NEWSLETTER
ST. LAWRENCE VISION 2000
VOLUME 10 – ISSUE 8 – FEBRUARY 2000
Preceding issues

	SUMMARY
	Health risks associated with eating St. Lawrence waterfowl
	Participation of Riverside Communities: Success through Co-operation and Partnership
	ZIP Chronicle
	News in brief

Le Fleuve is published jointly by St. Lawrence Vision 2000 partners.

Co-ordination
Raymonde Goupil, Clément Dugas and Suzanne Bourget

Text
Gaétane Tardif, Environmental Consultant

Realization
Françoise Lapointe, Editor, SLV 2000

Translation from French to English
PWGSC–Translation Bureau

This Newsletter is also available in PDF Version.

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In 1995, Health Canada issued a directive to the effect that contaminant concentrations found in waterfowl across the country were below detection limits or very low, and that this contamination did not pose a health risk to waterfowl eaters. "However, no directive specifically pertaining to St. Lawrence waterfowl was ever issued," says Jean-François Duchesne, of the CHUQ Public Health Research Unit. "To find out whether the national assessment applied to the St. Lawrence basin, we conducted a study to evaluate the health risks based on contamination data that was representative of birds taken by hunters along the St. Lawrence."

Since 1988, the Canadian Wildlife Service has been compiling contamination data on 22 species of waterfowl, including the Greater Snow Goose, the Canada Goose, a number of dabbling ducks (Black Duck, Mallard, Green-winged Teal, Northern Pintail, Blue-winged Teal, etc.) and diving ducks (Lesser Scaup, Golden-eye, Greater Scaup, Ring-necked Duck, etc.).

Contaminant concentrations found in St. Lawrence wildfowl are generally low and often below detection limits. However, some samples have contained relatively high concentrations of mercury, selenium, lead and PCBs.

Among the diving ducks, for example, Mergansers have the highest mercury contamination levels, particularly around Montreal. Dabbling ducks are generally less contaminated by mercury than diving ducks because diving ducks eat more animals, such as mollusks and fish, which are usually more contaminated than the plant matter that dabbling ducks feed on.

The health risk associated with eating wildfowl depends on several factors. First, it depends on how contaminated the migratory birds are. It is also a direct result of the level of exposure to contaminants, which depends chiefly on the quantity of bird flesh eaten, although it also depends on exposure to other foods and the air and water in a given region.

CHUQ Public Health Unit researchers used various scenarios to assess the degree of exposure to various contaminants of an average-sized hunter eating St. Lawrence waterfowl. The exposure scenarios were based on monthly consumption of between four and eight 230-g meals of waterfowl, which is a high consumption rate.

"Also, knowing that fish are people’s main source of exposure to chemical contaminants in the St. Lawrence, we incorporated into the scenarios exposure values representing four or eight fish meals per month," added Mr. Duchesne. "The exposure levels calculated were then compared with the acceptable daily intakes (ADI) recommended by health authorities."

In the case of mercury, for example, the calculations show that the exposure associated with eating eight or fewer meals of waterfowl each month over an entire lifetime is below the recommended ADI. The only exception is Mergansers because, depending on where they are harvested, a person eating four to eight meals of these birds per month throughout their lifetime might exceed the recommended ADI. However, we can safely assume that the number of people who eat enough Merganser flesh to exceed the ADI is very low, since it is not highly prized by hunters and the species is therefore not sought after.

"Based on the information available concerning the size of the migratory bird harvest and the extent of waterfowl consumption, we think that the health risks associated with eating St. Lawrence waterfowl are probably negligible for the vast majority of consumers of this type of game," said Mr. Duchesne. "However, although we have a fairly accurate overview of the extent of waterfowl contamination thanks to Canadian Wildlife Service data, we know far less about the waterfowl eating habits of the hunting population."

The CHUQ Public Health Research Unit has launched a survey of eating habits in order to remedy this information gap. In January 2000, one thousand Quebecers who obtained hunting licenses in the fall of 1999 will be asked to answer questions about their waterfowl eating habits. The results of the survey will make it possible to conduct a study of health risks based on complete, representative data. "We will then be able to determine whether guidelines on the eating of these birds should be issued to protect people from contaminants," said Mr. Duchesne.

Jean-François Duchesne
Research Professional
CHUQ Public Health Research Unit
2400 d'Estimauville Street
Beauport, Québec G1E 7G9
Telephone: (418) 666-7000, extension 205
Fax: (418) 666-2776
e-mail: JFDuchesne@cspq.qc.ca

DUCHESNE, J.-F., D. GAUVIN, B. LÉVESQUE and É. DEWAILLY. 1999. Risques à la santé reliés à la consommation de sauvagine du Saint-Laurent. Centre de recherche du Pavillon CHUL, Unité de recherche en santé publique du Centre hospitalier universitaire de Québec, 37 pp.