rare earth elements, lanthanides, water quality criteria, dissolved organic matter.
Name of project lead: Jim McGeer and Scott Smith
Project team/partners: M. Schwartz – testing – Natural Resources Canada, Mining & Minerals Sci Labs, Ottawa. K. Wilkinson – speciation & toxicity – University of Montreal, Montreal.
C. Fortin & P. Campbell – speciation & toxicity – INRS-Eau, Quebec City.
Status: in progress
Location: If research is localized please include lats and longs. Please attach shapefile or GoogleEarth image, if available. If the study is regional, please use a bounding box if possible. If multiple sample sights, and if possible, attach a spreadsheet with decimal degrees of sample locations.) Sampling sites to be determined, mostly laboratory based.
Year and month project started: 2012, February
Anticipated completion year of project? March, 2016
Executive year of project (example, year 1 or 2 or 3…) 2
Brief project description:
This project is focused on developing toxicological data for the rare earth (or the lanthanide series) elements that have the highest potential for environmental impact. The use of rare earth elements in consumer products and industrial processes is increasing and with rising global demand at least 2 new mines are being proposed for development in Canada (one at Thor Lake NWT). In spite of this, very little is known on their toxicity to aquatic biota and the potential environmental impact. The new toxicity information will be developed to understand the potential for impact to northern aquatic species. Aquatic organisms in northern ecosystems are often considered to be more sensitive compared to those from southern locales but there is a general lack of data and a poor understanding of this issue. Similarly the geochemistry of northern aquatic environments can be unlike those in southern Canada where most of the data used to develop water quality guidelines and criteria is generated. For example many northern waters are ion impoverished (e.g. hardness values <15 mg/L CaCO3) and standard aquatic invertebrate species such as Daphnia magna and Hyalella azteca generally cannot live under these conditions. Leading edge, site-specific toxicity prediction models, such as the biotic ligand model, are not calibrated for these waters.
Research efforts will be directed at establishing both acute and chronic toxicity thresholds for effects in aquatic invertebrates. A comparison of northern and commonly used southern species will be developed in the context of the biotic ligand approach where the influence of water chemistry (e.g. Ca2+, Na+, H+ and natural organic matter (NOM)) on responses will be characterized. Based on previous studies it is anticipated that NOM will mitigate toxicity and the relative protective qualities of different sources across northern ecosystems will be compared. Recent studies have shown that NOM from different southern Canadian sources vary considerably. Sources from anthropogenically disrupted ecosystems have reduced protective quality. The relative quality of NOM from northern ecosystems is not well understood.
Data from these experiments will provide new knowledge the fills critical data gaps on the potential for environmental impact of lanthanide on northern aquatic species. It will provide environmental managers and policy makers with information that can be directed towards hazard classification of material containing lanthanides as well as risk assessments of impacts in contaminated environments.
Significance of the results (rationale): / project linkages
Contributing to the development of models predicting the impact of toxic rare earth elements to northern aquatic invertebrate species on a site specific (water chemistry) basis. - Contributions to the relative sensitivity of northern invertebrate species and environments in relation to their southern counterparts (on which environmental thresholds for contaminants are based).
Improved understanding the sensitivity of northern species (or subspecies) and conditions in relation to the applicability/interpretation of water quality guidelines and criteria will provide important information for the risk and hazard assessment community that is specific to the northern Canadian context.
Aquatic toxicity thresholds for the effects of rare earth elements will contribute to the development of water quality guidelines and criteria and refine the interpretation of risk assessments related to effluent discharge objectives.
Key deliverables and reporting: Link to needs of NWT
Results are directed to environmental risk assessors and may be of interest to environmental decision- makers. Examples of key outputs include training sessions on risk assessment to Environment Canada assessment groups, conference presentations, journal publications.
Engagement, training and capacity building
Team leads have engaged with Environment Canada and provided training to enhance their assessment capacity.
The identification of northern specific thresholds is a research question that has been identified and prioritized by NWT regulatory boards. The results of this research will no doubt be of interest to NWT decision-makers and will be shared.
Links to WSIPlan and NWT Science Agenda
Key to Success 2.1 I Develop and implement collaborative research and monitoring programs for environmental stressors that can contribute to cumulative effects on NWT watersheds. Key to Success 2.1 G
Develop and implement collaborative research and monitoring programs for water quality and quantity that integrate with existing programs. Key to Success 3.1 B Develop an overarching protocol for developing, reviewing and implementing water-related regulatory procedures and guidelines.
Key project tasks for next year (work plan pieces – research)
Toxicological responses to rare earth elements in aquatic invertebrates. Comparison of southern and northern amphipods to contaminants. Training session on science issues to Environment Canada risk assessors.
Key project tasks for next year (work plan pieces – engagement, training and capacity building.