Investigation into atmospheric concentration and deposition of PCBS to the Lake Ontario due to sources from greater Toronto

Polychlorinated biphenyls (PCBs) are classified as persistent organic pollutants (POPs) and are part of the toxic substances under the treaty of Stockholm Convention. PCBs persist in the environment for long periods of time, which allow them to be transported long distance from source regions, are toxic and have tendency to bio-accumulate in food chain. It is our intent to investigate the impact of elevated concentration often found in air and precipitation of PCBs in greater Toronto area, the largest urban area on Lake Ontario. An integrated measurements and modeling experiment was conducted during 2008-09 over the Greater Toronto and adjoining lake and water areas. Inventory of PCBs in-use and in-storage and locations were compiled. Similarly survey, mapping and sampling of PCBs in building sealants were done. Some emission scenarios for select PCB congeners (28, 52,101,153 and 180) were developed for the study area of Greater Toronto. A coupled multimedia numerical mesoscale Boundary layer forecast model for POPs (BLFM-POP) is developed for the study of transport, dispersion and deposition of POPs through soil, water and atmospheric mediums. Loadings of PCBs to Lake Ontario were numerically simulated with the use of estimated emissions from scenario data set.

Comparison of modeled air concentrations and loadings to Lake Ontario with field measured values will be discussed.