Canada: projects/activities

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.

1) To determine tissue residue levels of organochlorines and metals in arctic fox feeding in or near an arctic coastal environment. 2) To assess whether or not residue levels found in arctic fox pose a potential wildlife health risk. 3) As part of a pilot project, to determine residue levels and assess potential wildlife health risk to wolverines feeding in or near a coastal environment.

1. Research area # 2 in the 1998/99 Announcement of Opportunity by CIFAR, "Study of anthropogenic influences on the Western Arctic/Bering Sea Ecosystem", and 2. Research area #4 in the 1998/99 Announcement of Opportunity by CIFAR, "Contaminant inputs, fate and effects on the ecosystem" specifically addressing objectives a-c, except "effects." a. "Determine pathways/linkages of contaminant accumulation in species that are consumed by top predators, including humans, and determine sub-regional differences in contaminant levels..." b. "Use an ecosystems approach to determine the effects of contaminants on food web and biomagnification." c. "Encourage local community participation in planning and implementing research strategies." The objectives of Phase I, Human Ecology Research are to: 1. Document reliance by indigenous arctic marine communities in Canada, Alaska and Russia on arctic resources at risk from chemical pollutants; and, 2. Incorporate traditional knowledge systems of subsistence harvesting. The human ecology components of the project were conducted within the frameworks of indigenous environmental knowledge and community participation. Using participatory mapping techniques, semi-structured interviews and the direct participation of community members in research design, data collection and implementation, research and data collection on the human ecology of indigenous arctic marine communities was undertaken in the communities of Holman, NWT (1998), Wainwright, Alaska (1999), and is underway in Novoe Chaplino, Russia. (2000).

This study investigates possible detrimental effects on the immune system of Inuit infants which may be induced by prenatal and postnatal (breast feeding) exposure to persistent environmental contaminants such as organochlorine compounds. These substances accumulate in the body of Inuit women in part due to their consumption of sea mammal fat and can be transferred to the foetus during pregnacy and to the infant during breast feeding. Immune system function will be evaluated using several parameters: 1) the level of antibody produced by the infant following Haemophilus influenza immunization; 2) the level of proteins which protect the infant against bacterial infections (complement system) before its immune system is fully developed; and 3) the level of chemical messengers (cytokines) which enable the various cells of the immune system to communicate with each other, thereby maintaining its proper function and assuring the protection of the infant against bacteria, parasitic and viral infections.

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).

The purpose of this research is to examine the long term consequences of prenatal exposure to PCBs and MeHg. This project is designed to study domains of effects overlooked in most of the previous studies. Of particular interest is the impact of exposure on neurophysiological and neurological endpoints that could be related to learning difficulties and disabilities. This study will support the health risk assessment process by providing dose-effect analysis for the neurophysiological and neurological domains of effects of preschool age children from Nunavik (Canada). The total sample will comprise 100 Nunavik Inuit children aged 5-6years. The following exclusion criteria will be applied: Apgar below 5 at 5 minutes of life, evidence of birth trauma, less than 37 weeks of gestation and less than 2500 grams at birth, congenital or chromosomal anomalies, epilepsy, significant disease history, major neurological impairment, fetal alcohol syndrome, presence of facial dysmorphologies associated with fetal alcohol effects.