| Project Title |  |
| Project
A1: The development and application of methods for the measurement of metals on
aeolian dust from natural settings.
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| Research Team | |
| Grant C. Edwards,
University of Guelph, School of Engineering – PI Email: gedwards@uoguelph.ca Tel: 519-824-4120 ext. 3665 Co-Investigators:
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| Project Summary | |
| This research is focussed on the
development and application of methods for measuring air surface exchange rates of mercury
and metal particulates from natural and anthropogenic settings. During the summer of 1998,
in situ measurements of gaseous mercury fluxes were conducted at Pinchie Lake,
B.C., a site which geologically has a significant high natural mercury concentration in
the substrate. Since the site is also a de-commissioned mercury mine, it offered the
opportunity to study both natural and anthropogenic emitters at the same location. Measurements were conducted using improved micrometeorological and flux chamber methods. Extensive biogeochemical surveys (bedrock, soil and vegetation sampling) of the site were conducted prior to and during the field study in 1998. The micrometeorological fluxes at the natural site averaged 300 " 13 ng/m2/h. Peak fluxes exceeded 2600 ng/m2/h, compared to chamber fluxes which showed peaks greater than 400 ng/m2/h for a quartz glass chamber and less than 200 ng/m2/h for a Teflon7 chamber. Chamber results from the tailings pond indicate that the fluxes measured at this site were comparable to those measured at the natural site. Mercury concentrations at the calcine site were beyond the maximum limits of the instrument, corresponding to flux values as high as 20,000 ng/m2/h. Ambient mercury concentrations near the surface were as high as 3,000 ng/m3. The Pinchie flux data along with the supporting biogeochemical survey data are presently being analyzed for correlations to determine which factors control the release of mercury to the atmosphere. This data set will be used for scaling up to reassess the role of natural emissions of mercury in local, regional and global mercury budgets.
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