The relationship between Polycyclic Aromatic Hydrocarbon (PAH) concentration and traffic count along the urban roadways of a small island state: a spatial analysis technique

Abstract

ABSTRACTA major contributor of Polycyclic Aromatic Hydrocarbons (PAHs) in road dust is vehicular emissions from gasoline- and diesel-powered engines. In this study, the modelling of the relations between PAH concentrations in road dust and traffic counts over two climatic seasons were explored using global ordinary least squares (OLS) and local geographically weighted regression (GWR) models. For the various roadways investigated, the performance of the GWR models showed great improvements over the OLS models as denoted by comparisons of the coefficients of determination (r2) and corrected Akaike Information Criterion (AICc) for both seasons. The GWR models also highlighted the existence of spatial non-stationarity in the relationship between PAH concentration and traffic count. The results from this study validate that PAH concentrations in road dust and traffic counts were spatially correlated, however, the possibility of improving the model by utilizing additional independent variables must be explored.