Royal Military College of Canada

Environment

Phytoremediation Paleolimnology - DDT in the Food Chain

By: B.A. Zeeb, BSc, PhD

The movement of dichlorodiphenyltrichloroethane (DDT) and associated metabolite residues through the terrestrial food chain is being studied at Kittigazuit, NWT. Kittigazuit is the site of a former Royal Canadian Air Force station operational between 1948-1950. Daily fogging of the site resulted in DDT soil residue concentrations far in excess of applicable criteria. Given that local Inuvialuit traditionally use the area for hunting and gathering, a comprehensive study was undertaken to quantify potential ecological and human health risks associated with DDT contamination.

This study involved the collection and analyses of plant tissues:

  1. that are routinely consumed by humans (Vaccinium uliginosum), and
  2. that are known to be consumed by resident omnivores (Elymus mollis).

Omnivores, themselves (Spermophilus parryii) were also collected and analysed. A quantitative ecological risk assessment is being developed to model the movement of DDT and its metabolites through the food chain, and to determine the probability of exceeding chemical exposure limits in the various receptors.

Collecting Plant Samples

Collecting plant samples for DDT food chain work at Kittigazuit, Northwest Territories.