Document Type

Thesis

Degree Name

Master of Environmental Studies (MES)

Department

Geography & Environmental Studies

Faculty/School

Faculty of Arts

First Advisor

Jody Decker

Advisor Role

Thesis Supervisor

Abstract

The Baffin Regional Health Board has recently expressed concern over lead poisoning in Iqaluit, NWT, manifested by low haemoglobin levels in children. Several studies in temperate regions have demonstrated links between environmental lead and human health. However, little is known about these links in a permafrost environment. While humans are exposed to lead via a number of different pathways, soils and sediments are two major pathways. The purpose of this study is to determine the spatial distribution of soil and sediment-associated lead in Iqaluit and to assess probable pathways between high lead levels and children. The research hypothesis is that elevated levels of lead (i.e. above natural background levels) are present in the study area. Three major objectives were identified: 1) to examine the distribution of total and bioavailable lead in soil and sediment; 2) to determine the proportion of total lead which is bioavailable; and 3) to infer possible linkages with human health. Field work was conducted in the summer of 1996 to collect soil and sediment samples from the study area. Samples were collected from areas outside the built-up area of the town, to reflect natural background concentrations. Samples were also collected from known point sources of lead: the Upper Base, the Sylvia Grinnell Dump (West 40) and the Metal Dump (North 40). Systematic sampling of the built-up areas of Iqaluit and Apex, a satellite community, was conducted using grids 200 by 200 m. Areas where humans may contact contaminated soil were targeted for sampling, and included playgrounds, roads, culverts and beaches. In the laboratory, samples were dried and sieved to less than 63 µm, because of the relationship between decreasing grain size and increasing lead concentrations, the role of fine-grained particles in fluvial transport and the ability of small particles to adhere to human hands and be ingested. Samples were analyzed for total and bioavailable (operationally-defined as 0.5N HCl extractable) lead concentrations. The research findings reveal that elevated levels of bioavailable lead (i.e. above average background concentrations of 10 ppm) are present in the study area. Total lead concentrations generally do not exceed environmental guidelines. However, lead concentrations in the Sylvia Grinnell Dump and Apex and Lower Base area of town exceed OMEE recommended guidelines derived from health-based criteria. The research concludes that there is not a serious health hazard posed by lead levels in the soil and sediment in the study area. However, several environmental (elevated lead levels, bioavailable forms of lead, bare soil surfaces) and behavioural factors (vigorous play outside) create a risk of lead exposure.

Convocation Year

1997

Convocation Season

Spring

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Soil Science Commons

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