Content uploaded by Martin Pilote
Author content
All content in this area was uploaded by Martin Pilote on Jan 16, 2015
Content may be subject to copyright.
A preview of the PDF is not available
The St. Lawrence River Case Study: linking Hg biogeochemistry, health and environmental education
Abstract
This case study integrates the pathways affecting Hg cycling in Lake St.
Pierre, a heavily-fished fluvial lake from the St. Lawrence River, characterized by very
large wetland areas. This initiative is part of the Collaborative Mercury Research
Network (COMERN). Our approach is to link fine scale critical gap studies to larger
scale Hg flux studies, in an effort to assess how Hg is imported to the lake, methylated
in the sediments and plants, and transferred through the food chain up to the human
population. Neurological studies on the population are being conducted in coordination
with the biogeochemical studies. Also, the community has been invited to participate in
this research initiative.
It has been decades now since the international scientific community initially raised the issue of mercury (Hg) contamination in the global environment. The presence of Hg in ecosystems is ubiquitous, even in the absence of local/regional contamination point sources. Almost all fish consumers (occasional or frequent) are exposed to this contaminant. Governments of the industrialized countries have invested considerable financial and human resources, in order to better understand the biogeochemical behavior and cycling of Hg and its impacts on the health of populations. Indeed, our knowledge of the sources and fate of this pollutant has greatly evolved since these early reports. Numerous protocols, technical documents, epidemiological and clinical studies, detailing precise aspects of the Hg cycle have been published. However, given the complexity of environmental processes leading to the accumulation of Hg in fish tissue, and the relative importance of fish as a protein source among communities, most available literature fails to fully evaluate the level of risk to health (and/or the health benefits related to fish consumption) encountered by fish consumers in their daily lives. This paper summarizes the learning acquired through a wide-scale integrated study of the mercury (Hg) pathways in lake environments of three distinct regions located in Eastern Canada: Lake St. Pierre (LSP), Labrador (Lab), and Abitibi (Ab). This research was accomplished by a multidisciplinary team of researchers assembled under the auspice of the Collaborative Mercury Research Network (COMERN), a major Canadian initiative supported by numerous universities and government agencies throughout the country. The prime focus of the study was to link human exposure to Hg with particular local/regional environmental and socioeconomic characteristics and settings. Two conditions must co-occur to define a situation where higher Hg exposure can be identified for populations/sub-populations/ groups: Frequent fish consumption; Mercury levels of concern in the edible fish resource. Thus, specific scientific objectives of the study were constructed to verify the occurrence of such situations by: 1) Describing and comparing Hg pathways, from its loading in the environment, its transfer to aquatic food webs and its final accumulation in edible fish species; 2) Assessing and comparing exposure levels (and related health impacts) of populations exploiting aquatic resources, in response to tradition, economic dependency or recreation, and stating on health risks/health benefits related to fish consumption in specific regional contexts.
ResearchGate has not been able to resolve any references for this publication.