Metals are a natural part of our environment. Life has evolved in this natural milieu and requires that metals be present in appropriate levels and combinations. Concentrations of metals that are too low can lead to health problems as a result of nutrient deficiencies, whereas metal concentrations that are too high can be toxic to plants, animals, and humans.

The concentrations of metals fluctuate across the Canadian landscape reflecting natural variations in geology, climate and other factors including anthropogenic activities. For example, as shown in the figure below, there is a wide range of mercury levels in the soils and sediments of Canada. Some of the highest values, shown in red on the map, are found in areas where the dominant bedrock is black shale. The presence of elevated levels of organic matter in an anoxic environment at the time of sediment deposition was responsible for concentrating anomalous amounts of mercury. Where there is an imbalance between the essential requirements of living organisms and the availability of inorganic resources the quality of life and its sustainability is at risk.

The MITE program will provide geoscience knowledge for the assessment and management of health risks posed by metals in the environment. In broad terms, research will be undertaken in 2 areas: natural vs. anthropogenic metal sources, and defining background levels of metals in our environment. This will lead to identifying environments where natural metal variations and anthropogenic inputs pose a risk to environmental and human health. Other departments, e.g. Environment Canada and Health Canada, have the primary responsibility for determining health risks, so the program will forge the necessary partnerships to ensure incorporation of ESS research results.

The program consists of three projects focusing on metal sources, fates and risks, and on source apportionment. They will provide spatial- and temporal-based knowledge for:

1. identifying environments and human communities at risk from metal toxicity
2. characterizing geochemical processes that control metal bioavailability
3. assessing and using techniques for apportioning metal loadings between natural and anthropogenic sources

Overall, the outcomes of the projects provide sound scientific information to help mitigate risks associated with metals in the environment. Together these projects respond to the basic questions of the source and the level of a metal available to enter the food chain. The combined information from these projects is required to manage risk.

Delivery of the program is based on several mechanisms. The basic science information will be promulgated through scientific reports and publications, the Atlas of Canada Web site, presentations at meetings, and online resources including the ESS Geoscience Data Repository. The projects are delivering geoscience knowledge, in partnership with other groups on specific issues that deal with potentially toxic metals and metalloids in the environment. The program has a communication strategy to target key messages and impacts at our stakeholders.

The fundamental objective of the program is to ensure that regulations and risk management decisions concerning potentially toxic metals include sound geoscience information. To ensure that the appropriate science is being done, ESS will collaborate/consult with the responsible agencies to ensure that the outputs of the program are designed to meet their needs. In some cases, such as AMAP (define/ link to web site), ESS will contribute directly to assessment reports. In others, including the UNECE (define/ link to web site), ESS will participate in scientific working groups. This will ensure our results are in front of the science community and in front of the people who apply the results when making decisions.

Program Manager: Dr. Andrew Rencz