manganese (Mn) and iron (Fe) in fifteen dated Arctic sediment cores over a three year period. Mercury is the main focus. 2. To quantify geographical trends in fluxes of the mercury and its enrichment factors in Nunavut, NWT, Nunavik, and Labrador. To link mercury findings with those of paleolimnological indicators, POPs, as well as indicators of biogeochemical processes of manganese and iron, all of which are obtained from the same cores, or cores from the same sites whenever possible. 3. To complement existing data on mercury in Arctic sediment cores with data generated over a much wider latitudinal and longitudinal range than previous work in order to provide a better understanding of Hg in Canada North. 4. Secondary to Hg, to provide loading data for Pb which may help elucidate the understanding of Hg pathways and sources.

This is not a National Implementation Plan (NIP) project

Time frame

Status
Ongoing
Project time span
2000 - 2002
Data collection
2000 - 2002
Data processing
2000 - 2002
Data reporting
2001 - 2002

Contact information

Contact person
Venghuot (Ven) F. Cheam
Address
National Water Research Institute Aquatic Ecosystems Pretection Research Branch Box 5050 Burlington, Ontario Canada L7R 4A6
Phone
+1 905 336-4755
Fax
+1 905 336-6430
Email
ac.wicc@maehc.nev
Other project contacts
Derek Muir, National Water Research Institute, Burlington ON (Phone 905 319-6921; Fax 905 336-6430); Doug Halliwell, Atmospheric Environment Branch, Environment Canada, Yellowknife NT (867-669-4741)

Parameters and Media

Parameter groups measured/observed/modelled
Heavy metals
Media sampled/studied/modelled
Freshwater sediments
Marine sediments

Geography

Regions studied
Canada
Canadia, Arctic Islands
Stations or areas where observations are made

Table 1A. Sediment cores that are available for mercury and metals analysis Location/Lake Latitude/Longitude N. Ellesmere Is., Lake A 83°00'N; 70°30'W N. Quebec, Lake Oksana 54°47.7'N; 66°47.3'W Tuktut Nogait NPR, Rummy L. 69°05'N; 123°38'W Axel Heiberg, Ax-AJ 79°41.8'N; 87°23'W Prince Patrick Is., MB-S 76°13.4'N; 119°19.'W Cornwallis Is., Small Lake 74°45.0'N; 95°00'W N. Quebec, Lac Noel 55°20'N; 77°37'W Nahanni Nat'l Park, HITW Lake 61°47'N, 127°16.'W NWT, north of Yellowknife 62°30.2'N, 113°38.2'W NWT, north of Yellowknife 64°30.7'N, 112°41.5'W NWT, north of Yellowknife 62°31.8'N, 113°50.3'W Table 1B. Sediment cores anticipated to be collected in 2000, 2001or 2002 Location/Lake Latitude/Longitude Northern Ellesmere, near Alert 82°00'N;65°W Lac Payne, Nunavik 59°N; 74°W Cornwallis Is., Resolute Lake 74°41'N, 94°55'W Lake on Somerset Is., Nunavut 73°N, 94°W Lake near Kuujjuaq, Nunavik 58° 06'N; 68° 24'W Lake near Kangiqsualujjuaq 58°42'N; 65° 54'W Lac Eau Claire, Nunavik 56°N; 72°W Auyuittuq NPR in N. Baffin Is. 68°N; 65°W Nahanni NPR 61°N, 127°W

Data availability

Are data archived or planned to be archived at an AMAP Thematic Data Centre?
yes-all
Data centres
Freshwater TDC
If no (or only part of data are reported to a TDC), where and how are (other) data stored?
1. The main deliverable will be a report on the time series of Hg, Pb and its isotopes, and Fe and Mn, which will be made available to community representatives and the Nunavut and NWT Contaminants Committee on a timely basis.
References to key publications (or planned publications) and data reports
2. A report will be prepared for the NCP synopsis reports for 2000/01 anticipated for June 2001
Samples/specimens archived in specimen banks?
No

Methods & Procedures

Procedures and methodology used for, e.g., sampling and sample storage, sample pretreatment, extraction and analysis, including which laboratories are involved, references to methods employed, etc.

Sediment cores will be first dated using 210PB and 137Cs (Robbins 1978). Sedimentation rates and dates will be estimated using CRS and CIC models (Turner and Delorme 1996). Subsamples from cores with interpretable 210PB and 137Cs profiles will be analysed for Hg, Pb, Mn, Fe and Pb isotopes. Sediment subsamples will be first acid-digested using high pressure microwave. Mercury will be analysed by cold vapor atomic absorption spectrometry (CVAAS), lead and its isotopes by ICPMS, Mn and Fe by ICP-AES. If a sample size of sediment is less than 0.5g, which is the case for some cores with low sedimentation rate, the more sensitive laser-excited atomic fluorescence spectrometry (LEAFS) may have to be used also to ensure reliable results of mercury and lead. The number of samples with low mass is estimated to be 40%.

QA/QC Information (what QA/QC procedures are implemented, laboratories involvment in QA/QC activities, model verification/validation routines, etc.)

NWRI is equipped with a Class 100 clean room, which will be used for all handling and analysis of the cores. Very high quality acids and clean room practices (class 100 environment) will be used to avoid high blanks and contamination. Certified sediment reference materials and spike recoveries will be used to ensure accuracy. Duplicate analyses will ensure precision of measurement. Recurrent runs of standards will be made to compensate for instrument drifts. High quality isotope standards will be used.

Additional Information

Is this a bi- AND multi-lateral project (i.e. a project involving cooperation between different countries)?
No
Other institutes involved in the project

Environment Canada, University of Toronto, Universite de Laval; Parks Canada Agency (Canadian Heritage), Tuktut Nogait & Nahanni National Parks

Is this project reporting to other organizations/programmes?

INAC, NCP, GNWT/Nunavut health, Naunavut Contaminants Committee, Health Canada; PaleoEcological & Analytical Environmental Laboratory, PEARL (Queens University Biology Department); Northern Ecosystem Initiative.

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