A passive air sampler for precise, spatially distributed atmospheric mercury monitoring and source characterization

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Mercury as a pollutant is globally distributed in the atmosphere and a health concern for those with a high intake of fish and seafood. The recently signed Minamata Convention seeks to reduce mercury emissions globally. We are proposing the further development and application of a novel activated carbon-based air sampling methodology for measuring mercury in air, that is simple, inexpensive and operates without the need for electrical power. A novel aspect of this sampler is that it can be used to derive time-averaged concentrations over time periods ranging from a few days to several months, if not even a year. Specifically, we propose to conduct a number of laboratory experiments and field tests aimed at determining exactly how much mercury the sampler can take up and how fast this occurs, whereby we consider that concentrations, temperature, wind speed and relative humidity can vary. We also plan to test the performance of this new sampler by comparing the results it yields with those obtained with more established techniques at a number of sites across Canada and the rest of the world. By collaborating with Environment Canada, we will test the sampler for use in monitoring mercury air concentrations in Canada's North. Furthermore, we propose to use the sampler to map the long term average mercury air concentration variability in two areas of ongoing mercury emissions, namely the urban area of eastern Toronto and a former mercury mine in Italy. This should allow for identification of hotspots with high mercury emissions in these areas and the quantification of emission rates. The new methodology will be particularly useful for (1) monitoring atmospheric mercury in places that have no access to power or are difficult to access and (2) for identifying and characterizing mercury emissions through highly spatially resolved concentration mapping.