NEWSLETTER
ST. LAWRENCE VISION 2000
VOLUME 10 – ISSUE 4 – SEPTEMBER 1999
Preceding issues

	SUMMARY
	Pollution of the St. Lawrence and the health of newborn infants on the North Shore
	Recreational shellfish gathering on the North Shore of the St. Lawrence Estuary
	ZIP Chronicle
	News in brief

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

Administration and coordination
Clément Dugas and Raymonde Goupil, Co-chairs Communications

Suzanne Bourget, Institutional Communications

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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• determine the proportions in newborns of certain essential fatty acids, transferred from the mother after eating fish;

• check the link between concentrations of pollutants and of fatty acids at birth and various indicators of newborn health, including weight.

Some 540 mothers took part in the study, completing a lifestylel questionnaire while they were in hospital. After the birth of the child, some of the blood taken for routine sampling was set aside for laboratory analyses. Also, medical information on the health of mother and child was taken from hospital records.

Analysis of blood samples showed average mercury levels in newborns on the Middle and Lower North Shore to be higher than in Sept Îles or in the Province of Quebec as a whole, though lower than in Nunavik. However, none of the samples analysed showed mercury concentrations exceeding the health risk threshold set by the World Health Organization.

For the Middle and Lower North Shore, average overall levels for PCBs (selected as representative of organochlorine products) are about three times higher than in newborns in the Sept Îles area, but lower than in those from Nunavik. Nearly 93% of the samples analysed were within safe limits.

On the North Shore, there are practically no direct sources of mercury or organochlorines, but the wind carries these products vast distances from their points of origin. These pollutants also accumulate in the food chain and are thus found in varying concentrations in the fat and flesh of animals, including fish and the eggs of seabirds, so that people who rely on these food sources increase their bodies’ contaminant load.

During pregnancy, these products are transferred across the placenta from mother to foetus. A number of scientific studies to determine whether exposure to such products may have adverse effects on the operation of the immune and endocrine systems and development of the nervous system are currently under way.

Sources of lead contamination abound; it is found in water, food, the soil and dust. It is feared that when contamination reaches a certain level in the tissues of children, learning may be affected.

Average lead concentrations for the Middle and Lower North Shore are between those recorded for Quebec as a whole and those for Nunavik. Concentrations are lowest in newborns in the Sept Îles area. All lead concentrations measured are within safe limits.

Other products, as well as environmental pollutants, were measured in newborn infants: omega-3 type essential fatty acids, such as are found in the tissues of fish. These fatty acids help prevent cardio-vascular diseases in adults and certain developmental disorders in children. They also promote better foetal growth and tend to extend pregnancy, thus increasing the child’s birth weight. Omega-3 type fatty acids are particularly abundant in fish of the cold seas.

Analysis results show that newborns on the Middle and Lower North Shore have three times the quantity of Omega-3 fatty acids as those in the rest of Quebec.

Although the newborn infants of the Middle and Lower North Shore have in their bodies levels of mercury and organochlorines (PCBs) that exceed the average for Quebec as a whole, there seem to be no associated adverse effects on foetal growth. Rather, the diet of North Shore residents, rich as it is in food from the sea, has significant benefits for the newborn, since a substantial intake of fatty acids during pregnancy helps prevent premature births. Moreover, birth weights on the Middle and Lower North Shore and in the Sept Îles area are higher than elsewhere in the province.

A fact worth noting is that over the course of the study the researchers detected a drop in mercury and lead levels in local newborns and an even more significant decline in PCBs. According to D^r Eric Dewailly, lead researcher on the study, the efforts that have been made to educate the public on the North Shore about the risks associated with eating seabird eggs may account for declining PCB levels, and he was pleased to see how in a mere five or six years lower consumption of seabird eggs has enabled the population of the North Shore to bring prenatal exposure to many contaminants down to acceptable levels.

In spite of these positive results, the research team’s further education efforts will need to focus on adoption of tighter preventive measures for PCB exposure in young women. Claire Laliberté, another member of the study team, said that PCBs are characterized by their dogged persistence in the organism. It is therefore not enough for women to abstain from eating seabird eggs once they are pregnant to minimize foetal exposure risks; young women have to be urged to desist entirely from eating these eggs so as to avoid accumulating PCBs in their bodies, which would then create exposure risks in subsequent pregnancies.

More intensive education is called for with certain groups where the declines seen in newborns are less marked. D^r Dewailly cited as an example Montagnais women, who are probably less responsive to the materials produced so far in French and English; it would therefore be a good idea to adapt published materials to suit the reality of the North Shore’s Montagnais communities.

Claire Laliberté
Telephone: (418) 666-7000, local 292
Éric Dewailly
Telephone: (418) 666-7000, local 222

Research Centre, CHUL Building

Fax: (418) 666-2776
E-mail: claliberte@cspq.qc.ca or edewailly@cspq.qc.ca

Sources:

DEWAILLY, Éric, Claire LALIBERTÉ, Germain LEBEL, Pierre AYOTTE, Jean-Philippe WEBER and Bruce HOLUB. 1999. Évaluation de l’exposition prénatale aux organochlorés et aux métaux lourds et des concentrations en oméga-3 des populations de la Moyenne et de la Basse-Côte-Nord du Saint-Laurent (Evaluation of prenatal exposure to organochlorines and heavy metals and omega-3 concentrations in the population of the Middle and Lower North Shore of the Gulf of St. Lawrence), St. Lawrence Vision 2000, 87 p. + appendices.

LALIBERTÉ, Claire. 1999. Les nouveau-nés de la Côte-Nord. Une étude en santé environnementale (Newborn infants on the North Shore. An environmental health study), St. Lawrence Vision 2000, leaflet.