Why is multiscale exposure modeling essential to determine the burden of disease of pollution in Australia

摘要

Background Spatialized emission inventory are available for close to 300 point sources and 100 substances in Australia. To use these data to prioritize possible actions, it is essential to understand the spatial distribution of intakes and health impacts. Aims We aim a) to parameterize Pangea - a multiscale model of fate and exposure that determines spatially distribute exposures, and b) to apply the model to analyze population intakes for emission sources across Australia. Methods We first build multi-scale multi-media grids refined around each source and high population density area. Concentrations and multi-pathways exposures are calculated for test substances. We then analyze overall intakes as well as intake fractions for four source-to-receptor patterns: outback Alice Springs, suburban Sydney, Sydney and an offshore platform NW from Australia. Results Depending on source location, cumulated intake fractions of benzene vary from 2ppm in Alice Springs to 23 ppm at Sydney airport. For Alice Springs, 10% of the intake is local, 20% is at 2300 km - Sydney and Melbourne, the rest at more than 3000 km, in particular in highly populated Indonesia which is under dominant wind direction. For an emission 150km West of Sydney, 70% of the 5ppm taken in occur in Sydney. This proportion rises to 90% for emission at Sydney airport. The offshore platform has most of its impact in Indonesia. In contrast, benzo[a]pyrene impacts are primarily associated to deposition on local fields and subsequent bioconcentration in food, with highest impacts in regions of high agriculture production intensity. Maps of resulting concentrations, intake and burden of disease will be presented. Conclusions The multiscale approach models accurately spatial distribution of intake fraction while limiting calculation time. Prioritization schemes for intervention need to consider both emission sources and exposed receptors to take full advantage of spatialized emission inventories.