Base de données de recherche des TNO

étiquettes: environmental health, mammals, metal contamination, rodents

Objectif(s): To test a model for the effects of food chain accumulation of metals and exposure to metals on human health and ecological receptors.

Description du projet: Tetra Tech modeled the effects of food chain accumulation of metals and exposure to metals on human health and ecological receptors. Tissue sampling of small rodents (and possibly hares) will be completed to identify trophic transfer of potential soil contaminants in order to verify the model. Snap traps and pitfall traps will be set out by Tetra Tech Staff and two First Nations subcontractors. Fieldwork will take place ideally in the fall of 2018 over a period of five consecutive days, or until the requested number of samples has been collected (ten individuals). Traps will be spaced approximately 10 to 15 m apart along transects in each area identified for sampling. Signs of small mammal presence such as scat, burrows, or travel paths will assist with trap placement in addition to the suggested minimum spacing. Trap locations will be clearly marked with stakes and flagging. Bait appropriate for sampling (blowfly larvae/pupae, rolled oats, peanut butter, and seeds) will be placed on and around the traps, which will then be set according to the manufacturer’s instructions. Traps will be checked twice daily (e.g., early in the morning and late in the day), with animals retrieved immediately. Living small mammals captured in traps will be euthanized in accordance with the appropriate method suggested for the animal by the Canadian Council on Animal Care – Guidelines on the Care and Use of Wildlife (2003) (cervical dislocation). Pitfall traps will be located along travel paths and will be monitored to determine if any animal has entered the pitfall and to retrieve any specimen as quickly as possible. A total of ten (10) individuals will be collected. This sample size was selected as it will provide more reliable average concentration values for assessing exposures to the site. Trapped small mammals will be identified to genus, measured, weighed, and their sex will be determined. A field collection log sheet will be filled out for each sample. Individual mammals will be wrapped in aluminum foil and placed in clean, re-sealable plastic bags. A sample label will be affixed to the outside of the bag, which will then be placed into a second bag to prevent loss of the sample label. Samples will be placed in a cooler on wet ice for temporary storage in the field. After leaving the field, the mammals will be frozen and shipped on dry ice to the laboratory for the appropriate chemical analysis. No wastage will be left on-site. Results of the study will be incorporated into the Health Hazards and Ecological Receptor report. Separate community meetings may be established to share the results of the study and receive feedback as well. The fieldwork for this study will be conducted from October 2, 2018 to December 31, 2018.