Bio: Frank Wania is Professor of Environmental Chemistry in the Department of Physical and Environmental Sciences at the University of Toronto at Scarborough since 1999. He has wide-ranging research interests related to environmental contaminant transport and distribution, with a focus on gaining a mechanistic understanding of contaminant enrichment processes through a combination of fieldwork, laboratory experimentation, and model simulations. He studied environmental science at the University Bayreuth in Germany and received his Doctorate in Chemical Engineering and Applied Chemistry from the University of Toronto in 1995.
Abstract: Combining models and atmospheric measurements to assign responsibility for toxic contaminant emissions globally
Reducing emissions of toxic contaminants to the atmosphere requires identifying those responsible for the emissions. Air concentration measurements are key to this identification. Using three examples I will illustrate how air monitoring data can be combined with model simulations to assign responsibility for the emissions of global contaminants. In the first example, I show that large scale networks relying on passive air samplers can fill huge spatial data gaps in the global monitoring of gaseous elemental mercury and – when combined with GEOS-Chem model simulation – probe the plausibility of current emission estimates. Our measurement-model comparison reveals instances of both over- (southern hemisphere) and underestimation (India and Gulf region) of mercury emissions. In the second example, observations have revealed that air concentrations of hexachlorobutadiene have increased rapidly in the last twenty years for it to become the most prevalent persistent organic pollutants in the global atmosphere. Combining air monitoring evidence, encompassing Japanese government data and global passive sampling data, with global scale simulations, based on FLEXPART and the Nested Exposure Model, we find that Chinese emissions, likely from chlorinated solvent manufacturing, are necessary and sufficient to explain the temporal and spatial trends in hexachlorobutadiene contamination recorded globally. In the third example, I will argue that assigning responsibility should be extended to those whose consumption ultimately drives contaminant emissions. International trade can decrease emissions in consumer economies at the expense of higher emissions in countries manufacturing products and handling waste. I will illustrate the feasibility of characterizing toxic chemical emissions, exposures and health risks embodied in international trade using the example of the fungicide chlorothalonil applied in the cultivation of bananas in Costa Rica, which are exported to Europe and North America. The international virtual flows of chlorothalonil embodied in the banana trade exceed by many orders of magnitude the flows via long range atmospheric transport and as residue in the traded commodity.