Joel Bannis

A geographic information system (GIS) was used to delineate sub-watersheds for each of the sample sites (n = 86) located in the Canadian portion of the Lake Ontario basin and analyzed land use patterns (area, urban, dense urban and industrial), roadway density, population density
and point source pollution (PAHs sediment loadings and mean particle size). Two methods were used to determine contributions of PAHs sources to stream sediments; these methods are multiple regression analysis and principal component analysis (PCA). Multiple regression analysis at the sub-watershed scale explained 61% of the variation. The results indicate that a positive correlation exists between population density (r2 = 0.48; p = 0.00) and roadway density (r2 =0.30; p = 0.00) and concentration levels of PAHs in stream sediments. Further analysis shows that the contributions of vehicle emissions and coal tar / coal combustion are 41% and 24% using PCA respectively.