Bridget Bergquist
Associate Professor of Geology
University of Toronto

The primary aim of my research program is to increase our understanding of the biogeochemical cycles that are important for life on Earth and how these cycles have evolved over time through the use of trace metal and stable isotope geochemistry.

Besides the inherent importance of metals in the environment (i.e., in their roles as nutrients or toxins), the chemistry of metals is often linked to, or plays a controlling role in, environmental processes including carbon cycling, ocean circulation, and weathering and transport of chemicals in nature. Understanding metals in the environment is especially important in a changing world where human activities are perturbing many natural cycles and will have impacts on our food sources, health, and climate. However, the biogeochemical cycles of many metals are not well constrained. New analytical advancements, especially in multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS), have opened the door for investigation of stable isotope fractionation of many metals. Isotopic variations of elements are powerful as tracers/proxies of environmental processes and can be used to identify and quantify sources and sinks, to understand biogeochemical cycles, and as proxies for significant climate variables and environmental processes. My research group uses metal isotopes to yield insights into the modern global cycles of metals as well as past conditions on Earth.

Current areas of research are:

• mercury biogeochemical cycling in the present and past
• differentiating mercury contamination from point sources versus remobilization of legacy Hg pollution
• the atmospheric deposition of coal related contaminants (e.g. lead and mercury)
• trace metal cycling in the ocean

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