My main research areas are human impacts on the geochemical cycles of potentially toxic trace elements, including archives of atmospheric change (peat bogs and polar ice cores), fate in soils and sediments, and impacts on natural freshwaters. My main research projects in Alberta involve:
1) Reconstructing atmospheric deposition of trace metals from natural and anthropogenic sources using peat cores from ombrotrophic (ie rain-fed) bogs in northern Alberta.
2) Distinguishing natural from anthropogenic inputs to the Lower Athabasca River. Both of these projects seek to improve our understanding of the impacts of the industrial development of the bituminous sands on the environment.
The three most significant research findings to date are:
1) Sphagnum moss from peat bogs surrounding the open pit mines and upgraders show no significant contamination by potentially toxic “heavy metals”, namely Ag, Cd, Pb, Sb and Tl.
2) Peat cores from the same bogs show that the maximum extent of contamination was in the past, reaching a zenith perhaps as long as 50 years ago.
3) Concentrations of this same list of potentially toxic trace metals in the Athabasca River are extremely low, with Pb concentrations in some tributary streams, for example, as low as 5 ng/l; this is no different than Arctic ice dating from the mid-Holocene ca. 5,000 to 8,000 years ago.
The three most important accomplishments of work in Europe were:
1) A detailed reconstruction of atmospheric Pb and many other trace metals, for the past 15,000 years, using a peat core from a bog in Switzerland.
2) A detailed reconstruction of atmospheric of Pb and many other trace metals, for the past 15,000 years, using an ice core from Devon Island in the Canadian High Arctic.
3) Creating a dedicated, metal-free groundwater sampling system, and producing the first reliable data for trace metals in spring water. The most significant findings of these studies include:
i) Human activities have dominated atmospheric Pb emissions continuously for more than 3,000 years.
ii) The recent decline in atmospheric Pb deposition pre-dates in the introduction of unleaded gasoline by a considerable margin.
iii) All commercially available bottled waters are contaminated by trace metals such as Pb which leaches from glass and Sb which leaches from PET plastic.