PARENT SESSION
Probabilistic Risk Assessment: Pesticides/Contaminants Case Studies.
Andy Hart, Ed Odenkirchen
Wednesday, November 15, 2000
8:00 AM to 12:00 PM
CC 209-210
(335) Ecological Risk Assessment of DDT Contamination at Kittigazuit, NWT.
Zeeb, Barbara A.1, Reimer, Kenneth J.1, Nirwal, Amar S.1, 1
ABSTRACT- In 1998, a standard environmental assessment of a former Royal Canadian Air Force station at Kittigazuit identified substantial dichlorodiphenyltrichloroethane (DDT) and associated metabolite residues in soil. Although the station was only operational between 1948-1950, daily fogging of the station has resulted in soil residue concentrations in excess of applicable criteria. Given that local Inuvialuit traditionally use the area for hunting and gathering, a more comprehensive study was undertaken in 1999 to quantify potential ecological and human health risks associated with the 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 and Salix sp.). Omnivores, themselves (Spermophilus parrryii) were also collected and analyzed. A quanititative ecological risk assessment was 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. The application of soil criteria, developed using temperate inputs, to an Arctic ecosystem was also examined.
Key words: DDT, risk, Arctic