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AN INTEGRATED ANALYSIS OF THE POTENTIAL EFFECTIVENESS OF MERCURY EMISSION REDUCTION STRATEGIES IN THE GREAT LAKES
Sunderland, E. AND G J. Foley. AN INTEGRATED ANALYSIS OF THE POTENTIAL EFFECTIVENESS OF MERCURY EMISSION REDUCTION STRATEGIES IN THE GREAT LAKES. Presented at Air Quality IV Conference, Arlington, VA, September 22-24, 2003.
Using atmospheric transport and fate models, it has been possible to link the changes in emissions to to the change in atmospheric deposition for the last thirty years for the criteria air pollutants, but it has only been in the last decade that advances have been made to allow these linkages to be done for persistent toxic substances, including mercury. Today, for mercury, several mercury source receptor models exist, but one of them, which will be mentioned later, provides the ability to examine the annual source-receptor relationships to determine which sources and/or source regions contribute the most mercury deposited to an area such as each of the Great Lakes.
The linkage of the contributions of mercury coming from the atmosphere, the tributaries, the sediments and the non-point run-off to the uptake and/or the bioaccumulation in fish is a much more difficult problem. Therefore, in evaluating the potential effectiveness of mercury control strategies, it is easier to show the benefit in terms of changes in atmospheric deposition than it is in terms of changes in level of mercury in fish tissue.
However, mercury mass balance models are being developed for lakes with fish uptake included. Their use is hampered by both missing process information and the lack of data for development and evaluation. Nevertheless, it is possible to use such a model in a screening analysis to explore the sensitivities to the model parameters and the data. Using a range of values for missing or less certain information, key uncertainties can be hypothesized. This is demonstrated using an application of mercuty emission reductions from the 1996 coal fired utilities in the US and Canada and the predicted changes in fish uptake of mercury in Lake Ontario.
This paper developes a set of source-to-uptake linkages and evaluates the nature and magnitude, as quantitatively as possible, of the uncertainty in relationships. From this analysis, it attempts to identify the most critical scientific information that would improve these linkages in the future. This abstract has been subjected to Agency review and approved for publication.